ABSTRACT
Non-biotic stress agents such as low or high temperatures, flooding, ultra-violet radiations (UV), heat waves, oxidizing agents, heavy metal and metalloids, and salts in the contemporary era of changing climate is escalating day by day due to various natural and anthropogenic sources. The sessile nature of crop plants is thus challenged by a myriad of abiotic and biotic pressures, thus restricting their growth and productivity worldwide. The plants’ growth and development involve various hormonal, metabolic, genetic, and environmental cues which are chiefly synchronized by ambient as well as internal factors. Plants respond to these factors morphologically and physiologically. In current times, when the global temperature is mounting at a shocking rate, plants have also adapted improved tolerance mechanisms to cope with temperature-induced perturbations. Under these changing conditions, phytohormones are crucial signaling agents which mediate growth and developmental functions by changing their endogenous content, and ameliorating temperature-induced stress to a great extent. The ameliorating role of phytohormones under temperature stress conditions in conferring plant adaptation is in the infancy stage. Therefore, in the present chapter, we try to shed light on the recent ecophysiological and morphological responses of various crop plants under temperature (high) stress. Nevertheless, the adaptive role of three important phytohormones (salicylic acid, nitric oxide, and brassinosteroids) in controlling vital processes and stress tolerance is also discussed.
