Methods and Materials for Conferring Resistance to Pests and Pathogens of Plants

Abstract

Methods and materials for conferring pest resistance to plants are provided. Plants are transformed with a silencing construct homologous to a gene of a plant pest that is essential for the survival, development, or pathogenicity of the pest. This results in the plant producing RNAi to the selected gene, which, when ingested by the pest results in silencing of the gene and a subsequent reduction of the pest's ability to harm the plant. In other embodiments, the pest's reduced ability to harm the plant is passed on to pest progeny. Methods and materials for depathogenesis of pests is also provided.

1 . A method for conferring pest resistance to a plant comprising a step of selecting a first pathogenicity gene, a step of selecting a second pathogenicity gene, a step of transforming a host plant cell with a heterologous polynucleotide, and a step of regenerating the plant from the host plant cell, said heterologous polynucleotide comprising:
 (a) a first antisense sequence having at least 80% homology to the first pest pathogenicity gene;   (b) a second antisense sequence having at least 80% homology to the second pest genicity gene;   (c) a first sense sequence substantially complementary to said first antisense sequence; and   (d) a second sense sequence substantially complementary to said second antisense sequence;   wherein:   a transcript of the heterologous polynucleotide is capable of hybridizing to form a double-stranded region comprising nucleotides encoded by the first antisense sequence and the first sense sequence;   the transcript is capable of hybridizing to form a double-stranded region comprising nucleotides encoded by the second antisense sequence and the second sense sequence;   the plant is a soybean;   the first pest pathogenicity gene is a fungus pathogenicity gene; and   the second pest pathogenicity gene is a gene from a pest selected from the group consisting of insects, bacteria, fungi, and nematodes;   whereby the plant is resistant to a first fungus expressing at least one gene having substantial homology to the first antisense sequence.   
     
     
         2 . The method of  claim 1 , wherein the first fungus is a fungus selected from the group consisting of  Fusarium solani, Sclerotinia sclerotiorum, Phialophora gregata, Phakospora pachyrhizi, Phytophthora sojae,  and  Peronospora berteroae.    
     
     
         3 . The method of  claim 2 , wherein the second pest pathogenicity gene is a fungus pathogenicity gene, whereby the plant is resistant to a second fungus expressing at least one gene having substantial homology to the second antisense sequence. 
     
     
         4 . The method of  claim 3 , wherein the second fungus is a fungus selected from the group consisting of  Fusarium solani, Sclerotinia sclerotiorum, Phialophora gregata, Phakospora pachyrhizi, Phytophthora sojae,  and  Peronospora berteroae.    
     
     
         5 . The method of  claim 4 , wherein the first fungus is  Fusarium solani  and wherein the second fungus is a fungus is  Phakospora pachyrhizi.    
     
     
         6 . The method of  claim 1 , wherein the first fungus can cause a fungal disease selected from the group consisting brown stem rot, stem and root rot, white mold disease, sudden death syndrome, Asian rust, and downy mildew. 
     
     
         7 . The athod of  claim 1 , wherein:
 the first pest pathogenicity gene is from a pest selected from the group consisting of a pest that causes  Phytophthora  root and stem rot, a pest that causes Asian rust, a soybean cyst nematode, and a pest that causes sudden death syndrome; and   the second pest pathogenicity gene is from a pest selected from the group consisting of a pest that causes  Phytophthora  root and stem rot, a pest that causes Asian rust, a soybean cyst nematode, a pest that causes sudden death syndrome, and an aphid.   
     
     
         8 . The method of  claim 1 , wherein the first pest pathogenicity gene is from a  Phytophthora,  and herein the second pathogenicity gene is from an aphid. 
     
     
         9 . The method of  claim 1 , wherein the first pest pathogenicity gene is from  Phytophthora sojae  and wherein the second pathogenicity gene is from  Phakospora pachyrhizi.    
     
     
         10 . A plant produced by the method of  claim 1 . 
     
     
         11 . A plant produced by the method of  claim 2 . 
     
     
         12 . A plant produced by the method of  claim 3 . 
     
     
         13 . A plant produced by the method of  claim 4 . 
     
     
         14 . A plant produced by the method of  claim 5 . 
     
     
         15 . A plant produced by the method of  claim 6 . 
     
     
         16 . A plant produced by the method of  claim 7 . 
     
     
         17 . A plant produced by the method of  claim 8 . 
     
     
         18 . A plant product comprising a cutting, pollen, a seed, a clone, a descendant, a propagule, an extract, or a derivative of the plant of  claim 10 . 
     
     
         19 . A plant product comprising a cutting, pollen, a seed, a clone, a descendant, a propagule, an extract, or a derivative of the plant of  claim 11 . 
     
     
         20 . A plant product comprising a catting, pollen, a seed, a clone, a descendant, a propagule, an extract, or a derivative of the plant of  claim 12 .