Physiological and Molecular Biology of High Temperature Stress in Plants

During the past few years, climate change induced by global warming had caused the appearance of extreme high temperatures worldwide, which had resulted in devastating damage to crop production. High Temperature Stress (HTS) is becoming an increasingly significant problem for agricultural production. Recent studies have elucidated the complex regulatory networks and versatile metabolites involved in HTS tolerance. Here, we provided an overview of current knowledge regarding the adverse effect of HTS on plant growth and development, the impairment of HTS on photosynthesis and membrane system, the role of carbohydrate metabolism, accumulation of osmo-protectants and secondary metabolites, the induced production of Reactive Oxygen Species (ROSs) and ROS detoxification system, and the synthesis of protective proteins like Heat Shock Proteins (HSPs) in HTS tolerance. Furthermore, the role of different phytohormones in plant response to HTS were discussed and epigenetic modifications are reported to be one of the three major signaling pathways associated with HTS response in plants, through the development of a ‘stress memory’ that is generated by hypomethylation to improve the plant’s survival under recurring HTS conditions. These physiological and molecular knowledge underlying plant response to cope with HTS will be helpful for the future directions of breeding crop tolerance to HTS using these factors or other strategies for agricultural applications.