XVI International Botanical Congess

The consequence of restricted mitochondrial metabolism on photosynthetic induction and light activation of chloroplastic enzymes was assessed in mesophyll protoplasts of pea. The lag or induction period of photosynthesis increased significantly in presence of oligomycin (inhibitor of oxidative phosphorylation) or antimycin A (inhibitor of cytochrome pathway) while light activation of NADP-GAPDH, FBPase, PRK and NADP-MDH decreased markedly in presence of SHAM (inhibitor of alternative pathway). Our results suggest cytochrome pathway or oxidative phosphorylation modulates photosynthetic induction while alternative pathway appears to modulate the light activation of chloroplastic enzymes.