High-temperature stress in wheat (Triticum aestivum L.): unfolding the impacts, tolerance and methods to mitigate the detrimental effects

High-temperature stress (HTS) is one of the most significant challenges that wheat has to face in changing climatic conditions. Rising atmospheric temperature worldwide severely affects its cultivation which ultimately impacts the yield parameters of wheat. To develop effective strategies toward mitigation of harmful effects of HTS, it becomes crucial to know the underlying changes occurring inside the plant. This review focuses on examining the morpho-physiological, biochemical, and molecular effects of HTS along with the tolerance mechanisms that plants employ. HTS damages membranes of chloroplast and decreases the efficiency of photosystem-II, reduces the activity state of RuBisCO, induces senescence during grain-filling stage that in turn reduces grain-filling time. Formation of more reactive oxygen species (ROS) has detrimental effects on photosynthesis and harms membrane properties. Grain weight, total protein and starch composition, and gliadin content are altered during HTS. Thermotolerance strategies used by plants viz., synthesis of enzymes that scavenge ROS, synthesis of heat shock proteins (HSPs) that guide in protein folding, translocation and regulation of phytohormones, post-translational mechanisms such as ubiquitin proteasome system and autophagy helps wheat plants minimize the heat stress effects. To combat future challenges of high-temperature stress, it becomes essential to implement rational scientific agricultural practices in cultivation and development of heat-stress-tolerant varieties. This review explores the impact of HTS on wheat at different levels. We also discuss agronomic practices, breeding techniques and molecular approaches for developing HTS-tolerant varieties that have better protection against high-temperature stress and better yield to meet with future food safety needs.