EP1196615A2 - Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement - Google Patents

Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement

Info

Publication number
EP1196615A2
EP1196615A2 EP00945486A EP00945486A EP1196615A2 EP 1196615 A2 EP1196615 A2 EP 1196615A2 EP 00945486 A EP00945486 A EP 00945486A EP 00945486 A EP00945486 A EP 00945486A EP 1196615 A2 EP1196615 A2 EP 1196615A2
Authority
EP
European Patent Office
Prior art keywords
acid
plant
hydroxyjasmonic
conjugate
jasmonic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00945486A
Other languages
German (de)
English (en)
Inventor
Luc Varin
Satinder Gidda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP1196615A2 publication Critical patent/EP1196615A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10—Transferases (2.)
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/82—Vectors or expression systems specially adapted for eukaryotic hosts for plant cells, e.g. plant artificial chromosomes (PACs)
    • C12N15/8241—Phenotypically and genetically modified plants via recombinant DNA technology
    • C12N15/8261—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield
    • C12N15/8262—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield involving plant development
    • C12N15/827—Flower development or morphology, e.g. flowering promoting factor [FPF]

Definitions

  • the invention relates to methods, compositions and genetic sequences to modulate flowering in plants and to plants genetically modified to flower early and plants genetically modified to flower tardily.
  • 5,523,281 ; 6,020,288 and 6,057,157 disclose various methods and compositions for inducing, accelerating and prolonging flowering in plants or enhancing their growth.
  • some of the molecules or compositions described in these patents were found to be inactive or even inhibitory to flower formation in other plant species. Some others are also known to affect the biomass or the plant morphology.
  • 12-hydroxyjasmonic acid (see Fig. 1A) is a natural metabolite and was first isolated from the leaves of Solarium tuberosum (potato) (Yoshihara et al. (1989), Agric. Biol. Chem. 53: 2835). The biosynthesis of 12-hydroxyjasmonic acid has not been studied at the biochemical level but recent studies suggest that jasmonic acid is converted to 12-hydroxyjasmonic acid by a single oxidation step catalyzed by the jasmonic acid 12-hydroxylase (Yoshihara et al. (1996), Plant Cell Physiol. 37: 586). 11 -hydroxyjasmonic acid (see Fig.
  • patent No 5,814,581 describes a plant growth promoter composition comprising jasmonate and brassinolide as active ingredients and Japanese patent application No 00292220 (A) published April 3, 1990, Yoshihara et al. (1989), Agric. Biol. Chem. 53: 2835-2837, Matsuki et al. (1992), Biosci. Biotech. Biochem. 56: 1329.; and Koda and Okazawa (1988), Plant Cell Physiol. 29: 969), suggest the use of 12-hydroxyjasmonic acid for inducing tuber formation in potatoes. None of these documents disclose nor suggest that compounds of the jasmonates family are involved in flower formation pathways.
  • the present invention relates to the modulation of flowering in plants. More particularly, the present invention pertains to methods, compositions and genetic sequences for modulating flowering in plants and to plants genetically modified to flower early and to plants genetically modified to flower tardily. According to an aspect of the invention, there is provided a method for modulating flowering in a plant.
  • the method comprises the step of modifying in said plant the endogenous level of at least one compound of the jasmonate family, and more particularly compounds selected from the group consisting of jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjugate, jasmonic acid-phenylalanine conjugate, jasmonic acid-isoleucine conjugate, jasmonic acid-leucine conjugate, jasmonic acid-valine conjugate, 12- hydroxyjasmonic acid, glucoside of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxyjasmonic acid, methyljasmonic acid, 12-hydroxymethyljasmonic acid, glucoside of 12-hydroxymethyljasraonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, 11 -hydroxyjasmonic acid, glucoside of 11- hydroxyjasmonic acid, sulfate ester of 11 -hydroxyjasmonic acid,
  • flowering of a plant is induced by increasing in the plant the endogenous level of at one flowering inducing compound selected from the previously mentioned jasmonate family compounds excluding sulfate ester of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, sulfate ester of 11 -hydroxyjasmonic acid, and sulfate ester of 11-hydroxymethyljasmonic acid.
  • this can be ⁇ achieved by: a) applying to the plant at least one flowering inducing compound and/or salts thereof; b) applying to the plant at least one inhibitor of a sulfotransferase sulfonating 12- hydroxyjasmonic acid and/or 11 -hydroxyjasmonic acid; c) applying to the plant at least one stimulator of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; d) increasing in the plant the endogenous level of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; and/or e) lowering in the plant the endogenous level of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11 -hydroxyjasmonic acid.
  • flowering of a plant can be delayed by lowering the endogenous level in the plant of at least one of the above mentioned flowering inducing compounds.
  • this can be achieved by: a) applying to the plant an inhibitor and/or an inactivator of at least one of the flowering inducing compounds; b) applying to the plant at least one stimulator of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11 -hydroxyjasmonic; c) applying to the plant at least one inhibitor of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; d) lowering in the plant the endogenous level of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; and/or e) increasing in the plant the endogenous level of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11 -hydroxyjasm
  • compositions for modulating flowering are provided.
  • a composition for inducing flowering in a plant comprising a flowering inducing effective amount of at least one of the previously mentioned flowering inducing compounds or salts thereof, in combination with a diluent or a carrier such that an induction in flowering of the plant occurs when compared to a corresponding plant in the absence of the flowering inducing composition.
  • a flowering delaying composition for delaying flowering in a plant comprising a flowering delaying effective amount of an inhibitor or of an inactivator of the previously mentioned jasmonate family compounds excluding sulfate ester of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, sulfate ester of 11 -hydroxyjasmonic acid, and sulfate ester of 11-hydroxymethyljasmonic acid, in combination with a diluent or a carrier such that a delay in flowering of said plant occurs when compared to a corresponding plant in the absence of the flowering delaying composition.
  • a plant is genetically modified to flower early when compared to a corresponding plant not genetically modified.
  • the genetically modified plant exhibits an increased endogenous level of at least one compound selected from the previously mentioned jasmonate family compounds, excluding sulfate ester of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, sulfate ester of 11-hydroxyjasmonic acid, and sulfate ester of 11-hydroxymethyljasmonic acid, when compared to a corresponding non- genetically modified plant.
  • a plant is genetically modified to flower tardily when compared to a corresponding plant not genetically modified, the genetically modified plant exhibiting a lowered level of at least one compound selected from the previously mentioned jasmonate family compounds excluding sulfate ester of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, sulfate ester of 11-hydroxyjasmonic acid, and sulfate ester of 11-hydroxymethyljasmonic acid.
  • the present invention is directed to an isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a plant hydroxyjasmonic acid sulfotransferase, and more particularly a plant 11- or 12-hydroxyjasmonic acid sulfotransferase.
  • the nucleotide sequence is selected from the group consisting of SEQ ID NO:1, nucleotide sequences having at least 50% similarity with SEQ ID NO:1 , SEQ ID NO:2 nucleotide sequences having at least 50% similarity with SEQ ID NO:2, and sequences hybridizing under low stringency conditions to one or more of these sequences.
  • these sequences are incorporated into a vector.
  • the invention provides transgenic plants incorporating at least one of these nucleotide sequences so that the transgenic plants are capable of flowering early or tardily.
  • the invention also provides methods for producing such transgenic plants.
  • An advantage of the present invention is that it allows to modulate flowering in plants without decreasing yield or modifying plant morphology. According to the invention it is possible to inhibit flowering in crop plants such as sugarcane, sugar beets or lettuce, just to mention a few, and thereby increase the taste, sweetness, and tenderness of these agricultural products. On the other hand, it is also possible according to the present invention, to induce flowering which is an advantage of great economic importance for horticultural plants and some crop plants such as cauliflower and broccoli.
  • Figures 1A and 1B show the chemical structures of 12-hydroxyjasmonic acid (Fig. 1A) and 11-hydroxyjasmonic acid (Fig. 1 B).
  • FIGs 2A and 2B are pictures showing the effect on flowering time of a treatment with 12-hydroxyjasmonic acid (Fig. 2B) in Arabidopsis thaliana, when compared to a treatment with water (Fig. 2A).
  • Figure 3 is a picture showing the phenotype of transgenic Arabidopsis plants expressing AtST2a gene under the control of a constitutive promoter when compared to wild type non-transgenic plant (WT).
  • WT wild type non-transgenic plant
  • S5, S6, S9, and S16 indicate independent transgenic lines.
  • Figure 4 is a Western blot of protein extracts from the plants shown in Fig. 3 probed with anti->4fS7 " 2a antibodies.
  • MW Molecular weight markers
  • WT wild type plants
  • S5, S6, S9, and S16 independent transgenic lines.
  • Figure 5 is a picture showing the phenotype of transgenic Arabidopsis plants expressing the AtST2a gene in the antisense orientation under the control of a constitutive promoter (TL 7-2-5) when compared to non transgenic plants (WT).
  • Figure 6 is a picture showing the effect of methyljasmonic acid treatment on the flowering time of wild type Arabidopsis thaliana plants (WT C24) and on transgenic Arabidopsis thaliana plants expressing the AtST2a gene in the antisense orientation under the control of a constitutive promoter (TL 7-2-5).
  • Figure 7 Shows nucleotide sequence of AtST2a gene (SEQ ID NO 1) taken from Arabidopsis thaliana database at Stanford University (clone number
  • FIG. 8 Shows the deduced amino acid sequence (SEQ ID NO 3) of the protein encoded by the AtST2a gene shown in Fig. 7.
  • Figure 9 Shows the nucleotide sequence of AtST2b gene (SEQ ID NO 2) taken from Arabidopsis thaliana database at Stanford University (clone number M0J9, gene MOJ9.15) and the GeneBank database (accession number AB010697, nucleotides 51670 to 50627).
  • Figure 10 Shows the deduced amino acid sequence (SEQ ID NO 4) of the protein encoded by the AtST2b gene shown in Fig. 9.
  • Figure 11 is a Northern blot of plants mRNA extracts showing the effect of various 12-hydroxyjasmonate concentrations on the expression of the
  • Figure 12 is a Northern blot of plants mRNA extracts showing the effect of the photoperiod on the expression of the AtST2a gene.
  • 11-hydroxyjasmonic acid 3-Oxo-2-(4-hydroxy-2-pentenyl)-cyclopentane-
  • 12-hydroxyjasmonic acid 3-Oxo-2-(5-hydroxy-2-pentenyl)-cyclopentane- 1 -acetic acid. Its chemical structure is shown in Fig. 1A.
  • 12-hydroxyjasmonic acid glucoside 3-Oxo-2-(5- ⁇ -D-glucopyranosyloxy- 2-pentenyl)-cyclopentane-1 -acetic acid.
  • 12-hydroxyjasmonic acid sulfate 3-Oxo-2-(5-hydroxysulfonyloxy-2- pentenyl)-cyclopentane-1 -acetic acid.
  • Antisense refers to nucleic acids molecules capable of regulating the expression of a corresponding gene in a plant.
  • An antisense molecule as used herein may also encompass a gene construct comprising a structural genomic gene, a cDNA gene or part thereof in reverse orientation relative to its or another promoter.
  • antisense nucleic acid sequences are not templates for protein synthesis but yet interact with complementary sequences in other molecules (such as a gene or RNA) thereby causing the function of those molecules to be affected.
  • Delay or retard or tardily When used in conjunction with the term flowering, it refers to the increase of the time of vegetative growth before flowering of a plant. A flowering delay may be observed when compared with a corresponding plant where flowering has not been delayed.
  • Effective amount refers to the amount or concentration of a suitable compound that is administered to a plant such that the compound induces or delays flowering of a plant.
  • Exogenous nucleic acid A nucleic acid sequence (such as cDNA, cDNA fragments, genomic DNA fragments, antisense RNA, oligonucleotide) which is not normally part of a plant genome.
  • the "exogenous nucleic acid” may be from any organism or purely synthetic.
  • the "exogenous nucleic acid sequence” encodes a plant gene such as a AtST2a, AtST2b or functional homologues of these genes.
  • Functional homologue refers to a molecule having at least 50%, more preferably at least 55%, even more preferably at least 60%, still more preferably at least 65-70%, and yet even more preferably greater than 85% similarity at the level of nucleotide or amino acid sequence to at least one or more regions of a given nucleotide or amino acid sequence.
  • the terms "functional homologue” refer to proteins or nucleic acid sequences encoding an enzyme having a substantially similar biological activity as 11- or 12-hydroxyjasmonate sulfotransferase and isoenzyme(s) thereof.
  • Such a functional homologue may exist naturally or may be obtained following a single or multiple amino acid substitutions, deletions and/or additions relative to the naturally occurring enzyme(s) using methods and principles well known in the art.
  • a functional homologue of a protein may or may not contain post-translational modifications such as covalently linked carbohydrate, if such modification is not necessary for the performance of a specific function. It should be noted, however, that nucleotide or amino acid sequences may have similarities below the above given percentages and still encode a 11- or 12-hydroxyjasmonate sulfotransferase-like molecule, and such molecules may still be considered within the scope of the present invention where they have regions of sequence conservation.
  • nucleotide sequence are used herein in their most general sense and encompass any contiguous series of nucleotide bases encoding directly, or via a complementary series of bases, a sequence of amino acids comprising a hydroxyjasmonic acid sulfotransferase molecule, and more particularly a 11- or 12-hydroxyjasmonic acid sulfotransferase.
  • Such a sequence of amino acids may constitute a full-length 11- or 12-hydroxyjasmonic acid sulfotransferase such as is set forth in SEQ ID No:1 and SEQ ID No:2 or an active truncated form thereof or a functional mutant, derivative, part, fragment, homologue or analogue thereof, or may correspond to a particular region such as an N-terminal, C-terminal or internal portion of the enzyme.
  • Genetic modification or genetic engineering refers to the introduction of an exogenous nucleic acid into one or more plant cells to create a genetically modified plant.
  • Methods for genetically modifying a plant are well known in the art. In some cases, in may be preferable that the genetic modification is permanent such that the genetically modified plant may regenerate into whole, sexually competent, viable genetically modified plants.
  • a plant genetically modified in a permanent manner would preferably be capable of self-pollination or cross- pollination with other plants of the same species, so that the exogenous nucleic acid, carried in the germ line, may be inserted into or bred into agriculturally useful plant varieties.
  • Endogenous level(s) refers to the concentration of a given substance which is normally found in a plant (intrinsic) at a given time and stage of growth. Reference herein is made to the altering of the endogenous level of a compound or of an enzyme activity relating to an elevation or reduction in the compound's level or enzyme activity of up to 30% or more preferably of 30-50%, or even more preferably 50-75% or still more preferably 75% or greater above or below the normal endogenous or existing levels.
  • the levels of a compound or the levels of activity of an enzyme can be assayed using known method and techniques.
  • Isolated nucleic acid molecule Means a genetic sequence in a non- naturally-occurring condition. Generally, this means isolated away from its natural state or formed by procedures not necessarily encountered in its natural environment. More specifically, it includes nucleic acid molecules formed or maintained in vitro, including genomic DNA fragments, recombinant or synthetic molecules and nucleic acids in combination with heterologous nucleic acids such as heterologous nucleic acids fused or operably-linked to the genetic sequences of the present invention.
  • isolated nucleic acid molecule also extends to the genomic DNA or cDNA or part thereof, encoding a hydroxyjasmonic acid sulfotransferase, preferably a 11- or 12-hydroxyjasmonic acid sulfotransferase, or a functional mutant, derivative, part, fragment, homologue or analogue of 11- or 12-hydroxyjasmonic acid sulfotransferase in reverse orientation relative to its or another promoter. It further extends to naturally-occurring sequences following at least a partial purification relative to other nucleic acid sequences.
  • isolated nucleic acid molecule as used herein is understood to have the same meaning as nucleic acid isolate.
  • Induce or increase When used in conjunction with the term flowering, it refers to the reduction of the time of vegetative growth before flowering of a plant. A flowering induction may be observed when compared with a corresponding plant wherein flowering has not been induced.
  • Modulation refers to the process by which a given variable is regulated to a certain proportion.
  • modulate refers in some cases to induction and in other cases delay, of flowering of a plant.
  • Plant refers to a whole plant or a part of a plant comprising, for example, a cell of a plant, a tissue of a plant, an explant, or seeds of a plant. This term further contemplates a plant in the form of a suspension culture or a tissue culture including, but not limited to, a culture of calli, protoplasts, embryos, organs, organelles, etc.
  • nucleic acid sequences In the context of nucleic acid sequences, these terms mean a hybridizable similarity under low, alternatively and preferably medium and alternatively and most preferably high stringency conditions, as defined below. Such a nucleic acid is useful, for example, in screening hydroxyjasmonic acid sulfotransferase genetic sequences, preferably a 11- or 12- hydroxyjasmonic acid sulfotransferase genetic sequences from various sources or for monitoring an introduced genetic sequence in a transgenic plant.
  • the preferred oligonucleotide is directed to a conserved hydroxyjasmonic acid sulfotransferase, preferably a 11- or 12-hydroxyjasmonic acid sulfotransferase genetic sequence or a sequence conserved within a plant genus, plant species and/or plant cultivar or variety.
  • Stringency For the purpose of defining the level of stringency, reference can conveniently be made to Maniatis et al. (1982) at pages 387-389, and especially paragraph 11.
  • a low stringency is defined herein as being in 4-6X SSC/1% (w/v) SDS at 37-45 °C for 2-3 hours.
  • alternative conditions of stringency may be employed such as medium stringent conditions which are considered herein to be 1-4X SSC/0.5-1% (w/v) SDS at greater than or equal to 45°C for 2-3 hours or high stringent conditions considered herein to be 0.1-1X SSC/0.1-1.0% SDS at greater than or equal to 60° C. for 1-3 hours.
  • Transformed plant Refers to introduction of an exogenous nucleic acid, typically a gene, into a whole plant or a part thereof, and expression of the exogenous nucleic acid in the plant.
  • Transgenic plant Refers to a whole plant or a part thereof stably transformed with an exogenous nucleic acid introduced into the genome of an individual plant cell using genetic engineering methods.
  • Vector A self-replicating RNA or DNA molecule which can be used to transfer an RNA or DNA segment from one organism to another.
  • Vectors are particularly useful for manipulating genetic constructs and different vectors may have properties particularly appropriate to express protein(s) in a recipient during cloning procedures and may comprise different selectable markers.
  • Bacterial plasmids are commonly used vectors.
  • the vectors of the invention are capable of facilitating transfer of a nucleic acid into a plant cell and/or facilitating integration into a plant genome.
  • the present inventors have now discovered that compounds of the jasmonate family are involved in the flowering of plants. They have also characterized the biological function of two highly homologous genes from A. thaliana (AtST2a and AtST2b) which encode enzymes that inactivate by sulfonation the biological activity of 11-hydroxyjasmonic acid and 12- hydroxyjasmonic acid. The inventors have also determine that expression of the AtST2a gene in under the control of photoperiod. These properties suggest that flowering could be induced or delayed, and yield to the elaboration of the following model which is given for purposes of clarification and not to limit the scope of the present invention.
  • compositions and genetically modified plants Using methods, compositions and genetically modified plants the present application demonstrates that flowering can actually be modulated in plants.
  • flowering of a plant is modulated by modifying in the plant the endogenous level of at least one compound of the jasmonate family selected from the group consisting of jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjugate, jasmonic acid- phenylalanine conjugate, jasmonic acid-isoleucine conjugate, jasmonic acid- leucine conjugate, jasmonic acid-valine conjugate, 12-hydroxyjasmonic acid, glucoside of 12-hydroxyjasmonic acid, sulfate ester of 12-hydroxyjasmonic acid, methyljasmonic acid, 12-hydroxymethyljasmonic acid, glucoside of 12- hydroxymethyljasmonic acid, sulfate ester of 12-hydroxymethyljasmonic acid, 1 1- hydroxyjasmonic acid, glucoside of 1 1-hydroxyjasmonic acid, sulfate ester of 11- hydroxyjasm
  • flowering is induced by increasing in a plant the endogenous level of at least one given flowering inducing compound of the jasmonate family selected preferably from the group consisting of jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjugate, jasmonic acid-phenylalanine conjugate, jasmonic acid-isoleucine conjugate, jasmonic acid- leucine conjugate, jasmonic acid-valine conjugate, 12-hydroxyjasmonic acid, glucoside of 12-hydroxyjasmonic acid, methyljasmonic acid, 12- hydroxymethyljasmonic acid, glucoside of 12-hydroxymethyljasmonic acid, 11- hydroxyjasmonic acid, glucoside of 11-hydroxyjasmonic acid, 11- hydroxymethyljasmonic acid, and glucoside of 11-hydroxymethyljasmonic acid.
  • the jasmonate family selected preferably from the group consisting of jasmonic acid, jas
  • the endogenous level of a selected jasmonate compound is increased by: a) applying to the plant at least one selected jasmonate compound and/or salts thereof; b) applying to the plant at least one inhibitor of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11-hydroxyjasmonic; and/or c) applying to the plant at least one stimulator of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid.
  • the selected jasmonate compound which is applied is 12- hydroxyjasmonic acid or 11-hydroxyjasmonic acid.
  • amino acid conjugates, glucosides, sulfate esters, salts, derivatives or any others natural or chemically synthesized compounds having a similar biological activity on flowering induction is suitable according to the invention.
  • inactive compounds such as sulfate ester of 12-hydroxyjasmonic acid, sulfate ester of 12- hydroxymethyljasmonic acid, sulfate ester of 11 -hydroxyjasmonic acid, and sulfate ester of 11-hydroxymethyljasmonic acid could be applied to a plant and it is possible that the bacterial or fungal flora of the plant or of its soil would hydrolyze these compounds in active jasmonate compounds. Any of the above mentioned compounds can be applied in a pure form or as a mixture of a plurality of compounds.
  • Inhibitors of hydroxyjasmonic acid sulfotransferase(s) should prevent in vivo inactivation of the flower-inducing molecule by sulfonation.
  • stimulators of jasmonic acid hydroxylase(s) should help in the production of jasmonate family compound(s).
  • the above mentioned jasmonate compounds, stimulators and/or inhibitors can be part of a composition for inducing flowering in a plant.
  • Such a composition would comprise a flowering inducing effective amount of at least one selected jasmonate compound, in combination with a diluent or a carrier.
  • the compound(s) and their amount would be selected such that an early flowering of the plant would occur following application of the flower inducing composition when compared to a corresponding plant in the absence of said compound(s).
  • the carrier or diluent can be a solvent such as water, oil or alcohol.
  • the composition may also comprise others active agents such as fertilizers and growth regulators.
  • the inducing composition may also be formulated with emulsifying agents in the presence or absence of fungicides or insecticides, if required.
  • the precise amount of compound employed in the practice of the present invention will depend upon the type of response desired, the formulation used and the type of plant treated. In the following examples, the plant culture medium was supplemented with about 10 ⁇ M of 12-hydroxyjasmonate or with 50 ⁇ M methyljasmonic acid for flowering induction. /) Flowering retardation
  • flowering is delayed by lowering the endogenous level in a plant of at least one given compound of the jasmonate family selected preferably from the group consisting of jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjugate, jasmonic acid-phenylalanine conjugate, jasmonic acid-isoleucine conjugate, jasmonic acid-leucine conjugate, jasmonic acid-valine conjugate, 12-hydroxyjasmonic acid, glucoside of 12- hydroxyjasmonic acid, methyljasmonic acid, 12-hydroxymethyljasmonic acid, glucoside of 12-hydroxymethyljasmonic acid, 11-hydroxyjasmonic acid, glucoside of 11-hydroxyjasmonic acid, 11-hydroxymethyljasmonic acid, and glucoside of 11- hydroxymethyljasmonic acid.
  • jasmonic acid jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjug
  • the levels of 12- hydroxymethyljasmonic acid and of 11-hydroxymethyljasmonic acid are reduced.
  • the flowering delay and the endogenous level lowering is detectable when compared to a corresponding plant in which the endogenous level of the compound has not been modified.
  • the endogenous level of a selected jasmonate compound is lowered by: a) applying to the plant at least one inhibitor and/or an inactivator of a selected jasmonate compound; b) applying to the plant at least one stimulator of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11 -hydroxyjasmonic acid; and/or c) applying to the plant at least one inhibitor of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid.
  • Inhibitor(s) and/or an inactivator(s) of jasmonate compounds should block or inhibit the biological activity of jasmonate compound(s).
  • Stimulator(s) of hydroxyjasmonic acid sulfotransferase(s) should stimulate in vivo inactivation of the flower-inducing molecule by sulfonation.
  • inhibitors of jasmonic acid hydroxylase(s) should prevent the production of hydroxylated jasmonate compound(s).
  • the above stimulators and/or inhibitors can be applied in a pure form, as a mixture of a plurality of compounds or be part of a flowering delaying composition.
  • genetic sequences encoding a plant hydroxyjasmonic acid sulfotransferase have been identified, cloned and used to generate transgenic plants.
  • SEQ ID NO 1 (Fig. 7; GeneBank: accession number AB010697, nucleotides 53939 to 55015; and Stanford University Arabidopsis thaliana database: clone number M0J9, gene MOJ9.16 and EST 119G6T7) corresponds to the gene AtST2a in Arabidopsis thaliana.
  • SEQ ID NO 3 (Fig. 8) is an amino acid sequence deduced from SEQ ID NO 1. This amino acid sequence is of public domain and comes from the Kazusa Arabidopsis Opening Site (KAOS) of the Kazusa DNA Research Institute (KDRI) (http://www.kazusa.or.jp/kaos/; clone number M0J9, gene MOJ9.16).
  • KAOS Kazusa Arabidopsis Opening Site
  • KDRI Kazusa DNA Research Institute
  • AtST2a gene from Arabidopsis thaliana encodes a sulfotransferase that sulfonates 12- hydroxyjasmonic acid and 11-hydroxyjasmonic acid with high specificity.
  • results obtained demonstrated that this hydroxyjasmonic acid sulfotransferase exhibits high affinity for its substrate with a Km value of 11 ⁇ M for 12-hydroxyjasmonic acid and 60 ⁇ M for 11-hydroxyjasmonic acid.
  • the enzyme did not accept structurally related compounds such as cucurbic acid, arachidonyl alcohol or prostaglandins. Maximum enzyme activity was observed at pH 7.5 in Tris/HCI buffer and did not require divalent cations for activity.
  • the purified recombinant protein expressed in E. coli migrated in SDS-PAGE at a position corresponding to approximately 35,000 daltons (see Fig. 4).
  • SEQ ID NO 2 (Fig. 9; GeneBank: accession number AB010697, nucleotides 50630 to 51670; and Stanford University Arabidopsis thaliana database: clone number M0J9 gene MOJ9.15), corresponds to the gene AtST2b in Arabidopsis thaliana.
  • SEQ ID NO 4 (Fig. 10) is an amino acid sequence deduced from SEQ ID NO 1. This amino acid sequence is of public domain and comes from the Kazusa Arabidopsis Opening Site (KAOS) of the Kazusa DNA Research Institute (KDRI) (http://www.kazusa.or.jp/kaos/; clone number M0J9, gene MOJ9.15). Amino acid sequence alignment between SEQ ID NOS 3 and 4 indicates that they share 85% amino acid sequence identity and 92% similarity, suggesting that AtST2a and AtST2b are functional homologues encoding isoenzymes.
  • KAOS Kazusa Arabidopsis Opening Site
  • one aspect of the present invention provides an isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a plant hydroxyjasmonic acid sulfotransferase enzyme. More particularly, the present invention is directed to an isolated nucleic acid molecule comprising a nucleotide sequence preferably selected from the group consisting of SEQ ID NO:1 , nucleotide sequences having at least 50% similarity with SEQ ID NO:1 , SEQ ID NO:2, nucleotide sequences having at least 50% similarity with SEQ ID NO:2, and sequences hybridizing under low stringency conditions to one or more of theses sequences.
  • the nucleic acid molecules contemplated herein may exist in either orientation alone or in combination with a vector and preferably an expression- vector capable of facilitating transfer and expression of the nucleic acid into the plant cell and/or facilitating integration into the plant genome.
  • a vector may, for example, be adapted for use in electroporation, microprojectile bombardment, Agrobacterium-mediated transfer or insertion via DNA or RNA viruses.
  • the vector and/or the nucleic acid molecule contained therein may or may not need to be stably integrated into the plant genome.
  • the vector may also replicate and/or express in prokaryotic cells.
  • the vector molecules or parts thereof are capable of integration into the plant genome.
  • the nucleic acid molecule and/or the vector may additionally contain a promoter sequence capable of directing expression of the nucleic acid molecule in a plant cell.
  • the nucleic acid molecule and/or the vector may also be introduced into the cell by any number of means such as those described above.
  • the vector may also comprise a genetic sequence encoding a ribozyme capable of cleaving a hydroxyjasmonic acid sulfotransferase mRNA transcript.
  • the present invention is exemplified using nucleic acid sequences derived from Arabidopsis thaliana since this plant is commonly studied in and it represents a convenient and easily accessible source of material.
  • nucleic acid sequences can be isolated from any number of sources such as other plants or certain microorganisms (e.g. fungi or bacteria). All such nucleic acid sequences encoding directly or indirectly a hydroxyjasmonic acid sulfotransferase are encompassed by the present invention regardless of their source. Examples of other suitable sources of genes encoding hydroxyjasmonic acid sulfotransferase include, but are not limited to Brassica napus, Brassica oleracea and Brassica juncea.
  • An aspect of the invention contemplates a plant genetically modified to flower early when compared to a corresponding plant not genetically modified, wherein the genetically modified plant has an increased endogenous level of at least one given compound of the jasmonate family selected preferably from the group consisting of jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid-tryptophan conjugate, jasmonic acid-phenylalanine conjugate, jasmonic acid- isoleucine conjugate, jasmonic acid-leucine conjugate, jasmonic acid-valine conjugate, 12-hydroxyjasmonic acid, glucoside of 12-hydroxyjasmonic acid, methyljasmonic acid, 12-hydroxymethyljasmonic acid, glucoside of 12- hydroxymethyljasmonic acid, 11-hydroxyjasmonic acid, glucoside of 11- hydroxyjasmonic acid, 11-hydroxymethyljasmonic acid, and glucoside of 11- hydroxymethyljasmonic acid,
  • the endogenous level of the selected jasmonate compound is increased by: a) increasing in the plant the endogenous level of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; and/or b) lowering in the plant the endogenous level of a sulfotransferase sulfonating
  • the plant is modified for inhibiting or blocking the expression of at least one gene selected from the group consisting of AtST2a, AtST2b and functional homologues of AtST2a or of AtST2b.
  • the expression of one of the above mentioned gene is inhibited by providing a transgenic plant expressing an exogenous nucleic acid sequence antisense to this gene.
  • the endogenous level of the sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11-hydroxyjasmonic acid is lowered by expressing into a genetically modified plant an exogenous nucleic acid sequence, the exogenous nucleic acid sequence encoding i) for a nucleic acid sequence antisense to a gene encoding at least one of said sulfotransferases or ii) for a nucleic acid sequence antisense to a fragment of this gene.
  • another aspect of the invention contemplates a method for producing a transgenic plant with reduced endogenous or existing hydroxyjasmonic acid sulfotransferase activity, such transgenic plant thereby being capable of flowering early.
  • the altered level would be less than the endogenous or existing level of activity in a comparable non-transgenic plant.
  • the method comprises the steps of: a) introducing into a cell of a suitable plant an exogenous nucleic acid molecule comprising a sequence of nucleotides antisense to a sequence encoding a plant hydroxyjasmonic acid sulfotransferase, preferably a 11- or 12- hydroxyjasmonic acid sulfotransferase; b) regenerating a transgenic plant from the cell; and where necessary c) growing the transgenic plant for a time and under conditions sufficient to permit expression of the antisense sequence and thereby inhibiting expression of the hydroxyjasmonic acid sulfotransferase.
  • the method for producing a transgenic plant with reduced endogenous or existing hydroxyjasmonic acid sulfotransferase activity comprises the step of altering the hydroxyjasmonic acid sulfotransferase gene(s), preferably the 11- or 12-hydroxyjasmonic acid sulfotransferase gene, through modification of the endogenous sequences via homologous recombination from an appropriately altered hydroxyjasmonic acid sulfotransferase gene or derivative or part thereof introduced into the plant cell, and regenerating a transgenic plant from the cell.
  • An aspect of the invention contemplates a plant, genetically modified to flower tardily when compared to a corresponding plant not genetically modified, wherein the genetically modified plant has a lowered endogenous level of at least one given compound of the jasmonate family selected preferably from the group consisting jasmonic acid, jasmonic acid-tyrosine conjugate, jasmonic acid- tryptophan conjugate, jasmonic acid-phenylalanine conjugate, jasmonic acid- isoleucine conjugate, jasmonic acid-leucine conjugate, jasmonic acid-valine conjugate, 12-hydroxyjasmonic acid, glucoside of 12-hydroxyjasmonic acid, methyljasmonic acid, 12-hydroxymethyljasmonic acid, glucoside of 12- hydroxymethyljasmonic acid, 11-hydroxyjasmonic acid, glucoside of 11- hydroxyjasmonic acid, 11-hydroxymethyljasmonic acid, and glucoside of 11- hydroxymethyljasm
  • the endogenous level of the selected jasmonate compound is lowered by: a) lowering in the plant the endogenous level of an hydroxylase hydroxylating jasmonic acid and/or methyljasmonic acid; and/or b) increasing in the plant the endogenous level of a sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11 -hydroxyjasmonic acid.
  • this is achieved by genetically modifying the plant so as to increase the expression of the sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or 11-hydroxyjasmonic acid, or functional homologues of this sulfotransferase. More preferably, the plant is modified to increase the expression of at least one gene selected from the group consisting of AtST2a, AtST2b and functional homologues of AtST2a or of AtST2b. Methods for increasing expression of genes in plants are well known in the art, such as activation tagging, transgenesis under the control of a strong promoter, and these methods could be used to reduce the present invention in practice. According to a preferred embodiment of the invention, the expression of one of the above-mentioned genes is increased by expressing into the plant a gene expressing the sulfotransferase sulfonating 12-hydroxyjasmonic acid and/or
  • another aspect of the invention contemplates a method for producing a transgenic plant with increased endogenous or existing hydroxyjasmonic acid sulfotransferase activity, such transgenic plant thereby being capable of flowering tardily.
  • the altered level would be higher than the endogenous or existing level of activity in a comparably non-transgenic plant.
  • the method comprises the step of: a) introducing into a cell of a suitable plant an exogenous nucleic acid molecule comprising a sequence of nucleotides encoding a plant hydroxyjasmonic acid sulfotransferase, preferably a 11- or 12-hydroxyjasmonic acid sulfotransferase; b) regenerating a transgenic plant from the cell; and where necessary c) growing the transgenic plant for a time and under conditions sufficient to permit expression of the nucleic acid sequence into a plant hydroxyjasmonic acid sulfotransferase, preferably a 11- or 12-hydroxyjasmonic acid sulfotransferase.
  • transgenic plants are known to those skilled in the art of plant genetic engineering and do not differ in kind from those practices which have previously been demonstrated to be effective in tobacco, petunia and other model plant species (e.g. electroporation, microprojectile bombardment, Agrobacterium-mediated transfer or insertion via DNA or RNA viruses).
  • tobacco, petunia and other model plant species e.g. electroporation, microprojectile bombardment, Agrobacterium-mediated transfer or insertion via DNA or RNA viruses.
  • the present invention therefore, extends to all transgenic plants containing all or part of the nucleic acid sequence of the present invention, or antisense forms thereof and/or any homologues or related forms thereof and in particular those transgenic plants which exhibit altered flowering properties.
  • the transgenic plants may contain an introduced nucleic acid molecule comprising a nucleotide sequence encoding or complementary to a sequence encoding a hydroxyjasmonic acid sulfotransferase.
  • the nucleic acid would be stably introduced into the plant genome, although the present invention also extends to the introduction of a hydroxyjasmonic acid sulfotransferase nucleotide sequence within an autonomously-replicating nucleic acid sequence such as a DNA or RNA virus capable of replicating within the plant cell.
  • the invention also extends to cut flowers and seeds from such transgenic plants.
  • a further aspect of the present invention is directed to an isolated plant hydroxyjasmonic acid sulfotransferase, and more particularly to an isolated hydroxyjasmonic acid sulfotransferase selected from the group of: a) an enzyme whose amino acid sequence is represented by SEQ ID NO 3 or SEQ ID NO 4; and b) functional homologues of enzyme a), isolated from a plant or derived from enzyme a) by substitution, deletion or addition of one or several amino acids in the amino acid sequences defined in a), and having similar biological activity or function(s).
  • These enzymes may be purified from plants or produced with routine recombinant techniques using SEQ ID NO 1 , SEQ ID NO 2, or portion(s) thereof.
  • Isolated hydroxyjasmonic acid sulfotransferase will provide a source of material for research to develop, for example, more active enzymes and to produce antibodies binding with affinity thereto. Accordingly, a related aspect of the invention is directed to antibodies binding with affinity to one or more of the above mentioned hydroxyjasmonic acid sulfotransferases.
  • hydroxyjasmonic acid sulfotransferases can be made against virtually any protein and should be capable of producing such antibodies using conventional techniques.
  • Antibodies binding to hydroxyjasmonic acid sulfotransferases could be particularly useful in flowering retardation compositions and also for studying the biological activity of this type of enzymes.
  • A. thaliana plants of ecotype Columbia (ColO) and C24 were used for this study. The plants were grown in soil in a growth chamber during a 16-hour photoperiod, at a day-time temperature of 24 °C and a night-time temperature of 20 °C. For some experiments, the plants were grown in magenta boxes under sterile conditions according to the following protocol. Seeds of Arabidopsis thaliana were sterilized for 5 minutes in a solution containing 1.5% sodium hypochlorite and 0.02% SDS, and washed five times in sterile water. Seeds were vernalized for four days at 4 °C. Seeds were then spread on agar-solidified medium containing Murashige and Skoog salts, 1 % sucrose and vitamins.
  • ubiquitin promoter may be used for constitutive expression.
  • inducible promoters may also be used such as the ethanol-inducible promoter or the glucocorticoid-inducible promoter.
  • A. tumefaciens strain GV3101 pMP90 was transformed with the AtST2a- pBI-101-525 sense and antisense constructs by the method described in Gynheung et al. (1988) Biology Manual, A3: 1-19.
  • A. thaliana plants of ecotype Columbia were transformed with Agrobacterium containing the AtST2a gene in the sense orientation by the vacuum infiltration method as described previously in Benchtold et al. (1993), CR Acad. Sci. Paris, Life Sciences, 316: 1194.
  • A. thaliana plants of ecotype C24 were transformed with the pBI-101-525 vector containing the AtST2a gene in the antisense orientation by the root explant method as described in Valvekans et al. (1988) Proc Natl Acad Sci USA, 85: 5536.
  • Seeds were collected from the T 0 plants, their surface was sterilized and transformants were selected on MS salt medium containing vitamins and supplemented with 50 ⁇ g/ml of kanamycin.
  • the T 2 or T 3 seeds were vernalized for four days at 4 °C. Seeds were then spread on agar-solidified medium containing Murashige and Skoog salts, 1% sucrose and vitamins. Alternatively, the vernalized seeds were planted in soil and grown in a growth chamber under a 16- hour photoperiod, at a day temperature of 24 °C and a night temperature of 20 °C.
  • Protein extracts from wildtype and transgenic plants were subjected to 12% SDS-PAGE. Following electrophoresis, the proteins were transferred to nitrocellulose membranes using a Bio-RadTM semidry transblot apparatus according to the manufacturer instructions. Blots were incubated with rabbit anti- ATST2a primary antibodies. Immunodetection was carried on with alkaline phosphatase-conjugated anti rabbits antibodies and the immunodetection kit from Bio-RadTM.
  • GC-MS (GCQ FinniganTM), 70 eV, NCI, ionization gas NH 3 , source temperature 140°, column Rtx-5 (30 m x 0.25 mm, 0.25 ⁇ m film thickness), injection temperature 250°C, interface temperature 275°; Helium 40 cm s "1 ; splitless injection; column temperature program: 1 min 60°C, 25°min "1 to 180° C,
  • the negative ion electrospray (ES) mass spectra were obtained from a FinniganTM MAT TSQ 7000 instrument (electrospray voltage 4 kV; heated capillary temperature 220 °C; sheath gas: nitrogen) coupled with a Micro-Tech Ultra-Plus MicroLCTM system equipped with a RP18-column (4 ⁇ m, 1x100 mm, UltrasepTM).
  • ES electrospray
  • CID collision-induced dissociation
  • Example 1 Flowering induction by treating A. thaliana plants with 12- hydroxyjasmonic acid
  • Arabidopsis plants of ecotype Colombia were grown in magenta boxes containing phytoagar and vitamins in a growth chamber under a sixteen hour photoperiod at a day-time temperature of 24 degrees and a night-time temperature of 20 degrees for a period of 18 days.
  • the plants were then treated with 10 ⁇ M of 12-hydroxyjasmonic acid (Fig. 2B) or with water as a negative control (Fig 2A) for a period of 6 days.
  • A. thaliana plants genetically modified were created by inserting therein a nucleic acid molecule encoding the AtST2a gene in the sense orientation under the control of a constitutive promoter.
  • the results demonstrate that a higher endogenous expression of the hydroxyjasmonic acid sulfotransferase encoded by this gene is effective to delay flowering.
  • FIG. 3 shows the phenotype of wild type non transgenic ColO Arabidopsis plants (WT) as compared to transgenic plants expressing the AtST2a gene under the control of the CaMV35S promoter 27 days after germination (S5, S6, S9, and S16).
  • WT wild type non transgenic ColO Arabidopsis plants
  • AtST2a gene under the control of the CaMV35S promoter 27 days after germination (S5, S6, S9, and S16).
  • expression of AtST2a gene in transgenic Arabidopsis thaliana affects flowering time since all the transgenic lines exhibited delayed flowering as compared with non-transformed plants.
  • Fig. 4 shows a Western blot of protein extracts of these plants probed with anti- ⁇ fS72a antibodies. This figure clearly shows that the length of the delay is correlated with the level of expression of the transgene. This suggests that it is possible to vary the length of the delay by selecting transgenic lines expressing AtST2a at different levels. Delaying flowering time results in increased vegetative growth and biomass which is a major advantage for crop such as lettuce, carrot, cabbage, sugar cane, sugar beet, to mention a few.
  • Table 1 hereinbelow also shows that a higher endogenous expression of the hydroxyjasmonic acid sulfotransferase results in higher endogenous level of 12-hydroxyjasmonate sulfate in the transgenic line S9.
  • Example 3 Transgenic plants flowering early in non-inductive flowering conditions
  • A. thaliana plants genetically modified were created by inserting therein a nucleic acid molecule encoding the AtST2a gene in the antisense orientation under the control of a constitutive promoter.
  • the results demonstrate that a lower endogenous expression of the hydroxyjasmonic acid sulfotransferase is effective to induce flowering.
  • Figure 5 shows the phenotype of wild type Arabidopsis plants of ecotype
  • Figure 6 shows the effect of methyljasmonic acid treatment on the phenotype of wild type non transgenic C24 Arabidopsis plants (WT C24) as compared to transgenic plants expressing the AtST2a in the antisense orientation under the control of the CAMV35S promoter (TL 7-2-5), 24 days after germination.
  • AtST2a expression of AtST2a in the antisense orientation results in lowered levels of the AtST2 protein and allows the transgenic plants to flower early in presence of methyljasmonic acid.
  • Example 6 Expression of AtST2a is under the control of photoperiod.
  • AtST2a When the plants are grown under short day conditions, the increased level of expression of AtST2a leads to the sulfonation of 11- and 12-hydroxyjasmonic acids resulting in delayed flowering. When the plants are grown under long day conditions, AtST2a is not expressed and the levels of 11- and 12-hydroxyjasmonic acids increase resulting in an early flowering time.
  • AtST2a and AtST2b gene expression is induced after the application of 12-hydroxyjasmonate with a maximum of six hours after the beginning of the treatment.
  • This pattern of induction demonstrates that the level of 12-hydroxyjasmonic acid is tightly regulated in vivo suggesting that 12- hydroxyjasmonic acid plays an important role in the plant.
  • AtST2a and AtST2b gene expression is also induced when the plants are grown in the dark. The kinetic of accumulation of AtST2a and AtST2b mRNA is slow with a maximum observed after 12 hours in the dark. Furthermore, there is a fast decrease in AtST2a and AtST2b mRNA levels when the plants are transferred back to light.
  • AtST2a and AtST2b are to modulate the activity of 12-hydroxyjasmonic acid and 11-hydroxyjasmonic acid in relation to the photoperiod.
  • the model presented in the section "General overview of the invention” integrates the different results obtained and tries to explain the role of the hydroxylated jasmonates and of the AtST2a and AtST2b genes in the control of flowering time.
  • 11- and 12- hydroxyjasmonic acids are synthesized slowly into the leaves from jasmonic acid or from early fatty acids precursors. The accumulation of these metabolites up to a threshold value induces flowering.
  • AtST2a and/or AtST2b When the plants are growing under short day time conditions, AtST2a and/or AtST2b will be expressed during the night and will inactivate 11- and 12-hydroxyjasmonic acids by sulfonation. This mechanism will retard flowering time until the photoperiod is favorable. When the plants are growing under long day time conditions, the level of expression of AtST2a and/or AtST2b is low and 11- and 12-hydroxyjasmonic acids will accumulate to levels sufficient to induce flowering.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Genetics & Genomics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Zoology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Biotechnology (AREA)
  • Molecular Biology (AREA)
  • Microbiology (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Physiology (AREA)
  • Cell Biology (AREA)
  • Physics & Mathematics (AREA)
  • Biophysics (AREA)
  • Plant Pathology (AREA)
  • Breeding Of Plants And Reproduction By Means Of Culturing (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Enzymes And Modification Thereof (AREA)

Abstract

La présente invention concerne des méthodes, des compositions et des séquences génétiques de modulation de la floraison de plantes ainsi que des plantes modifiées génétiquement pour fleurir précocement ainsi que des plantes modifiées génétiquement pour fleurir tardivement. Plus particulièrement, la présente invention concerne entre autres une séquence génétique codant pour un acide hydroxyjasmonique sulfotransférase ainsi que des méthodes de production de plantes transgéniques à l'aide de cette séquence.
EP00945486A 1999-07-06 2000-07-06 Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement Withdrawn EP1196615A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CA 2274873 CA2274873A1 (fr) 1999-07-06 1999-07-06 Methodes et compositions pour moduler la floraison
CA2274873 1999-07-06
PCT/CA2000/000801 WO2001002589A2 (fr) 1999-07-06 2000-07-06 Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement

Publications (1)

Publication Number Publication Date
EP1196615A2 true EP1196615A2 (fr) 2002-04-17

Family

ID=4163643

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00945486A Withdrawn EP1196615A2 (fr) 1999-07-06 2000-07-06 Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement

Country Status (4)

Country Link
EP (1) EP1196615A2 (fr)
AU (1) AU782180B2 (fr)
CA (1) CA2274873A1 (fr)
WO (1) WO2001002589A2 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2415062A1 (fr) * 2002-12-23 2004-06-23 Unknown Methodes et sequences genetiques pour la modulation de la tuberisation dans des plantes produisant des tubercules et plantes genetiquement modifiees en vue d'alterer la taille et le nombre des tubercules
CA2414487A1 (fr) * 2003-01-13 2004-07-13 Florisys Inc. Methodes et sequences genetiques pour produire des plantes males steriles et plantes genetiquement modifiees pour changer le developpement des antheres
CN107970213A (zh) 2011-09-16 2018-05-01 纳米整理技术公司 茉莉酮酸酯化合物的组合物和使用方法
EP3240534A4 (fr) * 2014-12-31 2018-12-19 Nanocare Technologies, Inc. Dérivés de jasmonate et compositions associées
CN113105285B (zh) * 2021-03-26 2022-04-22 浙江大学 一种用于粳不籼恢杂交水稻制种的母本花时调节剂及调节花时的方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD209379A1 (de) * 1982-04-06 1984-05-09 Adw Ddr Mittel zur regulation der bluehperiode bei kaffee
CA2157038C (fr) * 1993-02-26 2005-04-12 Yasuo Kamuro Stimulateur de croissance vegetale
US5436226A (en) * 1993-11-03 1995-07-25 The United States Of America, As Represented By The Secretary Of Agriculture Natural suppression of sprouting in stored potatoes using jasmonates
EP0777965A4 (fr) * 1994-08-26 1997-12-10 Nippon Zeon Co Promoteur de la croissance vegetale
EP1033405A3 (fr) * 1999-02-25 2001-08-01 Ceres Incorporated Fragments d'ADN avec des séquences déterminées et polypeptides encodées par lesdits fragments

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
GIDDA ET AL.: "Biochemical and molecular characterization of a hydroxyjasmonate sulfotransferase from Arabidopsis thaliana", JOURNAL OF BIOLOGICAL CHEMISTRY, vol. 278, no. 20, 16 May 2003 (2003-05-16), pages 17895 - 17890 *
See also references of WO0102589A3 *

Also Published As

Publication number Publication date
AU5957800A (en) 2001-01-22
WO2001002589A2 (fr) 2001-01-11
CA2274873A1 (fr) 2001-01-06
WO2001002589A3 (fr) 2001-08-09
AU782180B2 (en) 2005-07-07

Similar Documents

Publication Publication Date Title
Coles et al. Modification of gibberellin production and plant development in Arabidopsis by sense and antisense expression of gibberellin 20-oxidase genes
US20050210547A1 (en) Plant control genes
JP3183407B2 (ja) エチレンに対する修正された応答をもつ植物
US7482509B2 (en) Transgenic plants carrying neoxanthin cleavage enzyme gene
Curtis et al. Induction of dwarfism in transgenic Solanum dulcamara by over‐expression of a gibberellin 20‐oxidase cDNA from pumpkin
US7154028B2 (en) Gibberellin 2-oxidase gene, functions and uses thereof
US5919998A (en) Genetic control of plant hormone levels and plant growth
AU782180B2 (en) Methods, compositions and genetic sequences for modulating flowering in plants, and plants genetically modified to flower early and tardily
US9139841B2 (en) Plant having resistance to low-temperature stress and method of production thereof
US20070083948A1 (en) Method and composition for increasing branching and flowering response in plants
Champenoy et al. Expression of the yeast mevalonate kinase gene in trangenic tobacco
KR20020064352A (ko) 벼 유래의 지베렐린 3β수산화효소 유전자 및 그 이용
EP0967278A2 (fr) Gène pour la régulation de l'induction de la floraison et son utilisation
US5910627A (en) Ph genes and their uses
CA2377899A1 (fr) Methodes, composition et sequences genetiques de modulation de la floraison de plantes et plantes modifiees genetiquement pour fleurir precocement et tardivement
JPH08205873A (ja) 組換えジベレリンｄｎａ及びその用途
US20060236430A1 (en) Methods and compositions for producing male sterile plants
Champenoy et al. Activity of the yeast mevalonate kinase promoter in transgenic tobacco
CA2415062A1 (fr) Methodes et sequences genetiques pour la modulation de la tuberisation dans des plantes produisant des tubercules et plantes genetiquement modifiees en vue d'alterer la taille et le nombre des tubercules
EP0824591A4 (fr) Illets transgeniques presentant une vie prolongee apres recolte
Gomes Regulation and function of 1-aminocyclopropane-1-carboxylate oxidase in Petunia hybrida
US20040097717A1 (en) Control of aerial branching
CA2378814A1 (fr) Gene controlant la branchaison des pousses vegetales
CA2513168A1 (fr) Procedes et compositions de fabrication de plantes males steriles
WO1999023200A2 (fr) Gene de deshydrogenase de glucose de disphosphate d'uridine, et role que joue ce gene dans la modification de la croissance et des caracteristiques des plantes

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20020128

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17Q First examination report despatched

Effective date: 20040924

17Q First examination report despatched

Effective date: 20040924

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20071003