内源无机磷酸盐对叶绿体Mg^（2＋）－ATP酶功能的调节  

The Regulation of Endogenous Inorganic Phosphate in chloroplasts on Its Mg￣(2+)-ATPase Function

作　　者：魏家绵[1] 李德耀[1] 任汇森 

机构地区：[1]中国科学院上海植物生理研究所

出　　处：《植物生理学报（0257-4829)》1995年第2期105-110,共6页Acta Phytophysiologica Sinica

基　　金：国家自然科学基金

摘　　要：用ＳＴＮ（含蔗糖，０．４ｍｏｌ／Ｌ；ＮａＣｌ，０．０１ｍｏｌ／Ｌ和Ｔｒｉｓ－ＨＣｌ，０．０２ｍｏｌ／Ｌ，ｐＨ７．４）提取的菠菜叶片叶绿体再用ＳＴＮ洗涤后，它的内源无机磷酸盐含量急剧减少，其Ｍｇ２＋－ＡＴＰ酶水解ＡＴＰ的能力明显下降。进一步研究表明：叶绿体的内源无机磷酸盐含量减少会使反映叶绿体类囊体膜内外△ｐＨ变化的９－氨基吖啶的荧光猝灭减少，并加速光激活态ＡＴＰ酶的暗失活。The regulatory action of endogenous inorganic phosphate in the chloroplasts on Mg2+-ATPase function wasstudied. The endogenous inorganicphosphate content in chloroplasts decreased markedly after washing withSTN (sucrose, 0. 4 mol/L; NaCI,0. 01 mol/L and Tris-HCI, 0. 02 mol/L, pH 7. 4) buffer. This decrease inhibited the Mg2+-ATPase activitymarkedly (Table 1, 2).Further studies showed that thedecrease of endogenous inorganic phosphate content in.chloroplasts accelerated the dark deactivation of Mg2+-ATPase of chloroplasts after light activation (Fig. 2). At the same time it lowered the change of 9-aminoacridinefluorescence quenching of chloroplasts(Fig. 3 and Table 4). If the chloroplasts were washed with STNNa2HPO4 (5 mmol/L) and so that theinorganic phOSPhate content of chloroplasts between control and STNNa2HPO4 washed had no differencesignifcantlly, the above effects couldnot be obtained (Table 3 and Fig. 3).The above resultS indicate thatendogenous inorganic phosphate playan important role in regulating theMg2+-ATPase function of chloro-plas-ts. Itcan not only control the stabilityof the light activated state of ATPasebut also △pH formation across the thylakoid membranes.

关 键 词：叶绿体 内源无机磷酸盐 镁 腺苷三磷酸酶 

分 类 号：Q732[生物学—分子生物学]