REVERSIBLE AND IRREVERSIBLE CHANGES OF FLUORESCENCE PARAMETERS DURINGPHOTOINHIBITION IN THE SYNECHOCOCCUS-ELONGATUS CELLS

A decrease of F(m) followed with a certain delay by an increase of F(o ) was detected in the cells of Synechococcus elongatus in the first 12 0 min of the photoinhibitory treatment at 56-degrees-C (growth tempera ture). Then F(m) started to rise in parallel with F(o) and this proces s proceeded with the same rate both in the light and in the dark at 56 -degrees-C after light treatment. On the contrary, an increase of F(o) observed during the light treatment at 15-degrees-C was largely rever sed after subsequent transfer of the cells to the dark at 56-degrees-C but F(m) remained nearly unchanged during the dark incubation.