油菜根系质膜H^＋ -ATPase活性对缺磷胁迫的反应  

Response of plasma membrane H^+-ATPase activity in roots of oil rape(Brassica napus L.)to phosphate deficiency

作　　者：包勇[1] 许征宇[1] 朱毅勇[1] 王杨[1] 刘世峰[1] 丁传雨[1] 姜尧[1] 张晓曼[1] 徐国华[1] 

机构地区：[1]南京农业大学资源与环境科学学院

出　　处：《南京农业大学学报》2008年第2期71-75,共5页Journal of Nanjing Agricultural University

基　　金：南京农业大学SRT项目(0507A10)

摘　　要：采用两相法分离水培油菜根系细胞膜,并测定了细胞膜H+-ATPase水解活性。结果表明,与供磷植物相比,活体条件下,缺磷处理植株根系大量分泌H+并被钒酸盐抑制,缺磷处理植株磷含量明显下降。细胞膜纯度达90%以上。离体条件下,缺磷和对照植株细胞膜H+-ATPase的最佳pH值均为6.0左右;缺磷油菜根系细胞质膜上H+-ATPase水解活性和Vm ax略有升高,Km和对钒酸盐的敏感性则降低。表明油菜根系细胞膜H+-ATPase水解活性升高是其适应缺磷的一种生理机制,通过提高H+-ATPase的活性很可能促进有机酸的分泌,从而活化根际土壤中被固定的磷。Oil rape was cultivated with nutrient solution and then plasma membranes were isolated from the roots by the two-phase system method to determine the plasma membrane H^＋ -ATPase activity. The results showed that, in comparison with the P sufficient plants, in vivo, the H ^＋ exudation by the P deficient plants increased and was inhibited by vanadate, and the P accumulation in P-deficient plants was much less. The purity of plasma membrane ATPase was above 90%. In vitro, the pH optimum for the P-sufficient and-deficient plants plasma membrane was pH 6.0 ; and both the hydrolytic activity and Vmax of the plasma membrane H ^＋ - ATPase in roots of P deficient oil rape increased, of which the Km and the vanadate sensitivity decreased. In conclusion, the data indicated that the enhancement of plasma membrane H ^＋ -ATPase activity in roots of oil rape is one of the physiological adaptations to the phosphate deficiency. Increased plasma membrane H^＋ -ATPase activity may promote the exudation of organic acids from the roots, which can mobilize the unavailable phosphate in the soil.

关 键 词：油菜 缺磷 细胞膜H^+ -ATPase 两相法 

分 类 号：Q556.9[生物学—生物化学] S634.3[农业科学—蔬菜学]