目的 为了阐明水稻灌浆期耐夜间高温的分子机制,提高水稻耐热性,鉴定了水稻近等基因系耐热纯系XN0437T与热敏感纯系XN0437S在灌浆期夜间高温胁迫下的差异表达蛋白质。方法 采用桶栽方法培育水稻,于开花期标记同一天扬花的颖花以保障所取颖花样品的生育进程一致;于水稻灌浆初期(花后第8天)进行夜间高温处理。高温处理结束后剪取带标记的颖花提取水稻籽粒总蛋白质,采用8-plex iTRAQ试剂盒进行蛋白质样品的差异显色标记,标记样品采用高效液相系统进行质谱鉴定及定量分析。结果 鉴定并定量了3130个蛋白质,耐热与热敏感水稻纯系间存在36个差异表达蛋白质。蛋白质功能注释结果显示,鉴定的36个差异表达蛋白质中仅14个蛋白质(占38.9%)注释了功能,12个蛋白质(占33.3%)为推测性功能注释, 10个(占27.8%)为功能未知的蛋白质。已注释功能的14个蛋白质中,5个蛋白质参与能量代谢,3个蛋白质参与物质转运与代谢,2个蛋白质参与光合作用,3个蛋白质为响应逆境的锌指蛋白质,1个蛋白质为响应逆境的热激蛋白质。结论 灌浆期夜间高温影响水稻籽粒细胞内参与能量代谢、物质转运与代谢、光合作用等相关蛋白质的表达模式。水稻籽粒细胞中锌指蛋白质Q67TK9、Q10N88上调表达,锌指蛋白质Q5YLY5下调表达,有利于提高水稻灌浆期对夜间高温的耐热性。

【Objective】To understand molecular mechanism of rice tolerance to high night temperature at filling stage,we identify the differentially expressed proteins (DEPs) and screen the proteins involving in regulating the heat-tolerance in rice. 【Method】The heat-tolerant rice line XN0437T and the heat-sensitive rice line XN0437S originated from a near-genetic lines were used as plant materials. Rice was pot-cultivated under traditional management. To ensure that only grain samples with uniform growth were used for proteomes analysis, rice panicle bloomed on the same date were labeled with same markers and spikelets flowering on the same date on the labeled panicle were further labeled. On the 8th day after flowering, rice plants with same label were transferred to chambers for high night temperature treatment.Rice grains with same label were harvested and total proteins of the grain samples were extracted after high temperature treatment. The 8-plex iTRAQ kits combined with the LC-MS/MS technology were used to analyze the DEPs between the heat-tolerant and heat-sensitive lines. 【Result】After protein’s databases searching and differentially expressed proteins analysis, 3130 proteins were finally identified and 36 proteins showed differential expression levels between the heat-tolerant and heat-sensitive line. For the 36 DEPs, 14 proteins (38.9%) had functional annotation, 12 (33.3%) had putative function, and 10 (33.3%) were functional unknown proteins. The 14 function-known proteins were involved in energy metabolism (five proteins), transport and metabolism (three proteins), photosynthesis (two proteins) and defense response (four proteins). 【Conclusion】High night temperature impacts the expressed patterns of the proteins involved in energy metabolism, matter transport and metabolism, photosynthesis and defense response in rice at filling stage. We suggested that up-regulated expression of the zinc finger proteins (Q67TK9 and Q10N88), and down-regulated expression of the zinc finger protein (Q5YLY5) in rice grain could enhance the heat-tolerance in rice.