Effect of PG depletion on dark-induced inactivation of photosynthetic oxygen-evolving activity. Wild-type (squares), PG-depleted pgsA (circles), ΔpsbO (triangles), ΔpsbV (inverted triangles), and ΔpsbU (pentagons) cells were incubated under dark conditions for the designated time, and photosynthetic oxygen-evolving activity was measured at 30°C. One hundred percent activity that reflects the initial activity just prior to moving to the dark condition were 1,130, 398, 810, 851, and 913 μmol O2 mg Chl−1 108 cells−1 for the wild-type cells and the PG-depleted pgsA, ΔpsbO, ΔpsbV, and ΔpsbU mutant cells, respectively.