Impact of heat stress on wheat genes responsive to Hessian fly infestation

Heat stress compromises wheat (Triticum aestivium) resistance to Hessian fly (Mayetiola destructor (Say). This study aims to investigate the impact of heat stress on transcript expression profile of wheat plants resistant to Hessian fly infestation. Molly, a wheat cultivar containing the resistance gene (R gene) H13 was subjected to four different treatments: 1) CK (plants growing under normal temperature without Hessian fly infestation, 2) Infest (plants infested with an avirulent biotype GP Hessian fly). 3) Heat (plants heat stressed at 35ºC for 6-h without infestation, 4) Heat+Infest (plants treated with the combination of heat stress and Hessian fly infestation. Samples from Hessian fly feeding site tissue in wheat plants were collected for RNA isolation, cDNA library construction, and RNA-Seq analysis. Through differential gene expression analysis, we identified 21 genes that are regulated by Hessian fly infestation during the incompatible interaction and 155 genes that are regulated by Hessian fly in the heat stressed plants. We further analyzed the impact of heat stress on those Hessian fly regulated genes and identified 14 candidate genes that may contribute to the heat-induced loss of wheat resistance to Hessian fly.