[Effect of oxidizing and reducing agents on the rate of water proton relaxation in the chloroplasts of beans and particles of photosystem 2].

The change of longitudinal proton relaxation rate, 1/T1, in the native and shocked chloroplasts, PS2 chloroplasts' particles and exogenous complexes Mn2+--PPCI (pigment--protein complex of PSI), Mn2+--PPCII in the presence of the PS2 donors and acceptors and at different pH change were studied. It has been shown that 1/T1 increases in chloroplasts and PS2 particles in the presence of the PS2 donors and decreases in the presence of the acceptors in contrast to untreated preparations. The 1/T1 change of exogenous complexes is not specific. The results suggest that the manganese pool of the chloroplasts PS2 may be the main factor responsible for the chloroplasts' proton relaxation rate. The change of the manganese valency in the presence of donors and of acceptors may result in changing 1/T1.