[ESR signals of photosystem II after complete removal of manganese from pea subchloroplast particles].

The effect of reversible extraction of Mn on ESR signal II arising from the oxidized secondary electron donor (Z+) and the ESR doublet signal related to reduced spin-coupled pheophytin (pheo -) and "primary" electron acceptor (PA- -Fe (2+)) has been studied in oxygen evolving preparations of the photosystem 2. It is demonstrated that Mn extraction does not affect both dark and photoinduced ESR signal II and ESR doublet. A conclusion is made that Mn is not a component of the secondary electron donor Z of the Photosystem 2 and its complete removal has no effect on the exchange interaction of Pheo(-) and the PQ(-) -Fe(2+) complex.