Genetic loci associated with head smut resistance in maize

Abstract

Head smut is one of the most devastating diseases in maize, causing severe yield loss worldwide. The present invention describes the fine-mapping of a major QTL conferring resistance to head smut. Markers useful for breeding, and methods for conferring head smut resistance are described. Nucleic acid sequence from the genetic locus conferring head smut resistance is disclosed. Genes encoding proteins conferring head smut resistance are disclosed.

What is claimed is: 
     
         1 . A recombinant DNA construct comprising an isolated polynucleotide operably linked to at least one regulatory sequence, wherein said isolated polynucleotide comprises:
 a. a nucleotide sequence encoding a polypeptide conferring or improving resistance to head smut, wherein the polypeptide has an amino acid sequence of at least 90% sequence identity to SEQ ID NO:32;   b. a nucleotide sequence capable of encoding a polypeptide conferring or enhancing resistance to head smut, wherein said nucleotide sequence is at least 90% identical to SEQ ID NO:31; or   c. a complement of the nucleotide sequence of part (a) or (b), wherein the complement and the nucleotide sequence consist of the same number of nucleotides and are 100% complementary.   
     
     
         2 . A maize cell comprising the recombinant DNA construct of  claim 1 . 
     
     
         3 . A method for producing a maize plant, said method comprising:
 a. transforming a plant cell with the recombinant DNA construct of  claim 1 ; and   b. regenerating a plant from the transformed plant cell.   
     
     
         4 . A maize plant comprising the recombinant DNA construct of  claim 1 . 
     
     
         5 . A maize seed comprising the recombinant DNA construct of  claim 1 . 
     
     
         6 . A method of conferring or improving resistance to head smut, said method comprising transforming a plant with the recombinant DNA construct of  claim 1 , thereby conferring or improving resistance to head smut. 
     
     
         7 . A method of altering the level of expression of a protein capable of conferring resistance to head smut in a maize cell, said method comprising:
 a. transforming a maize cell with the recombinant DNA construct of  claim 1 ; and   b. growing the transformed maize cell under conditions that are suitable for expression of the recombinant DNA construct wherein expression of the recombinant DNA construct results in production of altered levels of a protein capable of conferring resistance to head smut in the transformed maize cell when compared to levels of expression in a wild-type maize plant having resistance to head smut.   
     
     
         8 . A method of altering the level of expression of a protein capable of conferring resistance to head smut in a maize plant, said method comprising:
 a. transforming a maize plant cell with the recombinant DNA construct of  claim 1 ;   b. regenerating a transformed maize plant from the transformed maize plant cell; and   c. growing the transformed maize plant under conditions that are suitable for expression of the recombinant DNA construct wherein expression of the recombinant DNA construct results in production of altered levels of a protein capable of conferring resistance to head smut in the transformed maize plant when compared to levels of expression in a wild-type maize plant having resistance to head smut.