Poster: Temperature responses

Abs # 121: The molecular regulation of heat stress avoidance and tolerance strategies in wheat

Presenter:	Hays, Dirk B, dbhays@neo.tamu.edu
Authors	Hays, Dirk B (A)   Do, Jung H (A)   Yang, Zhuping B (A)
Affiliations:	(A): Department of Soil & Crop Sciences, Texas A&M University
Web Site:	http://soilcrop.tamu.edu/cgi-bin/showfaculty.cgi?faculty_oid=807177&research=1

Heat stress is a primary constraint to wheat production in many regions worldwide. Additional yield reductions from the predicted rise in global temperatures, and input costs will add further strain to food security, and farming businesses. In heat susceptible wheat genotypes, as in many cool season grasses, heat stress during reproductive development reduces photosynthesis, causes premature senescence and seed desiccation, and reduces yield through pollen sterility, seed abortion, and reduced tests weights, flour yield, and dough quality. While physiological traits have been associated with heat tolerance, what are lacking are the identification of the key loci and an understanding of the molecular and physiological basis of their regulation. We hypothesize that heat tolerance and avoidance (heat susceptible) in wheat is regulated by distinct sets of QTLs that regulate the three known adaptations to heat stress; i) plant morphology ii) optimal photosynthesis/stomatal conductance, and iii) suppression of signaling molecules that promote leaf senescence, seed abortion, and early programmed seed desiccation. Both whole plant physiological and functional genomic responses to heat stress will be presented for two wheat cultivars exhibiting the two unique adaptive responses to heat stress (i.e. tolerance and avoidance).