ABSTRACT
Fluctuations in temperature are crucial factors that affect plant growth and the final fruit set. In plants, temperature stress is categorized into chilling, freezing or high temperatures. Temperature‐stressed plants display low germination rates, growth reduction and retarded photosynthesis, ultimately resulting in death. Temperature extremes cause evaporation or freezing of water available to the plants, thus affecting water absorption and transport, leading to osmotic stress. Moreover, temperature stresses stimulate the synthesis of reactive oxygen species (ROS) which then damage lipid, protein and DNA. To survive under stressed conditions, plants upregulate various defense mechanisms, which include osmolyte synthesis and antioxidant defense, which then enable the plants to maintain osmotic balance and stabilize membranes, thereby preventing oxidative burst. This chapter summarizes the impact of temperature extremes on osmotic and oxidative stress-induced redox imbalance in crops, with a special focus on the role of antioxidants and organic solutes in inducing thermotolerance.
