黄瓜叶片光合电子传递对水分胁迫的响应

黄瓜叶片在水分胁迫下叶片相对含水量减少，类囊体室温吸收光谱的吸收峰降低，同时其NADP光还原活性、Ca^2 -ATPase活性也相应降低，全链电子传递明显受阻。类囊体膜蛋白电泳分析结果显示：类囊体膜色素蛋白复合体含量有不同程度的降低，其中PSⅡ色素蛋白复合体含量下降较多，试验结果表明水分胁迫通过限制光能的吸收，传递双及转换效率，抑制了光合电子传递过程。

Respones of photosynthetic electron transfer to water stress in cucumber leaves

Under water stress,the relative water content of cucumber leaves decreased and the electron transfer velocity in whole chain significantly slowed down with the reduction of the activities on NADP photoreduction,on Ca2+-ATPase and the lowering peak of absorption spectrum at room temperature on cucumber thylakoids.Furthermore,the results,which were obtained by analyzing SDS-PAGE pattern,showed that the polypeptides content of thylakoid membrane declined in different degree,especially the protein complex polypeptides bound to photosystem Ⅱ.As demonstrated above,these observations suggest that the process of photosynthetic electron transport was inhibited under water stress is due to the decreased efficiency of light-energy absorption,transportation and transformation on thylakoid membrane.