Methods of Protecting Plants from Pathogenic Fungi

Abstract

Methods for protecting a plant from a plant pathogenic fungus are provided. A method for enhancing fungal pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antifungal polypeptide of the invention. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antifungal polypeptide of the embodiments, or variant or fragment thereof, are also disclosed.

1 . A transgenic plant having stably incorporated into its genome a polynucleotide encoding a polypeptide having at least 95% sequence identity to SEQ ID NO: 1 or SEQ ID NO: 2, wherein said polypeptide confers resistance to at least one plant pathogenic fungus, and wherein said plant has improved pathogen resistance to at least one plant pathogenic fungus, as compared to a control plant.  
     
     
         2 . The plant according to  claim 1 , wherein said plant is a monocot.  
     
     
         3 . The plant according to  claim 1 , wherein said plant is a dicot.  
     
     
         4 . Transformed seed of the plant of  claim 1 , wherein the seed comprise the polynucleotide.  
     
     
         5 . The plant according to  claim 1 , wherein said polynucleotide is operably linked to a promoter that drives expression in a cell of said plant, wherein said promoter is selected from the group consisting of: 
 a) a constitutive promoter;    b) a tissue-specific promoter; and    c) an inducible promoter.    
     
     
         6 . A transgenic plant having stably incorporated into its genome a polynucleotide encoding a polypeptide having 95% sequence identity to SEQ ID NO: 2 and confers resistance to at least one plant pathogenic fungus, wherein the polypeptide further comprises a heterologous signal sequence, and wherein said plant has improved pathogen resistance to said at least one plant pathogenic fungus as compared to a control plant.  
     
     
         7 . The plant according to  claim 6 , wherein the signal sequence is a secretion signal sequence.  
     
     
         8 . The plant according to  claim 6 , wherein the signal sequence is an organelle signal sequence.  
     
     
         9 . The plant according to  claim 8 , wherein the signal sequence is a plastid signal sequence.  
     
     
         10 . The plant according to  claim 1 , wherein said polypeptide is selected from the group consisting of SEQ ID NO: 1 and SEQ ID NO: 2.  
     
     
         11 . A method for enhancing resistance of a plant to a fungal pathogen, said method comprising: 
 (a) stably transforming a plant cell with at least one expression cassette comprising a nucleotide sequence operably linked to a promoter that drives expression in a cell of said plant, wherein said nucleotide sequence encodes a polypeptide having at least 95% sequence identity to SEQ ID NO: 1 or SEQ ID NO: 2, and wherein said polypeptide confers resistance against at least one plant fungal pathogen; and    (b) regenerating a transformed plant from said plant cell, wherein the plant has enhanced resistance to said fungal pathogen as compared to a plant that does not comprise said expression cassette.    
     
     
         12 . The method of  claim 11 , wherein said fungal pathogen is  Alternaria brassicicola.    
     
     
         13 . The method of  claim 11 , wherein said fungal pathogen is  Fusarium verticillioides.    
     
     
         14 . The method of  claim 11 , wherein said fungal pathogen is  Fusarium oxysporum.    
     
     
         15 . The method of  claim 11 , wherein said fungal pathogen is  Verticillium dahliae.    
     
     
         16 . The method of  claim 11 , wherein said fungal pathogen is  Botrytis cinerea.    
     
     
         17 . The method of  claim 11 , wherein said fungal pathogen is  Colletotrichum graminicola.    
     
     
         18 . The method of  claim 11 , wherein said fungal pathogen is  Diplodia maydis.    
     
     
         19 . The method of  claim 11 , wherein said fungus is  Fusarium graminearum.    
     
     
         20 . The method of  claim 11 , wherein said nucleotide sequence encodes a polypeptide selected from the group consisting of SEQ ID NO: 1 and SEQ ID NO: 2.  
     
     
         21 . The method of  claim 11 , wherein said promoter is selected from the group consisting of: 
 a) a constitutive promoter;    b) a tissue-specific promoter; and    c) an inducible promoter.    
     
     
         22 . A method for enhancing resistance of a plant to a fungal pathogen, said methods comprising: 
 (a) stably transforming a plant cell with at least one expression cassette comprising a nucleotide sequence operably linked to a promoter that drives expression in a cell of said plant, wherein said nucleotide sequence encodes a polypeptide having at least 95% sequence identity to SEQ ID NO: 2, wherein the polypeptide further comprises a heterologous signal sequence, and wherein the polypeptide confers resistance against at least one plant fungal pathogen; and    (b) regenerating a transformed plant from said plant cell, wherein the plant has enhanced resistance to said fungal pathogen as compared to a plant that does not comprise said expression cassette.    
     
     
         23 . The method of  claim 22 , wherein the signal sequence is a secretion signal sequence.  
     
     
         24 . The method of  claim 22 , wherein the signal sequence is an organelle signal sequence.  
     
     
         25 . The method of  claim 22 , wherein the signal sequence is a plastid signal sequence.  
     
     
         26 . A method for enhancing resistance of a plant to a pathogen, said method comprising: 
 (a) stably transforming a plant cell with at least one expression cassette comprising a nucleotide sequence operably linked to a promoter that drives expression in a cell of said plant, wherein said nucleotide sequence has at least 95% sequence identity to SEQ ID NO: 3, and wherein said nucleotide sequence encodes a polypeptide that confers resistance against at least one plant fungal pathogen; and    (b) regenerating a transformed plant from said plant cell, wherein the plant has enhanced resistance to said fungal pathogen as compared to a plant that does not comprise said expression cassette.    
     
     
         27 . The method of  claim 26 , wherein the promoter is selected from the group consisting of: 
 a) a constitutive promoter;    b) a tissue-specific promoter; and    c) an inducible promoter.    
     
     
         28 . The method of  claim 26 , wherein the polypeptide further comprises a heterologous signal sequence.  
     
     
         29 . The method of  claim 28 , wherein the signal sequence is a secretion signal sequence.  
     
     
         30 . The method of  claim 28 , wherein the signal sequence is an organelle signal sequence.  
     
     
         31 . The method of  claim 28 , wherein the signal sequence is a plastid signal sequence.  
     
     
         32 . The method of  claim 26 , wherein the nucleotide sequence is SEQ NO: 3.  
     
     
         33 . A transgenic plant having stably incorporated into its genome a polynucleotide sequence that is at least 95% identical to SEQ ID NO: 3, wherein said polynucleotide sequence encodes a polypeptide that confers resistance against at least one plant fungal pathogen, wherein said plant has improved resistance to said at least one plant pathogenic fungus, as compared to a control plant.  
     
     
         34 . The plant according to  claim 33 , wherein said plant is a monocot.  
     
     
         35 . The plant according to  claim 33 , wherein said plant is a dicot.  
     
     
         36 . Transformed seed of the plant of  claim 33 , wherein the seed comprise the polynucleotide sequence.  
     
     
         37 . The plant according to  claim 33 , wherein said polynucleotide is operably linked to a promoter that drives expression in a cell of said plant, wherein said promoter is selected from the group consisting of: 
 b) a constitutive promoter;    b) a tissue-specific promoter; and    c) an inducible promoter.    
     
     
         38 . The plant according to  claim 33 , wherein the polypeptide further comprises a heterologous signal sequence.  
     
     
         39 . The plant according to  claim 38 , wherein the signal sequence is a secretion signal sequence.  
     
     
         40 . The plant according to  claim 38 , wherein the signal sequence is an organelle signal sequence.  
     
     
         41 . The plant according to  claim 38 , wherein the signal sequence is a plastid signal sequence.  
     
     
         42 . The plant according to  claim 33 , wherein said polynucleotide sequence is selected from the group consisting of the polynucleotide sequences set forth in SEQ ID NO: 3.  
     
     
         43 . The plant of  claim 5 , wherein the tissue-specific promoter is a root-specific promoter, and the inducible promoter is a pathogen-inducible promoter.  
     
     
         44 . The method of  claim 21 , wherein the tissue-specific promoter is a root-specific promoter, and the inducible promoter is a pathogen-inducible promoter.  
     
     
         45 . The method of  claim 27 , wherein the tissue-specific promoter is a root-specific promoter, and the inducible promoter is a pathogen-inducible promoter.  
     
     
         46 . The plant of  claim 37 , wherein the tissue-specific promoter is a root-specific promoter, and the inducible promoter is a pathogen-inducible promoter.