Chapter 3 - Effect of High Temperature on Protein Metabolism in Plants

Abstract

Abiotic stresses such as heat and drought are major abiotic stresses restraining crop production. Heat stress reduces plant growth by upsetting various morphological, anatomical, phenological, physiological, and biochemical processes and the developmental stage of the plant is critical in demonstrating the vulnerability of various species and cultivars subjected to high temperature. Direct injuries due to high temperatures in plants include protein denaturation and aggregation, and increased fluidity of membrane lipids. Indirect or slower high temperature injuries include inactivation of enzymes in chloroplasts and mitochondria, inhibition of protein synthesis, protein degradation, and loss of membrane integrity. Heat stress did not affect protein content but there is a strong correlation between leaf nitrogen content and grain protein content. Induction of heat shock proteins seems to be the universal response and adaptation to temperature stress. Plant cells respond to a transient increase in temperature by inducing or enhancing the synthesis of a characteristic set of heat shock proteins with at least partial suspension of normal cellular proteins synthesis, to focus the cell’s activities on addressing the physiological and biochemical changes caused by heat stress. It has been documented that due to the significant roles of osmolytes in response to heat stress, tolerance might be enhanced by increased accumulation of compatible solutes through traditional plant breeding, marker-assisted selection, or genetic engineering approaches.