Fig. 4: Kinetics of light-dependent electron flow in Mn-depleted PSII at various concentrations of solvated Mn2+ ions.

The decrease in absorption at 604 nm monitors the light-driven reduction of the artificial electron acceptor (60 µM DCPIPox, pH 7) due to the oxidation of Mn2+ ions by PSII. See Supplementary Fig. 7 for traces on a longer time scale. The gray dashed line illustrates the rate of DCPIP reduction by fully intact PSII under similar conditions (Supplementary Fig. 5). Source data are provided as a Source Data file.