不同植物光合膜中镁离子诱导荧光同膜表面电荷变化相关性的比较研究

COMPARATIVE STUDY ON THE RELATIONSHIP BETWEEN Mg(2+)-INDUCED FLUORESCENCE CHANGE AND Mg(2+)-INDUCED THYLAKOID SURFACE CHARGE ALTERATION IN THE CHLOROPLASTS ISOLATED FROM DIFFERENT PLANTS

用水培的大麦苗及1992年夏、秋在青岛汇泉湾采集的大叶藻和利松藻制备叶绿体膜，观测了Mg2+诱导它们的PS－IICkla荧光和膜表面电荷变化之间的相互关系。发现在大麦和大叶藻中，Mg2+诱导荧光的增高与其诱导膜表面电荷密度的降低平行相关；而在刺松藻中，则无类似的相关性变化。这不仅证明在大麦和大叶藻的叶绿体膜中阳离子对激发能分配的调节作用受膜表面静电性质的控制，而在刺松藻的叶绿体膜中则与膜表面静电性质的变化无关；揭示这两种不同的调节机理与植物的生长环境无关，而可能取决于植物的进化程度。

Chloroplasts isolated from barley (Hordeum galgare L.) seedling grown in liquid solution and from Zot,era marina and Codium fragile collected in summer and autumn of 1992 at Huiquan Bight of Qingdao Were used in this study on the rela-tionship between Mg2+-induced Chla fluorescence change and Mg2+-induced thylakoid surface charge alteration in chloroplasts. Result shows that Mg2+-induced Chla fluorescence intensity increase from PS-II closely correlated with Mg2+-induced electric charge density decrease on the outer surface of the thylakoid in the chloroplasts from barley and Zostera marina. However, under the same conditions the correlation was not noted in the chloroplast from Codium jragile. These experimental results not only demonstrated that the regulating effect of the cation on excitation energy distribution between two photosystems was controlled by the electrostatic property of the thylakoid surface in the chloroplasts of barley and Zostera marina and not controlled by the electrostatic property of the thylakoid surface in the. Chloroplast of Codium lragile, but also illustrated that these two kinds of regulating mechanisms did not depend on the growing environment of plants while they might be associated with the evolutional level of plants.