Abstract: To verify the direct effect of H+ATPase on the root cell elongation, the T2  generation seeds of the rice plasma membrane H+ATPase gene OsA8 (AJ440219) overexpressed transgenic materials (OE1) were used as samples. Firstly, the differences in seed germination rate and the growth rate of primary roots between the overexpressed  line and the wildtype were determined. Secondly, the activities of H+ATPase in the root cell membranes isolated by twophase separation method were compared and then the OsA8 gene expression at the transcriptional level was  determined. The protein concentration of H+ATPase of these two materials was  analyzed by Western blot. The results showed that not only the germination rate but also the growth rate of primary roots of OE1 were higher than that of wildtype. In addition,  OE1 has  much higher  activity of the root plasma membrane H+ATPase  than wildtype. The expression of OsA8 gene  and protein concentration of   OE1 was also   higher than  that of wildtype. The results indicated that the overexpression of the plasma membrane H+ATPase gene OsA8 in the OE1 rice is the main factor of the elevation of the H+ATPase activity, which contributed to the increased seed germination rate and growth of primary root.

Key words: 水稻, 细胞膜H+ATPase, OsA8, 萌发

摘要： 构建了质子泵基因OsA8（AJ440219）超表达的水稻株系（OE1），以其T2代种子为材料，研究细胞膜质子泵基因超表达对种子萌发的影响。结果表明，质子泵超表达的种子不仅发芽速度快，而且初生根生长也比野生型快。鉴定了OsA8及其他质子泵基因在转录水平上的表达差异，并通过两相分离法纯化了初生根系质膜的H+ATPase，检测其活性。通过蛋白质免疫杂交技术分析比较超表达的水稻株系与野生型水稻根系H+ATPase酶蛋白浓度的差异。结果显示，超表达材料根系OsA8基因的表达量高于野生型，其单位膜蛋白中质膜H+ATPase蛋白的浓度也显著高于野生型，因而其根系质膜H+ATPase活性高于野生型。超表达材料OE1的种子萌发速率和初生根的生长速率均快于野生型的主要原因很可能就是质子泵基因OsA8在OE1水稻种子中超量表达所引起的下游生理效应。

关键词: 水稻, 细胞膜H+ATPase, OsA8, 萌发