WO2016095123A1

WO2016095123A1 - Compositions and methods for increasing drought tolerance in plants

Info

Publication number: WO2016095123A1
Application number: PCT/CN2014/094088
Authority: WO
Inventors: Juntao Liu; Jiang Li; Yu Chen; Jian LV; Xiangyang Hu
Original assignee: Kunming Institute Of Botany,The Chinese Academy Of Sciences; Syngenta Participations Ag
Priority date: 2014-12-17
Filing date: 2014-12-17
Publication date: 2016-06-23

Abstract

Provided are recombinant nucleic acid molecules and methods for increasing drought tolerance in a plant, comprising introducing the recombinant nucleic acid molecules into the plant.

Description

COMPOSITIONS AND METHODS FOR INCREASING DROUGHT TOLERANCE IN PLANTS

FIELD OF THE INVENTION

The invention relates to compositions and methods for increasing drought tolerance in plants.

BACKGROUND

Drought is a major limitation to plant production and agricultural productivity worldwide. For example, about 15％of the world's maize crop is lost every year to drought. Periods of drought stress can occur at any time during the growing season, but plants can be more sensitive to drought stress depending on the stage of development when drought occurs.

Identifying genes that enhance the drought tolerance in plants may lead to more efficient crop production by allowing for the identification, selection and production of plants with enhanced drought tolerance. Attempts to improve drought tolerance and tolerance to other abiotic stresses have used both traditional plant breeding techniques as well molecular approaches, which allow the introduction of useful heterologous genes across species.

To address the problem of loss in agricultural productivity due to abiotic stress, in particular, drought stress, it may be desirable to identify further novel genes that can confer increased tolerance to drought conditions when introduced into a plant.

SUMMARY OF THE INVENTION

The following summary lists several embodiments of the inventive subject matter, and in many cases lists variations and permutations of these embodiments. This summary is merely exemplary of the numerous and varied embodiments. Mention of one or more representative features of a given embodiment is likewise exemplary. Such an embodiment can typically exist with or without the feature (s) mentioned； likewise, those features can be applied to other embodiments of the invention, whether listed in this Summary or not. To avoid excessive repetition, this Summary does not list or suggest all possible combinations of such features.

In one aspect of the invention, a recombinant nucleic acid molecule is provided, said nucleic acid molecule comprising: (a) a nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, (b) a nucleotide sequence encoding a polypeptide having the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (c) anucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ； (d) anucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (e) anucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above； (f) anucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or (g) any combination of the nucleotide sequences of (a) to (f) above.

In another aspect, a plant or plant part comprising in its genome a recombinant nucleic acid molecule is provided, said recombinant nucleic acid molecule comprising: (a) a nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, (b) a nucleotide sequence encoding a polypeptide having the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (c) anucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ； (d) anucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (e) anucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above； (f) anucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or (g) any combination of the nucleotide sequences of (a) to (f) above.

In a further aspect, the invention provides a method of increasing the drought tolerance of a plant or plant part, comprising: introducing into a plant or plant part a recombinant nucleic acid molecule comprising a nucleotide sequence of the invention.

In some aspects, a method of producing a plant having increased drought tolerance is provided, the method comprising: detecting, in a plant part, a recombinant nucleic acid molecule comprising a nucleotide sequence of the invention； and producing a plant from said plant part.

In other aspects, the invention provides a method of producing a plant having increased drought tolerance, comprising: introducing into a plant cell or plant part a recombinant nucleic acid molecule comprising a nucleotide sequence of the invention to produce a transgenic plant cell or plant part； and growing the transgenic plant cell or plant part into a plant, thereby producing a plant having increased drought tolerance.

In additional aspects, a method of producing a plant having increased drought tolerance is provided, comprising: crossing a first parent plant with a second parent plant, wherein said first parent plant comprises within its genome a recombinant nucleic acid molecule comprising a nucleotide sequence of the invention, thereby producing a progeny generation, wherein said progeny generation comprises at least one plant that possesses said recombinant nucleic acid within its genome and has increased drought tolerance.

Other aspects of the invention provide a method of identifying a plant or plant part having increased drought tolerance, comprising: detecting, in a plant or plant part, a recombinant nucleic acid molecule comprising a nucleotide sequence of the invention, thereby identifying a plant or plant part having increased drought tolerance.

In further aspects, the invention provides expression cassettes and vectors comprising the nucleic acid molecules and nucleotide sequences of the invention as well as plant cells, seeds, a crop comprising a plurality ofthe transgenic plants of the invention planted together in an agricultural field, and harvested and post harvest products produced from the crops, plants and plant parts of the invention.

These and other aspects of the invention are set forth in more detail in the description ofthe invention below.

BRIEF DESCRIPTION OF THE SEQUENCES IN THE SEQUENCE LISTING

SEQ ID NOs: 1-4 are nucleotide sequences of the invention comprising the cloned DNA, cDNA, predicted ORF1 and predicted ORF2 for KIB3 (without 3’ UTR or 5’ UTR) , respectively.

SEQ ID NOs: 5-7 are nucleotide sequences of the invention comprising the cloned DNA, cDNA, predicted ORF for KIB11 (without 3’ UTR or 5’ UTR) , respectively.

SEQ ID NOs: 8-11 are nucleotide sequences of the invention comprising the cloned DNA, cDNA, predicted ORF1 and predicted ORF2 for KIB12 (without 3’ UTR or 5’ UTR) , respectively.

SEQ ID NOs: 12-14 are nucleotide sequences of the invention comprising the cloned DNA, cDNA, predicted ORF for KIB21 (without 3’ UTR or 5’ UTR) , respectively.

SEQ ID NOs: 15-20 are amino acid sequences of proteins of the invention, each of whichmay be exogenously expressed in a plant to confer drought tolerance or increased drought tolerance.

DETAILED DESCRIPTION OF THE INVENTION

This description is not intended to be a detailed catalog of all the different ways in which the invention may be implemented, or all the features that may be added to the instant invention. For example, features illustrated with respect to one embodiment may be incorporated into other embodiments, and features illustrated with respect to a particular embodiment may be deleted from that embodiment. Thus, the invention contemplates that in some embodiments of the invention, any feature or combination of features set forth herein can be excluded or omitted. In addition, numerous variations and additions to the various embodiments suggested herein will be apparent to those skilled in the art in light of the instant disclosure, which do not depart from the instant invention. Hence, the following descriptions are intended to illustrate some particular embodiments of the invention, and not to exhaustively specify all permutations, combinations and variations thereof.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art that this invention pertains. Further, publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entireties for the teachings relevant to the sentence and/or paragraph in which the reference is presented.

As used in the description of the embodiments of the invention and the appended claims, the singular forms “a, ” “an, ” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

As used herein, “and/or” refers to and encompasses any and all possible combinations of one or more of the associated listed items.

The term “about, ” as used herein when referring to a measurable value such as an amount of a compound, dose, time, temperature, and the like, refers to variations (+/-) of 20％, 10％, 5％, 1％, 0.5％, or even 0.1％of the specified amount.

The terms “comprise, ” “comprises” and/or “comprising, ” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the transitional phrase “consisting essentially of” (and grammatical variants) means that the scope of a claim is to be interpreted to encompass the specified materials or steps recited in the claim and those that do not materially alter the basic and novel characteristic (s) ” of the claimed invention. Thus, the term “consisting essentially of” when used in a claim of this invention is not intended to be interpreted to be equivalent to “comprising. ”

A characteristic is “associated with” atrait when it is linked to it and when the presence of the characteristic is an indicator of whether and/or to what extent the desired trait or trait form will occur in a plant/plant part comprising the characteristic. Similarly, a characteristic is “associated with” an allele when it is linked to it and when the presence of the characteristic is an indicator of whether the allele is present in a plant/plant part comprising the characteristic. For example, “acharacteristic associated with enhanced drought tolerance” refers to a characteristic whose presence or absence can be used to predict whether and/or to what extent a plant will display a drought tolerant phenotype.

As used herein, the terms “backcross” and “backcrossing” refer to the process whereby a progeny plant is repeatedly crossed back to one of its parents. In a backcrossing scheme, the “donor” parent refers to the parental plant with the desired allele or locus to be introgressed. The “recipient” parent (used one or more times) or “recurrent” parent (used two or more times) refers to the parental plant into which the gene or locus is being introgressed. The initial cross gives rise to the F1 generation. The term “BC1” refers to the second use of the recurrent parent, “BC2” refers to the third use of the recurrent parent, and so on.

A “chimeric gene” is a recombinant nucleic acid molecule in which a promoter or other regulatory nucleotide sequence is operatively associated with a nucleotide sequence that codes for an mRNA or which is expressed as a protein, such that the regulatory nucleotide sequence is able to regulate transcription or expression of the associated nucleotide sequence. The regulatory nucleotide sequence of the chimeric gene is not normally operatively linked to the associated nucleotide sequence as found in nature.

As used herein, the terms “cross” or “crossed” refer to the fusion of gametes via pollination to produce progeny (e.g., cells, seeds or plants) . The term encompasses both sexual crosses (the pollination of one plant by another) and selfing (self-pollination, e.g., when the pollen and ovule are from the same plant) . The term “crossing” refers to the act of fusing gametes via pollination to produce progeny.

As used herein, the terms "decrease, " "decreases, " "decreasing" and similar terms refer to a reduction of at least about 5％, 10％, 15％, 20％, 25％, 30％, 35％, 40％, 45％, 50％, 55％, 60％, 65％, 70％, 75％, 80％, 85％, 90％, 95％, 96％, 97％, 98％, 99％, 99.5％or more. In some embodiments, the reduction results in no or essentially no activity (i.e., an insignificant or undetectable amount of activity) .

As used herein, the terms “desired allele” and “allele of interest” are used interchangeably to refer to an allele associated with a desired trait. In some embodiments, a “desired allele” and/or “allele of interest” may be associated with either an increase or a decrease of or in a given trait, depending on the nature of the desired phenotype. In some embodiments, a “desired allele” and/or “allele of interest” may be associated with a change in morphology, color, etc.

As used herein, the terms “drought tolerance” and “drought tolerant” refer to a plant’s ability to endure and/or thrive underdrought stress conditions. When used in reference to a plant part, the terms refer to the ability of a plant that arises from that plant part to endure and/or thrive under drought conditions. In general, a plant or plant part is designated as “drought tolerant” if it displays “enhanced drought tolerance” or “increased drought tolerance. ” Drought tolerant or drought tolerance can also refer to an increase in drought tolerance relative to a control plant. Thus, in some embodiments, a plant having increased drought tolerance is increased relative to a parent plant or a native or wild type plant of the same species (e.g., a plant not comprising the recombinant nucleic acid molecule of the invention) grown under the same or substantially the same environmental conditions.

In some embodiments, as used herein, the terms “enhanced drought tolerance” or “increased drought tolerance” refer to an improvement in one or more water optimization traits as compared to one or more controls (e.g., a plant/plant part of the same species (e.g., a parent plant) when grown under the same environmental conditions) . Exemplary water optimization traits include, but are not limited to, water loss, accumulation of reactive oxygen species, accumulation of dehydrins, root architecture, accumulation of late embryogenesis abundant proteins, grain yield at standard moisture percentage (YGSMN) , grain moisture at harvest (GMSTP) , grain weight per plot (GWTPN) , percent yield recovery (PYREC) , yield reduction (YRED) , and percent barren (PB) . Thus, a plant that exhibits decreased water loss, decreased accumulation of reactive oxygen species, increased accumulation of dehydrins, improved root architecture, increased accumulation of late embryogenesis abundant proteins, increased grain yield at standard moisture percentage (YGSMN) , increased grain moisture at harvest (GMSTP) , increased grain weight per plot (GWTPN) , increased percent yield recovery (PYREC) , decreased yield reduction (YRED) , and/or decreased percent barren (PB) as compared to a control plant when each is grown under the same drought stress conditions displays enhanced drought tolerance and may be designated as “drought tolerant. ”

As used herein, with respect to nucleic acids, the term “exogenous” refers to a nucleic acid molecule that is not in the natural genetic background of the cell/organism in which it resides. In some embodiments, the exogenous nucleic acid molecule comprises one or more nucleotide sequences that are not found in the natural genetic background of the cell/organism. In some embodiments, the exogenous nucleic acid molecule can comprise one or more additional copies of a nucleotide sequence that is/are endogenous to the cell/organism.

As used herein, the terms “express, ” “expresses, ” “expressed” or “expression, ” and the like, with respect to a nucleic acid molecule and/or a nucleotide sequence (e.g., RNA or DNA) indicates that the nucleic acid molecule and/or a nucleotide sequence is transcribed and, optionally, translated. Thus, a nucleic acid molecule and/or a nucleotide sequence may express a polypeptide of interest or, for example, a functional untranslated RNA.

As used herein with respect to nucleic acids, the term “fragment” refers to a nucleic acid that is reduced in length relative to a reference nucleic acid and that comprises, consists essentially of and/or consists of a nucleotide sequence of contiguous nucleotides identical or almost identical (e.g., 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％identical) to a corresponding portion of the reference nucleic acid. Such a nucleic acid fragment may be, where appropriate, included in a larger polynucleotide of which it is a constituent. In some embodiments, the nucleic acid fragment comprises, consists essentially of or consists of at least about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, or more consecutive nucleotides. In some embodiments, the nucleic acid fragment comprises, consists essentially of or consists of less than about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450 or 500 consecutive nucleotides.

As used herein with respect to polypeptides, the term “fragment” refers to a polypeptide that is reduced in length relative to a reference polypeptide and that comprises, consists essentially of and/or consists of an amino acid sequence of contiguous amino acids identicalor almost identical (e.g., 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％ identical) to a corresponding portion of the reference polypeptide. Such a polypeptide fragment may be, where appropriate, included in a larger polypeptide of which it is a constituent. In some embodiments, the polypeptide fragment comprises, consists essentially of or consists of at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, 300 or more consecutive amino acids. In some embodiments, the polypeptide fragment comprises, consists essentially of or consists of less than about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, 300 consecutive amino acids.

As used herein with respect to nucleic acids, the term “functional fragment” refers to nucleic acid that encodes a functional fragment of a polypeptide.

As used herein with respect to polypeptides, the term “functional fragment” refers to polypeptide fragment that retains at least about 20％, 25％, 30％, 35％, 40％, 45％, 50％, 55％, 60％, 65％, 70％, 75％, 80％, 85％, 90％, 95％, 96％, 97％, 98％, 99％or more of at least one biological activity of the full-length polypeptide (e.g., the ability to convert all-trans-β-carotene into 9-cis-β-carotene) . In some embodiments, the functional fragment actually has a higher level of at least one biological activity of the full-length polypeptide.

As used herein, the term “germplasm” refers to genetic material of or from an individual plant, a group of plants (e.g., a plant line, variety or family) , or a clone derived from a plant line, variety, species, or culture. The genetic material can be part of a cell, tissue or organism, or can be isolated from a cell, tissue or organism.

As used herein, the term “heterologous” refers to a nucleotide/polypeptide that originates from a foreign species, or, if from the same species, is substantially modified from its native form in composition and/or genomic locus by deliberate human intervention.

A “native” or “wild type” nucleic acid, nucleotide sequence, polypeptide or amino acid sequence refers to a naturally occurring or endogenous nucleic acid, nucleotide sequence, polypeptide or amino acid sequence. Thus, for example, a “wild type mRNA” is an mRNA that is naturally occurring in or endogenous to the organism.

As used herein, the term “hybrid” refers to a seed and/or plant produced when at least two genetically dissimilar parents are crossed.

The terms “increase, ” “increasing, ” “increased, ” “enhance, ” “enhanced, ” “enhancing, ” and“enhancement” (and grammatical variations thereof) , as used herein, describe an elevation of at least about 20％, 25％, 30％, 35％, 40％, 45％, 50％, 75％, 100％, 125％, 150％, 175％, 200％, 350％, 300％, 350％, 400％, 450％, 500％or more) .

As used herein, the term “informative fragment” refers to a nucleotide sequence comprising a fragment of a larger nucleotide sequence, wherein the fragment allows for the identification of one or more alleles within the larger nucleotide sequence. For example, an informative fragment of the nucleotide sequence of SEQ ID NO: 1 comprises a fragment of the nucleotide sequence of SEQ ID NO: 1 and allows for the identification of one or more alleles located within the portion of the nucleotide sequence corresponding to that fragment of SEQ ID NO: 1.

As used herein, the terms “introgression, ” “introgressing” and “introgressed” refer to both the natural and artificial transmission of a desired allele or combination of desired alleles of a genetic locus or genetic loci from one genetic background to another. For example, a desired allele at a specified locus can be transmitted to at least one progeny via a sexual cross between two parents of the same species, where at least one of the parents has the desired allele in its genome. Alternatively, for example, transmission of an allele can occur by recombination between two donor genomes, e.g., in a fused protoplast, where at least one of the donor protoplasts has the desired allele in its genome. The desired allele may be a selected allele of a marker, a QTL, a transgene, or the like. Offspring comprising the desired allele can be repeatedly backcrossed to a line having a desired genetic background and selected for the desired allele, with the result being that the desired allele becomes fixed in the desired genetic background. For example, a marker associated with enhanced drought tolerance (e.g., an exogenous nucleic acid comprising one or more of the nucleotide sequences of the invention of any one of SEQ ID NOs: 1-14 or encoding the amino acid sequences of any one of SEQ ID NOs: 15-20 may be introgressed from a donor into a recurrent parent that is not drought tolerant or is only partially drought tolerant. The resulting offspring could then be repeatedly backcrossed and selected until the progeny possess the drought tolerance allele in the recurrent parent background.

As used herein with respect to nucleic acids, polynucleotides and polypeptides, the term “isolated” refers to a nucleic acid, polynucleotide or polypeptide that, by the hand of man, exists apart from its native environment and is therefore not a product of nature. In some embodiments, the nucleic acid, polynucleotide or polypeptide exists in a purified form that is substantially free of cellular material, viral material, culture medium (when produced by recombinant DNA techniques) , or chemical precursors or other chemicals (when chemically synthesized) . An “isolated fragment” is a fragment of a polynucleotide or polypeptide that is not naturally occurring as a fragment and would not be found in the natural state. “Isolated” does not mean that the preparation is technically pure (homogeneous) , but rather that it is sufficiently pure to provide the polynucleotide or polypeptide in a form in which it can be used for the intended purpose. In certain embodiments, the composition comprising the polynucleotide or polypeptide is at least about 50％, 55％, 60％, 65％, 70％, 75％, 80％, 85％, 90％, 95％, 96％, 97％, 98％, or 99％or more pure.

As used herein with respect to cells, the term “isolated” refers to a cell that, by the hand of man, exists apart from its native environment and is therefore not a product of nature. In some embodiments, the cell is separated from other components with which it is normally associated in its natural state. For example, an isolated plant cell may be a plant cell in culture medium and/or a plant cell in a suitable carrier. “Isolated” does not mean that the preparation is technically pure (homogeneous) , but rather that it is sufficiently pure to provide the cell in a form in which it can be used for the intended purpose. In certain embodiments, the composition comprising the cell is at least about 50％, 55％, 60％, 65％, 70％, 75％, 80％, 85％, 90％, 95％, 96％, 97％, 98％, or 99％or more pure.

In some embodiments, the recombinant nucleic acid molecules, nucleotide sequences and polypeptides of the invention are “isolated. ”

In other embodiments, an isolated nucleic acid molecule, nucleotide sequence or polypeptide may exist in a non-native environment such as, for example, a recombinant host cell. Thus, for example, with respect to nucleotide sequences, the term “isolated” means that it is separated from the chromosome and/or cell in which it naturally occurs. A polynucleotide is also isolated if it is separated from the chromosome and/or cell in which it naturally occurs in and is then inserted into a genetic context, a chromosome and/or a cell in which it does not naturally occur (e.g., a different host cell, different regulatory sequences, and/or different position in the genome than as found in nature) . Accordingly, the recombinant nucleic acid molecules, nucleotide sequences and their encoded polypeptides are “isolated” in that, by the hand of man, they exist apart from their native environment and therefore are not products of nature, however, in some embodiments, they can be introduced into and exist in a recombinant host cell.

In some embodiments, the recombinant nucleic acids molecules, nucleotide sequences and polypeptides of the invention are “nonnaturally occurring. ” As used herein with respect to nucleic acids and/or proteins the term “nonnaturally occurring” refers to nucleic acids and/or proteins that do not naturally exist in nature. Thus, they are nonnaturally occurring nucleic acids and/or proteins. In some embodiments, a nonnaturally occurring nucleic acid does not naturally exist in nature in that it is not in the natural genetic background of the cell/organism in which it resides. In some embodiments, the nonnaturally occurring nucleic acid molecules and/or proteins of the invention may comprise any suitable variation (s) from their closest naturally occurring counterparts. For example, nonnaturally occurring nucleic acid molecules of the present inventionmay comprise an otherwise naturally occurring nucleotide sequence having one or more point mutations, insertions or deletions relative to the naturally occurring nucleotide sequence. In some embodiments, nonnaturally occurring nucleic acid molecules of the present invention comprise a naturally occurring nucleotide sequence and one or more heterologous nucleotide sequences (e.g., one or more heterologous promoter sequences, intron sequences and/or termination sequences) . Likewise, nonnaturally occurring proteins of the invention may comprise an otherwise naturally occurring protein that comprises one or more mutations, insertions, additions or deletions relative to the naturally occurring protein (e.g., one or more epitope tags) . Similarly, nonnaturally occurring plants, plant parts, bacteria, viruses and fungi of the present invention may comprise one more exogenous or heterologous nucleotide sequences and/or one or more nonnaturally occurring copies of a naturally occurring nucleotide sequence (i.e., extraneous copies of a gene that naturally occurs in that species) . Nonnaturally occurring plants and plant parts may be produced by any suitable method, including, but not limited to, transforming/transfecting/transducing a plant or plant part with an recombinant nucleic acid molecule of the invention and crossing a naturally occurring plant with a recombinant plant. It is to be understood that all nucleic acids, proteins, plants, plant parts, bacteria, viruses and fungi claimed herein are recombinant and nonnaturally occurring.

Also as used herein, the terms “nucleic acid, ” “nucleic acid molecule, ” “nucleotide sequence” and “polynucleotide” can be used interchangeably and encompass both RNA and DNA, including cDNA, genomic DNA, mRNA, synthetic (e.g., chemically synthesized) DNA or RNA and chimeras of RNA and DNA. The term polynucleotide, nucleotide sequence, or nucleic acid refers to a chain of nucleotides without regard to length of the chain. The nucleic acid can be double-stranded or single-stranded. Where single-stranded, the nucleic acid can be a sense strand or an antisense strand. The nucleic acid can be synthesized using oligonucleotide analogs or derivatives (e.g., inosine or phosphorothioate nucleotides) . Such oligonucleotides can be used, for example, to prepare nucleic acids that have altered base-pairing abilities or increased resistance to nucleases. The present invention further provides a nucleic acid that is the complement (which can be either a full complement or a partial complement) of a nucleic acid, nucleotide sequence, or polynucleotide of this invention.

Nucleic acid molecules and/or nucleotide sequences provided herein are presented herein in the 5’ to 3’ direction, from left to right and are represented using the standard code for representing the nucleotide characters as set forth in the U.S. sequence rules, 37 CFR §§1.821-1.825 and the World Intellectual Property Organization (WIPO) Standard ST. 25.

Nucleic acids of the present invention may encode any suitable epitope tag, including, but not limited to, poly-Arg tags (e.g., RRRRR, SEQ ID NO: 27, and RRRRRR, SEQ ID NO: 28) and poly-His tags (e.g., HHHHHH, SEQ ID NO: 29) . In some embodiments, the nucleic acid comprises a nucleotide sequence encoding a poly-Arg tag, a poly-His tag, a FLAG tag (i.e., DYKDDDDK, SEQ ID NO: 30) , a Strep-tag II^TM (GE Healthcare, Pittsburgh, PA, USA) (i.e., WSHPQFEK, SEQ ID NO: 31) , and/or a c-myc tag (i.e., EQKLISEEDL, SEQ ID NO: 32) .

Different nucleic acids or proteins having homology are referred to herein as “homologues. ” The term homologue includes homologous sequences from the same and other species and orthologous sequences from the same and other species.

The term “homology” in the context of the invention refers to the level of similarity between nucleic acid or amino acid sequences in terms of nucleotide or amino acid identity or similarity, respectively, i.e., sequence similarity or identity. Homology, homologue, and homologous also refers to the concept of similar functional properties among different nucleic acids or proteins. Homologues include genes that are orthologous and paralogous. Homologues can be determined by using the coding sequence for a gene, disclosed herein or found in appropriate database (such as that at NCBI or others) in one or more of the following ways. For an amino acid sequence, the sequences should be compared using algorithms (for instance see section on “identity” and “substantial identity” ) . For nucleotide sequences the sequence of one DNA molecule can be compared to the sequence of a known or putative homologue in much the same way. Homologues are at least 20％identical, or at least 30％identical, or at least 40％identical, or at least 50％identical, or at least 60％identical, or at least 70％identical, or at least 80％identical, or at least 88％identical, or at least 90％identical, or at least 92％identical, or at least 95％identical, across any substantial region of the molecule (DNA, RNA, or protein molecule) .

In some embodiments, a homologue of this invention can have a substantial sequence similarity or identity (e.g., 70％, 75％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, and/or 100％) to the nucleotide or polypeptide sequences of the invention.

“Identity” or “percent identity” refers to the degree of similarity between two nucleic acid or amino acid sequences. For sequence comparison, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence (s) relative to the reference sequence, based on the designated program parameters.

“Identity” can be readily calculated by known methods including, but not limited to, those described in: Computational Molecular Biology (Lesk, A. M., ed. ) Oxford University Press, New York (1988) ； Biocomputing: Informatics and Genome Projects (Smith, D. W., ed. ) Academic Press, New York (1993) ； Computer Analysis of Sequence Data, Part I (Griffin, A. M., and Griffin, H. G., eds. ) Humana Press, New Jersey (1994) ； Sequence Analysis in Molecular Biology (von Heinje, G., ed. ) Academic Press (1987) ； and Sequence Analysis Primer (Gribskov, M. and Devereux, J., eds. ) Stockton Press, New York (1991) .

As used herein, the term “percent sequence identity” or “percent identity” refers to the percentage of identical nucleotides in a linear polynucleotide sequence of a reference (“query” ) polynucleotide molecule (or its complementary strand) as compared to a test (“subject” ) polynucleotide molecule (or its complementary strand) when the two sequences are optimally aligned. In some embodiments, “percent identity” can refer to the percentage of identical amino acids in an amino acid sequence.

Sequence comparison between two or more polynucleotides is generally performed by comparing portions of the two sequences over a comparison window to identify and compare local regions of sequence similarity. The “percentage of sequence identity” for polynucleotides, such as about 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98, 99 or 100 percent sequence identity, can be determined by comparing two optimally aligned sequences over a comparison window, wherein the portion of the polynucleotide sequence in the comparison window can include additions or deletions (i.e., gaps) as compared to the reference sequence for optimal alignment of the two sequences. The percentage is calculated by: (a) determining the number of positions at which the identical nucleic acid base occurs in both sequences； (b) dividing the number of matched positions by the total number of positions in the window of comparison； and (c) multiplying the result by 100.

Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith &Waterman, Adv. Appl. Math. 2: 482 (1981) , by the homology alignment algorithm of Needleman &Wunsch, J. Mol. Biol. 48: 443 (1970) , by the search for similarity method of Pearson &Lipman, Proc. Nat'l. Acad. Sci. USA 85: 2444 (1988) , by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, WI) , or by visual inspection (see generally, Ausubel et al., infra) .

One example of an algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mol. Biol. 215: 403-410 (1990) . Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (http: //www. ncbi. nlm. nih. gov/) . This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold (Altschul et al., 1990) . These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are then extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues； always > 0) and N (penalty score for mismatching residues； always < 0) . For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when the cumulative alignment score falls off by the quantity X from its maximum achieved value, the cumulative score goes to zero or below due to the accumulation of one or more negative-scoring residue alignments, or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, a cutoff of 100, M＝5, N＝-4, and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a wordlength (W) of 3, an expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff &Henikoff, Proc. Natl. Acad. Sci. USA 89: 10915 (1989) ) .

In addition to calculating percent sequence identity, the BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, e.g., Karlin &Altschul, Proc. Nat'l. Acad. Sci. USA 90: 5873-5787 (1993) ) . One measure of similarity provided by the BLAST algorithm is the smallest sum probability (P (N) ) , which provides an indication of the probability by which a match between two nucleotide or amino acid sequences would occur by chance. For example, a test nucleic acid sequence is considered similar to a reference sequence if the smallest sum probability in a comparison of the test nucleic acid sequence to the reference nucleic acid sequence is less than about 0.1, more preferably less than about 0.01, and most preferably less than about 0.001.

Another widely used and accepted computer program for performing sequence alignments is CLUSTALW v1.6 (Thompson, et al. Nuc. Acids Res., 22: 4673-4680, 1994) . The number of matching bases or amino acids is divided by the total number of bases or amino acids, and multiplied by 100 to obtain a percent identity. For example, if two 580 base pair sequences had 145 matched bases, they would be 25 percent identical. If the two compared sequences are of different lengths, the number of matches is divided by the shorter of the two lengths. For example, if there were 100 matched amino acids between a 200 and a 400 amino acid proteins, they are 50 percent identical with respect to the shorter sequence. If the shorter sequence is less than 150 bases or 50 amino acids in length, the number of matches are divided by 150 (for nucleic acid bases) or 50 (for amino acids) , and multiplied by 100 to obtain a percent identity.

The phrase “substantially identical, ” in the context of two nucleic acids or two amino acid sequences, refers to two or more sequences or subsequences that have at least about 50％nucleotide or amino acid residue identity when compared and aligned for maximum correspondence as measured using one of the following sequence comparison algorithms or by visual inspection. In certain embodiments, substantially identical sequences have at least about 60％, or at least about 70％, or at least about 80％, or even at least about 90％or 95％nucleotide or amino acid residue identity. In certain embodiments, substantial identity exists over a region of the sequences that is at least about 50 residues in length, or over a region of at least about 100 residues, or the sequences are substantially identical over at least about 150 residues. In further embodiments, the sequences are substantially identical when they are identicalover the entire length of the coding regions.

Thus, in some embodiments of the invention, the substantial identity exists over a region of the sequences that is at least about 50, about 60, about 70, about 80, about 90, about 100, about 110, about 120, about 130, about 140, about 150, or more residues in length. In some particular embodiments, the sequences are substantially identical over at least about 150 residues. In representative embodiments, substantially identical nucleotide or protein sequences perform substantially the same function (e.g., conferring increased drought tolerance) .

For sequence comparison, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are entered into a computer, subsequence coordinates are designated if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence (s) relative to the reference sequence, based on the designated program parameters.

An “identity fraction” for aligned segments of a test sequence and a reference sequence is the number of identical components which are shared by the two aligned sequences divided by the total number of components in the reference sequence segment, i.e., the entire reference sequence or a smaller defined part of the reference sequence.

Two nucleotide sequences can also be considered to be substantially complementary when the two sequences hybridize to each other under stringent conditions. In some representative embodiments, two nucleotide sequences considered to be substantially complementary hybridize to each other under highly stringent conditions.

In some embodiments, a polypeptide or nucleotide sequence of the invention canbe a conservatively modified variant. As used herein, “conservatively modified variant” refer to polypeptide and nucleotide sequences containing individual substitutions, deletions or additions that alter, add or delete a single amino acid or nucleotide or a small percentage of amino acids or nucleotides in the sequence, where the alteration results in the substitution of an amino acid with a chemically similar amino acid. Conservative substitution tables providing functionally similar amino acids are well known in the art.

As used herein, a conservatively modified variant of a polypeptide is biologically active and therefore possesses the desired activity of the reference polypeptide (e.g., conferring increased drought tolerance) as described herein. The variant can result from, for example, a genetic polymorphism or human manipulation. A biologically active variant of a reference polypeptide can have at least about 40％, 45％, 50％, 55％, 60％, 65％, 70％, 75％, 80％, 85％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, or more sequence identity or similarity (e.g., about 40％to about 99％or more sequence identity or similarity and any range therein) to the amino acid sequence for the reference polypeptide as determined by sequence alignment programs and parameters described elsewhere herein. An active variant can differ from the reference polypeptide sequence by as few as 1-15 amino acid residues, as few as 1-10, such as 6-10, as few as 5, as few as 4, 3, 2, or even 1 amino acid residue.

Naturally occurring variants may exist within a population. Such variants can be identified by using well-known molecular biology techniques, such as the polymerase chain reaction (PCR) , and hybridization as described below. Synthetically derived nucleotide sequences, for example, sequences generated by site-directed mutagenesis or PCR-mediated mutagenesis which still encode a polypeptide of the invention, are also included as variants. One or more nucleotide or amino acid substitutions, additions, or deletions can be introduced into a nucleotide or amino acid sequence disclosed herein, such that the substitutions, additions, or deletions are introduced into the encoded protein. The additions (insertions) or deletions (truncations) may be made at the N-terminal or C-terminal end of the native protein, or at one or more sites in the native protein. Similarly, a substitution of one or more nucleotides or amino acids may be made at one or more sites in the native protein.

For example, conservative amino acid substitutions may be made at one or more predicted, preferably nonessential amino acid residues. A “nonessential” amino acid residue is a residue that can be altered from the wild-type sequence of a protein without altering the biological activity, whereas an “essential” amino acid is required for biological activity. A “conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue with a similar side chain. Families of amino acid residues having similar side chains are known in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine) , acidic side chains (e.g., aspartic acid, glutamic acid) , uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine) , nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan) , beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine) . Such substitutions generally would not be made for conserved amino acid residues, or for amino acid residues residing within a conserved motif, where such residues are essential for protein activity.

For example, amino acid sequence variants of the reference polypeptide can be prepared by mutating the nucleotide sequence encoding the enzyme. The resulting mutants can be expressed recombinantly in plants, and screened for those that retain biological activity by assaying for drought tolerance using standard assay techniques as described herein. Methods for mutagenesis and nucleotide sequence alterations are known in the art. See, e.g., Kunkel (1985) Proc. Natl. Acad. Sci. USA 82: 488-492； Kunkel et al. (1987) Methods in Enzymol. 154: 367-382； and Techniques in Molecular Biology (Walker &Gaastra eds., MacMillan Publishing Co. 1983) and the references cited therein； as well as US Patent No. 4,873,192. Clearly, the mutations made in the DNA encoding the variant must not disrupt the reading frame and preferably will not create complimentary regions that could produce secondary mRNA structure. See, EP Patent Application Publication No. 75,444. Guidance as to appropriate amino acid substitutions that do not affect biological activity of the protein of interest may be found in the model of Dayhoff et al. (1978) Atlas of Protein Sequence and Structure (National Biomedical Research Foundation, Washington, D.C. ) , herein incorporated by reference.

The deletions, insertions and substitutions in the polypeptides described herein are not expected to produce radical changes in the characteristics of the polypeptide (e.g., the activity of the polypeptide) . However, when it is difficult to predict the exact effect of the substitution, deletion or insertion in advance of doing so, one of skill in the art will appreciate that the effect can be evaluated by routine screening assays that can screen for the particular polypeptide activities of interest (e.g., conferring increased drought tolerance) .

In some embodiments, the compositions of the invention can comprise active fragments of the polypeptide. As used herein, “fragment” means a portion of the reference polypeptide that substantially retains the polypeptide activity of conferring increased drought tolerance. A fragment also means a portion of a nucleic acid molecule encoding the reference polypeptide. An active fragment of the polypeptide can be prepared, for example, by preparing a portion of a polypeptide-encoding nucleic acid molecule that expresses the encoded fragment of the polypeptide (e.g., by recombinant expression in vitro) , and assessing the activity of the fragment. Nucleic acid molecules/nucleotide sequences encoding such fragments can be at least about 25, 50, 75, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 825, 830 and the like, and any range therein of contiguous nucleotides, or up to the number of nucleotides present in a full-length polypeptide-encoding nucleic acid molecules/nucleotide sequence. As such, polypeptide fragments can be at least about 10, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 120, 130, 140, 150, 160 or the like, and any range therein of contiguous amino acid residues, or up to the total number of amino acid residues present in the full-length polypeptide.

Thus, in some embodiments, a variant or functional fragment of a polypeptide of this invention or a variant or functional fragment having substantial similarity or identity to a polypeptide sequence of this invention (e.g., SEQ ID NOs: 15-20) when produced in a transgenic plant confers increased tolerance to drought in transgenic plants producing said polypeptides.

In certain embodiments, the polypeptides of the invention comprise at least one modified terminus, e.g., to protect the peptide against degradation. In some embodiments, the N-terminus is acetylated and/or the C-terminus is amidated.

In certain embodiments, the polypeptides of the invention comprise at least one non-natural amino acid (e.g., 1, 2, 3, or more) or at least one terminal modification (e.g., 1 or 2) . In some embodiments, the polypeptide comprises at least one non-natural amino acid and at least one terminal modification.

A polypeptide of the present invention may comprise any suitable epitope tag, including, but not limited to, poly-Arg tags (e.g., RRRRR, SEQ ID NO: 27 and RRRRRR, SEQ ID NO: 28) and poly-His tags (e.g., HHHHHH, SEQ ID NO: 29) . In some embodiments, the polypeptide comprises an amino acid sequence of, for example, a poly-Arg tag, a poly-His tag, a FLAG tag (i.e., DYKDDDDK, SEQ ID NO: 30) , a Strep-tag II^TM (GE Healthcare, Pittsburgh, PA, USA) (i.e., WSHPQFEK, SEQ ID NO: 31) , and/or a c-myc tag (i.e., EQKLISEEDL, SEQ ID NO: 32) .

Polypeptides and fragments of the invention can be modified for in vivo use by the addition, at the amino-and/or carboxyl-terminal ends, of a blocking agent to facilitate survival of the relevant polypeptide in vivo. This can be useful in those situations in which the peptide termini tend to be degraded by proteases prior to cellular uptake. Such blocking agents can include, without limitation, additional related or unrelated peptide sequences that can be attached to the amino and/or carboxyl terminal residues of the peptide to be administered. For example, one or more non-naturally occurring amino acids, such as D-alanine, can be added to the termini. Alternatively, blocking agents such as pyroglutamic acid or other molecules known in the art can be attached to the amino and/or carboxyl terminal residues, or the amino group at the amino terminus or carboxyl group at the carboxyl terminus can be replaced with a different moiety. Additionally, the peptide terminus can be modified, e.g., by acetylation of the N-terminus and/or amidation of the C-terminus. Likewise, the peptides can be covalently or noncovalently coupled to pharmaceutically acceptable “carrier” proteins prior to administration.

As used herein with respect to nucleic acids, the term “operably linked” refers to a functional linkage between two or more nucleic acids. For example, a promoter sequence may be described as being “operably linked” to a heterologous nucleic acid sequence because the promoter sequences initiates and/or mediates transcription of the heterologous nucleic acid sequence. In some embodiments, two operably linked nucleic acids are not contiguous with one another. In some embodiments, the operably linked nucleic acid sequences are contiguous and/or are in the same reading frame.

In some embodiments, the nucleotide sequences and/or nucleic acid molecules of the invention can be operatively associated with a variety of promoters for expression in host cells (e.g., plant cells) . As used herein, “operatively associated with, ” “operatively linked to” or “operably linked to” when referring to a first nucleic acid sequence that is operably linked to a second nucleic acid sequence, means a situation when the first nucleic acid sequence is placed in a functional relationship with the second nucleic acid sequence. For instance, a promoter is operably associated with a coding sequence if the promoter effects the transcription or expression of the coding sequence.

A DNA “promoter” is an untranslated DNA sequence upstream of a coding region that contains the binding site for RNA polymerase and initiates transcription of the DNA. A “promoter region” can also include other elements that act as regulators of gene expression. Promoters can include, for example, constitutive, inducible, temporally regulated, developmentally regulated, chemically regulated, tissue-preferred and tissue-specific promoters for use in the preparation of recombinant nucleic acid molecules, i.e., chimeric genes. In particular aspects, a “promoter” useful with the invention is a promoter capable of initiating transcription of a nucleotide sequence in a cell of a plant.

As used herein, the term “percent barren” (PB) refers to the percentage of plants in a given area (e.g., plot) with no grain. It is typically expressed in terms of the percentage of plants per plot and can be calculated as:

As used herein, the term “percent yield recovery” (PYREC) refers to the effect an allele and/or combination of alleles has on the yield of a plant grown under stress conditions (e.g., drought conditions) as compared to that of a plant that is genetically identical except insofar as it lacks the allele and/or combination of alleles. PYREC is calculated as:

By way of example and not limitation, if a control plant yields 200 bushels under full irrigation conditions, but yields only 100 bushels under drought stress conditions, then its percentage yield loss would be calculated at 50％. If an otherwise genetically identical hybrid that contains the allele (s) of interest yields 125 bushels under drought stress conditions and 200 bushels under full irrigation conditions, then the percentage yield loss would be calculated as 37.5％and the PYREC would be calculated as 25％ [1.00- (200-125) / (200-100) x 100) ] .

As used herein, the terms “phenotype, ” “phenotypic trait” or “trait” refer to one or more traits of an organism. The phenotype can be observable to the naked eye, or by any other means of evaluation known in the art, e.g., microscopy, biochemical analysis, or an electromechanical assay. In some cases, a phenotype is directly controlled by a single gene or genetic locus, i.e., a “single gene trait. ” In other cases, a phenotype is the result of several genes. It is noted that, as used herein, the term “water optimization phenotype” takes into account environmental conditions that might affect water optimization such that the water optimization effect is real and reproducible.

The terms “stringent conditions” or “stringent hybridization conditions” include reference to conditions under which a nucleic acid molecule will selectively hybridize to a target sequence to a detectably greater degree than other sequences (e.g., at least 2-fold over a non-target sequence) , and optionally may substantially exclude binding to non-target sequences. Stringent conditions are sequence-dependent and will vary under different circumstances. By controlling the stringency of the hybridization and/or washing conditions, target sequences can be identified that can be up to 100％complementary to the reference nucleotide sequence. Alternatively, conditions of moderate or even low stringency can be used to allow some mismatching in sequences so that lower degrees of sequence similarity are detected. For example, those skilled in the art will appreciate that to function as a primer or probe, a nucleotide sequence only needs to be sufficiently complementary to the target sequence to substantially bind thereto so as to form a stable double-stranded structure under the conditions employed. Thus, primers or probes can be used under conditions of high, moderate or even low stringency. Likewise, conditions of low or moderate stringency can be advantageous to detect homolog, ortholog and/or paralog sequences having lower degrees of sequence identity than would be identified under highly stringent conditions.

For DNA-DNA hybrids, the T_m can be approximated from the equation of Meinkoth and Wahl, Anal. Biochem., 138: 267-84 (1984) : T_m＝ 81.5℃+16.6 (log M) +0.41 (％GC) -0.61 (％formamide) -500/L； where M is the molarity of monovalent cations, ％GC is the percentage of guanosine and cytosine nucleotides in the DNA, ％formamide is the percentage of formamide in the hybridization solution, and L is the length of the hybrid in base pairs. The T_m is the temperature (under defined ionic strength and pH) at which 50％of a complementary target sequence hybridizes to a perfectly matched probe. T_m is reduced by about 1℃ for each 1％of mismatching； thus, T_m, hybridization and/or wash conditions can be adjusted to hybridize to sequences of the desired degree of identity. For example, if sequences with >90％identity are sought, the T_m can be decreased 10℃. Generally, stringent conditions are selected to be about 5℃ lower than the thermal melting point (T_m) for the specific sequence and its complement at a defined ionic strength and pH. However, highly stringent conditions can utilize a hybridization and/or wash at the thermal melting point (T_m) or 1, 2, 3 or 4℃ lower than the thermal melting point (T_m) ； moderately stringent conditions can utilize a hybridization and/or wash at 6, 7, 8, 9 or 10℃ lower than the thermal melting point (T_m) ； low stringency conditions can utilize a hybridization and/or wash at 11, 12, 13, 14, 15 or 20℃ lower than the thermal melting point (T_m) . If the desired degree of mismatching results in a T_m of less than 45℃ (aqueous solution) or 32℃ (formamide solution) , optionally the SSC concentration can be increased so that a higher temperature can be used. An extensive guide to the hybridization of nucleic acids is found in Tijssen, Laboratory Techniques in Biochemistry and Molecular Biology-Hybridization with Nucleic Acid Probes, part I, chapter 2, “Overview of principles of hybridization and the strategy of nucleic acid probe assays, ” Elsevier, New York (1993) ； Current Protocols in Molecular Biology, chapter 2, Ausubel, et al., eds, Greene Publishing and Wiley-Interscience, New York (1995) ； and Green &Sambrook, In: Molecular Cloning, A Laboratory Manual, 4th Edition, Cold Spring Harbor Press, Cold Spring Harbor, N.Y. (2012) .

Typically, stringent conditions are those in which the salt concentration is less than about 1.5 M Na ion, typically about 0.01 to 1.0 M Na ion concentration (or other salts) at about pH 7.0 to pH 8.3 and the temperature is at least about 30℃ for short probes (e.g., 10 to 50 nucleotides) and at least about 60℃ for longer probes (e.g., greater than 50 nucleotides) . Stringent conditions may also be achieved with the addition of destabilizing agents such as formamide or Denhardt's (5 g Ficoll, 5 g polyvinylpyrrolidone, 5 g bovine serum albumin in 500 ml of water) . Exemplary low stringency conditions include hybridization with a buffer solution of 30％to 35％formamide, 1 M NaCl, 1％SDS (sodium dodecyl sulfate) at 37℃ and a wash in 1X to 2X SSC (20X SSC ＝ 3.0 M NaCl/0.3 M trisodium citrate) at 50℃ to 55℃. Exemplary moderate stringency conditions include hybridization in 40％to 45％formamide, 1 M NaCl, 1％SDS at 37℃ and a wash in 0.5X to 1X SSC at 55℃ to 60℃. Exemplary high stringency conditions include hybridization in 50％formamide, 1 M NaCl, 1％SDS at 37℃ and a wash in 0.1X SSC at 60℃ to 65℃. A further non-limiting example of high stringency conditions include hybridization in 4X SSC, 5X Denhardt's , 0.1 mg/ml boiled salmon sperm DNA, and 25 mM Na phosphate at 65℃ and a wash in 0.1X SSC, 0.1％SDS at 65℃. Another illustration of high stringency hybridization conditions includes hybridization in 7％SDS, 0.5 M NaPO₄, 1 mM EDTA at 50℃ with washing in 2X SSC, 0.1％SDS at 50℃, alternatively with washing in 1X SSC, 0.1％SDS at 50℃, alternatively with washing in 0.5X SSC, 0.1％SDS at 50℃, or alternatively with washing in 0.1X SSC, 0.1％SDS at 50℃, or even with washing in 0.1X SSC, 0.1％SDS at 65℃. Those skilled in the art will appreciate that specificity is typically a function of post-hybridization washes, the relevant factors being the ionic strength and temperature of the final wash solution.

Nucleic acids that do not hybridize to each other under stringent conditions are still substantially identical if the proteins that they encode are substantially identical (e.g., due to the degeneracy of the genetic code) .

A nucleic acid sequence is “isocoding with” areference nucleic acid sequence when the nucleic acid sequence encodes a polypeptide having the same amino acid sequence as the polypeptide encoded by the reference nucleic acid sequence.

As used herein, the term “substantially complementary” (and similar terms) means that two nucleic acid sequences are at least about 50％, 60％, 70％, 75％, 80％, 85％, 90％, 95％, 96％, 97％, 98％, 99％or more complementary. Alternatively, the term “substantially complementary” (and similar terms) can mean that two nucleic acid sequences can hybridize together under high stringency conditions (as described herein) .

In representative embodiments, “substantially complementary” means about 70％, 71％, 72％, 73％, 74％, 75％, 76％, 77％, 78％, 79％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, or 99％complementary, or any value or range therein, to a target nucleic acid sequence.

The phrase “hybridizing specifically to” (and similar terms) refers to the binding, duplexing, or hybridizing of a molecule to a particular nucleic acid target sequence under stringent conditions when that sequence is present in a complex mixture (e.g., total cellular DNA or RNA) to the substantial exclusion of non-target nucleic acids, or even with no detectable binding, duplexing or hybridizing to non-target sequences. Selectively hybridizing sequences typically are at least about 40％complementary and are optionally substantially complementary or even completely complementary (i.e., 100％identical) to a nucleic acid sequence.

The term “bind (s) substantially” (and similar terms) as used herein refers to complementary hybridization between a nucleic acid molecule and a target nucleic acid and embraces minor mismatches that can be accommodated by reducing the stringency of the hybridization media to achieve the desired detection of the target nucleic acid sequence.

As used herein, the terms “transformation, ” “transfection, ” and “transduction” refer to the introduction of an exogenous/heterologous nucleic acid (RNA and/or DNA) into a host cell. A cell has been “transformed, ” “transfected” or “transduced” with an exogenous/heterologous nucleic acid when such nucleic acid has been introduced or delivered into the cell.

As used herein with respect to plants and plant parts, the term “transgenic” refers to a plant, plant part or plant cell that comprises one or more exogenous nucleic acids. Generally, the exogenous nucleic acid is stably integrated within the genome such that the polynucleotide is passed on to successive generations. The exogenous nucleic acid may be integrated into the genome alone or as part of a recombinant expression cassette. “Transgenic” may be used to designate any plant, plant part or plant cell the genotype of which has been altered by the presence of an exogenous nucleic acid, including those transgenic plants initially so altered and those created by sexual crosses or asexual propagation from the initial transgenic. As used herein, the term “transgenic” does not encompass the alteration of the genome (chromosomal or extra-chromosomal) by conventional plant breeding methods or by naturally occurring events such as random cross-fertilization, non-recombinant viral infection, non-recombinant bacterial transformation, non-recombinant transposition or spontaneous mutation.

As used herein, the term “water optimization trait” refers to any trait that can be shown to influence the growth and development of a plant under different sets of growth conditions related to water availability.

As used herein, the term “yield reduction” (YD) refers to the degree to which yield is reduced in plants grown under stress conditions. YD is calculated as:

The invention is directed in part to the discovery of novel nucleotide sequences that when introduced into a plant result in increased drought tolerance in said plant. The inventors made the surprising discovery that newly identified nucleic acids from the plant Incarvillea argutacanconfer increased drought tolerance when introduced into other plant species. Thus, the present invention provides drought tolerant plants and plant parts, as well as methods and compositions for identifying, selecting and/or producing drought tolerant plants and plant parts.

Accordingly, in some embodiments, a recombinant nucleic acid molecule is provided, said nucleic acid molecule comprising, consisting essentially of, or consisting of: (a) a nucleotide sequence ofany one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, (b) a nucleotide sequence encoding a polypeptide having the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (c) anucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ； (d) anucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (e) anucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above； (f) anucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or (g) any combination of the nucleotide sequences of (a) to (f) above.

In some embodiments of the invention, the nucleotide sequences comprised in the recombinant nucleic acid molecules of the invention can be expressed to produce polypeptides, each of which when produced in a plant confer increased drought tolerance and/or improvement in one or more characteristics associated with drought tolerance. Thus, in some embodiments of the invention, a polypeptide is provided, the polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence of any of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, or SEQ ID NO: 20, wherein production of said polypeptide in a plant results in increased tolerance to drought in the plant and improvement in one or more characteristics associated with drought tolerance.

Thus, in some embodiments, the present invention provides a plant and/or plant part comprising in its genome a recombinant nucleic acid molecule of the invention (e.g., a recombinant nucleic acid molecule comprising, consisting essentially of, or consisting of: (a) a nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, (b) a nucleotide sequence encoding a polypeptide having the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (c) anucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ； (d) anucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20； (e) anucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above； (f) anucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or (g) any combination of the nucleotide sequences of (a) to (f) above.

In further embodiments, the present invention provides methods for increasing drought tolerance in aplant, methods for producing aplant having increased drought tolerance and methods for identifying aplant having increased drought tolerance.

Accordingly, in some embodiments, a method of increasing drought tolerance of a plant and/or plant part is provided, comprising, consisting essentially of, or consisting of: introducing into a plant and/or plant part a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette and/or a vector.

In some embodiments, a method of increasing drought tolerance of a plant and/or plant part is provided, comprising, consisting essentially of, or consisting of: expressing in a plant and/or plant part a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette and/or a vector.

In some embodiments, a method of producing a plant having increased drought tolerance is provided, comprising, consisting essentially of, or consisting of: detecting, in a plant part, a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector； and producing a plant from said plant part.

In some embodiments, a method of producing a plant having increased drought tolerance is provided, comprising, consisting essentially of, or consisting of: introducing into a plant cell and/or plant part a recombinant nucleic acid molecule ofthe inventionto produce a transgenic plant cell and/or plant part, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector； and growing the plant cell and/or plant part into a plant, thereby producing a plant having increased drought tolerance.

In some embodiments, a method of producing a plant having increased drought tolerance is provided, comprising, consisting essentially of, or consisting of: crossing a first parent plant and/or plant part with a second parent plant and/or plant part, wherein said first parent plant and/or plant part comprises within its genome a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette and/or a vector； thereby producing a progeny generation, wherein said progeny generation comprises at least one plant that possesses said recombinant nucleic acid molecule within its genome and has increased drought tolerance.

In some embodiments, a method of identifying a plant and/or plant part having increased drought tolerance is provided, comprising, consisting essentially of, or consisting of: detecting, in a plant and/or plant part, a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette and/or a vector, thereby identifying a plant and/or plant part having increased drought tolerance. In some embodiments, the recombinant nucleic acid molecule or an informative fragment thereof is detected in an amplification product from a nucleic acid sample from said plant and/or plant part. In representative embodiments, the amplification product comprises, consists essentially of, or consists of the nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, the reverse complement thereof, an informative fragment thereof, or an informative fragment of the reverse complement thereof. In some embodiments, the recombinant nucleic acid is detected using a probe comprising, consisting essentially of, or consisting ofthe nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, the reverse complement thereof, an informative fragment thereof, or an informative fragment of the reverse complement thereof.

In some embodiments, the plant and/or plant part into which a recombination nucleic acid molecule is introduced or in which a recombination nucleic acid molecule is expressed or detected, produces a polypeptide comprising, consisting essentially of, or consisting ofthe amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, or any combination thereof, or a polypeptide having at least about 80％identity to the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, or any combination thereof, at an increased level as compared to a control plant and/or plant part. In some embodiments, a control plant can be a plant that does not comprise a nucleotide sequence encoding the polypeptides of the invention and therefore does not produce a polypeptide having the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, or a polypeptide having at least about 80％identity to the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20.

In some embodiments, a plant and/or plant part of the invention having increased drought tolerance comprises one or more characteristics associated with drought tolerance. In some embodiments, the one or more characteristics associated with drought tolerance include (s) but is/are not limited to decreased water loss, decreased accumulation of reactive oxygen species, increased accumulation of dehydrins, improved root architecture, increased accumulation of late embryogenesis abundant proteins, increased grain yield at standard moisture percentage (YGSMN) , increased grain moisture at harvest (GMSTP) , increased grain weight per plot (GWTPN) , increased percent yield recovery (PYREC) , decreased yield reduction (YRED) , and/or decreased percent barren (PB) .

Thus, in some embodiments, methods of producing plants having one or more characteristics associated with enhanced drought tolerance are provided, the method comprising, consisting essentially of or consisting of:

(a) introducing into a plant and/or plant part a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector, thereby producing a plant and/or plant part having one or more characteristics associated with enhanced drought tolerance；

(b) expressing in a plant and/or plant part a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector, thereby producing a plant and/or plant part having one or more characteristics associated with enhanced drought tolerance.

(c) detecting, in a plant part, a recombinant nucleic acid molecule comprising a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector； and producing a plant from said plant part having one or more characteristics associated with enhanced drought tolerance；

(d) introducing into a plant cell and/or plant part a recombinant nucleic acid molecule comprising the recombinant nucleic acid molecule of the inventionto produce a transgenic plant cell or plant part, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector； and growing the plant cell or plant part into a plant, thereby producing a plant having one or more characteristics associated with enhanced drought tolerance； and/or

(e) crossing a first parent plant with a second parent plant, wherein said first parent plant comprises within its genome a recombinant nucleic acid molecule of the invention, optionally wherein the recombinant nucleic acid molecule can be comprised in an expression cassette or a vector； thereby producing a progeny generation, wherein said progeny generation comprises at least one plant that possesses said recombinant nucleic acid molecule within its genome and has one or more characteristics associated with enhanced drought tolerance.

In some embodiments, the drought stress tolerance of a plant or plant part comprising a recombinant nucleic acid of the present invention can be increased by at least about 5％, 10％, 15％, 20％, 25％, 30％, 35％, 40％, 45％, 50％, 55％, 60％, 65％, 75％, 80％, 85％, 90％, 95％, 100％, 125％, 150％, 175％, 200％, 250％, 300％or more as compared to a control plant and/or plant part. A “control plant and/or plant part” as used herein, can include, but is not limited to, aparent plant or a native or wild type plant of the same species (e.g., a plant not comprising the recombinant nucleic acid molecule of the invention) grown under the same or substantially the same environmental conditions.

In some embodiments, a recombinant exogenous nucleic acid molecule of the invention comprises one or more promoter sequences operably linked to a nucleotide sequence of the invention. Promoters useful with the invention include, but are not limited to, those that drive expression of a nucleotide sequence constitutively, those that drive expression when induced, and those that drive expression in a tissue-or developmentally-specific manner. These various types of promoters are known in the art.

Of course, the choice of promoter will vary depending on the temporal and spatial requirements for expression, and also depending on the host cell to be transformed. Thus, for example, expression of the nucleotide sequences of the invention can be in any plant and/or plant part, (e.g., in cells, in leaves, in stalks or stems, in ears, in inflorescences (e.g. spikes, panicles, cobs, etc. ) , in roots, seeds and/or seedlings, and the like) . In many cases, however, expression in multiple tissues may be desirable. Although many promoters from dicotyledons have been shown to be operational in monocotyledons and vice versa, ideally dicotyledonous promoters are selected for expression in dicotyledons, and monocotyledonous promoters for expression in monocotyledons. However, there is no restriction to the provenance of selected promoters； it is sufficient that they are operational in driving the expression of the nucleotide sequences in the desired cell.

In some embodiments, a promoter useful with the invention includes but is not limited to a tissue-specific promoter, optionally a panicle-, sheath-, and/or leaf-specific promoter； a stress-inducible promoter sequence, optionally a drought-inducible promoter； or a developmental stage-specific promoter, optionally a promoter that drives expression prior to and/or during the early seedling, tillering, flowering and/or seed filling stage (s) of development.

Examples of constitutive promoters include, but are not limited to, cestrum virus promoter (cmp) (U.S. Patent No. 7,166,770) , the rice actin 1 promoter (Wang et al. (1992) Mol. Cell. Biol. 12: 3399-3406； as well as US Patent No. 5,641,876) , CaMV 35S promoter (Odell et al. (1985) Nature 313: 810-812) , CaMV 19S promoter (Lawton et al. (1987) Plant Mol. Biol. 9: 315-324) , nos promoter (Ebert et al. (1987) Proc. Natl. Acad. Sci USA 84: 5745-5749) , Adh promoter (Walker et al. (1987) Proc. Natl. Acad. Sci. USA 84: 6624-6629) , sucrose synthase promoter (Yang &Russell (1990) Proc. Natl. Acad. Sci. USA 87: 4144-4148) , and the ubiquitin promoter. The constitutive promoter derived from ubiquitin accumulates in many cell types. Ubiquitin promoters have been cloned from several plant species for use in transgenic plants, for example, sunflower (Binet et al., 1991. Plant Science 79: 87-94) , maize (Christensen et al., 1989. Plant Molec. Biol. 12: 619-632) , and arabidopsis (Norris et al. 1993. Plant Molec. Biol. 21: 895-906) . The maize ubiquitin promoter (UbiP) has been developed in transgenic monocot systems and its sequence and vectors constructed for monocot transformation are disclosed in the patent publication EP 0 342 926. The ubiquitin promoter is suitable for the expression of the nucleotide sequences of the invention in transgenic plants, especially monocotyledons. Further, the promoter expression cassettes described by McElroy et al. (Mol. Gen. Genet. 231: 150-160 (1991) ) can be easily modified for the expression of the nucleotide sequences of the invention and are particularly suitable for use in monocotyledonous hosts. Exemplary constitutive promoters that can be operably linked to the nucleic acids and/or nucleotide sequences of the invention include CaMV 19S, CaMV 35S, Arabidopsis At6669, maize H3 histone, rice actin, actin 2, rice cyclophilin, pEMU, GOS2, constitutive root tip CT2, and/or ubiquitin (e.g., maize Ubi) promoter sequences. In a representative embodiment, a promoter useful with the polynucleotides of the invention is a constitutive promoter.

In some embodiments, tissue specific/tissue preferred promoters can be used. Tissue specific or preferred expression patterns include, but are not limited to, green tissue specific or preferred, root specific or preferred, stem specific or preferred, and flower specific or preferred. Promoters suitable for expression in green tissue include many that regulate genes involved in photosynthesis and many of these have been cloned from both monocotyledons and dicotyledons. In one embodiment, a promoter useful with the invention is the maize PEPC promoter from the phosphoenol carboxylase gene (Hudspeth &Grula, Plant Molec. Biol. 12: 579-589 (1989) ) . Non-limiting examples of tissue-specific promoters include those associated with genes encoding the seed storage proteins (such as β-conglycinin, cruciferin, napin and phaseolin) , zein or oil body proteins (such as oleosin) , or proteins involved in fatty acid biosynthesis (including acyl carrier protein, stearoyl-ACP desaturase and fatty acid desaturases (fad 2-1) ) , and other nucleic acids expressed during embryo development (such as Bce4, see, e.g., Kridl et al. (1991) Seed Sci. Res. 1: 209-219； as well as EP Patent No. 255378) . Tissue-specific or tissue-preferential promoters useful for the expression of the nucleotide sequences of the invention in plants, particularly maize, include but are not limited to those that direct expression in root, pith, leaf or pollen. Such promoters are disclosed, for example, in WO 93/07278, herein incorporated by reference in its entirety. Other non-limiting examples of tissue specific or tissue preferred promoters useful with the invention the cotton rubisco promoter disclosed in US Patent 6,040,504； the rice sucrose synthase promoter disclosed in US Patent 5,604,121； the root specific promoter described by de Framond (FEBS 290: 103-106 (1991) ； EP 0 452 269 to Ciba-Geigy) ； the stem specific promoter described in U.S. Patent 5,625,136 (to Ciba-Geigy) and which drives expressionof the maize trpA gene； and the cestrum yellow leaf curling virus promoter disclosed in WO 01/73087, all incorporated by reference

Additional examples of tissue-specific/tissue preferred promoters include, but are not limited to, the root-specific promoters RCc3 (Jeong et al. Plant Physiol. 153: 185-197 (2010) ) and RB7 (U.S. Patent No. 5459252) , the lectin promoter (Lindstrom et al. (1990) Der. Genet. 11: 160-167； and Vodkin (1983) Prog. Clin. Biol. Res. 138: 87-98) , corn alcohol dehydrogenase 1 promoter (Dennis et al. (1984) Nucleic Acids Res. 12: 3983-4000) , S-adenosyl-L-methionine synthetase (SAMS) (Vander Mijnsbrugge et al. (1996) Plant and Cell Physiology, 37 (8) : 1108-1115) , corn light harvesting complex promoter (Bansal et al. (1992) Proc. Natl. Acad. Sci. USA 89: 3654-3658) , corn heat shock protein promoter (O'Dell et al. (1985) EMBO J. 5: 451-458； and Rochester et al. (1986) EMBO J. 5: 451-458) , pea small subunit RuBP carboxylase promoter (Cashmore, “Nuclear genes encoding the small subunit of ribulose-l, 5-bisphosphate carboxylase” pp. 29-39 In: Genetic Engineering of Plants (Hollaender ed., Plenum Press 1983； and Poulsen et al. (1986) Mol. Gen. Genet. 205: 193-200) , Ti plasmid mannopine synthase promoter (Langridge et al. (1989) Proc. Natl. Acad. Sci. USA 86: 3219-3223) , Ti plasmid nopaline synthase promoter (Langridge et al. (1989) , supra) , petunia chalcone isomerase promoter (van Tunen et al. (1988) EMBO J. 7: 1257-1263) , bean glycine rich protein 1 promoter (Keller et al. (1989) Genes Dev. 3: 1639-1646) , truncated CaMV 35S promoter (O'Dell et al. (1985) Nature 313: 810-812) , potato patatin promoter (Wenzler et al. (1989) Plant Mol. Biol. 13: 347-354) , root cell promoter (Yamamoto et al. (1990) Nucleic Acids Res. 18: 7449) , maize zein promoter (Kriz et al. (1987) Mol. Gen. Genet. 207: 90-98； Langridge et al. (1983) Cell 34: 1015-1022； Reina et al. (1990) Nucleic Acids Res. 18: 6425； Reina et al. (1990) Nucleic Acids Res. 18: 7449； and Wandelt et al. (1989) Nucleic Acids Res. 17: 2354) , globulin-1 promoter (Belanger et al. (1991) Genetics 129: 863-872) , a-tubulin cab promoter (Sullivan et al. (1989) Mol. Gen. Genet. 215: 431-440) , PEPCase promoter (Hudspeth &Grula (1989) Plant Mol. Biol. 12: 579-589) , R gene complex-associated promoters (Chandler et al. (1989) Plant Cell 1: 1175-1183) , and chalcone synthase promoters (Franken et al. (1991) EMBO J. 10: 2605-2612) . In some particular embodiments, the nucleotide sequences of the invention are operatively associated with a root-preferred promoter.

Particularly useful for seed-specific expression is the pea vicilin promoter (Czako et al. (1992) Mol. Gen. Genet. 235: 33-40； as well as the seed-specific promoters disclosed in U.S. Patent No. 5,625,136. Useful promoters for expression in mature leaves are those that are switched on at the onset of senescence, such as the SAG promoter from Arabidopsis (Gan et al. (1995) Science 270: 1986-1988) .

In addition, promoters functional in plastids can be used. Non-limiting examples of such promoters include the bacteriophage T3 gene 9 5' UTR and other promoters disclosed in U.S. Patent No. 7,579,516. Other promoters useful with the invention include but are not limited to the S-E9 small subunit RuBP carboxylase promoter and the Kunitz trypsin inhibitor gene promoter (Kti3) .

In some embodiments of the invention, inducible promoters can be used. Thus, for example, chemical-regulated promoters can be used to modulate the expression of a gene in a plant through the application of an exogenous chemical regulator. Regulation of the expression of nucleotide sequences of the invention via promoters that are chemically regulated enables the polypeptides of the invention to be synthesized only when the crop plants are treated with the inducing chemicals. Depending upon the objective, the promoter may be a chemical-inducible promoter, where application of a chemical induces gene expression, or a chemical-repressible promoter, where application of the chemical represses gene expression.

Chemical inducible promoters are known in the art and include, but are not limited to, the maize In2-2 promoter, which is activated by benzenesulfonamide herbicide safeners, the maize GST promoter, which is activated by hydrophobic electrophilic compounds that are used as pre-emergent herbicides, and the tobacco PR-1 a promoter, which is activated by salicylic acid (e.g., the PR1a system) , steroid steroid-responsive promoters (see, e.g., the glucocorticoid-inducible promoter in Schena et al. (1991) Proc. Natl. Acad. Sci. USA 88, 10421-10425 and McNellis et al. (1998) Plant J. 14, 247-257) and tetracycline-inducible and tetracycline-repressible promoters (see, e.g., Gatz et al. (1991) Mol. Gen. Genet. 227, 229-237, and U.S. Patent Numbers 5,814,618 and 5,789,156, Lac repressor system promoters, copper-inducible system promoters, salicylate-inducible system promoters (e.g., the PR1a system) , glucocorticoid-inducible promoters (Aoyama et al. (1997) Plant J. 11: 605-612) , and ecdysone-inducible system promoters.

Other non-limiting examples of inducible promoters include ABA-and turgor-inducible promoters, the auxin-binding protein gene promoter (Schwob et al. (1993) Plant J. 4: 423-432) , the UDP glucose flavonoid glycosyl-transferase promoter (Ralston et al. (1988) Genetics 119: 185-197) , the MPI proteinase inhibitor promoter (Cordero et al. (1994) Plant J. 6: 141-150) , and the glyceraldehyde-3-phosphate dehydrogenase promoter (Kohler et al. (1995) Plant Mol. Biol. 29: 1293-1298； Martinez et al. (1989) J. Mol. Biol. 208: 551-565； and Quigley et al. (1989) J. Mol. Evol. 29: 412-421) . Also included are the benzene sulphonamide-inducible (US Patent No. 5,364,780) and alcohol-inducible (Int'l Patent Application Publication Nos. WO 97/06269 and WO 97/06268) systems and glutathione S-transferase promoters. Likewise, one can use any of the inducible promoters described in Gatz (1996) Current Opinion Biotechnol. 7: 168-172 and Gatz (1997) Annu. Rev. Plant Physiol. Plant Mol. Biol. 48: 89-108. Other chemically inducible promoters useful for directing the expression of the nucleotide sequences of this invention in plants are disclosed in US Patent 5,614,395 herein incorporated by reference in its entirety. Chemical induction of gene expression is also detailed in the published application EP 0 332 104 (to Ciba-Geigy) and U.S. Patent 5,614,395. In some embodiments, a promoter for chemical induction can be the tobacco PR-1a promoter.

In further aspects, the nucleotide sequences of the invention can be operatively associated with a promoter that is wound inducible or inducible by pest or pathogen infection (e.g., a nematode plant pest) . Numerous promoters have been described which are expressed at wound sites and/or at the sites of pest attack (e.g., insect/nematode feeding) or phytopathogen infection. Ideally, such a promoter should be active only locally at or adjacent to the sites of attack, and in this way expression of the nucleotide sequences of the invention will be focused in the cells that are being invaded. Such promoters include, but are not limited to, those described by Stanford et al., Mol. Gen. Genet. 215: 200-208 (1989) , Xu et al. Plant Molec. Biol. 22: 573-588 (1993) , Logemann et al. Plant Cell 1: 151-158 (1989) , Rohrmeier and Lehle, Plant Molec. Biol. 22: 783-792 (1993) , Firek et al. Plant Molec. Biol. 22: 129-142 (1993) , Warner et al. Plant J. 3: 191-201 (1993) , U.S. Patent No. 5,750,386, U.S. Patent No. 5,955,646, U.S. Patent No. 6,262,344, U.S. Patent No. 6,395,963, U.S. Patent No. 6,703,541, U.S. Patent No. 7,078,589, U.S. Patent No. 7,196,247, U.S. Patent No. 7,223,901, and U.S. Patent Application Publication 2010043102.

In some embodiments, any nucleotide sequence and/or recombinant nucleic acid molecule of this invention can be codon optimized for expression in any plant species. Codon optimization is well known in the art and involves modification of a nucleotide sequence for codon usage bias using species specific codon usage tables. The codon usage tables are generated based on a sequence analysis of the most highly expressed genes for the species of interest. When the nucleotide sequences are to be expressed in the nucleus, the codon usage tables are generated based on a sequence analysis of highly expressed nuclear genes for the species of interest. The modifications of the nucleotide sequences are determined by comparing the species specific codon usage table with the codons present in the native polynucleotide sequences. As is understood in the art, codon optimization of a nucleotide sequence results in a nucleotide sequence having less than 100％identity (e.g., 70％, 71％, 72％, 73％, 74％, 75％, 76％, 77％, 78％, 79％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, and the like) to the native nucleotide sequence but which still encodes a polypeptide having the same functionas that encoded by the original, native nucleotide sequence. Thus, in representative embodiments of the invention, the nucleotide sequences and/or recombinant nucleic acid molecules of this invention and other components (including but not limited to the regulator sequences such as promoter sequences and terminator sequences, and the like) can be codon optimized for expression in any particular plant species of interest. In some embodiments, the codon optimized nucleotide sequences of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, and/or SEQ ID NO: 14 have about 70％to about 99％identity to the nucleotide sequences of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12； SEQ ID NO: 13, and/or SEQ ID NO: 14.

In some embodiments of the invention, nucleotide sequences having substantial sequence identity to the nucleotide sequences of the invention are provided. The phrase “substantially identical, ” or “substantially similar” in the context of two nucleic acids or two amino acid sequences, refers to two or more sequences or subsequences that have at least about 70％nucleotide or amino acid residue identity (e.g., 70％, 75％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, and/or 100％identity or similarity) when compared and aligned for maximum correspondence as measured using one of the following sequence comparison algorithms or by visual inspection. Thus, in additional embodiments, “substantial sequence identity” or “substantial sequence similarity” means a range of about 70％to about 100％, about 75％to about 100％, about 80％to about 100％, about 81％to about 100％, about 82％to about 100％, about 83％to about 100％, about 84％to about 100％, about 85％to about 100％, about 86％to about 100％, about 87％to about 100％, about 88％to about 100％, about 89％to about 100％, about 90％to about 100％, about 91％to about 100％, about 92％to about 100％, about 93％to about 100％, about 94％to about 100％, about 95％to about 100％, about 96％to about 100％, about 97％to about 100％, about 98％to about 100％, and/or about 99％to about 100％identity or similarity with another nucleotide sequence. In some embodiments, substantially identical or similar sequences have at least about 70％, or at least about 80％, or even at least about 90％or 95％nucleotide or amino acid residue identity. Therefore, in some embodiments, arecombinant nucleic acid molecule of the invention comprises, consists essentially of, or consists of a nucleotide sequence that is substantially identical to or identical to (e.g., at least 70％, 75％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, and/or 100％identical) to a nucleotide sequence of the inventionof any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12； SEQ ID NO: 13, and/or SEQ ID NO: 14. In some embodiments, a polypeptide of the invention comprises, consists essentially of, or consists of an amino acid sequence that is substantially identical to or identical to (e.g., at least 70％, 75％, 80％, 81％, 82％, 83％, 84％, 85％, 86％, 87％, 88％, 89％, 90％, 91％, 92％, 93％, 94％, 95％, 96％, 97％, 98％, 99％, and/or 100％identical) an amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and/or SEQ ID NO: 20.

In some embodiments, the recombinant nucleic acid molecule of the invention can be comprised in an expression cassette. As used herein, “expression cassette” means a nucleic acid molecule comprising a nucleotide sequence of interest (e.g., the nucleotide sequences of the invention) , wherein said nucleotide sequence is operatively associated with at least a control sequence (e.g., a promoter) . Thus, some embodiments of the invention provide expression cassettes designed to express the nucleotides sequences of the invention. In this manner, for example, one or more plant promoters operatively associated with one or more nucleotide sequences of the invention (e.g., SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14 or a nucleotide sequence encoding the polypeptide of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20) are provided in expression cassettes for expression in an organism or cell thereof (e.g., a plant, plant part and/or plant cell) .

An expression cassette comprising a nucleotide sequence of interest may be chimeric, meaning that at least one of its components is heterologous with respect to at least one of its other components. An expression cassette may also be one that is naturally occurring but has been obtained in a recombinant form useful for heterologous expression. Typically, however, the expression cassette is heterologous with respect to the host, i.e., the particular nucleotide sequence of the expression cassette does not occur naturally in the host cell and must have been introduced into the host cell or an ancestor of the host cell by a transformation event.

In addition to the promoters operatively linked to the nucleotide sequences of the invention, an expression cassette of the invention can also include other regulatory sequences. As used herein, “regulatory sequences” means nucleotide sequences located upstream (5' non-coding sequences) , within or downstream (3' non-coding sequences) of a coding sequence, and which influence the transcription, RNA processing or stability, or translation of the associated coding sequence. Regulatory sequences include, but are not limited to, promoters, enhancers, introns, translation leader sequences, termination signals, and polyadenylation signal sequences.

For purposes of the invention, regulatory sequences or regions can be native/analogous to the plant, plant part and/or plant cell and/or the regulatory sequences can be native/analogous to the other regulatory sequences. Alternatively, the regulatory sequences may be heterologous to the plant (and/or plant part and/or plant cell) and/or to each other (i.e., the regulatory sequences) . Thus, for example, a promoter can be heterologous when it is operatively linked to a polynucleotide from a species different from the species from which the polynucleotide was derived. Alternatively, a promoter can also be heterologous to a selected nucleotide sequence if the promoter is from the same/analogous species from which the polynucleotide is derived, but one or both (i.e., promoter and/or polynucleotide) are substantially modified from their original form and/or genomic locus, and/or the promoter is not the native promoter for the operably linked polynucleotide.

A number of non-translated leader sequences derived from viruses are known to enhance gene expression. Specifically, leader sequences from Tobacco Mosaic Virus (TMV, the “？ -sequence” ) , Maize Chlorotic Mottle Virus (MCMV) and Alfalfa Mosaic Virus (AMV) have been shown to be effective in enhancing expression (Gallie et al. (1987) Nucleic Acids Res. 15: 8693-8711； and Skuzeski et al. (1990) Plant Mol. Biol. 15: 65-79) . Other leader sequences known in the art include, but are not limited to, picornavirus leaders such as an encephalomyocarditis (EMCV) 5' noncoding region leader (Elroy-Stein et al. (1989) Proc. Natl. Acad. Sci. USA 86: 6126-6130) ； potyvirus leaders such as a Tobacco Etch Virus (TEV) leader (Allison et al. (1986) Virology 154: 9-20) ； Maize Dwarf Mosaic Virus (MDMV) leader (Allison et al. (1986) , supra) ； human immunoglobulin heavy-chain binding protein (BiP) leader (Macejak &Samow (1991) Nature 353: 90-94) ； untranslated leader from the coat protein mRNA of AMV (AMV RNA 4； Jobling &Gehrke (1987) Nature 325: 622-625) ； tobacco mosaic TMV leader (Gallie et al. (1989) Molecular Biology of RNA 237-256) ； and MCMV leader (Lommel et al. (1991) Virology 81: 382-385) . See also, Della-Cioppa et al. (1987) Plant Physiol. 84: 965-968.

An expression cassette also can optionally include a transcriptional and/or translational termination region (i.e., termination region) that is functional in plants. A variety of transcriptional terminators are available for use in expression cassettes and are responsible for the termination of transcription beyond the heterologous nucleotide sequence of interest and correct mRNA polyadenylation. The termination region may be native to the transcriptional initiation region, may be native to the operably linked nucleotide sequence of interest, may be native to the plant host, or may be derived from another source (i.e., foreign or heterologous to the promoter, the nucleotide sequence of interest, the plant host, or any combination thereof) . Appropriate transcriptional terminators include, but are not limited to, the CAMV 35S terminator, the tml terminator, the nopaline synthase terminator and/or the pea rbcs E9 terminator. These can be used in both monocotyledons and dicotyledons. In addition, a coding sequence's native transcription terminator can be used.

An expression cassette of the invention also can include a nucleotide sequence for a selectable marker, which can be used to select a transformed plant, plant part and/or plant cell. As used herein, “selectable marker” means a nucleotide sequence that when expressed imparts a distinct phenotype to the plant, plant part and/or plant cell expressing the marker and thus allows such transformed plants, plant parts and/or plant cells to be distinguished from those that do not have the marker. Such a nucleotide sequence may encode either a selectable or screenable marker, depending on whether the marker confers a trait that can be selected for by chemical means, such as by using a selective agent (e.g., an antibiotic, herbicide, or the like) , or on whether the marker is simply a trait that one can identify through observation or testing, such as by screening (e.g., the R-locus trait) . Of course, many examples of suitable selectable markers are known in the art and can be used in the expression cassettes described herein.

Examples of selectable markers include, but are not limited to, a nucleotide sequence encoding neo or nptII, which confers resistance to kanamycin, G418, and the like (Potrykus et al. (1985) Mol. Gen. Genet. 199: 183-188) ； a nucleotide sequence encoding bar, which confers resistance to phosphinothricin； a nucleotide sequence encoding an altered 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, which confers resistance to glyphosate (Hinchee et al. (1988) Biotech. 6: 915-922) ； a nucleotide sequence encoding a nitrilase such as bxn fromKlebsiella ozaenae that confers resistance to bromoxynil (Stalker et al. (1988) Science 242: 419-423) ； a nucleotide sequence encoding an altered acetolactate synthase (ALS) that confers resistance to imidazolinone, sulfonylurea or other ALS-inhibiting chemicals (EP Patent Application No. 154204) ； a nucleotide sequence encoding a methotrexate-resistant dihydrofolate reductase (DHFR) (Thillet et al. (1988) J. Biol. Chem. 263: 12500-12508) ； a nucleotide sequence encoding a dalapon dehalogenase that confers resistance to dalapon； a nucleotide sequence encoding a mannose-6-phosphate isomerase (also referred to as phosphomannose isomerase (PMI) ) that confers an ability to metabolize mannose (US Patent Nos. 5,767,378 and 5,994,629) ； a nucleotide sequence encoding an altered anthranilate synthase that confers resistance to 5-methyl tryptophan； and/or a nucleotide sequence encoding hph that confers resistance to hygromycin. One of skill in the art is capable of choosing a suitable selectable marker for use in an expression cassette of the invention.

Additional selectable markers include, but are not limited to, a nucleotide sequence encoding β-glucuronidase or uidA (GUS) that encodes an enzyme for which various chromogenic substrates are known； an R-locus nucleotide sequence that encodes a product that regulates the production of anthocyanin pigments (red color) in plant tissues (Dellaporta et al., “Molecular cloning of the maize R-nj allele by transposon-tagging with Ac, ” pp. 263-282 In: Chromosome Structure and Function: Impact of New Concepts, 18th Stadler Genetics Symposium (Gustafson &Appels eds., Plenum Press 1988) ) ； a nucleotide sequence encoding β-lactamase, an enzyme for which various chromogenic substrates are known (e.g., PADAC, a chromogenic cephalosporin) (Sutcliffe (1978) Proc. Natl. Acad. Sci. USA 75: 3737-3741) ； a nucleotide sequence encoding xylE that encodes a catechol dioxygenase (Zukowsky et al. (1983) Proc. Natl. Acad. Sci. USA 80: 1101-1105) ； a nucleotide sequence encoding tyrosinase, an enzyme capable of oxidizing tyrosine to DOPA and dopaquinone, which in turn condenses to form melanin (Katz et al. (1983) J. Gen. Microbiol. 129: 2703-2714) ； a nucleotide sequence encoding β-galactosidase, an enzyme for which there are chromogenic substrates； a nucleotide sequence encoding luciferase (lux) that allows for bioluminescence detection (Ow et al. (1986) Science 234: 856-859) ； a nucleotide sequence encoding aequorin, which may be employed in calcium-sensitive bioluminescence detection (Prasher et al. (1985) Biochem. Biophys. Res. Comm. 126: 1259-1268) ； or a nucleotide sequence encoding green fluorescent protein (Niedz et al. (1995) Plant Cell Reports 14: 403-406) . One of skill in the art is capable of choosing a suitable selectable marker for use in an expression cassette of the invention.

An expression cassette of the invention also can include nucleotide sequences that encode other desired traits. Such desired traits can be other nucleotide sequences which confer other agriculturally desirable traits. Such nucleotide sequences can be stacked with any combination of nucleotide sequences to create plants, plant parts or plant cells having the desired phenotype. Stacked combinations can be created by any method including, but not limited to, cross breeding plants by any conventional methodology, or by genetic transformation. If stacked by genetically transforming the plants, nucleotide sequences encoding additional desired traits can be combined at any time and in any order. For example, a transgenic plant comprising one or more desired traits can be used as the target to introduce further traits by subsequent transformation. The additional nucleotide sequences can be introduced simultaneously in a co-transformation protocol with a nucleotide sequence, nucleic acid molecule, nucleic acid construct, and/or composition of the invention, provided by any combination of expression cassettes. For example, if two nucleotide sequences will be introduced, they can be incorporated in separate cassettes (trans) or can be incorporated on the same cassette (cis) . Expression of the nucleotide sequences can be driven by the same promoter or by different promoters. It is further recognized that nucleotide sequences can be stacked at a desired genomic location using a site-specific recombination system. See, e.g., Int'l Patent Application Publication Nos. WO 99/25821； WO 99/25854； WO 99/25840； WO 99/25855 and WO 99/25853. In representative embodiments, a nucleic acid molecule, expression cassette or vector of the invention can comprise a transgene that confers resistance to one or more herbicides, optionally glyphosate-, sulfonylurea-, imidazolinione-, dicamba-, glufisinate-, phenoxy proprionic acid-, cycloshexome-, traizine-, benzonitrile-, and/or broxynil-resistance； a transgene that confers resistance to one or more pests, optionally bacterial-, fungal, gastropod-, insect-, nematode-, oomycete-, phytoplasma-, protozoa-, and/or viral-resistance, and/or a transgene that confers resistance to one or more diseases. In some embodiments, a nucleic acid molecule, expression cassette or vector of the invention can comprise one or more transgenes that confer tolerance to one or more abiotic stresses. "Abiotic stress" refers to non-living environmental factors such as extremes in temperature, frost, drought, high winds, and the like, that can have harmful effects on plants. Thus, for example, transgenes that confer abiotic stress tolerance may confer tolerance to abiotic stresses including, but not limited to, cold temperature that results in freezing, chilling, heat or high temperatures, drought, flooding, high light intensity, low light intensity, extreme osmotic pressures, extreme salt concentrations, high winds, ozone, poor edaphic conditions (e.g., extreme soil pH, nutrient-deficient soil, compacted soil, etc. ) , and/or combinations thereof. As used herein, the terms "abiotic stress tolerance" and "abiotic stress tolerant" refer to a plant's ability to endure and/or thrive under abiotic stress conditions (e.g., drought stress conditions, osmotic stress conditions, salt stress conditions and/or temperature stress conditions) . When used in reference to a plant part, the terms refer to the ability of a plant that arises from that plant part to endure and/or thrive under abiotic stress conditions.

In addition to expression cassettes, the nucleic acid molecules and nucleotide sequences described herein can be used in connection with vectors. Thus, in some embodiments, the recombinant nucleic acid can be comprised in a vector or can be comprised in an expression cassette that is comprised in a vector. The term “vector” refers to a composition for transferring, delivering or introducing a nucleic acid molecule (s) into a cell. A vector comprises a nucleic acid molecule comprising the nucleotide sequence (s) to be transferred, delivered or introduced. Vectors for use in transformation of plants and other organisms are well known in the art. Non-limiting examples of general classes of vectors include a viral vector including but not limited to an adenovirus vector, a retroviral vector, an adeno-associated viral vector, a plasmid vector, a phage vector, a phagemid vector, a cosmid, a fosmid, a bacteriophage, or an artificial chromosome,. The selection of a vector will depend upon the preferred transformation technique and the target species for transformation. Accordingly, in further embodiments, a recombinant nucleic acid molecule of the invention can be comprised within a recombinant vector. The size of a vector can vary considerably depending on whether the vector comprises one or multiple expression cassettes (e.g., for molecular stacking) . Thus, a vector size can range from about 3 kb to about 30 kb. Thus, in some embodiments, a vector is about 3 kb, 4kb, 5 kb, 6 kb, 7 kb, 8 kb, 9 kb, 10 kb, 11 kb, 12 kb, 13 kb, 14kb, 15 kb, 16 kb, 17 kb, 18 kb, 19 kb, 20 kb, 21 kb, 22 kb, 23 kb, 24kb, 25 kb, 26 kb, 27 kb, 28 kb, 29 kb, 30 kb, or any range therein, in size. In some particular embodiments, a vector can be about 3 kb to about 10 kb in size.

A large number of vectors known in the art may be used to manipulate nucleic acids, incorporate response elements and promoters into genes, etc. For example, the insertion of nucleic acid fragments corresponding to response elements and promoters into a suitable vector can be accomplished by ligating the appropriate nucleic acid fragments into a chosen vector that has complementary cohesive termini. Alternatively, the ends of the nucleic acid molecules may be enzymatically modified or any site may be produced by ligating nucleotide sequences (linkers) to the nucleic acid termini. Such vectors may be engineered to contain sequences encoding selectable markers that provide for the selection of cells that contain the vector and/or have incorporated the nucleic acid of the vector into the cellular genome. Such markers allow identification and/or selection of host cells that incorporate and express the proteins encoded by the marker. Examples of such markers are disclosed in Messing &Vierra., G_ENE 19: 259-268 (1982) ； Bevan et al., N_ATURE 304: 184-187 (1983) ； White et al., N_UCL. A_CIDS R_ES. 18: 1062 (1990) ； Spencer et al., T_HEOR. A_PPL. G_ENET. 79: 625-631 (1990) ； Blochinger &Diggelmann, M_OL. C_ELL B_IOL. 4: 2929-2931 (1984) ； Bourouis et al., EMBO J. 2(7) : 1099-1104 (1983) ； U.S. Patent No. 4,940,935； U.S. Patent No. 5,188,642； U.S. Pat. No. 5,767,378； and U.S. Patent No. 5,994,629. A “recombinant” vector refers to a viral or non-viral vector that comprises one or more heterologous nucleotide sequences (i.e., transgenes) . Vectors may be introduced into cells by any suitable method known in the art, including, but not limited to, transfection, electroporation, microinjection, transduction, cell fusion, DEAE dextran, calcium phosphate precipitation, lipofection (lysosome fusion) , and use of a gene gun or nucleic acid vector transporter.

A plant and/or plant part suitable for use withthe present invention may be of any plant type, including, but not limited to, plants belonging to the superfamily Viridiplantae and thus includes spermatophytes (e.g., angiosperms and gymnosperms) and embryophytes (e.g., bryophytes, ferns and fern allies) . In some embodiments, a plant or plant part useful with this invention includes any monocot and/or any dicot plant or plant part. In some embodiments the plant or plant part is a fodder crop, a food crop, an ornamental plant, a tree or a shrub. For example, in some embodiments, the plant or plant part is a variety of Acer spp., Actinidia spp., Abelmoschus spp., Agropyron spp., Allium spp., Amaranthus spp., Ananas comosus, Annona spp., Apium graveolens, Arachis spp, Artocarpus spp., Asparagus officinalis, Avena spp. (e.g. Avena sativa, Avena fatua, Avena byzantina, Avena fatua var. sativa, Avena hybrida ) , Averrhoa carambola, Benincasa hispida, Bertholletia excelsea, Beta vulgaris, Brassica spp. (e.g. Brassica napus, Brassica rapa ssp. [canola, oilseed rape, turnip rape] ) , Cadaba farinosa, Camellia sinensis, Canna indica, Capsicum spp., Carex elata, Carica papaya, Carissa macrocarpa, Carya spp., Carthamus tinctorius, Castanea spp., Cichorium endivia, Cinnamomum spp., Citrullus lanatus, Citrus spp., Cocos spp., Coffea spp., Colocasia esculenta, Cola spp., Coriandrum sativum, Corylus spp., Crataegus spp., Crocus sativus, Cucurbita spp., Cucumis spp., Cynara spp., Daucus carota, Desmodium spp., Dimocarpus longan, Dioscorea spp., Diospyros spp., Echinochloa spp., Elaeis (e.g. Elaeis guineensis, Elaeis oleifera ) , Eleusine coracana, Eriobotrya japonica, Eugenia uniflora, Fagopyrum spp., Fagus spp., Ficus carica, Fortunella spp., Fragaria spp., Ginkgo biloba, Glycine spp. (e.g. Glycine max, Soja hispida or Soja max ) , Gossypium hirsutum, Helianthus spp. (e.g. Helianthus annuus ) , Hemerocallis fulva, Hibiscus spp., Hordeum spp. (e.g. Hordeum vulgare) , Ipomoea batatas, Juglans spp., Lactuca sativa, Lathyrus spp., Lens culinaris, Linum usitatissimum, Litchi chinensis, Lotus spp., Luffa acutangula, Lupinus spp., Luzula sylvatica, Lycopersicon spp. (e.g. Lycopersicon esculentum, Lycopersicon lycopersicum, Lycopersicon pyriforme ) , Macrotyloma spp., Malus spp., Malpighia emarginata, Mammea americana, Mangifera indica, Manihot spp., Manilkara zapota, Medicago sativa, Melilotus spp., Mentha spp., Miscanthus spp., Momordica spp., Morus nigra, Musa spp., Nicotiana spp., Olea spp., Opuntia spp., Ornithopus spp., Oryza spp. (e.g. Oryza sativa, Oryza latifolia) , Panicum miliaceum, Passiflora edulis, Pastinaca sativa, Persea spp., Petroselinum crispum, Phaseolus spp., Phoenix spp., Physalis spp., Pinus spp., Pistacia vera, Pisum spp., Poa spp., Populus spp., Prosopis spp., Prunus spp., Psidium spp., Punica granatum, Pyrus communis, Quercus spp., Raphanus sativus, Rheum rhabarbarum, Ribes spp., Ricinus communis, Rubus spp., Saccharum spp., Sambucus spp., Secale cereale, Sesamum spp., Sinapis sp., Solanum spp. (e.g. Solanum tuberosum, Solanum integrifolium or Solanum lycopersicum ) , Sorghum bicolor, Spinacia spp., Syzygium spp., Tagetes spp., Tamarindus indica, Theobroma cacao, Trifolium spp., Triticosecale rimpaui, Triticum spp. (e.g. Triticum aestivum, Triticum durum, Triticum turgidum, Triticum hybernum, Triticum macha, Triticum sativum or Triticum vulgare) , Tropaeolum minus, Tropaeolum majus, Vaccinium spp., Vicia spp., Vigna spp., Viola odorata, Vitis spp., Zea mays, Zizania palustris or Ziziphus spp., amongst others. In some embodiments, the plant or plant part is a rice, maize, wheat, barley, sorghum, millet, oat, triticale, rye, buckwheat, fonio, quinoa, sugar cane, bamboo, banana, ginger, onion, lily, daffodil, iris, amaryllis, orchid, canna, bluebell, tulip, garlic, secale, einkorn, spelt, emmer, durum, kamut, grass (e.g., gramma grass) , teff, milo, flax, Tripsacum sp., or teosinte plant or plant part. In some embodiments, the plant or plant part is a blackberry, raspberry, strawberry, barberry, bearberry, blueberry, coffee berry, cranberry, crowberry, currant, elderberry, gooseberry, goji berry, honeyberry, lemon, lime, lingonberry, mangosteen, orange, pepper, persimmon, pomegranate, prune, cotton, clover, acai, plum, peach, nectarin, cherry, guava, almond, pecan, walnut, apple, amaranth, sweet pea, pear, potato, soybean, sugar beet, sunflower, sweet potato, tamarind, tea, tobacco or tomato plant or plant part. In representative embodiments, the plant or plant part is not Incarvillea arguta.

As used herein, the term “plant cell” refers to a cell existing in, taken from and/or derived from a plant (e.g., a cell derived from a plant cell/tissue culture) . Thus, the term “plant cell” may refer to an isolated plant cell, a plant cell in a culture, a plant cell in an isolated tissue/organ and/or a plant cell in a whole plant.

In some embodiments, the invention provides a transgenic plant cell comprising a recombinant nucleic acid molecule/nucleotide sequence of the invention and/or a transgenic plant regenerated from said transgenic plant cell. Accordingly, in some embodiments of the invention, a transgenic plant having increased tolerance to drought is provided, said transgenic plant regenerated from a transgenic plant cell comprising at least one recombinant nucleic acid molecule/nucleotide sequence of the invention. In representative embodiments, a transgenic plant or plant part of the invention can be a transgenic maize plant, a transgenic wheat plant, or a transgenic rice plant, or a part thereof.

As used herein, the term “plant part” refers to at least a fragment of a whole plant or to a cell culture or tissue culture derived from a plant. Thus, the term “plant part” may refer to plant cells, plant tissues and plant organs, as well as cell/tissue cultures derived from plant cells, plant tissues and plant cultures. Embodiments of the present invention may comprise and/or make use of any suitable plant part, including, but not limited to, anthers, branches, buds, calli, clumps, cobs, cotyledons, ears, embryos, filaments, flowers, fruits, husks, kernels, leaves, lodicules, ovaries, palea, panicles, pedicels, pods, pollen, protoplasts, roots, root tips, seeds, silks, stalks, stems, stigma, styles, and tassels. In some embodiments, the plant part is a plant germplasm.

Further, as used herein, “plant cell” refers to a structural and physiological unit of the plant, which comprises a cell wall and also may refer to a protoplast. A plant cell of the invention can be in the form of an isolated single cell or can be a cultured cell or can be a part of a higher-organized unit such as, for example, a plant tissue or a plant organ. A “protoplast” is an isolated plant cell without a cell wall or with only parts of the cell wall. Thus, in some embodiments of the invention, a transgenic cell comprising a nucleic acid molecule and/or nucleotide sequence of the invention is a cell of any plant or plant part including, but not limited to, a root cell, a leaf cell, a tissue culture cell, a seed cell, a flower cell, a fruit cell, a pollen cell, and the like. In some embodiments, a plant cell can be non-propagating plant cell that does not regenerate into a plant.

In some particular embodiments, the invention provides a transgenic seed produced from a transgenic plant of the invention, wherein the transgenic seed comprises a nucleic acid molecule/nucleotide sequence of the invention.

“Plant cell culture” means cultures of plant units such as, for example, protoplasts, cell culture cells, cells in plant tissues, pollen, pollen tubes, ovules, embryo sacs, zygotes and embryos at various stages of development. In some embodiments of the invention, a transgenic tissue culture or transgenic plant cell culture is provided, wherein the transgenic tissue or cell culture comprises a nucleic acid molecule/nucleotide sequence of the invention.

As used herein, a “plant organ” is a distinct and visibly structured and differentiated part of a plant such as a root, stem, leaf, flower bud, or embryo.

“Plant tissue” as used herein means a group of plant cells organized into a structural and functional unit. Any tissue of a plant in planta or in culture is included. This term includes, but is not limited to, whole plants, plant organs, plant seeds, tissue culture and any groups of plant cells organized into structural and/or functional units. The use of this term in conjunction with, or in the absence of, any specific type of plant tissue as listed above or otherwise embraced by this definition is not intended to be exclusive of any other type of plant tissue.

As used herein, the terms “progeny” and “progeny plant” refer to a plant generated from a vegetative or sexual reproduction from one or more parent plants. A progeny plant may be obtained by cloning or selfing a single parent plant, or by crossing two parental plants.

A further aspect of the invention provides transformed non-human host cells and transformed non-human organisms comprising the transformed non-human cells, wherein the transformed cells and transformed organisms comprise nucleic acid molecules comprising one or more nucleotide sequences of the invention. In some embodiments, the transformed non-human host cell includes but is not limited to a transformed fungal cell (e.g., a transformed yeast cell) , a transformed insect cell, a transformed bacterial cell, and/or a transformed plant cell. Thus, in some embodiments, the transformed non-human organism comprising the transformed non-human host cell includes, but is not limited to, a transformed yeast, a transformed insect, a transformed bacterium, and/or a transformed plant.

“Introducing, ” in the context of a nucleotide sequence of interest (e.g., the nucleotide sequences and recombinant nucleic acid molecules of the invention) , means presenting the nucleotide sequence of interest to the plant, plant part, and/or plant cell in such a manner that the nucleotide sequence gains access to the interior of a cell. Where more than one nucleotide sequence is to be introduced these nucleotide sequences can be assembled as part of a single polynucleotide or nucleic acid construct, or as separate polynucleotide or nucleic acid constructs, and can be located on the same or different transformation vectors. Accordingly, these polynucleotides can be introduced into plant cells in a single transformation event, in separate transformation events, or, e.g., as part of a breeding protocol. Thus, for example, “introducing” can encompass transformation of an ancestor plant with a nucleotide sequence of interest followed by conventional breeding process to produce progeny comprising said nucleotide sequence of interest.

“Transient transformation” in the context of a polynucleotide means that a polynucleotide is introduced into the cell and does not integrate into the genome of the cell.

“Stable transformation” or “stably transformed, ” “stably introducing, ” or “stably introduced” as used herein means that a nucleic acid is introduced into a cell and integrates into the genome of the cell. As such, the integrated nucleic acid is capable of being inherited by the progeny thereof, more particularly, by the progeny of multiple successive generations. “Genome” as used herein also includes the nuclear and the plastid genome, and therefore includes integration of the nucleic acid into, for example, the chloroplast genome. Stable transformation as used herein can also refer to a transgene that is maintained extrachromasomally, for example, as a minichromosome.

Transient transformation may be detected by, for example, an enzyme-linked immunosorbent assay (ELISA) or Western blot, which can detect the presence of a peptide or polypeptide encoded by one or more transgene introduced into an organism. Stable transformation of a cell can be detected by, for example, a Southern blot hybridization assay of genomic DNA of the cell with nucleic acid sequences which specifically hybridize with a nucleotide sequence of a transgene introduced into an organism (e.g., a plant) . Stable transformation of a cell can be detected by, for example, a Northern blot hybridization assay of RNA of the cell with nucleic acid sequences which specifically hybridize with a nucleotide sequence of a transgene introduced into a plant or other organism. Stable transformation of a cell can also be detected by, e.g., a polymerase chain reaction (PCR) or other amplification reactions as are well known in the art, employing specific primer sequences that hybridize with target sequence (s) of a transgene, resulting in amplification of the transgene sequence, which can be detected according to standard methods Transformation can also be detected by direct sequencing and/or hybridization protocols well known in the art.

A recombinant nucleic acid molecule/nucleotide sequence of the invention (e.g., one or more of the nucleotide sequences of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, and/or SEQ ID NO: 14, or a nucleotide sequence encoding one or more polypeptides having the amino acid sequence of any of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and/or SEQ ID NO: 20, or any combination thereof) can be introduced into a cell by any method known to those of skill in the art. In some embodiments of the invention, transformation of a cell comprises nuclear transformation. In other embodiments, transformation of a cell comprises plastid transformation (e.g., chloroplast transformation) .

Procedures for transforming plants are well known and routine in the art and are described throughout the literature. Non-limiting examples of methods for transformation of plants include transformation via bacterial-mediated nucleic acid delivery (e.g., via Agrobacteria) , viral-mediated nucleic acid delivery, silicon carbide or nucleic acid whisker-mediated nucleic acid delivery, liposome mediated nucleic acid delivery, microinjection, microparticle bombardment, calcium-phosphate-mediated transformation, cyclodextrin-mediated transformation, electroporation, nanoparticle-mediated transformation,, sonication, infiltration, PEG-mediated nucleic acid uptake, as well as any other electrical, chemical, physical (mechanical) and/or biological mechanism that results in the introduction of nucleic acid into the plant cell, including any combination thereof. General guides to various plant transformation methods known in the art include Miki et al. ( “Procedures for Introducing Foreign DNA into Plants” in Methods in Plant Molecular Biology and Biotechnology, Glick, B. R. and Thompson, J. E., Eds. (CRC Press, Inc., Boca Raton, 1993) , pages 67-88) and Rakowoczy-Trojanowska (Cell. Mol. Biol. Lett. 7: 849-858 (2002) ) .

Agrobacterium-mediated transformation is a commonly used method for transforming plants, in particular, dicot plants, because of its high efficiency of transformation and because of its broad utility with many different species. Agrobacterium-mediated transformation typically involves transfer of the binary vector carrying the foreign DNA of interest to an appropriate Agrobacterium strain that may depend on the complement of vir genes carried by the host Agrobacterium strain either on a co-resident Ti plasmid or chromosomally (Uknes et al. (1993) Plant Cell 5: 159-169) . The transfer of the recombinant binary vector to Agrobacterium can be accomplished by a triparental mating procedure using Escherichia coli carrying the recombinant binary vector, a helper E. coli strain that carries a plasmid that is able to mobilize the recombinant binary vector to the target Agrobacterium strain. Alternatively, the recombinant binary vector can be transferred to Agrobacterium by nucleic acid transformation (

fgen &Willmitzer (1988) Nucleic Acids Res. 16: 9877) .

Transformation of a plant by recombinant Agrobacterium usually involves co-cultivation of the Agrobacterium with explants fromthe plant and follows methods well known in the art. Transformed tissue is regenerated on selection medium carrying an antibiotic or herbicide resistance marker between the binary plasmid T-DNA borders.

Another method for transforming plants, plant parts and/or plant cells involves propelling inert or biologically active particles at plant tissues and cells. See, e.g., US Patent Nos. 4,945,050； 5,036,006 and 5,100,792. Generally, this method involves propelling inert or biologically active particles at the plant cells under conditions effective to penetrate the outer surface of the cell and afford incorporation within the interior thereof. When inert particles are utilized, the vector can be introduced into the cell by coating the particles with the vector containing the nucleic acid of interest. Alternatively, a cell or cells can be surrounded by the vector so that the vector is carried into the cell by the wake of the particle. Biologically active particles (e.g., dried yeast cells, dried bacterium or a bacteriophage, each containing one or more nucleic acids sought to be introduced) also can be propelled into plant tissue.

Thus, in particular embodiments of the invention, a plant cell can be transformed by any method known in the art and as described herein and intact plants can be regenerated from these transformed cells using any of a variety of known techniques. Plant regeneration from plant cells, plant tissue culture and/or cultured protoplasts is described, for example, in Evans et al. (Handbook of Plant Cell Cultures, Vol. 1, MacMilan Publishing Co. New York (1983) ) ； and Vasil I. R. (ed. ) (Cell Culture and Somatic Cell Genetics of Plants, Acad. Press, Orlando, Vol. I (1984) , and Vol. II (1986) ) . Methods of selecting for transformed transgenic plants, plant cells and/or plant tissue culture are routine in the art and can be employed in the methods of the invention provided herein.

Methods of introducing a nucleic acid into a plant can also comprise in vivo modification of nucleic acids, methods for which are known in the art. For example, in vivo modification can be used to insert a nucleic acid comprising, e.g., a promoter sequence into the plant genome. In a further non-limiting example, in vivo modification can be used to modify the endogenous nucleic acid itself and/or a endogenous transcription and/or translation factor associated with the endogenous nucleic acid, such that the transcription and/or translation of said endogenous nucleic acid is altered, thereby altering the expression said endogenous nucleic acid and/or in the case of nucleic acids encoding polypeptides, the production of said polypeptide.

Exemplary methods of in vivo modification include zinc finger nuclease, CRISPR-Cas, TALEN, TILLING (Targeted Induced Local Lesions IN Genomes) and/or engineered meganuclease technology.

For example, suitable methods for in vivo modification include the techniques described in Urnov et al. Nature Reviews 11: 636-646 (2010) ) ； Gao et. al., Plant J. 61, 176 (2010) ； Li et al., Nucleic Acids Res. 39, 359 (2011) ； Miller et al. 29, 143–148 (2011) ； Christian et al. Genetics 186, 757–761 (2010) ) ； Jiang et al. Nat. Biotechnol. 31, 233–239 (2013) ) ； U.S. Patent Nos. 7,897,372 and 8,021,867； U.S. Patent Publication No. 2011/0145940 and in InternationalPatent Publication Nos. WO 2009/114321, WO 2009/134714 and WO 2010/079430； U.S. Patent Nos. 8,795,965 and 8,771,945 For example, one or more transcription affector-like nucleases (TALEN) and/or one or more meganucleases may be used to incorporate an isolated nucleic acid comprising a promoter sequence of the invention into the plant genome. In representative embodiments, the method comprises cleaving the plant genome at a target site with a TALEN and/or a meganuclease and providing a nucleic acid that is homologous to at least a portion of the target site and further comprises a promoter sequence of the invention (optionally in operable association with a heterologous nucleotide sequence of interest) , such that homologous recombination occurs and results in the insertion of the promoter sequence of the invention into the genome. Alternatively, in some embodiments, a CRISPR-Cas system can be used to specifically edit the plant genome so as to alter the expression of endogenous nucleic acids described herein. In some embodiments, a genetic modification may also be introduced using the technique of TILLING, which combines high-density mutagenesis with high-throughput screening methods. Methods for TILLING are well known in the art (McCallum, Nature Biotechnol. 18, 455-457, 2000, Stemple, Nature Rev. Genet. 5, 145-150, 2004) .

As would be understood by the skilled artisan, the polynucleotides of the invention can be modified in vivo using the above described methods as well as any other method of in vivo modification known or later developed.

As would be understood by the skilled artisan, the polynucleotides of the invention can be modified in vivo using the above described methods as well as any other method of in vivo modification now known or later developed.

As would be well understood in the art, genetic properties engineered into the transgenic seeds and plants, plant parts, and/or plant cells of the invention described above can be passed on by sexual reproduction or vegetative growth and therefore can be maintained and propagated in progeny plants. Generally, maintenance and propagation make use of known agricultural methods developed to fit specific purposes such as harvesting, sowing or tilling.

A nucleotide sequence therefore can be introduced into the plant, plant part and/or plant cell in any number of ways that are well known in the art. The methods of the invention do not depend on a particular method for introducing one or more nucleotide sequences into a plant, only that they gain access to the interior of at least one cell of the plant. Where more than one nucleotide sequence is to be introduced, they can be assembled as part of a single nucleic acid construct, or as separate nucleic acid constructs, and can be located on the same or different nucleic acid constructs. Accordingly, the nucleotide sequences can be introduced into the cell of interest in a single transformation event, in separate transformation events, or, for example, in plants, as part of a breeding protocol.

Additional aspects of the invention include a harvested product produced from a transgenic plant and/or partthereof of the invention, as well as a post-harvest product produced from said harvested product. A harvested product can be a whole plant or any plant part, as described herein, wherein said harvested product comprises a recombinant nucleic acid molecule/nucleotide sequence of the invention. Thus, in some embodiments, non-limiting examples of a harvested product include a seed, a fruit, a flower or part thereof (e.g., an anther, a stigma, and the like) , a leaf, a stem, and the like. In other embodiments, a post-harvested product includes, but is not limited to, a flour, meal, oil, starch, cereal, and the like produced from a harvested seed of the invention, wherein said seed comprises in its genome a recombinant nucleic acid molecule/nucleotide sequence of the invention.

In some embodiments, the invention further provides a plant crop comprising a plurality of transgenic plants of the invention planted together in, for example, an agricultural field, a golf course, a residential lawn, a road side, an athletic field, and/or a recreational field.

In some embodiments, a method of improving the yield of a plant crop when said plant crop is exposed to drought conditions is provided, the method comprising cultivating a plurality of plants of the invention as the plant crop, wherein the plurality of plants of said plant crop have increased drought tolerance, thereby improving the yield of said plant crop as compared to a control plant crop (e.g., a plant crop is produced from a plurality of plants lacking said recombinant nucleic acid molecule grown under the same environmental conditions) . In some particular embodiments of the invention, the plant crop can be a maize crop, a rice crop, or a wheat crop.

In some embodiments, a use of a recombinant nucleic acid molecule of the invention for increasing drought tolerance in a plant or plant part is provided, optionally wherein the recombinant nucleic acid of the invention can be comprised in an expression cassette and/or a vector and/or wherein the drought tolerance of said plant or plant part is increased as compared to a control plant or plant part.

In some embodiments, a use of the recombinant nucleic acid molecule of the present invention for producing a drought tolerant plant or plant part is provided, optionally wherein the recombinant nucleic acid of the invention can be comprised in an expression cassette and/or a vector and/or wherein the drought tolerance of said plant or plant part is increased as compared to a control plant or plant part.

The invention will now be described with reference to the following examples. It should be appreciated that these examples are not intended to limit the scope of the claims to the invention, but are rather intended to be exemplary of certain embodiments. Any variations in the exemplified methods that occur to the skilled artisan are intended to fall within the scope of the invention.

EXAMPLES

High throughput drought screening was performed in Arabidopsis with cDNAs from Incarvillea argutato identify novel genes related to drought tolerance. In particular, plants transformed with cDNAs from Incarvillea argutawere identified in the screen which showed better growth under drought conditions when compared to wild type.

Example 1: cDNA library construction

A full-length cDNA library made from Incarvillea arguta DNA. cDNAs were purified using a 5’ -Cap antibody. The final Incarvillea arguta full length cDNA library has more than 1.1×10⁶ colonies. 200 colonies were randomly chosen for PCR and sequencing. The cDNA inserts had an average size of about 850bp and the ratio of full length cDNA inserts is about 65％.

Total RNA extraction. The extraction of total RNA was performed according to

Reagent manual described (Life technologies, Catalog No. 15596-026) . About 2 g plant materials were ground in a mortar with a pestle in the presence of liquid nitrogen. The resultant powder was mixed with 20 ml

Reagent, centrifuged and supernatant was extracted with Phenol: Chloroform: Isoamylalcohol (25: 24: 1) . The RNA was precipitated by isopropanol. After 2 rounds of washing with 70％ethanol, the RNA was dissolved into diethylpyrocarbonate (DEPC) water.

mRNA enrichment. mRNA enrichment was performed according to user manual of Dynabeads Oligo (dT) 25 described (Life technologies, Cat. No. 610.12) . ～10 mg total RNA was mixed with lysis/binding buffer, and incubated with beads with associated Oligo (dT) for isolating mRNA. The mRNA could specifically associate with the beads through polyA-Oligo dT coupling. After 2 rounds of wash, the purified mRNA was de-associated from beads and dissolved into DEPC water.

First strand cDNA synthesize procedure. First strand cDNA synthesize was performed according to the manual of

Full Length cDNA Library Construction Kit II with minor modification (Life technologies, Cat. No. A13268) . For the reaction mix, a volume of 25.5 μl of mRNA+DEPC-treated water was mixed with 2 μl of 3’ Primer (1.5 μg/μl) . The mix was incubate at 70℃ for 7 minutes and then the mix was allowed to gradually cool to 45℃ over 5–15 minutes, by ramping the temperature down (0.1℃/second) using a PCR thermo cycler.

For the first strand cDNA synthesis reaction mixture 5X First Strand Buffer (10 μL) , 0.1 M DTT (5μL) , 10 mM (each) dNTPs (2.5 μ) and SuperScriptR III RT (200 U/μL) (5 μL) was added and the reaction tube incubated in stepwise increments of 45℃ for 20 minutes, 50℃ for 30 minutes and 55℃ for 30 minutes.

Then the following adapters and reagents were added to the first strand cDNA mixture (about 22 μL) .

5’-TCGTCGGGGACAACTTTGTACAAAAAAGTTGG-3’ (SEQ ID NO: 21)

3’-CCCCTGTTGAAACATGTTTTTTCAACCp-5’ (SEQ ID NO: 22)

Reagents added: 10 μL of 5× Adapter Buffer, 5 μL of 5’A dapter Mix (0.5 μg/μL) , 8 μL of 0.1 M DTT, and 5 μL of T4 DNA Ligase (1 U/μL) . The contents were mixed gently by pipetting and incubate at 16℃ for 16–24 hours.

Full length cDNA selection. The produced full length mRNA: : cDNA hybrids have a 5’ Cap structure in the mRNA strand, allowing it to bind with Cap-antibody associated with beads through an antigen-antibody reaction. After treatment with sodium hydroxide, the mRNA strand was hydrolyzed and the first strand cDNA was eluted and enriched by spin column enrichment to produce enriched first strand cDNA.

Second strand cDNA synthesis. Second strand cDNA synthesis was performed according to the manual of

Full Length cDNA Library Construction Kit II described with minor modification (Life technologies, Cat. No. A13268) .

Enriched first strand cDNA was placed into a tube and the following reagents added: cDNA with 5’ Prime Adapter (79 μL) , 10× High Fidelity PCR Buffer (10 μL) , 10 mM (each) dNTPs (4 μL) , 50 mM MgSO4 (5 μL) , 5’ Primer (100 ng/μL) (1 μL) , and PlatinumR Taq DNA Polymerase High Fidelity (1 μL) . The contents are mixed gently and incubated in the reaction tube in stepwise increments as follows: 68℃ 20 minutes and 72℃ 20 minutes. Size fractionation of the produced cDNAs was carried out to enrich for cDNAs with a size greater than or equal to 1.0 kb by column chromatography.

Full length cDNA library assembling. The full length cDNA was transferred to cloning vector pDONR222 through standard BP recombination (LIfetech Cat. 11789-020) and the following DNA transformations were performed according to the manual of

Full Length cDNA Library Construction Kit II with minor modification (Life technologies, Cat. No. A13268) . The reaction mix recipe comprised attB-flanked cDNA (7 μL (100ng) ) ； pDONR 222 (150 ng/μL) (1μL) TE buffer, pH 8.0 (to 7 μL) . The reaction was stopped and the product was purified and transformed into competent cell to complete the full length cDNA library construction.

The titer of full length cDNA library (CFU) . CFU is a key index to evaluate the quality of a cDNA library. A cDNA library with less than 10⁶ colonies is thought not to cover all transcripts and thus be defined short of being representative. The formula of calculating cDNA Library titer (CFU) is

cfu/mL ＝ colonies on plate× dilution factor /volume plated (mL)

CFU ＝ average titer (cfu/mL) × total volume of cDNA library (mL)

The average size of isolated full length cDNA and cDNA redundancy The average size of cloned cDNA could be estimated based on sequencing results of randomly picked cDNA clones. In this case, 200 randomly picked cDNA clones were amplified with primers located in both sides of inserted cDNAs. The amplified fragments were following sequenced and the size and redundancy of cDNA inserts were measured according to the sequencing results.

Example 2. Transformation of full length cDNA library to Agrobacterium

Preparation of cDNA library plasmid. The cDNA library harbored in E. coliwas spread on 50 plates 150mm in diameter growing overnight, and the colonies were harvested for plasmid extraction according to the manual of QIAGEN Plasmid Purification Handbook (Qiagen Cat. 12963) .

Transfer cDNA library to binary vector through recombination. The cDNA library plasmids were transferred to a binary vector using the

LR Clonase^TM Enzyme system with L&R adapters through LR recombination (e.g., site-specific recombination) performed according to manual for the

LR Clonase^TM II enzyme mix(Lifetech Cat. 11791-020) . The binary vector (-) was modified with added L&R adapters to adopt cDNA inserts. The reaction mix was as follows: 7 μL ofpENTR222-cDNA (150ng/ul) , 3 μL of vector (150 ng/μL) (-) and 16 μL of TE buffer, pH 8.0. The binary vector contained a nucleotide sequence encoding Basta resistance as a selection marker.

Transformation of full length cDNA library into Agrobacterium. The produced binary vector harbored full length cDNA library was transformed into competent Agrobacterium cells by electronic transformation according to a general agrobacterium transformation method. The colony forming units (CFU) and cDNA redundancy of the library were measured as described above.

Example 3. Transformation of Arabidopsis with a full length cDNA library.

The cDNA library was transformed into Arabidopsis by an Agrobacterium mediated transformation method. cDNA fragments driven by 35S promoter were randomly inserted intoArabidopsis genome. One or more copies of cDNA fragments are generally inserted in one transgenic event. The positive transgenic plants were selected after BASTA spray. The positive plants were grown in greenhouse to harvest T1 seeds independently. Tens of thousands of plants were transformed and about 10,000 transgenic events of this library were obtained. The transgenic plants were screened for drought stress and those exhibiting enhanced drought tolerance were selected and the inserted cDNA sequences were isolated from the transgenic plants. The isolated DNAs were then re-transformed into Arabidopsis to reconfirm the phenotype.

Methods of transforming cDNA library into Arabidopsis. Arabidopsis transformation was carried out as described by Zhang et al. Nature Protocols 1, 641-646 (2006) ) with a minor modification. The agro strain used here is GV3101. The Incarvillea argutacDNA library was transformed into Arabidopsisecotype Col-0. Fresh-harvested T0 seeds were dried out for 2 weeks in low-humidity environment. After germinating T0 seeds in soil directly, seedlings are sprayed with 0.1％BASTA herbicide four times at two-day intervals. The T1 seeds from individual plants that survived were grown and T2 seeds harvested.

Methods of drought screening. The transgenic plants were first screened by a dry-down method and the ones which showed better performance were subsequently subjected to a prolonged drought treatment (Harb et al. Methods Mol Biol, 678: 191-198 (2011) ) .

1^st round dry down screening. The seeds were placed in water in 4℃ for 3 days for vernalization before sowing. Each T1 line was germinated in a square pot, sow 12 (4x3) spots with about 3 seeds/spot. Plants were thinned to one seedling/spot at 2-week stage, to have a total of 12 plants per pot. Each tray contained 15 pots, including 14 transgenic pots and 1 wild type control pot. Each control pot includes halfwild type (WT) and half positive controls and in each transgenic pot one plant line was included with 12 seedlings. The pots were randomized within the tray.

Plants are grown until about the 8 leaf stage, and then water is withheld until the wild type shows severe wilting and cannot be recovered. Water stress treatment and re-watering time will be applied on a per tray base, depending on the condition of the wild type plant. The length of drought treatment is about 3 to 4 weeks. Three days after re-watering, transgenic plants that performed better than wild type are identified by visual scoring and labeled. Transgenic plants were further confirmed by genomic PCR. Transgenic lines having more than five plants per pot performing well were identified as drought tolerant candidates. PCR was used to identify transgenic positive plants. Lines with more than 3 transgene positives are confirmed as drought tolerant candidates were grown and T3 seeds collected for next round of screening. Individual T3 lines were germinated on plates containing the herbicide, Basta, to identify non-segregating, homozygous lines for prolonged water stress screening

2^nd round prolonged drought screening (Harb et al. Methods Mol Biol678: 191-198 A (2011) ) . Seeds are placed in water in 4℃ for3 days for vernalization priorto sowing. Each T3 line is germinated in a square pot, sow 9 (3x3) spots with about 3 seeds/pot. Each line has 3 pots as replicates. Each tray contains 15 pots, including 12 transgenic pots (4 lines) and 3 wild type control pots. All the pots are randomized within the tray. Plants are thinned to one seedling/pot at the 2-week stage, for a total of 9 plants remaining per pot. The plants are grown to the 6 to 8-leaf stage； then the soil is watered until it is saturated, the extra water is drained and the weight of each pot is measured. The weight of each pot is determined at the target stress level. The soil is allowed to drydown and the pots weighed every day until field capacity of the soil was down to 30％ (approximately 7-8 days) . This stress level is then maintained for about 5-10 days by weighing and supplementing water every day； then all above-ground tissues are collected, placed in an 80 ？ oven for 48 hours and the biomass calculated. A summary of the methods used for the two rounds of drought screening are shown in Table 1.

Determine soil water content and soil field capacity for each bag of soil. The water content of a soil sample is equal to the mass of water divided by the mass of solids. The soil is screened and mixed very well. Samples are takenand the weight measured. The soil is completely dried in and oven and the dry weight measured. The water content is defined as:

Water content of wet soil＝ (M2-M3) / (M3-M1) x100

M1: Mass of pot

M2: Mass of pot and wetsoil

M3: Mass of pot with dry soil

Soil field capacityis the amount of soil moisture or water content held in soil after excess water has drained away. The soil is wetted until saturated, and then the excess water is drained and the weight measured.

Soil field capacity ＝ (M4-M3) / (M3-M1) x 100

M4: Mass of pot and soil at field capacity

Determine target weight and amount of water added. Target weight＝30％x field capacity x soil dry weight + soil dry weight +pot weight. Amount of water added to maintain stress level ＝ Target weight –Final weight.

Determine biomass reduction. Biomass reduction ＝ (Biomass of well watered plants –Biomass of drought treated plants) /Biomass of well watered plants

Table 1 Summary of the two step Arabidopsis screening system.

Wild type plants were used to determine biomass reduction at different soil water content levels. Wild type plants were grown until six leaf stage under optimal growth conditions. the pot was fully irrigated and the weight at full field capacity was measured. Water was withheld to dry down soil to around 30％field capacity or other predetermined levels. The water stress level was maintained for 5-10 days by checking weight and supplementing water when needed. The above ground plant parts were harvested and the fresh weight and dry weight (plants dried in 75C oven for two days) of each plant measured to determine water stress level that results in significant biomass reduction. Biomass reduction ＝ (Biomass of well watered plants –Biomass of drought treated plants) /Biomass of well watered plants

Using the T-test (p < 0.05) to measure the significance of the difference in biomass reductionbetween WT and transgenic lines, lines showing significant less biomass reduction than WT under stress were verified as drought tolerant lines.

Example 4. Transformation of Arabidopsis using a binary vector conferring Basta resistance and RFP/Luciferase expression.

The methods ofExample 2 and 3, above, were repeated but with abinary vector containing a nucleotide sequence conferring Basta resistance and nucleotide sequences conferring the expression of red fluorescent protein and luciferase. The transformed plants were grown and selected as in Example 3. T3 seeds were harvested from individual plants identified as drought tolerant. T3 seeds were visualized under fluorescent microscope using RFP marker to identify homozygous lines for T3 screening. For the luciferase marker, seedlings grown from the T3 seeds were assayed for luciferase activity at the three leaf seedling stage.

Example 5. Methods of gene cloning

The inserted cDNA fragments were cloned from transgenic plants by PCR and sequencing.

Genomic DNA is extracted from leaves of transgenic Arabidopsis according to the manual of MagneSil Paramagnetic Particles described (Promega, Cat no. FF3760) . About 8mm fresh leaf disks were placed in a sealed 96-well, deep-well plate (Geno/

) in the presence of 300μl of Lysis Buffer A and 1 grinding beads and processed in the Geno/

following 1000rpm, 3min. The 96-well, deep-well plates were centrifuged at 1,700 × g for 10 minutes to spin down cell debris. 125μl of each sample was transferred to the appropriate well of the plate, 60μl/well of Buffer B mixture was added and pipetted to mix well. The mixture was incubated at room temperature for 5 minutes, mixing once by pipetting. Fresh tips were used each time to avoid cross-contamination. The plate was placed onto the

96 Magnetic Separation Device with for 1 minute and then the liquid was discarded by pipetting/aspiration. The plate was removed from the

96 Magnetic Separation Device and 50μl of nuclease-free water solute was added to the DNA. The PCR reaction tube containing genomic DNA is placed on ice. The tube is kept on ice while adding the follow 30 cycles 200ng of genomic DNA, 1μL of MV2749, 1μL of MV2750, 50μL of Premix-EX-taq and 36 μL of ddH₂O. The total volume should be about 100 μL/per reaction. THe contents are mixed gently by pipetting and the reaction tube incubated as follows: 94℃ for 5 minutes and for 30 cycles (94℃ 30 sec, 58℃ 30 sec, 72℃ 2 min 30 sec) , then 72℃ for 10 min and hold at 4 ℃. The primers used were MV2749: 5’ -GGGGATCCAGAGACCCTGTACC-3’ (SEQ ID NO: 23) and MV2750: 5’ -AACGATCGGCGCCGTCTTCTTGC-3’ (SEQ ID NO: 24) . After agarose electrophoresis, the specific DNA (0.5 kb-3 kb) fragments were purified using QIAquick Gel Extraction Kit (Qiagen Cat no. 28706) .

Specific DNA fragment ligated into T-Vector. Using the T-Vector of

-T Easy Vector Systems (Progema Cat no. A3600) , the ligation reactions were set up as described below:

2×Rapid Ligation Buffer (including T4 DNA ligase) : 5μl

-T Easy Vector (50ng) : 1μl

PCR product: 4 μl

Total: 10 μl

The reactions were incubated for 1 hour at room temperature and the reaction was transformed into DH5a cells.

DNA sequencing. Using the M13 forward and reverse primer to do the DNA sequencing of ABI 9700 (Life technologies) .

M13 Forward: 5’ -GTAAAACGACGGCCAG-3’ S EQ ID NO: 25

M13 Reverse: 5’ -CAGGAAACAGCTATGAC-3’ S EQ ID NO: 26

Methods of phenotype reconfirmation. The prolongeddrought assay described above for the 2^nd round screening was used. 8 events per construct and 18 replicates per event were used in the assay. All the pots were randomly distributed together with wild type controls. The LSD test (p < 0.05) was used to measure the significance of the difference in biomass reduction between wild type and transgenic events. Lines showing significantly less biomass reduction when compared to the wild type under stress conditions are verified as drought tolerant events.

Example 6. Results of initial screens and revalidation.

Forty novel sequences were cloned from 66 lines. Among them seven sequences were cloned from two or more independent lines. In particular, SEQ ID NO: 12 (KIB21, putative nitrilase-associated protein) was cloned from seventeen independent lines. Eight lines had more than one insertion. The average insertion number is about 1.3. Among the isolated sequences, three sequences were obtained with homologs to well-known drought related function, which means the system works well for drought screening. Most of the sequences are novel at DNA sequence level, even though some of them were identified to have a conserved function domain. For ten of the sequences no similarity was found in the public databases.

Twenty-five sequences were selected and new constructs were made for retransformation and validation of the phenotype. The new constructs were made using the complete sequences using the same vector as for the cDNA library. The new constructs were transformed intoArabidopsis. After BASTA (i.e., glufosinate) selection, 10 to 20 independent lines were selected and harvested T1 seeds independently. Prolonged drought assay was again used to evaluate drought performance of the newly generated events. In the reconfirmation experiments, eight events per construct and eighteen replicates per event were used. Eighteen replicates were randomly distributed in three trays. A one-sided LSD (least significant difference) test (p < 0.05) was used to measure the significance of the difference in biomass reduction between wild type and the transgenic events. Six constructs showed good results with 2 or more events significantly better than wild type. No negative growth effects were observed in well watered control group.

Transgenic plants carrying the nucleotide sequences of the invention were identified that grow better under drought when compared to wild type. These nucleotide sequences may be useful in developing crops with improved drought tolerance.

Example 7. Further evaluation of four nucleotide sequences.

Four nucleotide sequences were selected for further evaluation: SEQ ID NO: 2 (KIB3) , SEQ ID NO: 6 (KIB11) , SEQ ID NO: 9 (KIB12, photosystem I reaction center) , and SEQ ID NO: 13 (KIB21, putative nitrilase-associated protein) .

Vector construction. In Arabidopsis, the genes are driven by CaMV35S promoter, which is a constitutive promoter with quite high expression in dicots. In order to introduce similar expression level in maize, promoter from maize ubiquitin is selected (prUbi1-10) and the terminator is selected as tUbi1-01.

The function of the proteins encoded by the nucleotide sequences of this invention are not known in the case of KIB-3 and KIB-11. The nucleotide sequence for KIB-encodes a photosystem reaction center and the nucleotide sequence for KIB-21 encodes a putative nitrilase-associated protein. To be able to separate seeds between null and transgenic (GM) , red fluorescence protein (cRed-08) from Discosoma spp driven by the promoter of an aleurone specific lipid transfer protein from barley (prHvLPT2-03) is used.

Vector construction. The gene cKIB-3 was synthesized by GENEWIZ Company (LF1407295) by introducing BsaI (compatible with BamHI) at the 5’ end and BsaI (compatible with SpeI) at the 3’ end. It was digested with BsaI and then cloned into 19597 base vector (BamHI /SpeI digested and purified the 17012bp fragment. Positive clones were verified with BsaI/AscI； MfeI /SbfI digestion. All cloning junctions were confirmed by sequencing with no error.

The gene cKIB-11 was synthesized by GENEWIZ Company (LF1407296) by introducing BsaI (compatible with BamHI) at the 5’ end and BsaI (compatible with SpeI) at the 3’ end. It was digested with BsaI and then cloned into 19597 base vector (BamHI /SpeI digested and purified the 17012bp fragment) . Positive clones were verified with AscI/BsrGI digestion. All cloning junctions were confirmed by sequencing with no error.

The gene cKIB12 was synthesized by GENEWIZ Company (LF1409106) by introducing BsaI (compatible with BamHI) at the 5' end and BsaI (compatible with SpeI) at the 3' end. It was digested with BsaI and then cloned into 19597 base vector (BamHI /SpeI digested and purified the 17012bp fragment) . Positive clones were verified with EcoRI/SacI digestion. All cloning junctions were confirmed by sequencing with no error.

The gene cKIB-21 was synthesized by GENEWIZ Company (LF1407297) by introducing BsaI (compatible with BamHI) at the 5’ end and BsaI (compatible with SpeI) at the 3’ end. It was digested with BsaI and then cloned into 19597 base vector (BamHI /SpeI digested and purified the 17012bp fragment) . Positive clones were verified with MfeI /SbfI digestion. All cloning junctions were confirmed by sequencing with no error.

Sequences in maize construct. Original sequences from Incarvillea argutaare used in maize without any maize codon optimization. The sequences used in the constructs for transformation of maize are provided below.

KIB3

KIB11

KIB12

KIB21

Maize transgenic events generation. Maize Inbred AX5707 is selected for transformation. PMI (phosphomannose isomerase) is used as a selection maker during maize transformation process. Primary zygosity check is used to select hemizygous transgenic plants via Taqman probe； about 20 T0 events are used to produce T1 seed via back-crossing with AX5707. Gene of interest expression is checked via qRT in T0 plant. Any observed abnormal phenotype is recorded.

T1 transgenic seeds are selected using RFP (Red Fluorescence Protein) marker check under blue light. Four transgenic seedlings in each event are selected for growth to the reproductive stage； while 2 more events are germinated to ensure 10 events for following gene efficacy test. Further back-crossing with AX5707 is used to generate T2 seed using transgenic seedlings as the female. Also gene of interest expression is checked via qRT at this stage. Any observed abnormal phenotype is recorded.

Gene effect evaluation. For each construct, ten events are selected to check gene efficacy in maize. The passing criteria is more shoot biomass accumulation in transgenic seedlings with ＝20％events at P<0.05 (or ＝30％events at P<0.1) . Pair drought assay is conducted.

Pair drought assay in maize transgenic event screening. Seeds are sown in 50-cell germination plates with normal water condition in the greenhouse (one seed in each cell) and grown to V3 stage. Pots are prepared (340*280 cm) and filled in with a similar weight of corn soil (nutrition sol: peat: vermiculite＝4: 4: 1, 2500-3000g) with well-irrigated. Het and null plants of same event ofsimilar size are selected as one pair and transfer to the pots. For one event, 24 pairs are selected (reserve 20％more seedlings to exclude transplant effect) ； finally 20 pairs per event are kept until harvest. After transplanting, all pots are fully watered one time to ensure the maximum water in soil； withhold water since V3 stage. When 90％of the null plants within same construct reachleaf score 5, plants are fully re-watered. The shoot above root is collected on the 3rd day after re-water, putting each plant into separate bag with corresponding label. Dry shoot weight is checked after 2days ofdrying in 80℃ oven. The difference between Het and Null in construct and event level is checked via ANOVA via JMP software. For each batch, quality is controlledby using no more than 20％in shoot dry biomass CV％in each genotype construct.

The foregoing is illustrative of the invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.

Claims

A recombinant nucleic acid molecule comprising:

a.a nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, or SEQ ID NO:14,

b.a nucleotide sequence encoding a polypeptide having the amino acid sequence ofany one ofSEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO:19, or SEQ ID NO: 20；

c.a nucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ；

d.a nucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one of SEQ ID NO:15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, or SEQ ID NO:20；

e.a nucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above；

f.a nucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or

g.any combination of the nucleotide sequences of (a) to (f) above.
The recombinant nucleic acid molecule of claim 1, wherein the nucleotide sequence is operably linked to a promoter functional in a plant.
The recombinant nucleic acid molecule of claim 2, wherein the promoter is a tissue-specific promoter, optionally a panicle-, sheath-, and/or leaf-specific promoter； a stress-inducible promoter sequence, optionally a drought-inducible promoter； or a developmental stage-specific promoter, optionally a promoter that drives expression prior to and/or during the early seedling, tillering, flowering and/or seed filling stage (s) of development.
The recombinant nucleic acid molecule of any one of claims 1 to 3, wherein the nucleotide sequence and/or the promoter are codon optimized.
An expression cassette comprising the recombinant nucleic acid molecule of any one of claims 1 to 4.
A vector comprising the recombinant nucleic acid molecule of any one of claims 1 to 4.
A vector comprising the expression cassette of claim 5.
The expression cassette of claim 5 or vector of claims 6 or 7, further comprising a transgene encoding a gene product that confers resistance to one or more herbicides, optionally glyphosate-, sulfonylurea-, imidazolinione-, dicamba-, glufisinate-, phenoxy proprionic acid-, cycloshexome-, traizine-, benzonitrile-, and/or broxynil-resistance.
The expression cassette of claim 5 or claim 8 or vector of any one of claims 6 to 8, further comprising a transgene encoding a gene product that confers resistance to one or more pests, optionally bacterial-, fungal, gastropod-, insect-, nematode-, oomycete-, phytoplasma-, protozoa-, and/or viral-resistance.
The expression cassette of any one of claims 5, 8 or 9 or vector of any one of claims 6 to 9, further comprising a transgene encoding a gene product that confers resistance to one or more diseases.
A plant or plant part comprising in its genome a recombinant nucleic acid molecule, said recombinant nucleic acid molecule comprising:

a.a nucleotide sequence ofany one ofSEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, or SEQ ID NO:14,

b.a nucleotide sequence encoding a polypeptide having the amino acid sequence ofany one ofSEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO:19, or SEQ ID NO: 20；

c.a nucleotide sequence having at least 80％identity to any one of the nucleotide sequences of (a) or (b) ；

d.a nucleotide sequence that encodes a polypeptide comprising an amino acid sequence having at least 80％identity to the amino acid sequence ofany one ofSEQ ID NO:15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, or SEQ ID NO:20；

e.a nucleotide sequence that is complementary to any one of the nucleotide sequences of (a) to (d) above；

f.a nucleotide sequence that hybridizes to any one of the nucleotide sequences of (a) to (e) above under stringent hybridization conditions； or

g.any combination of the nucleotide sequences of (a) to (f) above.
The plant or plant part of claim 11, wherein said nucleotide sequence is operably linked to a promoter functional in a plant,
The plant or plant part of claim 12, wherein the promoter is a constitutive promoter, a tissue-specific promoter, a stress inducible promoter, or a developmentally regulated promoter.
The plant or plant part of claim 13, wherein the tissue-specific promoter, is a panicle-, sheath-, and/or leaf-specific promoter； the stress-inducible promoter, is a drought-inducible promoter； or the developmental stage-specific promoter is a promoter that drives expression prior to and/or during the early seedling, tillering, flowering and/or seed filling stage (s) of development.
The plant or plant part of any one of claims 11 to 14, wherein the nucleotide sequence and/or promoter are codon optimized.
The plant or plant part of any one of claims 11 to 15, wherein the recombinant nucleic acid molecule is comprised in an expression cassette and/or a vector.
The plant or plant part of claim 16, wherein the expression cassette is comprised in a vector.
The plant or plant part of claim 16 or claim 17, wherein the expression cassette and/or vector further comprises a transgene encoding a gene product that provides resistance to one or more herbicides, optionally glyphosate-, sulfonylurea-, imidazolinione-, dicamba-, glufisinate-, phenoxy proprionic acid-, cycloshexome-, traizine-, benzonitrile-, and/or broxynil-resistance, and/or a gene product that provides resistance to one or more pests, optionally bacterial-, fungal, gastropod-, insect-, nematode-, oomycete-, phytoplasma-, protozoa-, and/or viral-resistance.
The plant or plant part of any one of claims 16 to 18, wherein the expression cassette and/or vector further comprises a transgene encoding a gene product that provides resistance to one or more diseases.
The plant or plant part of any one of claims 11 to 19, wherein the nucleotide sequence (s) comprised in the recombinant nucleic acid molecule is expressed in the plant or plant part at an increased level as compared to a control plant or plant part.
The plant or plant part of any one of claims 11 to 20, wherein said plant or plant part exhibits increased drought tolerance as compared to a control plant or plant part.
The plant or plant part of claim 21, wherein increased drought tolerance comprises decreased water loss, decreased accumulation of reactive oxygen species, increased accumulation of dehydrins, improved root architecture, increased accumulation of late embryogenesis abundant proteins, increased grain yield at standard moisture percentage (YGSMN) , increased grain moisture at harvest (GMSTP) , increased grain weight per plot (GWTPN) , increased percent yield recovery (PYREC) , decreased yield reduction (YRED) , and/or decreased percent barren (PB) .
The plant or plant part of any one of claims 11 to 22, wherein said plant or plant part is a monocot, optionally rice, maize, wheat, barley, oats, rye, millet, sorghum, triticale, secale, einkorn, spelt, emmer, teff, milo, flax, gramma grass, Tripsacum sp., or teosinte.
The plant or plant part of claim 23, wherein said monocot is rice, maize, or wheat.
The plant or plant part of any one of claims 11 to 22, wherein said plant or plant part is a dicot, optionally cotton, potato, soybean, sugar beet, sunflower, tobacco or tomato.
A plant cell from the plant or plant part of any one of claims 11 to 25.
A seed from the plant of any one of claims 11 to 25, wherein said seed comprises in its genome said recombinant nucleic acid molecule.
A plant produced from the plant cell of claim 26.
A plant grown from the seed of claim 27.
A crop comprising a plurality of the plant of any one of claims 11 to 25, 28 or 29.
A product harvested from the plant of any one of claims 11 to 25, 28 or 29 or the crop of claim 30.
A processed product produced from the harvested product of claim 31 or the seed of claim 27.
A method of increasing the drought tolerance of a plant or plant part, comprising:

introducing into a plant or plant part a recombinant nucleic acid molecule of any one of claims 1 to 4, the expression cassette of any one of claims 5 or 8 to 10, and/or the vector of any one of claims 6 to 10.
A method of increasing the drought tolerance of a plant and/or plant part, comprising:

expressing in a plant or plant part a recombinant nucleic acid molecule of any one of claims 1 to 4, the expression cassette of any one of claims 5 or 8 to 10, and/or the vector of any one of claims 6 to 10.
A method of producing a plant having increased drought tolerance, comprising:

detecting, in a plant part, a recombinant nucleic acid molecule of any one of claims 1 to 5, the expression cassette of any one of claims 5 or 8 to 10, and/or the vector of any one of claims 6 to 10； and

producing a plant from said plant part.
A method of producing a plant having increased drought tolerance, comprising:

introducing into a plant cell or plant part a recombinant nucleic acid molecule of any one of claims 1 to 4, the expression cassette of any one of claims 5 or 8 to 10, and/or the vector of any one of claims 6 to 10 to produce a transgenic plant cell or plant part； and

growing the plant cell or plant part into a plant,

thereby producing a plant having increased drought tolerance.
A method of producing a plant having increased drought tolerance, comprising:

crossing a first parent plant with a second parent plant, wherein said first parent plant comprises within its genome a recombinant nucleic acid molecule of any one of claims 1 to 4, the expression cassette of any one of claims 5 or 8 to 10, and/or the vector of any one of claims 6 to 10；

thereby producing a progeny generation,

wherein said progeny generation comprises at least one plant that possesses said recombinant nucleic acid molecule within its genome and has increased drought tolerance.
A method of identifying a plant orplant part having increased drought tolerance, comprising:

detecting, in a plant or plant part, a recombinant nucleic acid molecule of any one of claims 1 to 4,

thereby identifying a plant or plant part having increased drought tolerance.
The method of claim 38, wherein said recombinant nucleic acid molecule or an informative fragment thereof is detected in an amplification product from a nucleic acid sample from said plant or plant part.
The method of claim 39, wherein said amplification product comprises the nucleotide sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO:4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO:15, or SEQ ID NO: 16, the reverse complement thereof, an informative fragment thereof, or an informative fragment of the reverse complement thereof.
The method of any one of claims 38 to 40, wherein said recombinant nucleic acid is detected using a probe comprising the nucleotide sequence of any one of SEQ ID NO:1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12； SEQ ID NO: 13, SEQ ID NO: 14, the reverse complement thereof, an informative fragment thereof, or an informative fragment of the reverse complement thereof.
The method of any one of claims 33 to 41, wherein said plant or plant part produces a polypeptide having the amino acid sequence ofany one ofSEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and/or SEQ ID NO: 20, or a polypeptide having at least about 80％identity to the amino acid sequence of any one of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and/or SEQ ID NO: 20, or any combination thereof, at an increased level as compared to a control plant or plant part.
The method of any one of claims 33 to 42, wherein said plant or plant part is a monocot, optionally rice, maize, wheat, barley, oats, rye, millet, sorghum, triticale, secale, einkorn, spelt, emmer, teff, milo, flax, gramma grass, Tripsacum sp. , or teosinte.
The method of any one of claims 33 to 42, wherein said plant or plant part is a dicot, optionally soybean, tobacco, sunflower or cotton.
A plant produced according to the method of any one of claims 33 to 44.
A plant cell from the plant of claim 45.
A seed from the plant of claim 46, wherein said seed comprises in its genome said recombinant nucleic acid.
A plant grown from the seed of claim 47.
A crop comprising a plurality of a plant of claim 45 or claim 48.
A method of improving yield of a plant crop, comprising: cultivating a plurality of the plants of any one of claims 11-25, 28, 29, 45 or 48 as a plant crop, wherein the plurality of plants of said plant crop have increased drought tolerance, thereby improving the yield of said plant crop.
A product harvested from the plant of claims 45 or 48 or the crop of claim 49.
A post-harvest product produced from the harvested product of claim 51 or the seed of claim 47.
The post-harvest product of claim 52, wherein the product is seed meal, seed flour, seed oil or cereals manufactured in whole or in part to contain plant by-products.