WO1998041612A1 - Cercosporin-degrading bacteria - Google Patents
Cercosporin-degrading bacteria Download PDFInfo
- Publication number
- WO1998041612A1 WO1998041612A1 PCT/US1998/005279 US9805279W WO9841612A1 WO 1998041612 A1 WO1998041612 A1 WO 1998041612A1 US 9805279 W US9805279 W US 9805279W WO 9841612 A1 WO9841612 A1 WO 9841612A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cercosporin
- dna
- bacteria
- degrading
- gene
- Prior art date
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
-
- 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
- C12N15/8271—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield for stress resistance, e.g. heavy metal resistance
- C12N15/8279—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield for stress resistance, e.g. heavy metal resistance for biotic stress resistance, pathogen resistance, disease resistance
- C12N15/8282—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield for stress resistance, e.g. heavy metal resistance for biotic stress resistance, pathogen resistance, disease resistance for fungal resistance
Definitions
- the present invention relates to the identification of cercosporin- degrading bacteria, methods of use thereof, and the identification of a cercosporin breakdown product. Cercosporin-degrading bacteria are useful in producing cercosporin-resistant plant varieties.
- Cercosporin is a small (534 mw) lipid-soluble polyketide secreted by many species of Cercospora. While its synthesis is unknown but hypothesized to proceed through the polyketide pathway, much has been learned about its activation and toxicity.
- Cercosporin is a photosensitizer. Upon illumination, cercosporin is converted to an electronically activated state. In this state, it reacts with molecular oxygen to produce extremely toxic molecules such as singlet oxygen ('O ⁇ . Singlet oxygen has the ability to interact with and destroy cellular membranes (lipids), proteins, and nucleic acids. In plants, the primary site of localization appears to be in the cell and organelle membranes where it peroxidizes lipids. Following peroxidation, a breakdown of the membrane occurs leading to electrolyte leakage, loss of organelle structure, and cell death.
- Cercospora species infect tobacco, soybean, corn, coffee, sugar beat, and other crops. Studies utilizing toxin-deficient mutants and studies investigating the effects of light on disease development demonstrate that cercosporin-producing fungi require it for pathogenicity.
- Robeson (U.S. Patent No. 5,262,306) describes a method by which organisms able to degrade cercosporin should be identified. Through an extensive screen, we have tested the method of Robeson et al. and have identified additional bacteria able to degrade cercosporin.
- a first aspect of the present invention is a method of degrading cercosporin, comprising contacting a cercosporin-degrading bacteria to a composition containing cercosporin for a time sufficient to degrade the cercosporin.
- the cercosporin-degrading bacteria is selected from the group consisting of Xanthomonas campestris pv. pruni, Xanthomonas campestris pv. zinniae, Mycobacterium smegatis, and bacteria able to utilize propane but not propylene as a carbon source.
- the contacting step is preferably carried out in the dark, and preferably by combining the bacteria with a cercosporin-containing bacterial growth medium.
- a second aspect of the present invention is a cercosporin breakdown product that has a green hue in bacterial culture medium, is soluble in organic solvents at a pH below 3.0, has an absorbance spectrum with dual peaks at about 443 ran and 565 nm, and has a molecular weight of 517 or 518 as determined by fast atom bombardment.
- this compound is useful as a marker for detecting the presence or absence of a DNA as described below in transformed cells, and is useful in confirming the identity of DN As as DNAs encoding a cercosporin-degrading protein (by examining the structure of the encoded protein and comparing regions of expected enzyme activity with the activity indicated by the change in structure from cercosporin to the cercosporin breakdown product).
- a third aspect of the present invention is an isolated DNA encoding a cercosporm-degrading protein.
- the DNA encodes a protein that converts (in a single step or participates as one of multiples steps) cercosporin to a cercosporin breakdown product as described above.
- the DNA is: (a) DNA from a bacteria selected from the group consisting of Xanthomonas campestris pv. pruni, Xanthomonas campestris pv.
- vectors and expression cassettes or chimeric genes containing the aforesaid DNA, methods of transforming plants therewith, and transformed plants exhibiting a cercosporin- resistant phenotype produced therewith.
- Figure 1 illustrates the concentration of cercosporin present in cercosporin-c ⁇ ntaining medium (control) and medium inoculated with XCP-76 (non- degrading isolate) and XCP-77 and XCZ-1 (degrading isolates) at various times after inoculation. Cercosporin concentrations were determined by extraction of cercosporin and quantifying by measuring absorbance of the orgamc extract at 471 nm.
- Figure 2 illustrates the absorbance of cercosporin and the cercosporin breakdown product over time. Both compounds were extracted from liquid media containing cercosporin inoculated with isolate XCZ-1 (cercosporin degrader).
- the present invention is drawn to compositions and methods for providing or increasing cellular resistance to cercosporin in organisms that are sensitive to cercosporin.
- the compositions are proteins and the genes encoding them, which act to provide or increase cellular resistance to cercosporin in such organisms.
- the proteins and the genes encoding resistance to cercosporin, and the methods described herein that utilize these compounds, are useful in providing cellular resistance to pathogens that produce cercosporin, and survival of these cells, particularly after pathogen attack. These same compositions and methods also provide or increase resistance to singlet oxygen itself.
- One aspect of the invention is drawn to proteins which are involved in conferring resistance to cercosporin.
- the proteins function to inhibit the spread of infection caused by pathogenic fungi that encode cercosporin, and control resistance to such compounds in a number of organisms, including plants, bacteria, insects and animals. Therefore, the proteins are useful in a variety of settings involving the control of disease and toxicity resistance in plants and other organisms. Modifications of such proteins are also encompassed by the present invention. Such modifications include substitution of amino acid residues, deletions, additions, and the like.
- the proteins of the invention include naturally occurring proteins and modifications thereof. Such proteins fmd use in preventing or increasing resistance to cercosporin.
- the proteins are also particularly useful in protecting organisms against pathogenic infection.
- the organism is transformed with a nucleotide sequence encoding the protein.
- organisms transformed in this manner may be plants, bacteria, fungi, and animals, with plants being preferred.
- the expression of the protein in the organism prevents toxicity and injury caused by singlet oxygen-generating cercosporin, and confers resistance to infection by fungal pathogens.
- the first is to generate a genomic library to be maintained in a laboratory strain of Escherichia coli, then screen that library for isolates that exhibit the phenotype of interest (in our case the ability to degrade cercosporin).
- the second strategy is to mobilize a suicide vector carrying the TN5 transposon into the
- Xanthomonad of interest and screen for a loss of function or a change in phenotype (in our case, the loss of the ability to degrade cercosporin).
- Dr. Lindgren has donated the cloning vector pLAFR-6 and transposon-carrying suicide vectors pGS-9, pTN4431, and pSUP-2021. Conjugation experiments were conducted following standard protocols in which the pLAFR-6 carrying E. coli strain was mated to Xanthomonas isolates XCZ-1, XCZ-3, XCP-77, and XCP-76.
- pLAFR-6 was only able to mobilize into and be maintained in XCZ-1 and XCZ-3, with a frequency of approximately 10 "4 per recipient.
- suicide vector pGS-9 was able to mobilize into and function in these same isolates; it had a significantly low3er frequency of 10 "9 resulting in a few hundred transconjugants per experiment.
- Subsequent experiments have shown that the TN5 transposon will transpose from - pGS-9 into the recipient genome randomly. Based on this information, XCZ-3 and vector pLAFR-6 and pGS-9 have been chosen to be used in studies aimed at elucidating the genes and mechanisms involved in the bacterial degradation of cercosporin.
- Coding sequences from other species may be isolated according to well known techniques based on their sequence homology to the coding sequences of interest. In these techniques, all or part of the known coding sequence is used as a probe which selectively hybridizes to other cercosporin resistance coding sequences present in a population of cloned genomic DNA fragments or cDNA fragments (i.e. genomic or cDNA libraries) from a chosen organism.
- the entire sequence of interest, or portions thereof may be used as probes capable of specifically hybridizing to corresponding coding sequences and messenger RNAs.
- probes include sequences that are unique among coding sequences that encode resistance to cercosporin (hereinafter resistance coding sequences), and are preferably at least about 10 nucleotides in length, and most preferably at least about 20 nucleotides in length.
- resistance coding sequences may be used to amplify resistance coding sequences from a chosen organism by the well-know process of polymerase chain reaction (PCR). This technique may be used to isolate additional resistance coding sequences from a desired organism or as a diagnostic assay to determine the presence of resistance coding sequences in an organism.
- Such techniques include hybridization screening of plated DNA libraries (either plaques or colonies; see, e.g.. Sambrook et al. , Molecular Cloning, eds. , Cold Spring Harbor Laboratory Press (1989)) and amplification by PCR using oligonucleotide primers corresponding to sequence domains conserved among the amino acid sequences (see, e.g. Innis et al. , PCR Protocols, a Guide to Methods and
- hybridization of such sequences may be carried out under conditions of reduced stringency, medium stringency or even stringent conditions (e.g. , conditions represented by a wash stringency of 35-40% Formamide with 5x- Denhardt's solution, 0.5 % SDS and lx SSPE at 37° C; conditions represented by a wash stringency of 40-45 % Formamide with 5x Denhardt's solution, 0.5% SDS, and lx SSPE at 42° C; and conditions represented by a wash stringency of 50% Formamide with 5x Denhardt's solution, 0.5% SDS and lx SSPE at 42° C, respectively), to DNA encoding resistance to cercosporin disclosed herein in a standard hybridization assay. See J. Sambrook et al. , Molecular Cloning, A
- sequences which code for a cercosporin resistance protein and hybridize to the DNA of interest will be at least 50% homologous, 70% homologous, and even 85% homologous or more with that DNA. That is, the sequence similarity of sequences may range, sharing at least about 50%, about 70%, and even about 85% sequence similarity.
- mutant forms of the cercosporin resistance gene and the proteins they encode.
- Methods for mutagenesis and nucleotide sequence alterations are well known in the art. See, for example, Kunkel, T. (1985) Proc. Natl. Acad. Sci. USA 32:488-492; Kunkel et al. (1987) Methods in Enzymol.
- genes and nucleotide sequences of the invention include both the naturally occurring sequences as well as mutant forms.
- proteins of the invention encompass both naturally occurring proteins as well as variations and modified forms thereof.
- the nucleotide sequences encoding the proteins or polypeptides of the invention are useful in the genetic mampulation of organisms, including bacteria, fungi, plants and animals. This aspect of the invention is illustrated herein with respect to the genetic manipulation of plants.
- the nucleotide sequences of the present invention are provided in expression cassettes for expression in the plant of interest.
- the cassette will include 5' and 3' regulatory sequences operably linked to the gene of interest.
- operably linked refers to DNA sequences on a single DNA molecule which are associated so that the function of one is affected by the other.
- a promoter is operatively associated with a gene of the present invention when it is capable of affecting the expression of the gene of the present invention (i.e. , the gene is under the transcriptional control of the promoter).
- the promoter is said to be "upstream” from the gene, which is in turn said to be “downstream” from the promoter.
- Expression cassettes of the present invention include, 5 '-3' in the direction of transcription, a promoter as discussed above, a gene of the present invention operatively associated with the promoter, and, optionally, a termination sequence including stop signal for RNA polymerase and a polyadenylation signal for polyadenylase (e.g., the nos terminator). All of these regulatory regions should be capable of operating in the cells of the tissue to be transformed.
- the 3' termination region may be derived from the same gene as the transcriptional initiation region or may be derived from a different gene.
- the cassette may additionally contain at least one additional gene to be cotransformed into the organism.
- the gene(s) of interest can be provided on another expression cassette.
- the gene(s) may be optimized for increased expression in the transformed plant.
- the expression cassettes may additionally contain 5' leader sequences in the expression cassette construct.
- leader sequences can act to enhance translation.
- Translation leaders are known in the art and include: picornavirus leaders, for example, EMCV leader (Encephalomyocarditis 5' noncoding region) (Elroy-Stein, O. , Fuerst, T.R. , and Moss, B. (1989) PNAS USA, 56:6126-6130); poty virus leaders, for example, TEV leader (Tobacco Etch Virus) (Allison et al. (1986); MDMV leader (Maize Dwarf Mosaic Virus); Virology, 154:9-20), and human immunoglobulin heavy-chain binding protein (BiP), (Macejak, D.G.
- EMCV leader Engelphalomyocarditis 5' noncoding region
- poty virus leaders for example, TEV leader (Tobacco Etch Virus) (Allison et al. (1986); MDMV leader (Maize Dwar
- MCMV MCMV
- MCMV MCMV
- Other methods known to enhance translation can also be utilized, for example, introns, and the like.
- the various DNA fragments may be manipulated, so as to provide for the DNA sequences in the proper orientation and, as appropriate, in the proper reading frame.
- adapters or linkers may be employed to join the DNA fragments or other manipulations may be involved to provide for convenient restriction sites, removal of superfluous DNA, removal of restriction sites, or the like.
- in vitro mutagenesis, primer repair, restriction, annealing, resection, ligation, PCR, or the like may be employed, where insertions, deletions or substitutions, e.g. transitions and trans versions, may be involved.
- compositions and methods of the present invention can be used to transform any plant, or any portion of a plant thereof. In this manner, genetically modified plants, plant cells, plant tissue, seed, and the like can be obtained.
- Transformation protocols may vary depending on the type of plant or plant cell, i.e. monocot or dicot, targeted for transformation. Suitable methods of transforming plant cells include microinjection (Crossway et al. (1986) Biotechniques 4:320-334), electroporation (Riggs et al. (1986) Proc. Natl. Acad. Sci. USA, 55:5602-5606, Agrobacterium mediated transformation (Hinchee et al. (1988) Biotechnology,
- Plant species may be transformed with the DNA construct of the present invention by the DNA-mediated transformation of plant cell protoplasts and subsequent regeneration of the plant from the transformed protoplasts in accordance with procedures well known in the art.
- organogenesis means a process by which shoots and roots are developed sequentially from meristematic centers;
- embryogenesis means a process by which shoots and roots develop together in a concerted fashion (not sequentially), whether from somatic cells or gametes.
- the particular tissue chosen will vary depending on the clonal propagation systems available for, and best suited to, the particular species being transformed.
- Exemplary tissue targets include leaf disks, pollen, embryos, cotyledons, hypocotyls, megagametophytes, callus tissue, existing meristematic tissue (e.g. , apical meristems, axillary buds, and root meristems), and induced meristem tissue (e.g., cotyledon meristem and hypocotyl meristem).
- Plants of the present invention may take a variety of forms.
- the plants may be chimeras of transformed cells and non-transformed cells; the plants may be clonal transformants (e.g. , all cells transformed to contain the expression cassette); the plants may comprise grafts of transformed and untransformed tissues (e.g.
- Plants which may be employed in practicing the present invention include (but are not limited to) tobacco (Nicotiana tabacum), potato (Solanum tuber osum), soybean (glycine max), peanuts (Arachis hypogaea), cotton (Gossypium hirsutum), sweet potato (Ipomoea batatus), cassava (Manihot esculenta) , coffee (Cofea spp.), coconut (Cocos nucifera), pineapple (Ananas comosus), citrus trees (Citrus spp.), cocoa (Theobroma cacao), tea (Camellia sinensis), banana (Musa spp.), Avocado (Persea americana), Fig (Ficus casica), Guava (Psidium guajava), Mango (Mangifera indica), Olive (Olea europaea), papaya (Carica papaya
- Vegetables include tomatoes (Lycopersicon esculentum), lettuce (e.g. , Lactuea sativa), green beans (Phaseolus vulgaris), lima beans (Phaseolus limensis), peas (Lathy rus spp.) and members of the genus Cucumis such as cucumber (C. sativus), cantaloupe (C.
- Ornamentals include azalea (Rhododendron spp.), hydrangea (Macrophylla hydrangea), hibiscus (Hibiscus rosasanensis) , roses (Rosa spp.), tulips (Tulipa spp.), daffodils (Narcissus spp.), petnunias (Petunia hybrida), carnation (dianthus caryophyllus) , poinsettia (Euphorbia pulcherima), and chyrsanthemum.
- Conifers which may be employed in practicing the present invention include, for example, pines such as loblolly pine (Pinus ⁇ taeda) , slash pine (Pinus ellioti ⁇ ), ponderosa pine (Pinus ponderosa), lodgepole pine (Pinus contona), and Monterey pine (Pinus radiata); Douglas-fir (Pseudotsuga menziesii); Western hemlock (Tsuga canadensis); Sitka spruce (Picea glauca); redwood (Sequoia sempervirens); true firs such as silver fir (Abies amabilis) and balsam fir (Abies balsamea); and cedars such as Western red cedar (Thuja plicat ⁇ ) and Alaska yellow-cedar (Chamaecyparis nootkatensis) .
- pines such as loblolly pine (Pinus ⁇ taeda
- the cells which have been transformed may be grown into plants in accordance with conventional ways. See, for example, McCormick et al. (1986)
- Plant Cell Repo s 5:81-84. These plants may then be grown, and either pollinated with the same transformed strain or different strains, and the resulting hybrid having - lithe desired phenotypic characteristic identified. Two or more generations may be grown to ensure that the subject phenotypic characteristic is stably maintained and inherited and then seeds harvested to ensure the desired phenotype or other property has been achieved.
- a gene encoding resistance to a cercosporin is included in an expression cassette, the gene may be used in combination with a marker gene, which may be useful in one or more hosts, or different markers for individual hosts.
- one marker may be employed for selection in a prokaryotic host, while another marker may be employed for selection in a eukaryotic host, particularly the plant host.
- the markers may be protection against a biocide, such as antibiotics, toxins, heavy metals, or the like; provide complementation, by imparting prototrophy to an auxotrophic host: or provide a visible phenotype through the production of a novel compound in the plant.
- Exemplary genes which may be employed include neomycin phosphotransferase (NPTII), hygromycin phosphotransferase (HPT), chloramphenicol acetyltransf erase (CAT), nitrilase, and the gentamicin resistance gene.
- markers are beta-glucuronidase, providing indigo production, luciferase, providing visible light production, NPTII, providing kanamycin resistance or G418 resistance, HPT, providing hygromycin resistance, and the mutated aroA gene, providing glyphosate resistance.
- NPTII providing indigo production
- NPTII providing kanamycin resistance or G418 resistance
- HPT providing hygromycin resistance
- mutated aroA gene providing glyphosate resistance.
- genes of interest may additionally be included.
- the respective genes may be contained in a single expression cassette, or alternatively in separate cassettes. Methods for construction of the cassettes and transformation methods have been described above.
- the genes of the invention can be manipulated to enhance disease resistance in plants. In this manner, the expression or activity of the gene encoding resistance to cercosporin is altered. Such means for alteration of the gene include co-suppression, antisense, mutagenesis, alteration of the sub-cellular localization of the protein, etc.
- Such promoters include those from pathogenesis-related proteins (PR proteins) which are induced following infection by a pathogen; e.g. , PR proteins, SAR proteins, beta-
- 1,3-glucanase, chitinase, etc. See, for example, Redolfi et al. (1983) Neth. J. Plant Pathol. 59:245-254; Uknes et al. (1992) 77ze Plant Cell 4:645-656; and Van Loon (1985) Plant Mol. Virol. 4: 111-116.
- EXAMPLE 2 Time Course of Cercosporin Degradation
- 1 ml of log phase liquid cultures of XCP-76, XCP-77, and XCZ-1 were inoculated into flasks of LB broth containing 50 ⁇ M cercosporin and incubated in the dark at 28°C. Every 12 hours over a 110 hour period, 5 ml of the growing culture was removed and stored at -20 °C until analyzed. Each sample was extracted with 2 ml acetone and 2 ml chloroform.
- the unidentified compound separated into two spots, one running just ahead of the cercosporin front and one significantly below. No other spots were found that differed from thos from extracts of XCP-76 (non-degrader) grown in cercosporin. These two spots were scraped from TLC plates and the compound analyzed by spectrophotometry, fast atom bombardment (FAB), and separated again on TLC. Compounds from both spots have the same absorbance spectrum with dual peaks at approximately 443 nm and 565 nm. When run a second time on TLC, the eluted compounds migrated to the same point above the cercosporin front. This is strong evidence that the two spots represent the same compound.
- Fast atom bombardment data shows two major peaks at molecular weights 517 and 518 for both spots.
- the appearance of two peaks one mass unit apart may be a result of certain anomalies associated with the FAB procedure.
- a molecular weight of 518 is 16 mass units less than that of cercosporin (534). It can be hypothesized that this indicates a loss of a single oxygen molecule possibly through an initial reduction and then the removal of water.
- the color and spectrum indicate that this compound has the same chromaphore as reduced cercosporin giving the idea that a reduction event is the first step in the degradation process.
- CS-8 Cercospora nicotianae
- Mutant CS-8 was developed in -our laboratory by ultraviolet irradiation.
- XCZ-3 was grown in cercosporin containing malt medium for eight days. The bacteria was removed by centrifugation. Mycelial plugs of CS-8 were inoculated into the cleared media and assayed for growth compared to controls in cercosporin containing medium with no prior bacteria and in control medium.
- EXAMPLE 5 Isolation of genes necessary for cercosporin breakdown with pLAFR-6 It has been established that the " promoters from many X. campestris genes will function normally in E. coli. We will exploit this fact by generating a genomic library of isolate XCZ-3 in pLAFR-6 to be maintained in e. coli strain DH5- a, and plating this library on medium containing cercosporin. We will consider 1,500 individual clones a complete representation of the bacterial genome (C-H. Liao et al., MPMI 9: 14-21 (1996)). Plasmid inserts that confer the ability to degrade cercosporin to E. coli will be isolated and the corresponding gene located.
- the nucleotide and derived amino acid sequence will be analyzed for homology to other sequences using the National Center for Biotechnology Institute BLAST network service.
- the expression patterns of this DNA sequence will be assayed by first identifying promoter sequences and subsequently cloning them in front of the reporter gene sequences for -gaucuronidase (GUS).
- the bacterial cells will then be assayed for enzyme activity over time after incubation in cercosporin containing medium following established protocols (S. Fenselau and U. Bonas, MPMI 8: 845-854 (1995)). Further characterization may include mobilizing the gene coding for cercosporin degradation (under the control of fungal promoters and terminators currently used in our laboratory) into cercosporin sensitive fungi and determining if transformants are no longer sensitive to the toxin.
- PCR will result in DNA fragments containing part of the Tn5 transposon plus flanking DNA representing sequences of the loci that the transposon inserted into (J.
- the DNA is first cut with the restriction enzyme Eco Rl (this enzyme will not cut in the Tn5 transposon), and then circularized by ligating diluted DNA.
- the resulting circular DNA fragments are subjected to PCR cycling reactions following standard protocols using primers designed complementary to and extending outward from the Tn5 transposon (Rich and Willis 1990).
- the amplified DNA will represent sequences into which the transposon inserted.
- the genomic library will be screened for clones carrying the loci of interest by hybridization of the PCR generated DNA fragment. Positively hybridizing clones will be isolated and the gene(s) conferring the cercosporin-degrading phenotype will be identified and characterized as described above. .
- transposon mutagenesis experiments will yield non- degrading mutants with different transposon insertion sites.
- Each gene subsequently identified following the experimental design above, will functionally complement only the mutant strain from which it was initially identified. If this scenario occurs, we will isolate the different genes necessary for cercosporin degradation and dissect the cercosporin degradation pathway while exploring methods to mobilize these into plants.
- the gene(s) that confer the cercosporin degrading phenotype are mobilized into a plant expression cassette maintained in Agrobacterium tumefaciens.
- plasmid vectors that are currently in use in the laboratory (M. Daub et al. Tob. Sci. 38: 51-54 (1994), M. Ni et al., Plant J. 7: 661-676 (1995)).
- These vectors contain eukaryotic promoter (CaMV 35S and A. tumefaciens octopine and mannopine synthase promoters) and terminator (nopoline synthase) sequences allowing for expression of bacterial genes in plants.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU64708/98A AU6470898A (en) | 1997-03-17 | 1998-03-13 | Cercosporin-degrading bacteria |
EP98910473A EP1003838A4 (en) | 1997-03-17 | 1998-03-13 | Cercosporin-degrading bacteria |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US4061497P | 1997-03-17 | 1997-03-17 | |
US60/040,614 | 1997-03-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998041612A1 true WO1998041612A1 (en) | 1998-09-24 |
Family
ID=21911959
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1998/005279 WO1998041612A1 (en) | 1997-03-17 | 1998-03-13 | Cercosporin-degrading bacteria |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1003838A4 (en) |
AU (1) | AU6470898A (en) |
WO (1) | WO1998041612A1 (en) |
ZA (1) | ZA982196B (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991005061A1 (en) * | 1989-09-26 | 1991-04-18 | The Plant Cell Research Institute Incorporated | Methods for identifying cercosporin-degrading microorganisms and producing cercosporin-resistant plant species |
-
1998
- 1998-03-13 EP EP98910473A patent/EP1003838A4/en not_active Withdrawn
- 1998-03-13 AU AU64708/98A patent/AU6470898A/en not_active Abandoned
- 1998-03-13 WO PCT/US1998/005279 patent/WO1998041612A1/en not_active Application Discontinuation
- 1998-03-16 ZA ZA982196A patent/ZA982196B/en unknown
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991005061A1 (en) * | 1989-09-26 | 1991-04-18 | The Plant Cell Research Institute Incorporated | Methods for identifying cercosporin-degrading microorganisms and producing cercosporin-resistant plant species |
US5262306A (en) * | 1989-09-26 | 1993-11-16 | Robeson David J | Methods for identifying cercosporin-degrading microorganisms |
Non-Patent Citations (1)
Title |
---|
See also references of EP1003838A4 * |
Also Published As
Publication number | Publication date |
---|---|
AU6470898A (en) | 1998-10-12 |
EP1003838A1 (en) | 2000-05-31 |
ZA982196B (en) | 1998-10-30 |
EP1003838A4 (en) | 2003-07-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Tu et al. | Transgenic rice variety ‘IR72’with Xa21 is resistant to bacterial blight | |
CA2658926C (en) | Cosmid vector for transforming plant and use thereof | |
CN101182523B (en) | Plants flower pesticide specificity promoter and uses thereof | |
WO1993019181A1 (en) | Biological material | |
CN101421295A (en) | Genes for enhancing nitrogen utilization efficiency in crop plants | |
US20210163973A1 (en) | Plant constitutive expression promoter and applications thereof | |
MXPA02007130A (en) | Novel root preferred promoter elements and methods of use. | |
CN111118053B (en) | Rice fertility regulation and control construct, transformation event and application thereof | |
US20140366219A1 (en) | Increasing Soybean Defense Against Pests | |
EA001039B1 (en) | Method for integrating of exzogenous dna into genome of a plant cell and method for producing fertile transgenic plant integrated into the genome of the exzogenous dna | |
CN101589147A (en) | The maize ERECTA genes for improving plant growth, transpiration efficiency and drought tolerance in crop plants | |
CN101784656B (en) | Nitrate reductases from porphyra, compositions and methods of use thereof | |
US9157087B2 (en) | Inducible plant promoters and the use thereof | |
CN102471779A (en) | The use of dimerization domain component stacks to modulate plant architecture | |
HUT62333A (en) | Process ofr producing herbicide-resistant mutants of acetohydroxy acid synthesis enzyme | |
KR102408985B1 (en) | OsMOR1a gene from Oryza sativa regulating disease resistance of plant and uses thereof | |
CN111534536B (en) | Method for improving rice blast resistance and related biological material thereof | |
JPH11504521A (en) | Plant pathogen resistance gene and use thereof | |
AU2009277515B2 (en) | Plant having resistance to multiple diseases and method for production thereof | |
EP1003838A1 (en) | Cercosporin-degrading bacteria | |
YU et al. | Breeding of selectable marker-free transgenic rice lines containing AP1 gene with enhanced disease resistance | |
US20230392159A1 (en) | Engineering increased suberin levels by altering gene expression patterns in a cell-type specific manner | |
US6063987A (en) | Isolated genes and proteins encoding resistance to photosensitizers | |
Hille et al. | Genetic transformation of tomato and prospects for gene transfer | |
WO1998041082A9 (en) | Isolated genes and proteins encoding resistance to photosensitizers |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AT AU AZ BA BB BG BR BY CA CH CN CU CZ CZ DE DE DK DK EE EE ES FI FI GB GE HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SK TJ TM TR TT UA UG US UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1998910473 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
NENP | Non-entry into the national phase |
Ref country code: JP Ref document number: 1998540747 Format of ref document f/p: F |
|
WWP | Wipo information: published in national office |
Ref document number: 1998910473 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: CA |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1998910473 Country of ref document: EP |