Mg2+对生长在不同光强下的小麦叶绿体光合功能的影响

研究结果表明,Mg~(2+)对生长在不同光强度下的小麦叶绿体光合功能有不同影响。与生长在低光强(2×10~8勒克斯)下的小麦叶绿体相比,Mg~(2+)更加明显地降低从生长在高光强(2×10~4勒克斯)下的小麦所分离的叶绿体的吸收光谱在红区和蓝区的吸收峰值;但它更大幅度地提高后者在低温(77K)下的PSⅡ相对荧光产量(F_(687))与PSⅠ相对荧光产量(F_(742))的比值,PSⅡ活性和PSⅡ原初光能转化效率。实验结果证明,更高的光强度可能有利于叶绿体形成更多可流动的LHC-Ⅱ和LHC-Ⅰ。

EFFECTS OF MG~(2+) ON PHOTOSYNTHETIC FUNCTIONS OF CHLOROPLASTS FROM WHEAT SEEDLING GROWN UNDER DIFFERENT LIGHT INTENSITIES

Effects of Mg2+ on photosynthetic functions of chloroplasts from wheat seedling grown under different light intensities were studied. The experimental results showed that the absorption peak values at both the red and blue regions of the absorption spectrum of chloroplasts of wheat grown under high light intensity were decreased by Mg2+ according to a bigger margin as compared with those of chloroplasts of wheat grown under low light intensity; nevertheless, the ratio of the relative fluorescence yield of PS Ⅱ (F687)to that of PSⅠ(F742) , the activity and efficiency of primary conversion of light energy of PS Ⅱ in high-light wheat chloroplasts were raised by Mg2+ accordnig to a bigger margin. The experimental result showed that higher light intenstiy was probably advantageous to chloroplasts to form more movable LHC- Ⅱ and LHC-Ⅰ.