Plants having increased tolerance to heat stress

Abstract

The invention relates to methods of producing a desired phenotype in a plant by manipulation of gene expression within the plant. The method relates to means which increase the level of expression of a MYB-subgroup14 polynucleotide or a MYB68 polypeptide. The method also relates to expression of a nucleic acid sequence encoding a MYB-subgroup14 or a MYB68 transcriptional factor. The methods are directed to elevating the levels of a MYB-subgroup14 or a MYB68 expression, wherein a desired phenotype such as reduced flower abortion and increased yield during heat stress is observed. The invention also relates to nucleic acid sequences useful in such methods.

1 . A method of producing a heat stress tolerant plant comprising:
 a) providing a nucleic acid construct that increases the expression of a MYBsubgroup-14 polypeptide;   b) inserting said nucleic construct into a vector;   c) transforming a plant, tissue culture, or a plant cell with the vector to obtain a plant, tissue culture or a plant cell with increased expression of said MYB subgroup-14 polypeptide;   d) growing said plant or regenerating a plant from said tissue culture or plant cell, wherein a heat stress tolerant plant is produced.   
     
     
         2 . A heat stress tolerant transgenic plant produced by the method claim of  1 . 
     
     
         3 . A transgenic seed produced by the transgenic plant of  claim 2 , wherein said seed produces a heat stress tolerant plant. 
     
     
         4 . A method of identifying a heat stress tolerant plant, wherein the plant has reduced flower abortion and increased yield as compared to a control plant comprising
 a. exposing a population of flowering plants to a heat stress treatment; and   b. selecting a plant from said population of plants having reduced flower abortion thereby identifying a heat stress tolerant plant.   
     
     
         5 . A plant identified by the method of  claim 4 . 
     
     
         6 . A seed produced by the plant identified by the method of  claim 4 , wherein said seed produces a heat stress tolerant plant.