Abstract:

【Objective】 To evaluate the influence of high temperature stress on the quality formation of storage protein in rice, since the protein content and its composition in endosperm are important target to improve rice quality and nutrition value. 【Method】 A treatment of high temperature stress during filling stage was conducted to analyze the influence of high-temperature stress on the composition and accumulation configuration of storage protein in rice. 【Result】 Filling process, single-grain weight, accumulation process and accumulation configuration of storage protein in grain at 25℃ treatment were coincide with these at natural condition. Filling process of grain was accelerated and single-grain weight was reduced by 35℃ treatment. Not only content of crude protein was increased, but also the composition and accumulation configuration of storage protein changed by high temperature stress. The relative content of prolamin was decreased by 7.5% compared to control. Although the relative content of glutelin, the staple storage protein, not changed with high-temperature stress, but the relative content of two glutelin subunits was reduced by 12.7%. Simultaneously, the pro-glutelin of 57 kD and the glutelin polymer above 57 kD was improved by 19.5%. 【Conclusion】 These data in this trial indicated that the composition and accumulation configuration of storage protein in rice grain changed with high temperature stress, and the reduction of content of two glutelin subunits and prolamin has no relation with the ability of nitrogen supplied to grain and with the ability of protein synthesis, but has close correlation with procedure of transformation, transport, aggregation and degradation of post-translation protein under the condition of high-temperature stress.

Key words: rice(Oryza sativa L.), filling stage, high-temperature stress, storage protein, aggregation, quality characters