EFFECT OF HEAVY METALS ON THE PHOTOSYNTHESIS AND PHOTOSYNTHATES TRANSFORMATION IN RICE
GE Cai-linLUO Jian-fengLIU ChongYIN Chao-zhenWANG Ze-gangMA FeiLUO Shi-shi(Key Laboratory of Crop Genetics and Physiology of Jiangsu, Yangzhou University, Yangzhou, Jiangsu,225009)
The photosynthetic rate in rice leaf was significantly inhibited by 0.025～1.0mmol/L of Cu~(2+), Cd~(2+) and Hg~(2+). With increasing of Cu~(2+), Cd~(2+) and Hg~(2+) concentration, the inhibiting degree of photosynthetic rate was enhanced. Tracer kinetic analysis indicated that, 0.5mmol/L Cu~(2+), Cd~(2+) and Hg~(2+) inhibited the transformation between starch and sugar, disturbed the translocation of photosynthates from leaves. Consequently, sugar accumulated in the leaves, which might induce a feedback-regulation of photosynthetic rate. Using polyacrylamide concentration gradient gel electrophoresis to analyze the activity of amylase isozymes indicateed that, the amylase isozymes expression in rice leaf was inhibited by 0.1～0.5mmol/L Cu~(2+), Cd~(2+) and Hg~(2+), hence, the transformation between starch and sugar was blocked.