Fig. 1.

EPR spectra of the Tyr radicals from the Tris-washed PS II membranes at pH 8.5 induced by white light illumination (A, black spectra) or far-red light illumination (B, red spectra). Spectra shown are after 10 h dark incubation at room temperature (dotted line spectra), during continuous illumination (dashed line spectra) and after 5 min of dark incubation (solid line spectra). The arrows indicate the field position (3465 G) for the kinetics measurements. EPR conditions: microwave frequency 9.75 GHz, microwave power 8 mW, modulation amplitude 5 G, temperature 293 K