Role of salicyclic acid in helping wheat maintain resistance against hessian fly (Mayetiola destructor) infestation under heat stress

Resistance of plants to parasites is heavily impacted by environmental factors. In this study, we analyzed the survival and development of an avirulent Hessian fly (HF), Mayetiola destructor (Say), population ‘White eye’ on a resistant wheat cultivar ‘Molly’, and a susceptible cultivar ‘Newton’ exposed to varying periods of 40ºC heat stress. We observed that Molly began to lose resistance when subjected to 3 h heat stress, and the loss of resistance increasingly continued with 6 h of heat stress. When 2 mM salicylic solution (SA) was applied to Molly foliage before heat stress, more plants maintained their resistance than plants without SA application. Our results indicate that short periods of heat stress decreases the effectiveness of wheat resistance against Hessian fly infestation, but the application of SA significantly restores resistance in plants under heat stress.