中文摘要：

[目的]进一步揭示千湿交替灌溉对水稻籽粒灌浆影响的机制。[方法]两优培九（两系杂交籼稻）和扬粳4038（粳稻）种植于土培池，自抽穗至成熟设置常规灌溉（conventional irrigation，CI）、轻干一湿交替灌溉（alternate wetting and moderate drying irrigation，WMD）和重干一湿交替灌溉（alternate wetting and severe drying irrigation，WSD）3种土壤水分处理，运用双向电泳技术测定水稻强、弱势粒蛋白质表达量。[结果]与CI相比，WMD和WSD对强势粒的灌浆速率和粒重无显著影响；WMD显著增加了弱势粒的灌浆速率和粒重，WSD则显著降低了弱势粒的灌浆速率和粒重。WMD和WSD对强势粒蛋白质表达无显著影响，但wMD上调了弱势粒中丙酮酸磷酸双激酶、甘油醛-3-磷酸脱氢酶、5-甲基四氢叶酸-同型高半胱氨酸甲基转移酶、S-腺苷甲硫氨酸合酶、乙二醛酶I和锰超氧化物歧化酶等蛋白质的表达，WSD则下调了弱势粒中上述蛋白质的表达。WSD还上调了抑制信号传导和能量代谢等有关蛋白的表达。两品种结果趋势一致。[结论]说明在WMD或WSD条件下，弱势粒中多种与灌浆相关蛋白质表达的差异是其灌浆速率和粒重增加或降低的重要原因。

英文摘要：

[Objective] This study aimed to understand the mechanism underlying the effect of alternate wetting and drying irrigation on grain filling of rice. [Method] Two rice cultivars, Liangyoupeijiu （two-line indica hybrids） and Yangjing 4038 （japonica）, were grown in cement tanks. Three irrigation regimes, conventional irrigation （CI）, alternate wetting and moderate drying irrigation （WMD） and alternate wetting and severe drying irrigation （WSD）, were imposed from full heading to maturity. The expressions of the proteins in superior and inferior spikelets were investigated using the method of two-dimensional gel electrophoresis. [Result] No significant differences in grain-filling rate and grain weight were observed for the earlier-flowering superior spikelets among the three irrigation regimes. For the later-flowering inferior spikelets, however, their grain-filling rate and grain weight were significantly increased under the WMD, but significantly reduced under the WSD when compared with those under the CI. Both WMD and WSD showed no significant impact on the protein expressions in superior spikelets. However, the WMD enhanced expressions of many proteins, such as orthophosphate dikinase, glyeeraldehyde-3-phosphatedehydrogenase, 5-methyltetrahydropteroyltfiglutamate-homocysteine methyltransferase, S-adenosylmethionine synthetase, glyoxalase I and manganese superoxide dismutase in inferior spikelets, whereas the WSD inhibited expressions of these proteins. The WSD also up-regulated expressions of some proteins, such as the proteins related to the inhibition of signal transduction and energy metabolism.The two cultivars exhibited the same tendencies. [Conclusion] Expression differences of the proteins related to grain filling in inferior spikelets account for their increases or decreases in grain-filling rate and grain weight under the WMD or WSD.