Heat Stress Effects and Tolerance in Wheat: A Review

Wheat is a major cereal crop and considered as source of basic calories and protein for more than 80% of the world population. Regarding the global climate change at the past few decades, the impact of rising temperature on wheat production is gaining concern worldwide. Heat and drought are the major abiotic stress limiting the wheat production. Heat stress interrupts the important physiological and biochemical process of the plant. High temperature stress reduces grain number, photosynthetic activity and chlorophyll content and starch synthesis in the endosperm. Reactive oxygen species accumulated under heat stress cause severe oxidative damage to the crop. Plant rapidly produces heat shock proteins to minimize the effect of heat stress. Several traits such as stay green, chlorophyll fluorescence and canopy temperature play significant role in heat tolerance. In order to develop new crop varieties that can cope with future climate, knowledge of heat stress effect and tolerance at physiological, biochemical and morphological level is highly important.