ABSTRACT
Temperature stress is becoming the major area of concern due to global climate change for researchers worldwide. Temperatures above the normal optimum are sensed as heat stress (HS) by all living organisms. It disturbs cellular homeostasis, uncouples major physiological and biochemical processes and leads to severe retardation in the growth and development and production of crops. Heat stress causes an abrupt increase in the expression of stress-associated proteins which provide tolerance by stimulating the defense response in plants. Heat-shock proteins (HSPs) and antioxidant enzymes are important in encountering heat stress in plants. The heat-shock response is characterized by repression of normal cellular protein synthesis and induction of HSP synthesis. Under heat stress, upregulation of various enzymatic and non-enzymatic antioxidants, maintenance of cell membrane stability, production of various compatible solutes and hormonal changes occur. However, strategies exist to crop improvement for heat stress tolerance. In this chapter, we present biochemical and molecular mechanisms of high temperature stress in crop plants.
