Tolerance to stress in wheat

Abstract

Achieving tolerance to stress is one of the main objectives of wheat breeding, and genes or chromosomal regions with positive effects on tolerance to biotic and abiotic stresses need to be identified. The interaction between defence signaling pathways mediated by several phythormones is an important mechanism for regulating defence responses against various types of pathogens and herbivories. The response of bread wheat, Triticum aestivum (2n=6x=42) to greenbug attack or to exogenous application of the stress-induced hormones ethylene (E), jasmonic acid (JA), salicylic acid (SA) or ABA was analysed. In recent years, several components regulating the cross-talk between SA, JA and ET pathways have been identified. Treatment of plants with these hormones results in enhanced resistance to biotic challenge. However, the underlying physiological mechanisms are not well understood. Some of the main wheat physiological pathways affected by the cross-talk between biotic stress and stress-induced hormones are described below.