Figure 2.

EPR signal of the Pheo⁻ radical in doubly reduced PS II membranes, after continuous illumination with white (black) and far-red at 732 nm light (red), at 20 °C, for 6 and 10  min respectively. EPR conditions were as follows: microwave power 1.27 μW, microwave frequency 9.139 GHz, modulation amplitude 3.5 G, temperature, 15 K.