Regulation of temperature stress in plants

Abstract

Plant, during its entire life cycle, from seedling to reproductive stage, faces changing environment that is sometimes unfavorable for growth and developmental processes; plants develop specific mechanism to overcome these environmental stresses. Adverse environmental factors are categorized majorly in two categories: first biotic factors that include pathogen and herbivore attacks, and second, abiotic factors that include drought, heat, cold, nutrient deficiency, and heavy-metal accumulation in the soil. Among these, salt, drought, and temperature affect the geographical distribution of plant species as well as disrupt the plant metabolism. As a consequence, they limit the quality and quantity of food production in agriculture and reducing the food demand for growing population, and to overcome these adverse effects, tolerance mechanism in plants has been well studied. In general, various environmental factors (biotic and abiotic) induce the plant resistance by activation of stress tolerance genes. The average temperature was found to be increased by 0.2°C/year and it has to be increased by 1.8°C-4°C at the end of year 2100, hence temperature is pondered to be one of the utmost detrimental stress. Climate change due to temperature is a global concern that has altered the physiological and biochemical activities of plant, thereby reducing the productivity of crops. Increased temperature continuously caused heat stress in plants, which depends upon the quality, intensity, and duration of light. Generation of reactive oxygen species is a common phenomenon exhibited by all environmental factors (biotic and abiotic), including heat stress that damaged the macromolecules, such as DNA, proteins, and lipids, and plants are under oxidative stress. Furthermore, heat stress also altered the expression of genes that participate in the formation of and responsible for production of osmoprotectants, detoxifying enzymes, transporters, and regulatory proteins. On contrary to this, heat stress inhibits the protein folding, affects the membrane (lipid bilayer) fluidity and cytoskeleton arrangement, and also affects the vegetative and reproductive tissue. Rise in temperature up to a certain limit is beneficial for plant that regulates the circadian rhythms in plants, regulates plant movements (opening/closing of corolla), and also affects the geographical distribution of plants in nature. Plants susceptibility toward pathogen was also enhanced by high temperature. Infection capacity of tobacco mosaic and tomato-spotted wilt viruses were found to be increased when ambient temperature increased and caused viral diseases in tobacco (Nicotiana tabacum) and pepper (Capsicum annuum), respectively. In wheat genotypes, its sensitivity toward Cochliobolus sativus (caused spot blotch) was associated with increase in nighttime temperature. © 2020 Elsevier Inc. All rights reserved.