Microrna polymorphisms conferring enhanced drought tolerance in a plant

Abstract

Methods of identifying a single nucleotide polymorphism associated with a plant trait and methods of identifying a plant having an improved trait. The plant trait is correlated with at least one single nucleotide polymorphism in a microRNA region of a plant genome. Isolated nucleic acids, transgenic plants, and methods of producing the same are also disclosed.

What is claimed is: 
     
         1 . A method of producing a maize plant using marker-assisted breeding, wherein said maize plant confers increased grain yield at standard moisture percentage, the method comprising the steps of:
 (a) crossing a first maize plant or a progeny thereof with a second maize plant, wherein said first maize plant or progeny thereof has been selected for said crossing based on the presence of at least one polymorphism within a marker locus of its genome, wherein said marker locus is associated with increased grain yield at standard moisture percentage and wherein said marker locus is SEQ ID NO: 69;   (b) producing a progeny plant population from the cross of (a);   (c) selecting a progeny plant from the progeny plant population of (b) based on genotyping the progeny plant's genomic DNA and selecting a progeny plant having at least one polymorphism within the marker locus of its genome, wherein said marker locus is associated with increased grain yield at standard moisture percentage and wherein said marker locus is SEQ ID NO: 69; and   (d) producing a maize plant using marker-assisted breeding wherein said maize plant confers increased grain yield at standard moisture percentage.   
     
     
         2 . The method of  claim 1 , wherein the at least one single nucleotide polymorphism is located in a pre-miRNA portion of the microRNA region. 
     
     
         3 . The method of  claim 1 , wherein the at least one single nucleotide polymorphism is located at a nucleotide corresponding to a position selected from the group consisting of:
 (a) position 444 of SEQ ID NO: 69, wherein the nucleotide is a C;   (b) position 500 of SEQ ID NO: 69, wherein the nucleotide is a C;     
     
     
         4 . The method of  claim 2 , wherein the pre-miRNA portion of the microRNA region comprises SEQ ID NO: 67. 
     
     
         5 . The method of  claim 2 , wherein the pre-miRNA portion of the microRNA region comprises SEQ ID NO: 68. 
     
     
         6 . The method of  claim 1 , wherein the at least one single nucleotide polymorphism is located in a mature miRNA portion of the microRNA region. 
     
     
         7 . The method of  claim 6 , wherein the mature miRNA portion of the microRNA region comprises SEQ ID NO: 67. 
     
     
         8 . A method of identifying a maize plant having enhanced drought tolerance, the method comprising:
 (a) correlating at least one single nucleotide polymorphism in a microRNA region of a plant genome with enhanced drought tolerance;   (b) sequencing a corresponding microRNA region in the plant; and   (c) detecting the at least one single nucleotide polymorphism in the microRNA region comprising SEQ ID NO: 69.   
     
     
         9 . The method of  claim 8 , wherein the at least one single nucleotide polymorphism is located in a pre-miRNA portion of the microRNA region. 
     
     
         10 . The method of  claim 8 , wherein the at least one single nucleotide polymorphism is located at a nucleotide corresponding to a position selected from the group consisting of:
 (a) position 444 of SEQ ID NO: 69, wherein the nucleotide is a C;   (b) position 500 of SEQ ID NO: 69, wherein the nucleotide is a C;     
     
     
         11 . The method of  claim 9 , wherein pre-miRNA portion of the microRNA region comprises SEQ ID NO: 67. 
     
     
         12 . The method of  claim 9 , wherein pre-miRNA portion of the microRNA region comprises SEQ ID NO: 68. 
     
     
         13 . The method of  claim 8 , wherein the at least one single nucleotide polymorphism is located in a mature miRNA portion of the microRNA region. 
     
     
         14 . The method of  claim 13 , wherein the mature miRNA portion of the microRNA region comprises SEQ ID NO: 67.