Patent Publication Number: US-2002007501-A1

Title: Receptors for hypersensitive response elicitors and uses thereof

Description:
[0001] This application claims benefit of U.S. Provisional Patent Application Serial No. 60/191,649, filed Mar. 23, 2000 and Ser. No. 60/250,710, filed Dec. 1, 2000. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention relates to receptors for hypersensitive response elicitors and uses thereof.  
       BACKGROUND OF THE INVENTION  
       [0003] Plants have evolved a complex array of biochemical pathways that enable them to recognize and respond to environmental signals, including pathogen infection. There are two major types of interactions between a pathogen and plant—compatible and incompatible. When a pathogen and a plant are compatible, disease generally occurs. If a pathogen and a plant are incompatible, the plant is usually resistant to that particular pathogen. In an incompatible interaction, a plant will restrict pathogen proliferation by causing localized necrosis, or death of tissues, to a small zone surrounding the site of infection. This reaction by the plant is defined as the hypersensitive response (“HR”) (Kiraly, Z. “Defenses Triggered by the Invader: Hypersensitivity,”  Plant Disease: An Advanced Treatise  5:201-224 J. G. Horsfall and E. B. Cowling, eds. Academic Press, New York (1980); (Klement “Hypersensitivity,”  Phytopathogenic Prokarvotes  2:149-177, M. S. Mount and G. H. Lacy, eds. Academic Press, New York (1982)). The localized cell death not only contains the infecting pathogen from spreading further but also leads to a systemic resistance preventing subsequent infections by other pathogens. Therefore, HR is a common form of plant resistance to diseases caused by bacteria, fungi, nematodes, and viruses.  
       [0004] A set of genes designated as hrp (Hypersensitive Response and Pathogenicity) is responsible for the elicitation of the HR by pathogenic bacteria, including Erwinia spp, Pseudomonas spp, Xanthomonas spp, and  Ralstonia solanacearum  (Willis et al. “hrp Genes of Phytopathogenic Bacteria,”  Mol. Plant-Microbe Interact.  4:132-138 (1991), Bonas, U. “hrp Genes of Phytopathogenic Bacteria,” pages 79-98 in: Current Topics in Microbiology and Immunology, Vol. 192, Bacterial Pathogenesis of Plants and Animals: Molecular and Cellular Mechanisms. J. L. Dangl, ed. Springer-Verlag, Berlin (1994); Alfano et al., “Bacterial Pathogens in Plants: Life Up Against the Wall,”  Plant Cell  8:1683-98 (1996). Typically, there are multiple hrp genes clustered in a 30-40 kb DNA. Mutation in any one of the hrp genes will result in the loss of bacterial pathogenicity in host plants and the HR in non-host plants. On the basis of genetic and biochemical characterization, the function of the hrp genes can be classified into three groups: 1) structural genes encoding extracellularlly located HR elicitors, for example harpin of  Erwinia amylovora  (Wei et al. “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85 (1992)); 2) secretion genes encoding a secretory apparatus for exporting HR elicitors and other proteins from the bacterial cytoplasm to the cell surface or extracellular space (Van Gijsegem et al., “Evolutionary Conservation of Pathogenicity Determinants Among Plant and Animal Pathogenic Bacteria,”  Trends Microbiol.  1:175-180 (1993); He et al, “ Pseudomonas syringae  pv. Syringae harpin pss. : A Protein that is Secreted Via the Hrp Pathway and Elicits the Hypersensitive Response in Plants,”  Cell  73:1255 (1993); Wei et al., “HrpI of  Erwinia amylovora  Functions in Secretion of Harpin and is a Member of a New Protein Family,”  J. Bacteriol.  175:7985-67 (1993), Arlat et al. “PopA1, a Protein which Induces a Hypersensitive-Like Response on Specific Petunia Genotypes, is Secreted via the Hrp Pathway of  Pseudomonas solanacearum,” EMBO J.  13:543-53 (1994), Galan et al., “Cross-talk between Bacterial Pathogens and their Host Cells,”  Ann. Rev. Cell Dev. Biol.  12:221-55 (1996); Bogdanove et al., “ Erwinia amylovora  Secretes Harpin via a Type III Pathway and Contains a Homolog of yopN of Yersinia,”  J. Bacteriol.  178:1720-30 (1996); Bogdanove et al., “Homology and Functional Similarity of a hrp-linked Pathogenicity Operon, dspEF, of  Erwinia amylovora  and the avrE locus of  Pseudomonas syringae  pathovar tomato,”  Proc Natl Acad Sci USA  95:1325-30 (1998)); and 3) regulatory genes that control the expression of hrp genes (Wei, Z. M., “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85 (1992); Wei et al., “hrpL Activates  Erwinia amylovora  hrp Genes in Response to Environmental Stimuli,”  J. Bacteriol.  174:1875-82 (1995); Xiao et al., “A Single Promoter Sequence Recognized by a Newly Identified Alternate Sigma Factor Directs Expression of Pathogenicity and Host Range Determinants in  Pseudomonas syringae,” J. Bacterial  176:3089-91 (1994); Kim et al., “The hrpA and hrpC Operons of  Erwinia amylovora  Encode Components of a Type III Pathway that Secrets Harpin,”  J. Bacteriol  179:1690-97 (1997); Kim et al., “HrpW of  Erwinia amylovora , a New Harpin that Contains a Domain Homologous to Pectate Lyases of a Distinct Class,”  J. Bacteriol.  180:5203-10 (1998); Wengelnik et al., “HrpG, A Key hrp Regulatory Protein of Xanthomonas campestris pv. Vesicatoria is Homologous to Two Component Response Regulators,”  Mol. Plant-Microbe Interact.  9:704-12 (1996)). Because of their role in interactions between plants and microbes, hrp genes have been a focus for bacterial pathogenicity and plant defense studies.  
       [0005] In addition to the local defense response, HR also activates the defense system in uninfected parts of the same plant. This results in a general systemic resistance to a secondary infection termed Systemic Acquired Resistance (“SAAR”) (Ross, R. F. “Systemic Acquired Resistance Induced by Localized Virus Infections in Plants,”  Virology  14:340-58 (1961); Malamy et al., “Salicylic Acid and Plant Disease Resistance,”  Plant J.  2:643-654 (1990)). SAR confers long-lasting systemic disease resistance against a broad spectrum of pathogens and is associated with the expression of a certain set of genes (Ward et al. “Coordinate Gene Activity in Response to Agents that Induce Systemic Acquired Resistance,” Plant Cell 3:1085-94 (1991)). SAR is an important component of the disease resistance of plants and has long been of interest, because the potential of inducing the plant to protect itself could significantly reduce or eliminate the need for chemical pesticides. SAR can be induced by biotic (microbes) and abiotic (chemical) agents (Gorlach et al. “Benzothiadiazole, a Novel Class of Inducers of Systemic Acquired Resistance, Activates Gene Expression and Disease Resistance in Wheat,”  Plant Cell  8:629-43 (1996)). Historically, weak virulent pathogens were used as a biotic inducing agent for SAR. Non-virulent plant growth promotion bacteria (PGPR) were also reported to be able to induce resistance of some plants against various diseases. Biotic agent-induced SAR has been the subject of much research, especially in the late 70s and early 80s. Only very limited success was achieved, however, due to: 1) inconsistency of the performance of living organisms in different environmental conditions; 2) considerable concerns regarding the unpredictable consequences of the intentional introduction of weakly virulent pathogens into the environment; and 3) the technical complication of applying a living microorganism into a variety of environmental conditions. To overcome the limitations of using living organisms to induce SAR, scientists have long been looking for an HR elicitor derived from a pathogen for SAR induction. With the advancement of molecular biology, the first proteinaceous HR elicitor with broad host spectrum was isolated in 1992 from  Erwinia amylovora , a pathogenic bacterium causing fire blight in apple and pear. The HR elicitor was named “harpin”. It consists of 403 amino acids with a molecular weight about 40 kDa. The harpin protein is heat-stable and glycine-rich with no cysteine. The gene encoding the harpin protein is contained in a 1.3 kB DNA fragment located in the middle of the hrp gene cluster. Harpin is secreted into the extracellular space and is very sensitive to proteinase digestion. Since the first harpin was isolated from  Erwinia amylovora , several harpin or harpin-like proteins have been isolated from other major groups of plant pathogenic bacteria. In addition to the harpin of  Erwinia amylovora , the following harpin or harpin-like proteins have been isolated and characterized: HrpN of  Erwinia chrysanthemi, Erwinia carotovora  (Wei et al. “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science,  257:85 (1992)), and  Erwinia stewartii ; HrpZ of  Pseudomonas syringae  (He et al, “ Pseudomonas syringae  pv. Syringae harpin pss : A Protein that is Secreted Via the Hrp Pathway and Elicits the Hypersensitive Response in Plants,”  Cell  73:1255 (1993)), PopA of  Ralstonia solanacearum , (Arlat et al. “PopA1, a Protein which Induces a Hypersensitive-Like Response on Specific Petunia Genotypes, is Secreted via the Hrp Pathway of  Pseudomonas solanacearum,” EMBO J.  13:543-53 (1994)); HrpW of  Erwinia amylovora  (Kim et al., “HrpW of  Erwinia amylovora , a New Harpin that Contains a Domain Homologous to Pectate Lyases of a Distinct Class,”  J. Bacteriol.  180:5203-10 (1998)), and  Pseudomonas syringae . All of the currently described harpin or harpin-like proteins share common characteristics. They are heat-stable and glycine-rich proteins with no cysteine amino acid residue, are very sensitive to digestion by proteinases, and elicit the HR and induce resistance in many plants against many diseases. Based on their shared biochemical and biophysical characteristics as well as biological functions, these HR elicitors from different pathogenic bacteria belong to a new protein family—i.e. the harpin protein family. The described characteristics, especially their ability to induce HR in a broad range of plants, distinguish the harpin protein family from other host specific proteinaceous HR elicitors, for example elicitins from Phytophthora spp (Bonnet et al., “Acquired Resistance Triggered by Elicitors in Tobacco and Other Plants,”  Eur. J. Plant Path.  102:181-92 (1996); Keller, et al. “Physiological and Molecular Characteristics of Elicitin-Induced Systemic Acquired Resistance in Tobacco,”  Plant Physiol  110:365-76 (1996)) or avirulence proteins (such as Avr9) from  Cladosporium fulvum , which are only able to elicit the HR in a specific variety or species of a plant.  
       [0006] In nature, when certain bacterial infections occur, harpin protein is expressed and then secreted by the bacteria, signaling the plant to mount a defense against the infection. Harpin serves as a signal to activate plant defense and other physiological systems, which include SAR, growth enhancement, and resistance to certain insect damage.  
       [0007] The current understanding of critical plant molecules that may have a significant role in interacting with elicitors and then triggering a sequential signal transduction cascade is described as follows.  
       [0008] Interaction of Plant Resistance Genes (R) and Pathogen Avirulence Genes (avr)  
       [0009] The concept of gene-for-gene interaction is that “for each gene determining resistance (R gene) in the host, there is a corresponding gene determining avirulence in the pathogen (avr gene)”. In this model, pathogen avirulence genes generate a specific ligand molecule, called an elicitor. Only plants carrying the matching resistance gene respond to this elicitor and invoke the HR. In the past few years, several disease-resistance, R genes, have been cloned and sequenced. It was expected that R genes might encode components involved in signal recognition or signal transduction pathways that ultimately lead to defense responses. The cloned R genes could be grouped into four classes: (1) cytoplasmic protein kinase; (2) protein kinases with an extracellular domain; (3) cytoplasmic proteins with a region of leucine-rich repeats and a nucleotide-binding site; and (4) proteins with a region of leucine-rich repeats that appear to encode extracellular proteins (Review in Bent, A. F. “Plant Disease Resistance Genes: Function Meets Structure,”  Plant Cell  8:1757-71 (1996); Baker B., et al., “Signaling in Plant-Microbe Interactions,”  Science  276:726-33 (1997)). The first R gene cloned, Pto, encodes a serine/threonine protein kinase. The protein product of Pto directly interacts with the cognate avirulence gene protein, AvrPro, which has been demonstrated in a yeast two-hybrid system. It was shown that only co-existence of both AvrPro and Pto proteins could elicit HR in plants (Tang et al., “Initiation of Plant Disease Resistance by Physical Interaction of AvrPto and Pto kinase,”  Science  274:2060-63 (1996); Scofield et al., “Molecular Basis of Gene-for-Gene Specificity in Bacterial Speck Disease of Tomato,”  Science  274:2063-65 (1996); Zhou et al., “The Pto kinase Conferring Resistance to Tomato Bacterial Speck Disease Interacts with Proteins that Bind a cis-element of Pathogenesis-related Genes,”  EMBO J.  16:3207-18 (1997)). The results from cloned R genes support the view that plant-pathogen interactions involve protein-protein interactions. Syringolide, a water-soluble, low-molecular-weight elicitor, triggers a defense response in soybean cultivars carrying the Rpg4 disease-resistance gene. A 34-KDa protein has been isolated from soybean and is considered to be the physiological active syringolide receptor (Ji et al., “Characterization of a 34-kDa Soybean Binding Protein for the syringolide Elicitors,”  Proc. Natl. Acad. Sci. USA  95:3306-11 (1998)).  
       [0010] Putative Binding Factor of Elicitin  
       [0011] Elicitins are a family of small proteins secreted by Phytophthora species that have a high degree of homology. Pure elicitins alone can cause a hypersensitive response, a local cell death, and trigger systemic acquired resistance in tobacco and other plants (Bonnet et al., “Acquired Resistance Triggered by Elicitors in Tobacco and Other Plants,”  Eur. J. Plant Path.  102:181-92 (1996); Keller, et al. “Physiological and Molecular Characteristics of Elicitin-Induced Systemic Acquired Resistance in Tobacco,”  Plant Physiol  110:365-76 (1996)). However, the spectrum of HR elicitation and induced systemic resistance in plants is much narrower than that achieved by harpin family elicitors. Like harpin, elicitins induce a series of metabolic events in tobacco cells, including the accumulation of phytoalexins, ethylene production, transmembrane electrolyte leakage, H 2 O 2  accumulation, and expression of plant defense related genes (Yu L, et al., “Elicitins from Phytophthora and Basic Resistance in Tobacco,”  Proc. Natl.  (1995); Keller et al., “Pathogen-Induced Elicitin Production in Transgenic Tobacco Generates a Hypersensitive Response and Nonspecific Disease Resistance,”  The Plant Cell  11:223-35 (1999)). A putative receptor-like binding factor has been identified in tobacco plasma membrane, which has a specific high-affinity to the crytogein, one member of the elicitin family (Wendehenne, et al., “Evidence for Specific, High-Affinity Binding Sites for a Proteinaceous Elicitor in Tobacco Plasma Membrane,”  FEBS Letters  374:203-207 (1995)). Recently, it was found that 2 basic elicitins (i.e. cryptogein and cinnamomin) and two acidic elicitins (i.e. capsicein and parasiticein) were able to interact with the same binding sites on tobacco plasma membranes (Bourque et al., “Comparison of Binding Properties and Early Biological Effects of Elicitins in Tobacco Cells,”  Plant Physiol.  118:1317-26 (1998)). However, the gene of the receptor-like factor has not been isolated.  
       [0012] Putative Binding Factor of Glycoprotein Elicitors  
       [0013] A 42 kDa glycoprotein elicitor has been isolated from  Phytophthora megasperma  (Parker et al., “An Extracellular Glycoprotein from  Phytophthora megasperma  f. sp.  glycinea  Elicits Phytoalexin Synthesis in Cultured Parsley Cells and Protoplasts,”  Mol. Plant Microbe Interact.  4:19-27 (1991)). An oligopeptide of 13 amino acids within the glycoprotein (“Pep-13”) was able to induce a response in plants like that achieved by the full glycoprotein. A high affinity-binding pattern has been observed in parsley microsomal membranes with an isotope labeled oligopeptide. There are estimated to be about 1600 to 2900 binding sites per cell with evidence indicating that a low abundant protein receptor of the Pep-13 is localized in the plasma membrane (Nurnberger et al., “High Affinity Binding of a Fungal Oligopeptide Elicitor to Parsley Plasma Membranes Triggers Multiple Defense Responses,” Cell 78:449-60 (1994)).  
       [0014] Harpin Protein Binding Factors  
       [0015] Harpin proteins, which elicit HR in a variety of different nonhost plants, have been isolated from plant pathogens (Wei et al. “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85 (1992)). A family of harpin proteins has been identified from plant bacterial pathogens. All of them have similar biological activities. It is well documented that harpin protein can induce plants to produce active oxygen, change ion flux, lead to local cell death, and induce systemic acquired resistance (“SAR”) (Wei et al. “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85 (1992); He et al., “ Pseudomonas syringae  pv.  syringae  Harpin pss : A Protein that is Secreted via the Hrp Pathway and Elicits the Hypersensitive Response in Plants,”  Cell  73:1255-66 (1993); Baker, C. J., et al., “Harpin, an Elicitor of the Hypersensitive Response in Tobacco Caused by  Erwinia amylovora , Elicits Active Oxygen Production in Suspension Cells,”  Plant Physiol.  102:1341-44 (1993)). No harpin protein binding factor has been isolated so -far. It was reported that an amphipathic protein, named HRAP, isolated from sweet pepper could dissociate harpin pss  in multimeric form (hrpZ from  Pseduomonas syringae ). The biological activity of the HRAP is believed to be its ability to intensify harpin pss -mediated hypersensitive response. HRAP protein does not bind to harpinp pss  directly (Chen et al., “An Amphipathic Protein from Sweet Pepper can Dissociate Harpin pss  Multimeric Forms and Intensify the Harpin pss -Mediated Hypersensitive Response,”  Physiological &amp; Molecular Pathology  52:139-49 (1998)). Using a fluorochrome tagged antibody to harpin to examine the interaction of harpin pss  and tobacco suspension cells, it was found that harpin pss  interacted with the cultured cells, but not with protoplasts with the cell walls being digested and removed. It was interpreted that harpin pss  was localized in the outer portion of the plant cell, probably on the cell well. However, it was not ruled out that the binding factor was located on the plasma membrane.  
       [0016] The present invention seeks to identify receptors for hypersensitive response elicitor proteins or polypeptides and uses of such receptors.  
       SUMMARY OF THE INVENTION  
       [0017] The present invention is directed to an isolated protein which serves as a receptor in plants for a plant pathogen hypersensitive response elicitor. Also disclosed are nucleic acid molecules encoding such receptors as well as expression vectors, host cells, transgenic plants, and transgenic plant seeds containing such nucleic acid molecules.  
       [0018] The protein of the present invention can be used with a method of identifying agents targeting plant cells by forming a reaction mixture including the protein and a candidate agent, evaluating the reaction mixture for binding between the protein and the candidate agent, and identifying candidate compounds which bind to the protein in the reaction mixture as plant cell targeting agents.  
       [0019] The nucleic acid molecule of the present invention can be used in a method of identifying agents targeting plant cells by forming a reaction mixture including a cell transformed with the nucleic acid molecule of the present invention and a candidate agent, evaluating the reaction mixture for binding between protein produced by the host cell and candidate agent, and identifying candidate compounds which bind to the protein or the host cell in the reaction mixture as plant cell targeting agents.  
       [0020] Another aspect of the present invention relates to a method of enhancing a plant&#39;s receptivity to treatment with hypersensitive response elicitors by providing a transgenic plant or transgenic plant seed transformed with the nucleic acid molecule of the present invention.  
       [0021] The present invention is also directed to a method of imparting disease resistance, enhancing growth, controlling insects, and/or imparting stress resistance to plants by providing a transgenic plant or transgenic plant seed transformed with a DNA construct effective to silence expression of a nucleic acid molecule encoding a receptor in accordance with the present invention.  
       [0022] The discovery of the present invention has great significance. This putative receptor protein can be used as a novel way to screen for new inducers of plant resistance against insect, disease, and stress, and of growth enhancement. This protein is the first step toward the understanding of the harpin induced signal transduction pathway in plants. Further studies of this pathway will provide more possible targets for new plant vaccine and growth enhancement products development. In addition, this protein can serve as an anchor providing a new way to target anything to the plant cells. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0023]FIG. 1 shows a yeast two-hybrid screening with the  Erwinia amylovora  hypersensitive response elicitor (i.e. harpin) and a schematic representation of the interaction between harpin and a cDNA encoded polypeptide. Harpin is fused to LexA protein which contains a DNA binding domain (“BD”). The cDNA encoded polypeptide is fused to the GAL4 transcription activation domain (“AD”). This interaction targets the activation domain to two different LexA-dependent promoters with consequent activation of the transcription of the HIS3 and lacZ reporter genes.  
     [0024] FIGS.  2 A-B show that the  Erwinia amylovora  hypersensitive response elicitor (i.e. harpin) is a good yeast two-hybrid bait. Reporter genes were not expressed in yeast strain L40 containing plasmids expressing the LexA-harpin fusion in combination with plasmids expressing the GAL4 activation domain alone, or fused to unrelated protein. Therefore, harpin is not autoactive in this yeast two-hybrid system. In addition, reporter genes were not expressed in yeast strain L40 containing plasmids expressing the GAL4 activation domain-harpin fusion in combination with plasmids expressing LexA alone, or fused to unrelated protein. FIG. 2A shows a β-galactosidase assay where blue color indicates the expression of lacZ reporter gene.  
     [0025]FIG. 2B shows a synthetic minimal (“SD”) media plate which lacks leucine, tryptophan, and histidine. Growth on such a plate indicates the expression of the HIS3 reporter gene.  
     [0026] FIGS.  3 A-B show the interaction between HrBP1 (hypersensitive response elicitor binding protein 1) and a hypersensitive response elicitor (i.e. harpin) is specific. Reporter genes were expressed in yeast strain L40 containing plasmids expressing the GAL4 activation domain-HrBP1 fusion in combination with plasmids expressing LexA fused to hypersensitive response elicitor (i.e. harpin), but were not expressed in combination with LexA alone, or LexA fused to unrelated proteins.  
     [0027]FIG. 3A is a β-galactosidase assay where the blue color indicates the expression of lacZ reporter gene.  
     [0028]FIG. 3B is an SD media plate which lacks leucine, tryptophan, and histidine. Growth on such a plate indicates the expression of the HIS3 reporter gene.  
     [0029] FIGS.  4 A-B show the interaction of HrBP1 and a hypersensitive response elicitor (i.e. harpin) in another orientation. Reporter genes were expressed in yeast strain L40 containing plasmids expressing the LexA-HrBP1 fusion in combination with plasmids expressing GAL4 activation domain fused to harpin, but were not expressed in combination with GAL4 activation domain alone, or GAL4 activation domain fused to unrelated proteins. Therefore, interaction between harpin and HrBP1 is specific.  
     [0030]FIG. 4A shows a β-galactosidase assay where blue color indicates the expression of lacZ reporter gene.  
     [0031]FIG. 4B shows an SD media plate which lacks leucine, tryptophan, and histidine. Growth on such a plate indicates the expression of the HIS3 reporter gene.  
     [0032]FIG. 5 shows the gene structure of HrBP 1 and a schematic representation of the exons and introns of the HrBP1 gene. When comparing the HrBP1 cDNA sequence with the  Arabidopsis thaliana  genomic DNA sequence published in a public database, four exons and three introns were discovered.  
     [0033]FIG. 6 shows a Northern blot using RNA probe complementary to bases 651-855 of HrBP1 coding region (SEQ. ID. No. 9).  
     [0034] FIGS.  7 A-B show that the interaction between rHrBP1 (R6) and harpin is specific. Reporter genes were expressed in yeast strain L40 containing plasmids expressing the GAL4 activation domain-rHrBP1 fusion in combination with plasmids expressing LexA fused to harpin or harpin 137-180 amino acids, but were not expressed in combination with LexA alone, LexA fused to unrelated proteins, or fused to harpin 210-403 amino acids.  
     [0035]FIG. 7A shows a β-galactosidase assay where blue color indicates the expression of lacZ reporter gene.  
     [0036]FIG. 7B shows a SD media plate, which lacks leucine, tryptophan, and histidine. Growth on such a plate indicates the expression of the HIS3 reporter gene.  
     [0037]FIG. 8 shows the constructs used to “knockout” HrBP1 gene in Arabidopsis.  
     [0038] FIGS.  9 A-C show a  Pseudomonas syringae  p.v. tomato DC3000 assay on wild type and HrBP1 “knockout” transgenic Arabidopsis plants. FIG. 9A is a picture taken 7 days after  P. syringae  inoculation.  
     [0039] In FIG. 9B, leaf disks were harvested. Bacteria were extracted from leaf disks and plated onto King&#39;s B agar plate containing 100 μg/ml rifampicin.  
     [0040]FIG. 9C shows the bacteria count from plates in FIG. 9B. This signifies an anti-sense line and d refers to a double-stranded RNA line.  
     [0041]FIG. 10 shows the construct used to overexpress HrBP1 in tobacco.  
     [0042] FIGS.  11 A-B show the height of wild type and HrBP1 overexpressing tobacco plants 52 days after they were transferred to soil.  
     [0043]FIG. 11A is a picture taken 52 days after plants were transferred to soil.  
     [0044]FIG. 11B shows average height of 8 plants per line.  
     [0045] FIGS.  12 A-B show a TMV assay results on wild type and HrBP1 overexpressing tobacco plants. FIG. 12A is a picture taken 3 days after TMV inoculation. FIG. 12B shows the average virus lesion diameter from 5 plants per line 3 days after TMV inoculation. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0046] The present invention is directed to isolated receptors for hypersensitive response elicitor proteins or polypeptides. Also disclosed are DNA molecules encoding such receptors as well as expression systems, host cells, and plants containing such molecules. Uses of the receptors themselves and the DNA molecules encoding them are disclosed. The receptor for a hypersensitive response elicitor from a plant pathogen can be from a monocot or a dicot.  
     [0047] One example of such a receptor is that found in  Arabidopsis thaliana  which has the amino acid sequence of SEQ. ID. No. 1 as follows:  
                          Met Ala Thr Ser Ser Thr Phe Ser Ser Leu Leu Pro Ser Pro Pro Ala             1               5                  10                  15       Leu Leu Ser Asp His Arg Ser Pro Pro Pro Ser Ile Arg Tyr Ser Phe                   20                  25                  30       Ser Pro Leu Thr Thr Pro Lys Ser Ser Arg Leu Gly Phe Thr Val Pro                35                  40                  45       Glu Lys Arg Asn Leu Ala Ala Asn Ser Ser Leu Val Glu Val Ser Ile            50                  55                  60       Gly Gly Glu Ser Asp Pro Pro Pro Ser Ser Ser Gly Ser Gly Gly Asp        65                  70                  75                  80       Asp Lys Gln Ile Ala Leu Leu Lys Leu Lys Leu Leu Ser Val Val Ser                        85                  90                  95       Gly Leu Asn Arg Gly Leu Val Ala Ser Val Asp Asp Leu Glu Arg Ala                   100                 105                 110       Glu Val Ala Ala Lys Glu Leu Glu Thr Ala Gly Gly Pro Val Asp Leu               115                 120                 125       Thr Asp Asp Leu Asp Lys Leu Gln Gly Lys Trp Arg Leu Leu Tyr Ser           130                 135                 140       Ser Ala Phe Ser Ser Arg Ser Leu Gly Gly Ser Arp Pro Gly Leu Pro       145                 150                 155                 160       Thr Gly Arg Leu Ile Pro Val Thr Lau Gly Gln Val Phe Gln Arg Ile                       165                 170                 175       Asp Val Phe Ser Lys Asp Phe Asp Asn Ile Ala Glu Val Glu Leu Gly                   180                 185                 190       Ala Pro Trp Pro Phe Pro Pro Leu Glu Ala Thr Ala Thr Leu Ala His               195                 200                 205       Lys Phe Glu Leu Leu Gly Thr Cys Lys Ile Lys Ile Thr Phe Glu Lys           210                 215                 220       Thr Thr Val Lys Thr Ser Gly Asn Leu Ser Gln Ile Pro Pro Phe Asp       225                 230                 235                 240       Ile Pro Arg Lau Pro Asp Ser Phe Arg Pro Ser Ser Asn Pro Gly Thr                       245                 250                 255       Gly Asp Phe Glu Val Thr Tyr Val Asp Asp Thr Met Arg Ile Thr Arg                   260                 265                 270       Gly Asp Arg Gly Glu Leu Arg Val Phe Val Ile Ala               275                 280          
 
     [0048] This protein, known as HrBP1p, is encoded by a cDNA molecule having SEQ. ID. No. 2 as follows:  
                              tttttccttc tcaacaatgg cgacttcttc tactttctcg tcactactac cttcaccacc   60           agctcttctt tccgaccacc gttctcctcc accatccatc agatactcct tttctccctt   120       aactactcca aaatcgtctc gtttgggttt cactgtaccg gagaagagaa acctagctgc   180       taattcgtct ctcgttgaag tatccattgg cggagaaagt gacccaccac catcatcatc   240       tggatcagga ggagacgaca agcaaattgc attactcaaa ctcaaattac ttagtgtagt   300       ttcgggatta aacagaggac ttgtggcgag tgttgatgat ttagaaagag ctgaagtggc   360       tgctaaagaa cttgaaactg ctgggggacc ggttgattta accgatgatc ttgataagct   420       tcaagggaaa tggaggctgt tgtatagtag tgcgttctct tctcggtctt taggtggtag   480       ccgtcctggt ctacctactg gacgtttgat ccctgttact cttggccagg tgtttcaacg   540       gattgatgtg tttagcaaag attttgataa catagcagag gtggaattag gagccccttg   600       gccatttccg ccattagaag ccactgcgac attggcacac aagtttgaac tcttaggcac   660       ttgcaagatc aagataacat ttgagaaaac aactgtgaag acatcgggaa acttgtcgca   720       gattcctccg tttgatatcc cgaggcttcc cgacagtttc agaccatcgt caaaccctgg   780       aactggggat ttcgaagtta cctatgttga tgataccatg cgcataactc gcggggacag   840       aggtgaactt agggtattcg tcattgctta attctcaaag ctttgacatg taaagataaa   900       taaatacttt ctgcttgatg cagtctcatg agttttgtac aaatcatgtg aacatataaa   960       tgcgctttat aagtaaatga gtgtcttgtt caatgaatca   1000          
 
     [0049] The genomic DNA molecule containing the receptor encoding cDNA molecule of SEQ. ID. No. 2 has SEQ. ID. No. 3 as follows:  
                              aattagaaaa attaacaacc aacatctagt tagaatattt aatttgcacc aatgtcttcg   60           agtatagtga aaaaaataga agatcgaata tcgaatagta cgtatagaat catctagatc   120       cattcgaact aacgtctact tttcttttcc agcattaaca tgtagcttgt cattagcatt   180       tacatgttgc aaataacaca aattgggaaa ttgaaagact aaaaaacctt gtacagcaga   240       tggtttaaca cgtggattca tggacacaaa cagaaaacgg cagaactaag cacaaaaacg   300       tcaactaagc atatcaaagc ttttaatgca aycctaatat aaacacaagt ggttatccat   360       aatctgttct taatctcttg cagtagttat cttttcatta ttcgcaattc gcaattctat   420       attcttatat ttcaacttgt tcttcttcca aattgtaatt atatctacat cgtcttagct   480       tgaccattat agctccaqta ccaagttctc ttcttaactt taatatcagc tactattctc   540       atactgtaaa tatcttttgt tcaccaaaca tatatttcga accaaactgc taaaagctta   600       tcataaattg cagttctaqc cacacaattt tgcayttcca accattaaat gccacaaaat   660       ttggacgatt tcttaagaca agaagaacat agcaaccaaa ccttattgat taaatatgaa   720       atgtctccat aaaactggga gatttcccca aataaaqaqa acacggcaaa tyttcacgta   780       atctccaaga tgaatgttta attttttctt tcagaaaaaa acaaaaaaac ttaactcaat   840       atagacaact agaatggata ccaactaagc aaaagaaatt caaaagacaa atatatattg   900       gatatgaagt tacattattt tcaaacttta tatactacta aaagcctaaa aatttgttct   960       aaaatgatat ccaaataaat ggaaggcatg aatgtcatat gactaaaaga gaaaaacaca   1020       cctgtatata agtattggat catgctgcct ccgagtgaca aaacatacya tgtgggtctt   1080       tattgggcca tacttaaatg gaaaaaggag aaaaaaaatt gggcaatgtc tatggtcgaa   1140       atttatatgt tttacatcaa taaaatcaat atttaatttt atatatgtqg gtcttaatct   1200       agtattatct acatagatta aaatcaaagt actgcatatg gtccataata atacaaccaa   1260       agcaaattaa aattttgtgg cacaaaacga catcatttta ctcagaaagt aatatgcaat   1320       ttcgtttacg cacacacgta tacgcgctaa taacccgtgg tgcttctcaa atcacataat   1380       aattaaagtc ttcttcttct tcttcttctc tacaaattat ctcactctct tcgttttttt   1440       ttccttctca acaatggcga cttcttctac tttctcgtca ctactacctt caccaccagc   1500       tcttctttcc gaccaccgtt ctcctccacc atccatcaga tactcctttt ctcccttaac   1560       tactccaaaa tcgtctcgtt tgggtttcac tgtaccggag aagagaaacc tcgctgctaa   1620       ttcgtctctc gttgaagtat ccattggcgg agaaagtgac ccaccaccat catcatctgg   1680       atcaggagga gacgacaagc aaattgcatt actcaaactc aaattacttg tgagtctgat   1740       tcaaaccaat cggtgaaatt ataagaaatt ggtttcgttt ctttggaatt agggtttata   1800       ttactgttaa gattcgatta tagagtgaat tttgggaaga tttttcagat ttgatttgtg   1860       atgtgttgtg ttgtgagaaa ttgcagagtq tagtttcggg attaaacaga ggacttgtgg   1920       cgagtgttga tgatttagaa agaqctgaag tggctgctaa agaacttgaa actgctgggg   1980       gaccggttga tttaaccgat gatcttgata agcttcaagg gaaatggagg ctgttgtata   2040       gtagtgcgtt ctcttctcgg tctttaggtg gtagccgtcc tgqtctacct actggacgtt   2100       tgatccctgt tactcttggc caggtaattc ttgaatcatt gctctgtttt tacccgtcaa   2160       gattcggttt ttcgggtaag ttgttgagga gtttatgtgc atggtctagt ctatcatcaa   2220       tagtcttgct tgagtttgaa tggggctgag ctaagaatct agctttctga ggttacaatt   2280       tggtaatgtc atcttatact cgaaagcaaa cttttttcta tattgtcaag tttatgtgta   2340       cggtctggtc tatcattggt agtctttgtt gagcttgaat ggtgaggagc ttagaatcta   2400       qcaatgtcat ctactcctta atcatttttt tctatattgc caagtttatg tgtacggtct   2460       tagtcaatca tctttattct tggttgagtt tgaatggtga tgagcttaga atctagcttt   2520       ctttggttta aatttggcaa agaaccatac ctgaatcggt agaaagcaaa cttctttaat   2580       attatctctt gtttctgaat cattaaaaca ggtgtttcaa cggattgatg tgtttagcaa   2640       agattttgat aacatagcag aggtgyaatt aggagcccct tggccattta cgccattaga   2700       agccactgcg acattggcac acaagtttga actcttaggt ttgcatttcc ctttctctca   2760       ttaagtttat cgaattgtgt aagagcaaaa taacttatct gtatctttga catttatggg   2820       gaaaacaggc acttgcaaga tcaagataac atttgagaaa acaactgtga agacatcggg   2880       aaacttgtcg cagattcctc cgtttgatat cccgaggctt cccgacagtt tcagaccatc   2940       gtcaaaccct ggaactgggg atttcgaagt tacctatgtt catgatacca tgcgcataac   3000       tcgcggggac agaggtgaac ttagggtatt cgtcattgct taattctcaa agctttgaca   3060       tgtaaagata aataaatact ttctgcttga tgcagtctca tgagttttgt acaaatcatg   3120       tgaacatata aatgcgcttt ataagtaaat gagtgtcttg ttcaatgaat catatgaaag   3180       aatttgtatg actcagaaaa ttggacaatg atatagacct tccaaatttt gcaccctcta   3240       atgtgagata ttagtgattt tttcttaggt tggtagagag aacggattgg caaaaaaata   3300       tcgaaggtca atgattaaca gcaaaaccat atcttgatga ttcaaaatat agagttaaca   3360       agcaaagatg agacaatctt atacgagaga gctaaaacaa atggattcca aatccagcaa   3420       gtacaaaaat cgcagaaaat aagatgaaac caacttaaaa cagagatgtt ccctttccct   3480       tcttgtcacc accgatctcg aaatgcttgc acctctgaaa taaacaacaa accaacacaa   3540       tgtaagcaaa ttaacaagtt acaaatccgg tataatgaac tgatctatgt tctatgcacc   3600       ttgataggac gctgcgaaaa gtgcttgcag ctttgacact gaagcctcaa aacaatcttc   3660       ttcgtggtct taycctgtta acaagattca caagatgtat ctcagtccaa aactgagact   3720       attggaatgt ctgtttcctc acagctcact tacaaaattc tactataaat ggttccttaa   3780       aactacctca tttcaactaa ctagacctaa ttcaaactya aaaaacaatc aatgcatgat   3840       aatcaatgtt acctttttgt ggaagacagg cttagtctga ccaccataac cagattgttt   3900       acggtcataa cgacgctttc cttgagcagc aagactgtat ttacccttct tgtattgggt   3960       aaccttgtgc aaagtatgct ttttgcattc cttgttctta cagtaagtgt tctttgtctt   4020       tggaatgttc accttcaaaa ttcataaaat caaaaatgaa tcactcacac acatacaaaa   4080       tcaagagact tttaaggtta atcaaaatac aaacatcatt tagattgaaa acttttatga   4140       tagatctgaa aaacaataca ataaatcaat caaccatgta ttgttgttct tcaaagtcaa   4200       cgaactttac aaattccaaa atcacatcga aagagaagaa acaatttace attttcgcgt   4260          
 
     [0050] Another example of a receptor in accordance with the present invention is that found in rice which has a partial amino acid sequence of SEQ. ID. No. 4 as follows:  
                          Val Ala Ala Leu Lys Val Lys Leu Leu Ser Ala Val Ser Gly Leu Asn             1               5                  10                  15       Arg Gly Leu Ala Gly Ser Gln Glu Asp Leu Asp Arg Ala Asp Ala Ala                    20                  25                  30       Ala Arg Glu Leu Glu Ala Ala Ala Gly Gly Gly Pro Val Asp Leu Glu                35                  40                  45       Arg Asp Val Asp Lys Leu Gln Gly Arg Trp Arg Leu Val Tyr Ser Ser            50                  55                  60       Ala Phe Ser Ser Ary Thr Leu Gly Gly Ser Arg Pro Gly Pro Pro Thr        65                  70                  75                  80       Gly Arg Leu Leu Pro Ile Thr Leu Gly Gln Val Phe Gln Arg Ile Asp                        85                  90                  95       Val Val Ser Lys Asp Phe Asp Asn Ile Val Asp Val Glu Leu Gly Ala                   100                 105                 110       Pro Trp Pro Leu Pro Pro Val Glu Leu Thr Ala Thr Leu Ala His Lys               115                 120                 125       Phe Glu Ile Ile Gly Thr Ser Ser Ile Lys Ile Thr Phe Asp Lys Thr           130                 135                 140       Thr Val Lys Thr Lys Gly Asn Leu Ser Gln Leu Pro Pro Leu Glu Val       145                 150                 155                 160       Pro Arg Ile Pro Asp Asn Len Arg Pro Pro Ser Asn Thr Gly Ser Gly                       165                 170                 175       Glu Phe Glu Val Thr Tyr Leu Asp Gly Asp Thr Arg Ile Thr Arg Gly                   180                 185                 190       Asp Arg Gly Glu Leu Arg Val Phe Val Ile Ser               195                 200          
 
     [0051] This protein, known as R6p, is encoded by a cDNA molecule which has a partial sequence corresponding to SEQ. ID. No. 5 as follows:  
                              cgtggctgcg ctcaaagtca agcttctgag cgcggtgtcc gggctgaacc gcggcctcgc   60           ggggagccag gaggatcttg accgcgccga cgcggcggcg cgggagctcg aggcggcggc   120       gggtggcggc cccgtcgacc tggagaggga cgtggacaag ctgcaggggc ggtggaggct   180       ggtgtacagc agcgcgttct cgtcgcggac gctcggcggc agccgccccg gcccgcccac   240       cggccgcctc ctccccatca ccctcgggca ggtgtttcag aggatcgatg ttgtcagcaa   300       ggacttcgac aacatcgtcg atgtcgagct cggcgcgcca tggccgctgc cgccggtgga   360       gctgacggcg accctggctc acaagtttga gatcatcggc acctcgagca taaagatcac   420       attcgacaag acgacggtga agacgaaggg gaacctgtcc cagctgccgc cgctggaggt   480       ccctcgcatc ccggacaacc tccggccgcc gtccaacacc ggcagcggcg agttcgaggt   540       gacctacctc gacggcgaca cccgcatcac ccgcggggac agaggggagc tcagggtgtt   600          
 
     [0052] Hypersensitive response elicitors recognized by the receptors of the present invention are able to elicit local necrosis in plant tissue contacted by the elicitor.  
     [0053] Examples of suitable bacterial sources of hypersensitive response elicitor polypeptides or proteins include Erwinia, Pseudomonas, and Xanthamonas species (e.g., the following bacteria:  Erwinia amylovora, Erwinia chrysantliemi, Erwinia stewartii, Erwinia carotovora, Pseudomonas syringae, Pseudomonas solancearum, Xanthomonas campestris , and mixtures thereof).  
     [0054] An example of a fungal source of a hypersensitive response elicitor protein or polypeptide is Phytophthora. Suitable species of Phytophthora include  Phytophthora parasitica, Phytophthora cryptogea, Phytophthora cinnamomi, Phytophthora capsici, Phytophthora megasperma , and  Phytophthora citrophthora.    
     [0055] The hypersensitive response elicitor polypeptide or protein from  Erwinia chrysanthemi  is disclosed in U.S. Pat. No. 5,850,015 and U.S. Pat. No. 6,001,959, which are hereby incorporated by reference. This hypersensitive response elicitor polypeptide or protein has a molecular weight of 34 kDa, is heat stable, has a glycine content of greater than 16%, and contains substantially no cysteine.  
     [0056] The hypersensitive response elicitor polypeptide or protein derived from  Erwinia amylovora  has a molecular weight of about 39 kDa, has a pI of approximately 4.3, and is heat stable at 100° C. for at least 10 minutes. This hypersensitive response elicitor polypeptide or protein has a glycine content of greater than 21% and contains substantially no cysteine. The hypersensitive response elicitor polypeptide or protein derived from  Erwinia amylovora  is more fully described in U.S. Pat. No. 5,849,868 to Beer and Wei, Z. -M., et al., “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85-88 (1992), which are hereby incorporated by reference.  
     [0057] The hypersensitive response elicitor polypeptide or protein derived from  Pseudomonas syringae  has a molecular weight of 34-35 kDa. It is rich in glycine (about 13.5%) and lacks cysteine and tyrosine. Further information about the hypersensitive response elicitor derived from  Pseudomonas syringae  and its encoding DNA molecule is found in U.S. Pat. Nos. 5,708,139 and 5,858,786 and He et al., “ Pseudomonas syringae  pv.  syringae  Harpin pss : A Protein that is Secreted via the Hrp Pathway and Elicits the Hypersensitive Response in Plants,”  Cell  73:1255-66 (1993), which are hereby incorporated by reference.  
     [0058] The hypersensitive response elicitor polypeptide or protein derived from  Pseudomonas solanacearum  is set forth in Arlat, M., F. Van Gijsegem, J. C. Huet, J. C. Pemollet, and C. A. Boucher, “PopA1, a Protein which Induces a Hypersensitive-like Response in Specific Petunia Genotypes, is Secreted via the Hrp Pathway of  Pseudomonas solanacearum,” EMBO J.  13:543-533 (1994), which is hereby incorporated by reference. This protein has 344 amino acids, a molecular weight of 33.2 kDa, and a pI of 4.16, is heat stable and glycine rich (20.6%).  
     [0059] The hypersensitive response elicitor polypeptide or protein from  Xanthomonas campestris  pv. glycines has a partial amino acid sequence corresponding to SEQ. ID. No. 6 as follows:  
                          Thr Leu Ile Glu Leu Met Ile Val Val Ala Ile Ile Ala Ile Leu Ala             1               5                  10                  15       Ala Ile Ala Leu Pro Ala Tyr Gln Asp Tyr                    20                  25          
 
     [0060] This sequence is an amino terminal sequence having only 26 residues from the hypersensitive response elicitor polypeptide or protein of  Xanthomonas campestris  pv. glycines. It matches with fimbrial subunit proteins determined in other  Xanthomonas campestris  pathovars.  
     [0061] The hypersensitive response elicitor polypeptide or protein from  Xanthomonas campestris  pv.  pelargonii  is heat stable, protease sensitive, and has a molecular weight of 20 kDa. It has the amino acid sequence of SEQ. ID. No. 7 as follows:  
                          Met Asp Ser Ile Gly Asn Asn Phe Ser Asn Ile Gly Asn Leu Gln Thr             1               5                  10                  15       Met Gly Ile Gly Pro Gln Gln His Glu Asp Ser Ser Gln Gln Ser Pro                    20                  25                  30       Ser Ala Gly Ser Glu Gln Gln Leu Asp Gln Leu Leu Ala Met Phe Ile                35                  40                  45       Met Met Met Leu Gln Gln Ser Gln Gly Ser Asp Ala Asn Gln Glu Cys            50                 55                   60       Gly Asn Glu Gln Pro Gln Asn Gly Gln Gln Glu Gly Leu Ser Pro Leu        65                  70                  75                  80       Thr Gln Met Leu Met Gln Ile Val Met Gln Leu Met Gln Aen Gln Gly                        85                  90                  95       Gly Ala Gly Met Gly Gly Gly Gly Ser Val Asn Ser Ser Leu Gly Gly                   100                 105                 110       Asn Ala          
 
     [0062] This amino acid sequence is encoded by the nucleotide sequence of SEQ. ID. No. 8 as follows:  
                              atggactcta tcggaaacaa cttttcgaat atcggcaacc tgcagacgat gggcatcggg   60           cctcagcaac acgaggactc cagccagcag tcgccttcgg ctggctccga gcagcagctg   120       gatcagttgc tcgccatgtt catcatgatg atgctgcaac agagccaggg cagcgatgca   180       aatcaggagt gtggcaacga acaaccgcag aacggtcaac aggaaggcct gagtccgttg   240       acgcagatgc tgatgcagat cgtgatgcag ctgatgcaga accagggcgg cgccggcatg   300       ggcggtggcg gttcggtcaa cagcagcctg ggcggcaacg cc   342          
 
     [0063] Isolation of  Erwinia carotovora  hypersensitive response elictor protein or polypeptide is described in Cui et al., “The RsmA Mutants of  Erwinia carotovora subsp.  carotovora  Strain Ecc7l Overexpress hrp N Ecc  and Elicit a Hypersensitive Reaction-like Response in Tobacco Leaves,”  MPMI,  9(7):565-73 (1996), which is hereby incorporated by reference. This protein has 356 amino acids, a molecular weight of 35.6 kDa, and a pI of 5.82 and is heat stable and glycine rich (21.3%).  
     [0064] The hypersensitive response elicitor protein or polypeptide of  Erwinia stewartii  is set forth in Ahmad et al., “Harpin is Not Necessary for the Pathogenicity of  Erwinia stewartii  on Maize,” 8 th Int&#39;l. Cong. Molec. Plant - Microbe Interact. , Jul. 14-19, 1996 and Ahmad, et al., “Harpin is Not Necessary for the Pathogenicity of  Erwinia stewartii  on Maize,”  Ann. Mtg. Am. Phytopath. Soc. , Jul. 27-31, 1996, which are hereby incorporated by reference.  
     [0065] Hypersensitive response elicitor proteins or polypeptides from  Phytophthora parasitica, Phytophthora cryptogea, Phytophthora cinnamoni, Phytophthora capsici, Phytophthora megasperma , and  Phytophora citrophthora  are described in Kaman, et al., “Extracellular Protein Elicitors from Phytophthora: Most Specificity and Induction of Resistance to Bacterial and Fungal Phytopathogens,”  Molec. Plant-Microbe Interact.,  6(1):15-25 (1993), Ricci et al., “Structure and Activity of Proteins from Pathogenic Fungi Phytophthora Eliciting Necrosis and Acquired Resistance in Tobacco,”  Eur. J. Biochem.,  183:555-63 (1989), Ricci et al., “Differential Production of Parasiticein, and Elicitor of Necrosis and Resistance in Tobacco, by Isolates of Phytophthora parasitica,” Plant Path. 41:298-307 (1992), Baillreul et al, “A New Elicitor of the Hypersensitive Response in Tobacco: A Fungal Glycoprotein Elicits Cell Death, Expression of Defence Genes, Production of Salicylic Acid, and Induction of Systemic Acquired Resistance,”  Plant J.,  8(4):551-60 (1995), and Bonnet et al., “Acquired Resistance Triggered by Elicitors in Tobacco and Other Plants,” Eur. J. Plant Path., 102:181-92 (1996), which are hereby incorporated by reference. These hypersensitive response elicitors from Phytophthora are called eliciting. All known elicitins have 98 amino acids and show &gt;66% sequence identity. They can be classified into two groups, the basic elicitins and the acidic eliciting, based on the physicochemical properties. This classification also corresponds to differences in the eliciting&#39; ability to elicit HR-like symptoms. Basic elicitins are 100 times more effective than the acidic ones in causing leaf necrosis on tobacco plants.  
     [0066] The hypersensitive response elicitor from Gram positive bacteria like  Clavibacter michiganesis  is described in WO 99/11133, which is hereby incorporated by reference.  
     [0067] The above elicitors are exemplary. Other elicitors can be identified by growing fungi or bacteria that elicit a hypersensitive response using conditions under which genes encoding an elicitor are expressed. Cell-free preparations from culture supernatants can be tested for elicitor activity (i.e. local necrosis) by using them to infiltrate appropriate plant tissues.  
     [0068] Turning again to the receptor of the present invention for such hypersensitive response elicitors, fragments of the above receptor protein are encompassed by the method of the present invention. In addition, fragments of fill length receptor proteins from other plants can also be utilized.  
     [0069] Suitable fragments can be produced by several means. In the first, subclones of the gene encoding a known receptor protein are produced by conventional molecular genetic manipulation by subcloning gene fragments. The subclones then are expressed in vitro or in vivo in bacterial cells to yield a smaller protein or peptide that can be tested for receptor activity according to the procedure described above.  
     [0070] As an alternative, fragments of a receptor protein can be produced by digestion of a full-length receptor protein with proteolytic enzymes like chymotrypsin or Staphylococcus proteinase A, or trypsin. Different proteolytic enzymes are likely to cleave receptor proteins at different sites based on the amino acid sequence of the receptor protein. Some of the fragments that result from proteolysis may be active receptors.  
     [0071] In another approach, based on knowledge of the primary structure of the receptor protein, fragments of the receptor protein gene may be synthesized by using the PCR technique together with specific sets of primers chosen to represent particular portions of the protein. These then would be cloned into an appropriate vector for expression of a truncated peptide or protein.  
     [0072] Chemical synthesis can also be used to make suitable fragments. Such a synthesis is carried out using known amino acid sequences for the receptor being produced. Alternatively, subjecting a full length receptor to high temperatures and pressures will produce fragments. These fragments can then be separated by conventional procedures (e.g., chromatography, SDS-PAGE).  
     [0073] Variants may be made by, for example, the deletion or addition of amino acids that have minimal influence on the properties, secondary structure, and hydropathic nature of the polypeptide. For example, a polypeptide may be conjugated to a signal (or leader) sequence at the N-terminal end of the protein which co-translationally or post-translationally directs transfer of the protein. The polypeptide may also be conjugated to a tag or other sequence for ease of synthesis, purification, or identification of the polypeptide.  
     [0074] Suitable DNA molecules are those that hybridize to a DNA molecule comprising a nucleotide sequence of 50 continuous bases of SEQ. ID. No. 2 under stringent conditions characterized by a hybridization buffer comprising 0.9M sodium citrate (“SSC”) buffer at a temperature of 37° C. and remaining bound when subject to washing with the SSC buffer at 37° C.; and preferably in a hybridization buffer comprising 20% formamide in 0.9M saline/0.09M SSC buffer at a temperature of 42° C. and remaining bound when subject to washing at 42° C. with 0.2× SSC buffer at 42° C.  
     [0075] The receptor of the present invention is preferably produced in purified form (preferably at least about 60%, more preferably 80%, pure) by conventional techniques. Typically, the receptor of the present invention is produced but not secreted into the growth medium of recombinant host cells. Alternatively, the receptor protein of the present invention is secreted into growth medium. In the case of unsecreted protein, to isolate the receptor protein, the host cell (e.g.,  E. coli ) carrying a recombinant plasmid is propagated, lysed by sonication, or chemical treatment, and the homogenate is centrifuged to remove bacterial debris. The cell lysate can be further purified by conventionally utilized chromatography procedures (e.g., gel filtration in an appropriately sized dextran or polyacrylamide column to separate the receptor protein). If necessary, the protein fraction may be further purified by ion exchange or HPLC.  
     [0076] The DNA molecule encoding the receptor protein can be incorporated in cells using conventional recombinant DNA technology. Generally, this involves inserting the DNA molecule into an expression system to which the DNA molecule is heterologous (i.e. not normally present). The heterologous DNA molecule is inserted into the expression system or vector in sense orientation and correct reading frame. The vector contains the necessary elements for the transcription and translation of the inserted protein-coding sequences.  
     [0077] U.S. Pat. No. 4,237,224 to Cohen and Boyer, which is hereby incorporated by reference, describes the production of expression systems in the form of recombinant plasmids using restriction enzyme cleavage and ligation with DNA ligase. These recombinant plasmids are then introduced by means of transformation and replicated in unicellular cultures including procaryotic organisms and eucaryotic cells grown in tissue culture.  
     [0078] Recombinant genes may also be introduced into viruses, such as vaccina virus. Recombinant viruses can be generated by tranfection of plasmids into cells infected with virus.  
     [0079] Suitable vectors include, but are not limited to, the following viral vectors such as lambda vector system gt11, gt WES.tB, Charon 4, and plasmid vectors such as pBR322, pBR32S, pACYC177, pACYC1084, pUC8, pUC9, pUC18, pUC19, pLG339, pR290, pKC37, pKC101, SV 40, pBluescript 11 SK +/− or KS +/− (see “Stratagene Cloning Systems” Catalog (1993) from Stratagene, La Jolla, Calif., which is hereby incorporated by reference), pQE, pIH821, pGEX, pET series (see F. W. Studier et. al., “Use of T7 RNA Polymerase to Direct Expression of Cloned Genes,”  Gene Expression Technology  vol. 185 (1990), which is hereby incorporated by reference), and any derivatives thereof. Recombinant molecules can be introduced into cells via transformation, transduction, conjugation, mobilization, or electroporation. The DNA sequences are cloned into the vector using standard cloning procedures in the art, as described by Sambrook et al.,  Molecular Cloning: A Laboratory Manual , Cold Springs Laboratory, Cold Springs Harbor, N.Y. (1989), which is hereby incorporated by reference.  
     [0080] A variety of host-vector systems may be utilized to express the protein-encoding sequence(s). Primarily, the vector system must be compatible with the host cell used. Host-vector systems include but are not limited to the following: bacteria transformed with bacteriophage DNA, plasmid DNA, or cosmid DNA; microorganisms such as yeast containing yeast vectors; mammalian cell systems infected with virus (e.g., vaccinia virus, adenovirus, etc.); insect cell systems infected with virus (e.g., baculovirus); and plant cells infected by bacteria. The expression elements of these vectors vary in their strength and specificities. Depending upon the host-vector system utilized, any one of a number of suitable transcription and translation elements can be used.  
     [0081] Different genetic signals and processing events control many levels of gene expression (e.g., DNA transcription and messenger RNA (mRNA) translation).  
     [0082] Transcription of DNA is dependent upon the presence of a promotor which is a DNA sequence that directs the binding of RNA polymerase and thereby promotes mRNA synthesis. The DNA sequences of eucaryotic promotors differ from those of procaryotic promoters. Furthermore, eucaryotic promoters and accompanying genetic signals may not be recognized in or may not function in a procaryotic system, and, further, procaryotic promotors are not recognized and do not function in eucaryotic cells.  
     [0083] Similarly, translation of mRNA in procaryotes depends upon the presence of the proper procaryotic signals which differ from those of eucaryotes. Efficient translation of mRNA in procaryotes requires a ribosome binding site called the Shine-Dalgarno (“SD”) sequence on the mRNA. This sequence is a short nucleotide sequence of mRNA that is located before the start codon, usually AUG, which encodes the amino-terminal methionine of the protein. The SD sequences are complementary to the 3′-end of the 16S rRNA (ribosomal RNA) and probably promote binding of mRNA to ribosomes by duplexing with the rRNA to allow correct positioning of the ribosome. For a review on maximizing gene expression, see Roberts and Lauer,  Methods in Enzymology,  68:473 (1979), which is hereby incorporated by reference.  
     [0084] Promotors vary in their “strength” (i.e. their ability to promote transcription). For the purposes of expressing a cloned gene, it is desirable to use strong promotors in order to obtain a high level of transcription and, hence, expression of the gene. Depending upon the host cell system utilized, any one of a number of suitable promotors may be used. For instance, when cloning in  E. coli , its bacteriophages, or plasmids, promotors such as the T7 phage promoter, lac promotor, trp promotor, recA promotor, ribosomal RNA promotor, the P R  and P L  promotors of coliphage lambda and others, including but not limited, to lacUV5, ompF, bla, lpp, and the like, may be used to direct high levels of transcription of adjacent DNA segments. Additionally, a hybrid trp-lacUV5 (tac) promotor or other  E. coli  promoters produced by recombinant DNA or other synthetic DNA techniques may be used to provide for transcription of the inserted gene.  
     [0085] Bacterial host cell strains and expression vectors may be chosen which inhibit the action of the promotor unless specifically induced. In certain operations, the addition of specific inducers is necessary for efficient transcription of the inserted DNA. For example, the lac operon is induced by the addition of lactose or IPTG (isopropylthio-beta-D-galactoside). A variety of other operons, such as trp, pro, etc., are under different controls.  
     [0086] Specific initiation signals are also required for efficient gene transcription and translation in procaryotic cells. These transcription and translation initiation signals may vary in “strength” as measured by the quantity of gene specific messenger RNA and protein synthesized, respectively. The DNA expression vector, which contains a promotor, may also contain any combination of various “strong” transcription and/or translation initiation signals. For instance, efficient translation in  E. coli  requires an SD sequence about 7-9 bases 5′ to the initiation codon (“ATG”) to provide a ribosome binding site. Thus, any SD-ATG combination that can be utilized by host cell ribosomes may be employed. Such combinations include but are not limited to the SD-ATG combination from the cro gene or the N gene of coliphage lambda, or from the  E. coli  tryptophan E, D, C, B or A genes. Additionally, any SD-ATG combination produced by recombinant DNA or other techniques involving incorporation of synthetic nucleotides may be used.  
     [0087] Once the isolated DNA molecule encoding the receptor protein has been cloned into an expression system, it is ready to be incorporated into a host cell. Such incorporation can be carried out by the various forms of transformation noted above, depending upon the vector/host cell system. Suitable host cells include, but are not limited to, bacteria, virus, yeast, mammalian cells, insect, plant, and the like.  
     [0088] One aspect of the present invention involves enhancing a plant&#39;s receptivity to treatment with a hypersensitive response elicitor by providing a transgenic plant or transgenic plant seed, transformed with a nucleic acid molecule encoding a receptor protein for a hypersensitive response elicitor. It has been found that hypersensitive response elicitors are useful in imparting disease resistance to plants, enhancing plant growth, effecting insect control and/or imparting stress resistance in a variety of plants. In view of the receptor of the present invention&#39;s interaction with such elicitors, it is expected that these beneficial effects would be enhanced by carrying out such elicitor treatments with plants transformed with the receptor encoding gene of the present invention.  
     [0089] Transgenic plants containing a gene encoding a receptor in accordance with the present invention can be prepared according to techniques well known in the art.  
     [0090] A vector containing the receptor encoding gene described above can be microinjected directly into plant cells by use of micropipettes to transfer mechanically the recombinant DNA. Crossway,  Mol. Gen. Genetics,  202:179-85 (1985), which is hereby incorporated by reference. The genetic material may also be transferred into the plant cell using polyethylene glycol. Krens, et al.,  Nature,  296:72-74 (1982), which is hereby incorporated by reference.  
     [0091] Another approach to transforming plant cells with a gene is particle bombardment (also known as biolistic transformation) of the host cell. This can be accomplished in one of several ways. The first involves propelling inert or biologically active particles at cells. This technique is disclosed in U.S. Pat. Nos. 4,945,050, 5,036,006, and 5,100,792, all to Sanford et al., which are hereby incorporated by reference. Generally, this procedure involves propelling inert or biologically active particles at the cells under conditions effective to penetrate the outer surface of the cell and to be incorporated within the interior thereof. When inert particles are utilized, the vector can be introduced into the cell by coating the particles with the vector containing the heterologous DNA. Alternatively, the target cell can be surrounded by the vector so that the vector is carried into the cell by the wake of the particle. Biologically active particles (e.g., dried bacterial cells containing the vector and heterologous DNA) can also be propelled into plant cells.  
     [0092] Yet another method of introduction is fusion of protoplasts with other entities, either minicells, cells, lysosomes, or other fusible lipid-surfaced bodies. Fraley, et al.,  Proc. Natl. Acad. Sci. USA,  79:1859-63 (1982), which is hereby incorporated by reference.  
     [0093] The DNA molecule may also be introduced into the plant cells by electroporation. Fromm et al.,  Proc. Natl. Acad. Sci. USA,  82:5824 (1985), which is hereby incorporated by reference. In this technique, plant protoplasts are electroporated in the presence of plasmids containing the expression cassette. Electrical impulses of high field strength reversibly permeabilize biomembranes allowing the introduction of the plasmids. Electroporated plant protoplasts reform the cell wall, divide, and regenerate.  
     [0094] Another method of introducing the DNA molecule into plant cells is to infect a plant cell with  Agrobacterium tumefaciens  or  A. rhizogenes  previously transformed with the gene. Under appropriate conditions known in the art, the transformed plant cells are grown to form shoots or roots, and develop further into plants. Generally, this procedure involves inoculating the plant tissue with a suspension of bacteria and incubating the tissue for 48 to 72 hours on regeneration medium without antibiotics at 25-28° C.  
     [0095] Agrobacterium is a representative genus of the gram-negative family Rhizobiaceae. Its species are responsible for crown gall ( A. tumefaciens ) and hairy root disease ( A. rhizogenes ). The plant cells in crown gall tumors and hairy roots are induced to produce amino acid derivatives known as opines, which are catabolized only by the bacteria. The bacterial genes responsible for expression of opines are a convenient source of control elements for chimeric expression cassettes. In addition, assaying for the presence of opines can be used to identify transformed tissue. Heterologous genetic sequences can be introduced into appropriate plant cells, by means of the Ti plasmid of  A. tumefaciens  or the Ri plasmid of  A. rhizogenes . The Ti or Ri plasmid is transmitted to plant cells on infection by Agrobacterium and is stably integrated into the plant genome. J. Schell,  Science,  237:1176-83 (1987), which is hereby incorporated by reference.  
     [0096] After transformation, the transformed plant cells must be regenerated.  
     [0097] Plant regeneration from cultured protoplasts is described in Evans et al.,  Handbook of Plant Cell Cultures, Vol.  1: (MacMillan Publishing Co., New York, 1983); and Vasil I. R. (ed.), Cell Culture and Somatic Cell Genetics of Plants, Acad. Press, Orlando, Vol. 1, 1984, and Vol. III (1986), which are hereby incorporated by reference.  
     [0098] It is known that practically all plants can be regenerated from cultured cells or tissues, including but not limited to, all major species of sugarcane, sugar beets, cotton, fruit trees, and legumes.  
     [0099] Means for regeneration vary from species to species of plants, but generally a suspension of transformed protoplasts or a petri plate containing transformed explants is first provided. Callus tissue is formed and shoots may be induced from callus and subsequently rooted. Alternatively, embryo formation can be induced in the callus tissue. These embryos germinate as natural embryos to form plants. The culture media will generally contain various amino acids and hormones, such as auxin and cytokinins. It is also advantageous to add glutamic acid and proline to the medium, especially for such species as corn and alfalfa. Efficient regeneration will depend on the medium, on the genotype, and on the history of the culture. If these three variables are controlled, then regeneration is usually reproducible and repeatable.  
     [0100] After the expression cassette is stably incorporated in transgenic plants, it can be transferred to other plants by sexual crossing. Any of a number of standard breeding techniques can be used, depending upon the species to be crossed.  
     [0101] Once transgenic plants of this type are produced, the plants themselves can be cultivated in accordance with conventional procedures. Alternatively, transgenic seeds or propagules (e.g., cuttings) are recovered from the transgenic plants. The seeds can then be planted in the soil and cultivated using conventional procedures to produce transgenic plants. The transgenic plants are propagated from the planted transgenic seeds.  
     [0102] These elicitor treatment methods can involve applying the hypersensitive response elicitor polypeptide or protein in a non-infectious form to all or part of a plant or a plant seed transformed with a receptor gene in accordance with the present invention under conditions effective for the elicitor to impart disease resistance, enhance growth, control insects, and/or to impart stress resistance. Alternatively, the hypersensitive response elicitor protein or polypeptide can be applied to plants such that seeds recovered from such plants themselves are able to impart disease resistance in plants, to enhance plant growth, to effect insect control, and/or to impart resistance to stress.  
     [0103] As an alternative to applying a hypersensitive response elicitor polypeptide or protein to plants or plant seeds in order to impart disease resistance in plants, to effect plant growth, to control insects, and/or to impart stress resistance in the plants or plants grown from the seeds, transgenic plants or plant seeds can be utilized. When utilizing transgenic plants, this involves providing a transgenic plant transformed with both a DNA molecule encoding a receptor in accordance with the present invention and with a DNA molecule encoding a hypersensitive response elicitor polypeptide or protein. The plant is grown under conditions effective to permit the DNA molecules to impart disease resistance to plants, to enhance plant growth, to control insects, and/or to impart resistance to stress. Alternatively, a transgenic plant seed transformed with a DNA molecule encoding a hypersensitive response elicitor polypeptide or protein and a DNA molecule encoding a receptor can be provided and planted in soil. A plant is then propagated from the planted seed under conditions effective to permit the DNA molecules to impart disease resistance to plants, to enhance plant growth, to control insects, and/or to impart resistance to stress.  
     [0104] The embodiment where the hypersensitive response elicitor polypeptide or protein is applied to the plant or plant seed can be carried out in a number of ways, including: 1) application of an isolated elicitor or 2) application of bacteria which do not cause disease and are transformed with a gene encoding the elicitor. In the latter embodiment, the elicitor can be applied to plants or plant seeds by applying bacteria containing the DNA molecule encoding the hypersensitive response elicitor polypeptide or protein. Such bacteria must be capable of secreting or exporting the elicitor so that the elicitor can contact plant or plant seeds cells. In these embodiments, the elicitor is produced by the bacteria in planta or on seeds or just prior to introduction of the bacteria to the plants or plant seeds.  
     [0105] The hypersensitive response elicitor treatment can be utilized to treat a wide variety of plants or their seeds to impart disease resistance, enhance growth, control insects, and/or impart stress resistance. Suitable plants include dicots and monocots. More particularly, useful crop plants can include: alfalfa, rice, wheat, barley, rye, cotton, sunflower, peanut, corn, potato, sweet potato, bean, pea, chicory, lettuce, endive, cabbage, brussel sprout, beet, parsnip, turnip, cauliflower, broccoli, turnip, radish, spinach, onion, garlic, eggplant, pepper, celery, carrot, squash, pumpkin, zucchini, cucumber, apple, pear, melon, citrus, strawberry, grape, raspberry, pineapple, soybean, tobacco, tomato, sorghum, and sugarcane. Examples of suitable ornamental plants are:  Arabidopsis thaliana , Saintpaulia, petunia, pelargonium, poinsettia, chrysanthemum, carnation, and zinnia.  
     [0106] With regard to the use of hypersensitive response elicitors in imparting disease resistance, absolute immunity against infection may not be conferred, but the severity of the disease is reduced and symptom development is delayed. Lesion number, lesion size, and extent of sporulation of fungal pathogens are all decreased. This method of imparting disease resistance has the potential for treating previously untreatable diseases, treating diseases systemically which might not be treated separately due to cost, and avoiding the use of infectious agents or environmentally harmful materials.  
     [0107] The method of imparting pathogen resistance to plants is useful in imparting resistance to a wide variety of pathogens including viruses, bacteria, and fungi. Resistance, inter alia, to the following viruses can be achieved by the method of the present invention: Tobacco mosaic virus and Tomato mosaic virus. Resistance, inter alia, to the following bacteria can also be imparted to plants  Pseudomonas solancearum; Pseudomonas syringae  pv.  tabaci ; and  Xanthamonas campestris  pv.  pelargonii . Plants can be made resistant, inter alia, to the following fungi:  Fusarium oxysporum  and  Phytophthora infestans.    
     [0108] With regard to the use of the hypersensitive response elicitor protein or polypeptide to enhance plant growth, various forms of plant growth enhancement or promotion can be achieved. This can occur as early as when plant growth begins from seeds or later in the life of a plant. For example, plant growth according to the present invention encompasses greater yield, increased quantity of seeds produced, increased percentage of seeds germinated, increased plant size, greater biomass, more and bigger fruit, earlier fruit coloration, and earlier fruit and plant maturation. As a result, there is significant economic benefit to growers. For example, early germination and early maturation permit crops to be grown in areas where short growing seasons would otherwise preclude their growth in that locale. Increased percentage of seed germination results in improved crop stands and more efficient seed use. Greater yield, increased size, and enhanced biomass production allow greater revenue generation from a given plot of land.  
     [0109] The use of hypersensitive response elicitors for insect control encompasses preventing insects from contacting plants to which the hypersensitive response elicitor has been applied, preventing direct insect damage to plants by feeding injury, causing insects to depart from such plants, killing insects proximate to such plants, interfering with insect larval feeding on such plants, preventing insects from colonizing host plants, preventing colonizing insects from releasing phytotoxins, etc. The present invention also prevents subsequent disease damage to plants resulting from insect infection.  
     [0110] Elicitor treatment is effective against a wide variety of insects. European corn borer is a major pest of corn (dent and sweet corn) but also feeds on over 200 plant species including green, wax, and lima beans and edible soybeans, peppers, potato, and tomato plus many weed species. Additional insect larval feeding pests which damage a wide variety of vegetable crops include the following: beet armyworm, cabbage looper, corn ear worm, fall armyworm, diamondback moth, cabbage root maggot, onion maggot, seed corn maggot, pickleworm (melonworm), pepper maggot, tomato pinworm, and maggots. Collectively, this group of insect pests represents the most economically important group of pests for vegetable production worldwide.  
     [0111] Hypersensitive response elicitor treatment is also useful in imparting resistance to plants against environmental stress. Stress encompasses any enviromnental factor having an adverse effect on plant physiology and development. Examples of such environmental stress include climate-related stress (e.g., drought, water, frost, cold temperature, high temperature, excessive light, and insufficient light), air pollution stress (e.g., carbon dioxide, carbon monoxide, sulfur dioxide, NO x , hydrocarbons, ozone, ultraviolet radiation, acidic rain), chemical (e.g., insecticides, fungicides, herbicides, heavy metals), and nutritional stress (e.g., fertilizer, micronutrients, macronutrients).  
     [0112] The application of the hypersensitive response elicitor polypeptide or protein can be carried out through a variety of procedures when all or part of the plant is treated, including leaves, stems, roots, etc. This may (but need not) involve infiltration of the hypersensitive response elicitor polypeptide or protein into the plant. Suitable application methods include high or low pressure spraying, injection, and leaf abrasion proximate to when elicitor application takes place. When treating plant seeds or propagules (e.g., cuttings), the hypersensitive response elicitor protein or polypeptide can be applied by low or high pressure spraying, coating, immersion, or injection. Other suitable application procedures can be envisioned by those skilled in the art provided they are able to effect contact of the elicitor with cells of the plant or plant seed. Once treated with a hypersensitive response elicitor, the seeds can be planted in natural or artificial soil and cultivated using conventional procedures to produce plants. After plants have been propagated from seeds treated with an elicitor, the plants may be treated with one or more applications of the hypersensitive response elicitor protein or polypeptide to impart disease resistance to plants, to enhance plant growth, to control insects on the plants, and/or to impart stress resistance.  
     [0113] The hypersensitive response elicitor polypeptide or protein can be applied to plants or plant seeds alone or in a mixture with other materials. Alternatively, the elicitor can be applied separately to plants with other materials being applied at different times.  
     [0114] A composition suitable for treating plants or plant seeds contains a hypersensitive response elicitor polypeptide or protein in a carrier. Suitable carriers include water, aqueous solutions, slurries, or dry powders.  
     [0115] Although not required, this composition may contain additional additives including fertilizer, insecticide, fungicide, nematacide, and mixtures thereof. Suitable fertilizers include (NH 4 ) 2 NO 3 . An example of a suitable insecticide is Malathion. Useful fungicides include Captan.  
     [0116] Other suitable additives include buffering agents, wetting agents, coating agents, and abrading agents. In addition, the hypersensitive response elicitor can be applied to plant seeds with other conventional seed formulation and treatment materials, including clays and polysaccharides.  
     [0117] In the alternative technique involving the use of transgenic plants and transgenic seeds encoding a hypersensitive response elicitor encoding gene, a hypersensitive response elicitor need not be applied topically to the plants or seeds. Instead, transgenic plants transformed with a DNA molecule encoding such an elicitor are produced according to procedures well known in the art as described above.  
     [0118] In another embodiment, the present invention relates to a DNA construct which is an antisense nucleic acid molecule to a nucleic acid molecule encoding a receptor in plants for plant pathogen hypersensitive response elicitors. An example of such a construct would be an antisense DNA molecule of the DNA molecule having the nucleotide sequence of SEQ. ID. Nos. 2 or 3. Alternatively, the DNA construct can have a DNA molecule having the nucleotide sequence of SEQ. ID. Nos. 2 or 3 (or a portion thereof) and its complementary strand and is used to generate a single transcript with an inverted repeat (i.e. a double-stranded) RNA. This transcript as well as the above-discussed antisense nucleic acid molecule can be used to induce silencing of a nucleic acid molecule encoding a receptor for a hypersensitive response elicitor.  
     [0119] Sensing the hypersensitive response elicitor by the receptor is the very first step of the signal transduction pathway in plants which eventually leads to disease resistance, growth enhancement, insect control, and stress resistance. Silencing the receptor provides a powerful tool to find and study the downstream components of this pathway. Additionally, the receptor could be a negative regulator of such plant signal transduction pathway. Silencing of the receptor will impart to plants the ability to resist disease and stress, control insects, and enhance growth without hypersensitive response elicitor treatment.  
     EXAMPLES  
     Example 1  
     Materials and Methods  
     [0120] The laboratory technique used in the following example is straight forward. All DNA manipulations described here followed conventional protocols (Sambrook et al., “Molecular Cloning: A Laboratory Manual,” 2 nd  ed., Cold Spring Harbor Laboratory (1989); Ausubel, et al., “Current Protocols in Molecular Biology,” John Wiley (1987), which are hereby incorporated by reference). The plasmids and microorganisms described herein, used for making the present invention, were obtained from commercial sources, or from the authors of previous publications. Sequences were analyzed with Clone Manager 5 (Scientific &amp; Educational Software, Durham, N.C.).  
     [0121] Yeast strain L40 was grown in YPD or in different minimal synthetic dropout selection media at 30° C.  E. coli  strains DH5α and HB101 were grown in LB at 37° C.  
     [0122] The yeast Two-Hybrid system is based on the fact that many eukaryotic transcription factors are composed of a physically separable, functionally independent DNA-binding domain (DNA-BD) and an activation domain (AD). Both the DNA-BD and the AD are required to activate a gene. When physically separated by recombinant DNA technology and expressed in the same host cell, the DNA-BD and the AD do not interact directly with each other and, thus, cannot activate the responsive gene (Ma, et al., “Converting a Eukaryotic Transcriptional Inhibitor into an Activator,”  Cell  55:443 (1988) and Brent, et al., “A Eukaryotic Transcriptional Activator Bearing the DNA Specificity of a Prokaryotic Repressor,”  Cell  43:729 (1985), which are hereby incorporated by reference). But if the DNA-BD and the AD are brought into close physical proximity in the promoter region, the transcriptional activation function will be restored. Therefore, the yeast  Saccharomyces cerevisiae  and the Two-Hybrid system have become essential genetic tools for studying the macromolecular interactions.  
     [0123] In the Two-Hybrid system utilized here, the DNA-BD, encoded in the bait vector pVJL11 (Jullien-Flores, V., “Bridging Ral GTPase to Rho Pathways. RLIP76, a Ral Effector with CDC42/Rac GTPase-activating Protein Activity,”  J. Biol. Chem.  27:22473 (1995), which is hereby incorporated by reference), is the prokaryotic LexA protein, and the activation domain, encoded in the prey vector pGAD 10 or pGAD GH (Clontech; Hannon, GJ., “Isolation of the Rb-related p130 Through its Interaction with CDK2 and Cyclins,”  Genes Dev.  7:2378 (1993), which is hereby incorporated by reference) is derived from the yeast GAL4 protein. pVJL11 also has a TRP1 marker, and the pGAD a LEU2 marker. An interaction between the bait protein (fused to the DNA-BD) and a library-encoded protein (fused to the AD) creates a novel transcriptional activator with binding affinity for LexA operators. The yeast host L40 {MATa his3D200 trp1-901 leu2-3, 112 ade2 LYS2::(lexAop) 4 -HIS3 URA3::(lexAop) 8 -lacZ} harbors two reporter genes, lacZ and HIS3, which contain upstream LexA binding site. The HIS3 nutritional reporter provides a sensitive growth selection that can identify a single positive transformant out of several million candidate clones. The expression of the reporter genes indicates interaction between a candidate protein and the bait protein. See FIG. 1.  
     [0124] Erwinia amylovora  harpin was used as the bait protein to screen the  Arabidopsis thaliana  MATCHMAKER cDNA library cloned in the pGAD 10 vector (Clontech Laboratories, Inc., Palo Alto, Calif.). One cDNA library encoded protein was identified as a strong harpin interacting protein and, thus, a putative harpin receptor. The present invention reports the nucleic acid sequence and the deduced amino acid sequence of this cDNA.  
     Example 2  
     [0125] HrpN of  Erwinia amylovora  was subcloned into the yeast Two-Hybrid bait vector pVJL11. PCR was carried out using the 1.3 Kb harpin fragment (Wei et al., “Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen  Erwinia amylovora,” Science  257:85 (1992), which is hereby incorporated by reference) as a template to amplify the harpin encoding region. A Bam HI site was added to the 5′ end of the coding sequence, and a Sal I site to the 3′ end. A Bam HI and Sal I digested PCR fragment was ligated with the bait vector pVJL11 digested with the same restriction enzymes. pVJL11 has a TRP1 marker to be selected in yeast and an Amp resistance marker to be selected in  E. coli . The plasmid DNA was amplified in  E. coli  strain DH5α. When tested in the Two-Hybrid system with empty prey vector pGAD GH and several unrelated proteins, HrpN didn&#39;t show auto-activation or nonspecific interaction with unrelated proteins, as shown in FIG. 2.  
     Example 3  
     [0126] HrpN-pVJL 11 was transformed into yeast strain L40 by a lithium acetate (LiAc)-mediated method (Ito et al., “Transformation of Intact Yeast Cells Treated with Alkali Cations,”  J. Bacteriol.  153:163 (1983) and Vojtek et al., “Mammalian Ras Interacts Directly with the Serine/Threonine Kinase Raf.,”  Cell  74:205 (1993), which are hereby incorporated by reference). The Arabidopsis thaliana MATCHMAKER cDNA library (Clontech Laboratories, Inc., Palo Alto, Calif.) was screened for harpin interacting proteins. Approximately 6.8 million primary library transformants were plated onto plates lacking histidine, leucine, and tryptophan. A total of 148 colonies grew on the histidine dropout plates, 55 of which stained positive when tested for expression of β-galactosidase. After three rounds of selection on synthetic minimal (SD) media plates lacking leucine, tryptophan, and histidine, and confirming by the expression of the second reporter gene lacZ using a β-galactosidase assay, 47 colonies seemed to be strong interacting candidates.  
     Example 4  
     [0127] Plasmid DNA was extracted from the 47 independent yeast colonies and shuttled into  E. coli  strain HB101, which carries the leuB mutation. Therefore, the prey plasmid (cDNA-pGAD 10) was selected for on minimal nutrient plates since pGAD 10 bears the LEU2 marker.  
     [0128] The 47 independently rescued prey plasmids purified from  E. coli  were re-tested in the yeast two-hybrid system with harpin as bait. They were also tested against unrelated proteins. 25 turned out to be interacting candidates, 20 of which were strong specific interacting candidates. Sequencing analysis showed that the 20 independent cDNA clones were actually from the same gene with different integrity at the 5′ end. The sequence reactions were performed using the PE Prism BigDye™ dye terminator reaction kit. The sequencing gel was run in Thatagen (Bothell, Wash.).  
     [0129] One of the eight plasmids, which had the longest cDNA insert of 1 kb, was used for further analysis. When co-transformed into yeast strain L40, it was shown to be negative with empty bait and unrelated proteins in the Two-Hybrid system, indicating the specificity of the interaction between harpin and this receptor candidate. See FIG. 3.  Example  5  
     [0130] The longest cDNA insert, HrBP1, was subcloned into the Bam HI and SalI sites of the bait vector pVJL 11. This construct didn&#39;t show auto-activation of the reporter genes, nor interaction with unrelated proteins in the yeast Two-Hybrid system. However, the expression of the reporter genes was activated when L40 was co-transformned with HrBPl-pVJL11 and HrpN-pGAD GH, indicating the specific interaction between HrBP1p (the protein encoded by HrBP1) and harpin. See FIG. 4.  
     Example 6  
     [0131] Total RNA was extracted from two-week-old  Arabidopsis thaliana  using QIAGEN RNeasy plant mini kit (Qiagen, Inc., Valencia, Calif.). Poly A +  RNA was further purified from the total RNA with a QIAGEN Oligotex column (Qiagen, Inc., Valencia, Calif.). A Northern blot was carried out using the translated region of HrBP1 as a probe. One single species with an apparent molecular weight of about 1.1 Kb was detected from both total RNA and Poly A +  RNA. Therefore, the longest cDNA of HrBP1 from the yeast two-hybrid screen seems to be the full-length cDNA. The integrity of the 5′ of cDNA was further confirmed by a primer extension assay.  
     [0132] As described, a yeast Two-Hybrid system was used to screen for harpin interacting proteins. HrpN of  Erwinia amylovora  was subcloned into the yeast Two-Hybrid bait vector pVJL11, which has a TRP1 marker. The lexA harpin fusion protein is expressed from this construct in yeast. The  Arabidopsis thaliana  MATCHMAKER cDNA library (Clontech Laboratories, Inc., Palo Alto, Calif.) was screened for hypersensitive response elicitor interacting proteins. 6.8 million independent colonies were screened, and HrBP1 was identified as a strong specific harpin interacting candidate. HrBP 1 was mapped to  Arabidopsis thaliana  genomic DNA, chromosome 3, P1 clone MLM24 (Nakamura, “Structural Analysis of  Arabidopsis thaliana  chromosome 3,” Direct submission to the DDBJ/EMBL/GenBank databases (1998), which is hereby incorporated by reference). Four exons and three introns were discovered (See FIG. 5). Exon 4 includes a 130 bp non-translated 3′ region. The in-frame open reading frame from the first methionine encodes a polypeptide (named HrBP1p) of 284 amino acids. The predicted molecular weight of HrBP1p is 30454.3 and pI is 5.72. There is no apparent hydrophobic trans-membrane domain in this polypeptide. SMART Simple Modular Architecture Research Tool (V3.1) predicted the first 18 amino acids as a signal sequence. The HrBP1-AD fusion prey was negative with empty bait and unrelated proteins in the yeast 2-H system, indicating the specificity of the interaction between harpin and this receptor candidate. When being put in the opposite orientation, i.e. HrBP1p fused with the DNA-BD and harpin with the AD, they still specifically interacted with each other.  
     [0133] HrBP1 has no significant sequence similarity with sequences deposited in major sequence database accessible with the Blast search program. Therefore, HrBP1p is a novel protein.  
     Example 7  
     [0134] The HrBP1 cDNA was subcloned into the Nde I and Sal I sites of the vector pET-28a (Novagen, Madison, Wis.). HrBP1p was expressed from this vector in  E. coli  as a His-tagged protein and purified with Ni-NTA resion (QIAGEN Inc., Valencia, Calif.) according to the manual provided by the manufacturer. This recombinant protein increased harpin&#39;s ability to induce HR in tobacco plants. His-tag removed HrBP1 recombinant protein was used to generate anti-HrBP1 antibody to facilitate biochemical and functional studies of HrBP1. Preliminary localization study using anti-HrBP1 antibody in a Western blot showed that HrBP1p exists everywhere in Arabidopsis, including its leaves, stems, and roots.  
     Example 8  
     [0135] 10 μg of total RNA from 14 different plant species was separated on 1% agarose gel, and then transferred to Amersham Hybond NX membrane (Amersham Pharmacia Biotech, Piscataway, N.J.). The RNA probe, which was complementary to bases 651-855 of HrBP1 coding region, was generated using Ambion Strip-EZ RNA kit (Ambion Inc., Houston, Tex.). Membrane hybridization was done with Ambion ULTRAhyb (Ambion Inc., Houston, Tex.), procedure according to manufacturer recommendation.  
     [0136] The sequence of the HrBP1 fragment used to generate the Northern probe (SEQ. ID. No. 9) is as follows:  
                              gatcaagata acatttgaga aaacaactgt gaagacatcg ggaaacttgt cgcagattcc   60           tccgtttgat atcccgaggc ttcccgacag tttcagacca tcgtcaaacc ctggaactgg   120       ggatttcgaa gttacctatg ttgatgatac catgcgcata actcgcgggg acagaggtga   180       acttagggta ttcgtcattg cttaa   205          
 
     [0137] This Northern blot picked up a band with similar size as HrBP1 in all the plant species tested, including tobacco, wheat, corn, citrus, cotton, grass, pansy, pepper, potato, tomato, soybean, sun flower, and lima bean, which indicated HrBP 1-like genes exist universally. See FIG. 6.  
     Example 9  
     [0138] HrBP1 homologue from rice, R6, was clone by yeast two-hybrid screening using harpin as bait. It not only interacted with full length harpin but also interacted with a harpin fragment that contains the second HR domain (see FIG. 7). However, it is not a full-length cDNA; there is some sequence information missing from the 5′ end. The partial sequence of HrBP1 -like cDNA from rice encodes a peptide of 203 amino acids, R6-p, which starts at amino acid 84 of HrBP1p. They are 74.4% identical and 87.2% positive at the protein level, they are 65% identical at the DNA level.  
     [0139] The following shows the sequence alignment of HrBP1 (SEQ. ID. No. 1 starting at amino acid 84) and R6 (SEQ. ID. No. 4) at the protein level:  
                      At protein level: Identities = 151 203 (74.4%), Positives = 177 203 (87.2%), Gaps = 2 203 (0%)+HZ,1 54                              R6-p:   1   VAALKVKLLSAVSGLNRGLAGSQEDLDRADAAARELEAAAGGGPVDLERDVDKLQGRWRL                   + LK+KLLS VSGLNRGL  S +DL+RA+ AA+ELE A  GGPVDL  D+DKLQG+WRL       HrBP1p:   84   IALLKLKLLSVVSGLNRGLVASVDDLERAEVAAKELETA--GGPVDLTDDLDKLQGKWRL       R6-p:   61   VYSSAFSSRTLGGSRPGPPTGRLLPITLGQVFQRIDVVSKDFDNIVDVELGAPWPLPPVE               +YSSAFSSR+LGGSRPG PTGRL+P+TLGQVFQRIDV SKDFDNI +VELGAPWP PP+E       HrBP1p:   142   LYSSAFSSRSLGGSRPGLPTGRLIPVTLGQVFQRIDVFSKDFDNIAEVELGAPWPFPPLE       R6-p:   121   LTATLAHKFEITGTSSIKITFDKTTVKTKGNLSQLPPLEVPRIPDNLRPPSNTGSGEFEV               TATLAHKFE++GT  IKITF+KTTVKT GNLSQ+PP ++PR+PD+ RP SN G+G+FEV       HrBP1p:   202   ATATLAHKFELLGTCKIKITFEKTTVKTSGNLSQIPPFDIPRLPDSRRPSSNPGTGDFEV       R6-p:   181   TYLDGDTRITRGDRGELRVFVIS 203               TY+D   RITRGDRGELRVFVI+       HrBP1p:   262   TYVDDTMRITRGDRGELRVFVIA 284          
 
     [0140] The sequence alignment, on a DNA level, of R6 (SEQ. ID. No. 5) and HrBP1 (SEQ. ID. No. 2) starting at nucleotide 265 (i.e. nucleotide 249 of the open reading frame))  
                      At DNA level: Identities = 397/610 (65%) (dots indicate identical bases)                         R6   1   cgtggctgcgctcaaagtcaagcttctgagcgcggtgtccgggctgaaccgcggcctcgc       HrBP1   249   aa.t..atta......c....at.a..t..t.ta..t..g..at.a...a.a..a..t.t               R6   61   ggggagccaggaggatcttgaccgcgccgacgcggcggcgcgggagctcgaggcggcggc       HrBP1   309   ..c...tgtt..t...t.a..aa.a..t..a.t...t..taaa..a..t..aa.t..---               R6   121   gggtggcggccccgtcgacctggagagggacgtggacaagctgcaggggcggtggaggct       HrBP1   386   ---...g..a..g..t..tt.aaccgat..tc.t..t.....t..a...aaa........               R6   181   ggtgtacagcagcgcgttctcgtcgcggacgctcggcggcagccgccccggcccgcccac       HrBP1   423   .t....t..t..t........t..t...t.tt.a..t..t.....t..t..t.ta..t..               R6   241   cggccgcctcctccccatcaccctcgggcaggtgtttcagaggatcgatgttgtcagcaa       HrBP1   483   t..a..tt.ga....tg.t..t..t..c...........ac....t.....gt.t.....               R6   301   ggacttcgacaacatcgtcgatgtcgagctcggcgcgccatggccgctgccgccggtgga       HrBP1   543   a..t..t..t.....a.ca..g..g..at.a..a..c..t.....at.t.....at.a..               R6   381   gctgacggcgaccctggctcacaagtttgagatcatcggcacctcgagcataaagatcac       HrBP1   603   agcc..t.....at....a...........ac..t.a.....t.gc.ag..c.....a..               R6   421   attcgacaagacgacggtgaagacgaaggggaacctgtcccagctgccgccgctggaggt       HrBP1   663   ...t..g..a..a..t........atc...a...t....g...a.t..t...t.t..ta.               R6   481   ccctcgcatcccggacaacctccggccgccgtccaacaccggcagcggcgagttcgaggt       HrBP1   723   ...ga.gc.t..c....gtt..a.a..at....a...c.t..a.ct..g..t.....a..               R6   541   gacctacctcgacggcgacacccgcatcaccgcgggacagagaggggagctcagggtgtt       HrBP1   783   t.....tg.t..t.atac..tg.....a..t..............t..a..t.....a..               R6   601   cgtcatctcq       HrBP1   843   ......tg.t          
 
     Example 10  
     [0141] Arabidopsis thaliana  Columbia plants were grown in autoclaved potting mix in a controlled environment room at a day and night temperature of 23-20° C. and a photoperiod of 14 h light.  
     [0142] A transgenic approach was used for functional analysis of HrBP1. Anti-sense HrBP1, which is complementary to SEQ. ID. No. 2, was sub-cloned into binary vector pPZP212, and is under the control of NOS promoter.  Arabidopsis thaliana  plants were transformed with this construct via an Agrobacteria mediated method. The  Agrobacterium tumefaciens  strain used was GV3101 (C58C1 Rifr) pMP90 (Gmr). These antisense lines were designated “as” lines.  
     [0143] Arabidopsis plants were also transformed with a construct, which has an inverted repeat with a sense strand of HrBP1 coding region bases 4-650 (i.e. bases 20-666 of SEC. ID. No. 2) and the complementary sequence of bases 20-516 of HrBP1 cDNA (i.e. SEQ. ID. No. 2). This construct generated a double-stranded mRNA in transformed plants. These transgenic lines were designated “d” lines.  
     [0144]FIG. 8 shows the constructs used to transform Arabidopsis.  
     [0145] Both antisense and double-stranded approaches were to silence the expression of HrBP1. The double stranded RNA method was found to be more efficient in silencing the HrBP1 gene. Some transgenic Arabidopsis lines showed spontaneous HR-mimic lesion. The most severe line was developmentally retarded, looked very sick, and did not produce seeds.  
     Example 11  
     [0146] Plants were grown in autoclaved potting mix in a controlled environment room with a day and night temperature of 23-20° C. and a photoperiod of 14 h light. 25-day-old plants were inoculated with  Pseudomonas syringae  p.v. tomato DC3000 by dipping the above soil parts of the plants in 10 8  cells ml −1  bacteria suspension for 10 second. Seven days after DC3000 inoculation, leaf disks were harvested with cork borer. Bacteria were extracted from leaf disk in 10 mM MgCl 2  and plated on King&#39;s B agar containing 100 μg/ml rifampicin. Plates were incubated at 28° C. for 2 days (FIG. 9B) and colonies counted. In FIG. 9A, wild type Arabidopsis plants had significantly more disease development than transgenic plants. Bacteria counting (FIG. 9C) showed that transgenic plants had at least one magnitude less of DC3000 growing inside the leaves. HrBP1 seemed like a negative regulator of plant defense signal transduction pathway in Arabidopsis. Its silencing imparted plants with the ability to resist  Pseudomonas syringae  p.v. tomato DC3000.  
     Example 12  
     [0147] HrBP1 coding region, bases 17-871 of SEQ. ID. No. 2, was sub-cloned into binary vector pPZP212 which is under the control of the NOS promoter (see FIG. 10). Tobacco plants were transformed with this construct via an Agrobacteria mediated method. The  Agrobacterium tumefaciens  strain used was LBA4404.  
     Example 13  
     [0148] HrBP1 was over-expressed in tobacco plants under the control of an NOS promoter. FIG. 10 shows the construct used for tobacco transformation. Three high expression lines were chosen for further studies in the T2 generation. When infiltrated with purified harpin, the transgenic lines developed HR much faster than wild type plants, which is consistent with previous experiment in which His-tagged HrBP1 increased tobacco&#39;s sensitivity to harpin protein. The HrBP1 over-expressing lines were about 20-30% taller than wild type Xanthi NN plants (see FIG. 11).  
     Example 14  
     [0149] 61-day-old wild type and HrBP1 over-expressing Xanthi NN tobacco plants were inoculated with tobacco mosaic virus by rubbing TMV with diatomaceous earth on the upper surface of leaves. Lesions appeared 2 days after manual inoculation. The picture in FIG. 12A was taken 3 days after inoculation. The diameter of disease spots was measured. On average, the diameter of lesions on transgenic plant leaves were 33.4% less than that on wild type plants (FIG. 12B). Therefore, the surface area of lesions on transgenic plant leaves was about 44.3% of those of the wild type plants. HrBP1 seemed to be a positive regulator of the plant signal transduction pathway for growth and disease resistance in tobacco.  
     [0150] Although the invention has been described in detail for the purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.  
    
     
       
         1 
         
           
             9  
           
           
             1  
             284  
             PRT  
             Arabidopsis thaliana  
           
            1 

Met Ala Thr Ser Ser Thr Phe Ser Ser Leu Leu Pro Ser Pro Pro Ala 
  1               5                  10                  15 

Leu Leu Ser Asp His Arg Ser Pro Pro Pro Ser Ile Arg Tyr Ser Phe 
             20                  25                  30 

Ser Pro Leu Thr Thr Pro Lys Ser Ser Arg Leu Gly Phe Thr Val Pro 
         35                  40                  45 

Glu Lys Arg Asn Leu Ala Ala Asn Ser Ser Leu Val Glu Val Ser Ile 
     50                  55                  60 

Gly Gly Glu Ser Asp Pro Pro Pro Ser Ser Ser Gly Ser Gly Gly Asp 
 65                  70                  75                  80 

Asp Lys Gln Ile Ala Leu Leu Lys Leu Lys Leu Leu Ser Val Val Ser 
                 85                  90                  95 

Gly Leu Asn Arg Gly Leu Val Ala Ser Val Asp Asp Leu Glu Arg Ala 
            100                 105                 110 

Glu Val Ala Ala Lys Glu Leu Glu Thr Ala Gly Gly Pro Val Asp Leu 
        115                 120                 125 

Thr Asp Asp Leu Asp Lys Leu Gln Gly Lys Trp Arg Leu Leu Tyr Ser 
    130                 135                 140 

Ser Ala Phe Ser Ser Arg Ser Leu Gly Gly Ser Arg Pro Gly Leu Pro 
145                 150                 155                 160 

Thr Gly Arg Leu Ile Pro Val Thr Leu Gly Gln Val Phe Gln Arg Ile 
                165                 170                 175 

Asp Val Phe Ser Lys Asp Phe Asp Asn Ile Ala Glu Val Glu Leu Gly 
            180                 185                 190 

Ala Pro Trp Pro Phe Pro Pro Leu Glu Ala Thr Ala Thr Leu Ala His 
        195                 200                 205 

Lys Phe Glu Leu Leu Gly Thr Cys Lys Ile Lys Ile Thr Phe Glu Lys 
    210                 215                 220 

Thr Thr Val Lys Thr Ser Gly Asn Leu Ser Gln Ile Pro Pro Phe Asp 
225                 230                 235                 240 

Ile Pro Arg Leu Pro Asp Ser Phe Arg Pro Ser Ser Asn Pro Gly Thr 
                245                 250                 255 

Gly Asp Phe Glu Val Thr Tyr Val Asp Asp Thr Met Arg Ile Thr Arg 
            260                 265                 270 

Gly Asp Arg Gly Glu Leu Arg Val Phe Val Ile Ala 
        275                 280 

 
           
             2  
             1000  
             DNA  
             Arabidopsis thaliana  
           
            2 

tttttccttc tcaacaatgg cgacttcttc tactttctcg tcactactac cttcaccacc     60 

agctcttctt tccgaccacc gttctcctcc accatccatc agatactcct tttctccctt    120 

aactactcca aaatcgtctc gtttgggttt cactgtaccg gagaagagaa acctcgctgc    180 

taattcgtct ctcgttgaag tatccattgg cggagaaagt gacccaccac catcatcatc    240 

tggatcagga ggagacgaca agcaaattgc attactcaaa ctcaaattac ttagtgtagt    300 

ttcgggatta aacagaggac ttgtggcgag tgttgatgat ttagaaagag ctgaagtggc    360 

tgctaaagaa cttgaaactg ctgggggacc ggttgattta accgatgatc ttgataagct    420 

tcaagggaaa tggaggctgt tgtatagtag tgcgttctct tctcggtctt taggtggtag    480 

ccgtcctggt ctacctactg gacgtttgat ccctgttact cttggccagg tgtttcaacg    540 

gattgatgtg tttagcaaag attttgataa catagcagag gtggaattag gagccccttg    600 

gccatttccg ccattagaag ccactgcgac attggcacac aagtttgaac tcttaggcac    660 

ttgcaagatc aagataacat ttgagaaaac aactgtgaag acatcgggaa acttgtcgca    720 

gattcctccg tttgatatcc cgaggcttcc cgacagtttc agaccatcgt caaaccctgg    780 

aactggggat ttcgaagtta cctatgttga tgataccatg cgcataactc gcggggacag    840 

aggtgaactt agggtattcg tcattgctta attctcaaag ctttgacatg taaagataaa    900 

taaatacttt ctgcttgatg cagtctcatg agttttgtac aaatcatgtg aacatataaa    960 

tgcgctttat aagtaaatga gtgtcttgtt caatgaatca                         1000 

 
           
             3  
             4260  
             DNA  
             Arabidopsis thaliana  
           
            3 

aattagaaaa attaacaacc aacatctagt tagaatattt aatttgcacc aatgtcttcg     60 

agtatagtga aaaaaataga agatcgaata tcgaatagta cgtatagaat catctagatc    120 

cattcgaact aacgtctact tttcttttcc agcattaaca tgtagcttgt cattagcatt    180 

tacatgttgc aaataacaca aattgggaaa ttgaaagact aaaaaacctt gtacagcaga    240 

tggtttaaca cgtggattca tggacacaaa cagaaaacgg cagaactaag cacaaaaacg    300 

tcaactaagc atatcaaagc ttttaatgca agcctaatat aaacacaagt ggttatccat    360 

aatctgttct taatctcttg cagtagttat cttttcatta ttcgcaattc gcaattctat    420 

attcttatat ttcaacttgt tcttcttcca aattgtaatt atatctacat cgtcttagct    480 

tgaccattat agctccagta ccaagttctc ttcttaactt taatatcagc tactattctc    540 

atactgtaaa tatcttttgt tcaccaaaca tatatttcga accaaactgc taaaagctta    600 

tcataaattg cagttctagc cacacaattt tgcagttcca accattaaat gccacaaaat    660 

ttggacgatt tcttaagaca agaagaacat agcaaccaaa ccttattgat taaatatgaa    720 

atgtctccat aaaactggga gatttcccca aataaagaga acacggcaaa tgttcacgta    780 

atctccaaga tgaatgttta attttttctt tcagaaaaaa acaaaaaaac ttaactcaat    840 

atagacaact agaatggata ccaactaagc aaaagaaatt caaaagacaa atatatattg    900 

gatatgaagt tacattattt tcaaacttta tatactacta aaagcctaaa aatttgttct    960 

aaaatgatat ccaaataaat ggaaggcatg aatgtcatat gactaaaaga gaaaaacaca   1020 

cctgtatata agtattggat catgctgcct ccgagtgaca aaacatacga tgtgggtctt   1080 

tattgggcca tacttaaatg gaaaaaggag aaaaaaaatt gggcaatgtc tatggtcgaa   1140 

atttatatgt tttacatcaa taaaatcaat atttaatttt atatatgtgg gtcttaatct   1200 

agtattatct acatagatta aaatcaaagt actgcatatg gtccataata atacaaccaa   1260 

agcaaattaa aattttgtgg cacaaaacga catcatttta ctcagaaagt aatatgcaat   1320 

ttcgtttacg cacacacgta tacgcgctaa taacccgtgg tgcttctcaa atcacataat   1380 

aattaaagtc ttcttcttct tcttcttctc tacaaattat ctcactctct tcgttttttt   1440 

ttccttctca acaatggcga cttcttctac tttctcgtca ctactacctt caccaccagc   1500 

tcttctttcc gaccaccgtt ctcctccacc atccatcaga tactcctttt ctcccttaac   1560 

tactccaaaa tcgtctcgtt tgggtttcac tgtaccggag aagagaaacc tcgctgctaa   1620 

ttcgtctctc gttgaagtat ccattggcgg agaaagtgac ccaccaccat catcatctgg   1680 

atcaggagga gacgacaagc aaattgcatt actcaaactc aaattacttg tgagtctgat   1740 

tcaaaccaat cggtgaaatt ataagaaatt ggtttcgttt ctttggaatt agggtttata   1800 

ttactgttaa gattcgatta tagagtgaat tttgggaaga tttttcagat ttgatttgtg   1860 

atgtgttgtg ttgtgagaaa ttgcagagtg tagtttcggg attaaacaga ggacttgtgg   1920 

cgagtgttga tgatttagaa agagctgaag tggctgctaa agaacttgaa actgctgggg   1980 

gaccggttga tttaaccgat gatcttgata agcttcaagg gaaatggagg ctgttgtata   2040 

gtagtgcgtt ctcttctcgg tctttaggtg gtagccgtcc tggtctacct actggacgtt   2100 

tgatccctgt tactcttggc caggtaattc ttgaatcatt gctctgtttt tacccgtcaa   2160 

gattcggttt ttcgggtaag ttgttgagga gtttatgtgc atggtctagt ctatcatcaa   2220 

tagtcttgct tgagtttgaa tggggctgag ctaagaatct agctttctga ggttacaatt   2280 

tggtaatgtc atcttatact cgaaagcaaa cttttttcta tattgtcaag tttatgtgta   2340 

cggtctggtc tatcattggt agtctttgtt gagcttgaat ggtgaggagc ttagaatcta   2400 

gcaatgtcat ctactcctta atcatttttt tctatattgc caagtttatg tgtacggtct   2460 

tagtcaatca tctttattct tggttgagtt tgaatggtga tgagcttaga atctagcttt   2520 

ctttggttta aatttggcaa agaaccatac ctgaatcggt agaaagcaaa cttctttaat   2580 

attatctctt gtttctgaat cattaaaaca ggtgtttcaa cggattgatg tgtttagcaa   2640 

agattttgat aacatagcag aggtggaatt aggagcccct tggccatttc cgccattaga   2700 

agccactgcg acattggcac acaagtttga actcttaggt ttgcatttcc ctttctctca   2760 

ttaagtttat cgaattgtgt aagagcaaaa taacttatct gtatctttga catttatggg   2820 

gaaaacaggc acttgcaaga tcaagataac atttgagaaa acaactgtga agacatcggg   2880 

aaacttgtcg cagattcctc cgtttgatat cccgaggctt cccgacagtt tcagaccatc   2940 

gtcaaaccct ggaactgggg atttcgaagt tacctatgtt gatgatacca tgcgcataac   3000 

tcgcggggac agaggtgaac ttagggtatt cgtcattgct taattctcaa agctttgaca   3060 

tgtaaagata aataaatact ttctgcttga tgcagtctca tgagttttgt acaaatcatg   3120 

tgaacatata aatgcgcttt ataagtaaat gagtgtcttg ttcaatgaat catatgaaag   3180 

aatttgtatg actcagaaaa ttggacaatg atatagacct tccaaatttt gcaccctcta   3240 

atgtgagata ttagtgattt tttcttaggt tggtagagag aacggattgg caaaaaaata   3300 

tcgaaggtca atgattaaca gcaaaaccat atcttgatga ttcaaaatat agagttaaca   3360 

agcaaagatg agacaatctt atacgagaga gctaaaacaa atggattcca aatccagcaa   3420 

gtacaaaaat cgcagaaaat aagatgaaac caacttaaaa cagagatgtt ccctttccct   3480 

tcttgtcacc accgatctcg aaatgcttgc acctctgaaa taaacaacaa accaacacaa   3540 

tgtaagcaaa ttaccaagtt acaaatccgg tataatgaac tgatctatgt tctatgcacc   3600 

ttgataggac gctgcgaaaa gtgcttgcag ctttgacact gaagcctcaa aacaatcttc   3660 

ttcgtggtct tagcctgtta acaagattca caagatgtat ctcagtccaa aactgagact   3720 

attggaatgt ctgtttcctc acagctcact tccaaaattc tactataaat ggttccttaa   3780 

aactacctca tttcaactaa ctagacctaa ttcaaactga aaaaacaatc aatgcatgat   3840 

aatcaatgtt acctttttgt ggaagacagg cttagtctga ccaccataac cagattgttt   3900 

acggtcataa cgacgctttc cttgagcagc aagactgtct ttacccttct tgtattgggt   3960 

aaccttgtgc aaagtatgct ttttgcattc cttgttctta cagtaagtgt tctttgtctt   4020 

tggaatgttc accttcaaaa ttcataaaat caaaaatgaa tcactcacac acatacaaaa   4080 

tcaagagact tttaaggtta atcaaaatac aaacatcatt tagattgaaa acttttatga   4140 

tagatctgaa aaacaataca ataaatcaat caaccatgta ttgttgttct tcaaagtcaa   4200 

cgaactttac aaattccaaa atcacatcga aagagaagaa acaatttacc attttcgcgt   4260 

 
           
             4  
             203  
             PRT  
             oryza  
           
            4 

Val Ala Ala Leu Lys Val Lys Leu Leu Ser Ala Val Ser Gly Leu Asn 
  1               5                  10                  15 

Arg Gly Leu Ala Gly Ser Gln Glu Asp Leu Asp Arg Ala Asp Ala Ala 
             20                  25                  30 

Ala Arg Glu Leu Glu Ala Ala Ala Gly Gly Gly Pro Val Asp Leu Glu 
         35                  40                  45 

Arg Asp Val Asp Lys Leu Gln Gly Arg Trp Arg Leu Val Tyr Ser Ser 
     50                  55                  60 

Ala Phe Ser Ser Arg Thr Leu Gly Gly Ser Arg Pro Gly Pro Pro Thr 
 65                  70                  75                  80 

Gly Arg Leu Leu Pro Ile Thr Leu Gly Gln Val Phe Gln Arg Ile Asp 
                 85                  90                  95 

Val Val Ser Lys Asp Phe Asp Asn Ile Val Asp Val Glu Leu Gly Ala 
            100                 105                 110 

Pro Trp Pro Leu Pro Pro Val Glu Leu Thr Ala Thr Leu Ala His Lys 
        115                 120                 125 

Phe Glu Ile Ile Gly Thr Ser Ser Ile Lys Ile Thr Phe Asp Lys Thr 
    130                 135                 140 

Thr Val Lys Thr Lys Gly Asn Leu Ser Gln Leu Pro Pro Leu Glu Val 
145                 150                 155                 160 

Pro Arg Ile Pro Asp Asn Leu Arg Pro Pro Ser Asn Thr Gly Ser Gly 
                165                 170                 175 

Glu Phe Glu Val Thr Tyr Leu Asp Gly Asp Thr Arg Ile Thr Arg Gly 
            180                 185                 190 

Asp Arg Gly Glu Leu Arg Val Phe Val Ile Ser 
        195                 200 

 
           
             5  
             613  
             DNA  
             oryza  
           
            5 

cgtggctgcg ctcaaagtca agcttctgag cgcggtgtcc gggctgaacc gcggcctcgc     60 

ggggagccag gaggatcttg accgcgccga cgcggcggcg cgggagctcg aggcggcggc    120 

gggtggcggc cccgtcgacc tggagaggga cgtggacaag ctgcaggggc ggtggaggct    180 

ggtgtacagc agcgcgttct cgtcgcggac gctcggcggc agccgccccg gcccgcccac    240 

cggccgcctc ctccccatca ccctcgggca ggtgtttcag aggatcgatg ttgtcagcaa    300 

ggacttcgac aacatcgtcg atgtcgagct cggcgcgcca tggccgctgc cgccggtgga    360 

gctgacggcg accctggctc acaagtttga gatcatcggc acctcgagca taaagatcac    420 

attcgacaag acgacggtga agacgaaggg gaacctgtcc cagctgccgc cgctggaggt    480 

ccctcgcatc ccggacaacc tccggccgcc gtccaacacc ggcagcggcg agttcgaggt    540 

gacctacctc gacggcgaca cccgcatcac ccgcggggac agaggggagc tcagggtgtt    600 

cgtcatctcg tga                                                       613 

 
           
             6  
             26  
             PRT  
             Xanthomonas campestris pv. glycines  
           
            6 

Thr Leu Ile Glu Leu Met Ile Val Val Ala Ile Ile Ala Ile Leu Ala 
  1               5                  10                  15 

Ala Ile Ala Leu Pro Ala Tyr Gln Asp Tyr 
             20                  25 

 
           
             7  
             114  
             PRT  
             Xanthomonas campestris pv. pelargonii  
           
            7 

Met Asp Ser Ile Gly Asn Asn Phe Ser Asn Ile Gly Asn Leu Gln Thr 
  1               5                  10                  15 

Met Gly Ile Gly Pro Gln Gln His Glu Asp Ser Ser Gln Gln Ser Pro 
             20                  25                  30 

Ser Ala Gly Ser Glu Gln Gln Leu Asp Gln Leu Leu Ala Met Phe Ile 
         35                  40                  45 

Met Met Met Leu Gln Gln Ser Gln Gly Ser Asp Ala Asn Gln Glu Cys 
     50                  55                  60 

Gly Asn Glu Gln Pro Gln Asn Gly Gln Gln Glu Gly Leu Ser Pro Leu 
 65                  70                  75                  80 

Thr Gln Met Leu Met Gln Ile Val Met Gln Leu Met Gln Asn Gln Gly 
                 85                  90                  95 

Gly Ala Gly Met Gly Gly Gly Gly Ser Val Asn Ser Ser Leu Gly Gly 
            100                 105                 110 

Asn Ala 

 
           
             8  
             342  
             DNA  
             Xanthomonas campestris pv. pelargonii  
           
            8 

atggactcta tcggaaacaa cttttcgaat atcggcaacc tgcagacgat gggcatcggg     60 

cctcagcaac acgaggactc cagccagcag tcgccttcgg ctggctccga gcagcagctg    120 

gatcagttgc tcgccatgtt catcatgatg atgctgcaac agagccaggg cagcgatgca    180 

aatcaggagt gtggcaacga acaaccgcag aacggtcaac aggaaggcct gagtccgttg    240 

acgcagatgc tgatgcagat cgtgatgcag ctgatgcaga accagggcgg cgccggcatg    300 

ggcggtggcg gttcggtcaa cagcagcctg ggcggcaacg cc                       342 

 
           
             9  
             205  
             DNA  
             Artificial Sequence  
             
               Description of Artificial Sequence  probe  
             
           
            9 

gatcaagata acatttgaga aaacaactgt gaagacatcg ggaaacttgt cgcagattcc     60 

tccgtttgat atcccgaggc ttcccgacag tttcagacca tcgtcaaacc ctggaactgg    120 

ggatttcgaa gttacctatg ttgatgatac catgcgcata actcgcgggg acagaggtga    180 

acttagggta ttcgtcattg cttaa                                          205