CHLOROPHYLL VARIABLE FLUORESCENCE UPON PHOSPHORYLATION OF THE CHLOROPLAST MEMBRANE-PROTEINS UNDER ANAEROBIC CONDITIONS

The induction curves of chlorophyll fluorescence were measured in pea chloroplasts phosphorylated under anaerobic conditions in the presence of the electron transport inhibitor 2,5-dibromo-3-methyl-6-isopropyl- p-bensoquinone. In the absence of the inhibitor, upon chloroplast phos phorylation, F0 and F(m) decreased in parallel, the ratio F(v)/F(m) re maining unchanged. In the presence of the inhibitor, F0 decreased and F(m) increased, leading to a rising F(v)/F(m) ratio. The possible caus es of these phenomena are discussed.