Effects of short-term post-anthesis high-temperature stress on dynamic process of accumulation of grain protein and its composition in rice (Oryza sativa L.)

Extremely high temperature decreases grain yield and grain quality in rice (Oryza sativa L.). To investigate the effects of short-term post-anthesis high-temperature stress on accumulation of grain protein and protein compositions in rice, 2-year experiments were carried out in phytotron with two different cultivars, Nanjing 41 (NJ41, heat-sensitive) and Wuxiangjing 14 (WJ14, heat-tolerant), under different conditions of high-temperature levels and durations during anthesis and grain-filling stages. The results showed that grain protein content and its components (albumin, globulin, and glutelin) increased with rising temperature levels and durations, while prolamin content decreased. The contents of total protein, storage protein, albumin, globulin, and prolamin in NJ41 were more sensitive to different temperature levels than those in WJ14. Moreover, the contents of albumin and prolamin in NJ41 changed greater under temperature durations than those in WJ14. The effects of high-temperature stress on accumulation of grain protein and composition were more sensitive to high-temperature levels and durations during anthesis stage than those during grain-filling stage. The results could help us further understand the physiochemical processes governing rice yield and quality under high-temperature conditions during rice anthesis and grain-filling stages.