[Light-dependent reactions of Mn2+ and P700+ in chloroplasts during flash illumination]

The changes of the light-induced ESR signal I and exogeneous Mn2+ ions in chloroplasts of Vicia faba plants have been studied under short flash excitation and weak background far red illumination. It is shown that Mn2+ ions reactivate the noncyclic electron transport in chloroplast previously inactivated with high tris concentrations under pulse illumination. Simultaneously with P700+ reduction the ESR signal of free Mn2+ ions decays stoichometrically to P700+ reduction.