Physiological, Biochemical, and Molecular Mechanisms of Heat Stress Tolerance in Plants

Abstract

High temperature (HT) stress is a major environmental stress that limits plant growth, metabolism, and productivity worldwide. Plant growth and development involve numerous biochemical reactions that are sensitive to temperature. Plant responses to HT vary with the degree and duration of HT and the plant type. HT is now a major concern for crop production and approaches for sustaining high yields of crop plants under HT stress are important agricultural goals. Plants possess a number of adaptive, avoidance, or acclimation mechanisms to cope with HT situations. In addition, major tolerance mechanisms that employ ion transporters, proteins, osmoprotectants, antioxidants, and other factors involved in signaling cascades and transcriptional control are activated to offset stress-induced biochemical and physiological alterations. Plant survival under HT stress depends on the ability to perceive the HT stimulus, generate and transmit the signal, and initiate appropriate physiological and biochemical changes. HT-induced gene expression and metabolite synthesis also substantially improve tolerance. The physiological and biochemical responses to heat stress are active research areas, and the molecular approaches are being adopted for developing HT tolerance in plants. This article reviews the recent findings on responses, adaptation, and tolerance to HT at the cellular, organellar, and whole plant levels and describes various approaches being taken to enhance thermotolerance in plants.

Spatio-Temporal Analysis of Meteorological Elements in the North China District of China during 1960–2015

“…When the T max was under 30 • C, the higher the T max , the more yield obtained. Once the T max > 30 • C, which was defined as a high temperature by Schauberger [44], the crop enzymes and tissues are damaged [63,64] and the temperature impairs flowering [65], leads to precocious maturity and senescence [66], and triggers oxidative stress [67]. So, crop yields decline rapidly due to high temperatures, especially under rainfed conditions [4,6,44].…”

Heat shock increases oxidative stress to modulate growth and physico-chemical attributes in diverse maize cultivars

“…The ROS are strong oxidizing agents that cause cell death by lipid peroxidation, oxidation of proteins and induce substantial damage to DNA (Hasanuzzaman et al, 2013). Plants are able to circumvent ROS-induced oxidative stress through the antioxidant defense system.…”

“…Plant growth and development involve many biochemical reactions that are sensitive to HT stress. Plant responses to HT vary with the degree, duration and the plant type (Hasanuzzaman et al, 2013). The global air temperatures are expected to raise 2.0ºC per decade, which could lead to temperatures 1.8-4.0ºC greater by the end of this century mostly due to greenhouse gas emissions (IPCC, 2007).…”

“…High temperature alters the photosynthetic acclimation and physiological processes directly and modifies the pattern of development indirectly. Heat shock (HS) stress causes various, and often severe changes in plant growth, development, physiological processes and final economic yield in different crop species (Hasanuzzaman et al, 2013).…”

Phenological and Growth Responses of Indian Mustard (Brassica juncea L.) Genotypes to Different Sowing Dates

“…The rise in temperature, even by a single degree beyond the threshold level is considered as heat stress in the plants (Hasanuzzaman et al, 2013, Wahid et al, 2007. The global mean surface air temperature increased by 0.5°C in the twentieth century and is expected to increase a further 1.5-4.5°C by the late twenty-first century (IPCC, 2012).Climate change has increased the intensity of heat stress and heat stress due to increased temperature is an agricultural problem in many areas in the world as well as in India (Beck et al, 2007).…”