Effects of high-temperature stress on crop plants

Abstract

High-temperature stress is leading abiotic stress that restricts plant growth, development and yield globally. It reduces plants' productivity, affecting their morphological, physiological, phenological, biochemical and molecular reactions. Major effects of heat stress include impaired membrane systems, denaturation of proteins, enzyme inactivation etc. Responses of plants towards high-temperature stress vary from species to species, with duration and degree of the stress. Plant scientists' main goal is to develop various techniques/practices for satisfying enhanced crop yields and quality. In the cropping system, legumes grains have a significant role in promising food security to the increasing world population. However, legumes are susceptible to several abiotic stresses and heat stress has been known as a primary constraint in limiting their production. Also, the quantity and quality of seed storage proteins are negatively affected by high-temperature stress. Therefore, new approaches to improve legume heat tolerance are critical for reducing yield losses. Plants have several mechanisms for high-temperature stress such as enzymatic and non-enzymatic antioxidant systems, ion transporter and heat shock proteins activated to cope with stress-induced alterations. This review highlights the current research on various responses of plants to heat stress and plant thermo-tolerance mechanisms at the molecular level and illustrates the role of different exogenous molecules in alleviating the heat-induced damages and transgenic methods used to improve plants' tolerance to high temperatures.