Impact of climate change on wheat grain composition and quality

Wheat grain quality, an important determinant for human nutrition, is often overlooked when improving crop production for stressed environments. Climate change makes this task more difficult by imposing combined stresses. The scenarios relevant to climate change include elevated CO2 concentrations (eCO(2)) and extreme climatic events such as drought, heat waves, and salinity stresses. However, data on wheat quality in terms of climate change are limited, with no concerted efforts at the global level to provide an equitable and consistent climate risk assessment for wheat grain quality. Climate change induces changes in the quality and composition of wheat grain, a premier staple food crop globally. Climate-change events, such as eCO(2), heat, drought, salinity stress stresses, heat + drought, eCO(2) + drought, and eCO(2) + heat stresses, alter wheat grain quality in terms of grain weight, nutrient, anti-nutrient, fiber, and protein content and composition, starch granules, and free amino acid composition. Interestingly, in comparison with other stresses, heat stress and drought stress increase phytate content, which restricts the bioavailability of essential mineral elements. All climatic events, except for eCO(2) + heat stress, increase grain gliadin content in different wheat varieties. However, grain quality components depend more on inter-varietal difference, stress type, and exposure time and intensity. The climatic events show differential regulation of protein and starch accumulation, and mineral metabolism in wheat grains. Rapid climate shifting impairs wheat productivity and causes grain quality to deteriorate by interrupting the allocation of essential nutrients and photoassimilates. (c) 2022 Society of Chemical Industry.

Automated summary

The quality of wheat grain, which is crucial for human nutrition, is often neglected when focusing on crop production in stressed environments. Climate change, with combined stresses such as elevated CO2 concentrations and extreme climatic events, affects the quality and composition of wheat grain. This study highlights the limited data and lack of global efforts in assessing climate risks on wheat grain quality. Climate-change events, including eCO(2), heat, drought, salinity stress, and their combinations, alter various aspects of wheat grain quality, such as weight, nutrient content, fiber content, protein composition, starch granules, and free amino acid composition. Different stress types and exposure conditions also influence grain quality components. Impairment of wheat productivity and degradation of grain quality can occur due to disrupted nutrient allocation and assimilation under rapid climate shifts.