Disease resistance factors

Abstract

This invention relates to isolated nucleic acid fragments encoding corn ( Zea mays ), rice ( Oryza sativa ), or wheat ( Triticum aestivum ) NPR1 homologs. The invention also relates to the construction of a chimeric gene encoding all or a portion of the NPR1 homolog, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the NPR1 homolog in a transformed host cell.

What is claimed is:  
     
         1 . An isolated polynucleotide that encodes an NPR1 polypeptide having a sequence identity of at least 80% based on the Clustal method of alignment when compared to a polypeptide selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, and 16.  
     
     
         2 . The polynucleotide of  claim 1  wherein the sequence identity is at least 85%.  
     
     
         3 . The polynucleotide of  claim 1  wherein the sequence identity is at least 90%.  
     
     
         4 . The polynucleotide of  claim 1  wherein the sequence identity is at least 95%.  
     
     
         5 . The polynucleotide of  claim 1  wherein the polynucleotide encodes a polypeptide selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, and 16.  
     
     
         6 . The polynucleotide of  claim 1  wherein the polynucleotide comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, 3, 5, 7, 9, 11, 13, and 15.  
     
     
         7 . The polynucleotide of  claim 1  wherein the polypeptide is an NPR1.  
     
     
         8 . An isolated complement of the polynucleotide of  claim 1 , wherein 
 (a) the complement and the polynucleotide consist of the same number of nucleotides, and    (b) the nucleotide sequences of the complement and the polynucleotide have 100% complementarity.    
     
     
         9 . An isolated nucleic acid molecule that (1) comprises at least 100 nucleotides and (2) remains hybridized with the isolated polynucleotide of  claim 1  under a wash condition of 0.1×SSC, 0.1% SDS, and 65° C.  
     
     
         10 . A cell comprising the polynucleotide of  claim 1 .  
     
     
         11 . The cell of  claim 10 , wherein the cell is selected from the group consisting of a yeast cell, a bacterial cell and a plant cell.  
     
     
         12 . A virus comprising the polynucleotide of  claim 1 .  
     
     
         13 . A transgenic plant comprising the polynucleotide of  claim 1 .  
     
     
         14 . A method for transforming a cell, comprising introducing into a cell the polynucleotide of  claim 1 .  
     
     
         15 . A method for producing a transgenic plant comprising 
 (a) transforming a plant cell with the polynucleotide of  claim 1 , and    (b) regenerating a plant from the transformed plant cell.    
     
     
         16 . A method for producing a polynucleotide fragment comprising 
 (a) selecting a nucleotide sequence comprised by the polynucleotide of  claim 1 , and    (b) synthesizing a polynucleotide fragment containing the nucleotide sequence.    
     
     
         17 . The method of  claim 16 , wherein the fragment is produced in vivo.  
     
     
         18 . An isolated NPR1 polypeptide that has a sequence identity of at least 80% based on the Clustal method compared to an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, and 16.  
     
     
         19 . The isolated polypeptide of  claim 18  wherein the sequence identity is at least 85%.  
     
     
         20 . The isolated polypeptide of  claim 18  wherein the sequence identity is at least 90%.  
     
     
         21 . The isolated polypeptide of  claim 18  wherein the sequence identity is at least 95%.  
     
     
         22 . The polypeptide of  claim 18  wherein the polypeptide has a sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, and 16.  
     
     
         23 . The polypeptide of  claim 18 , wherein the polypeptide is aNPR1 .  
     
     
         24 . A chimeric gene comprising the polynucleotide of  claim 1  operably linked to at least one regulatory sequence.  
     
     
         25 . A method for altering the level of pathogen resistance in a plant, the method comprising the steps of: 
 (a) transforming a plant cell with a chimeric gene containing the polypeptide of  claim 1;     (b) culturing the transformed plant cell under conditions suitable for the expression of the chimeric gene;    (c) maintaining the plant cell under conditions that are suitable for its development into a plant; and    (d) comparing the level of pathogen resistance of the plant cell containing the polynucleotide of  claim 1  and a plant cell not containing the polynucleotide of  claim 1.