[ESR study of the state of manganganese in chloroplasts].

In chloroplasts isolated in tris-HCl buffer in the presence of 0.1 M NaCl or in the absence of salts an asymmetric ESR spectrum of Mn2+ was observed which differs in shape from the ESR spectrum of Mn2+ aquanions usually observed in chloroplasts treated with ultrasonics, reducer, 0.8 M tis-HCl buffer, pH 8. The transition from asymmmetric spectrum to the symetric one takes place in the presence of reducers and in some cases is induced with light. Causes of asymmetry of the ESR spectrum of Mn2+ in chloroplasts are discussed.