Flash-induced relaxation changes of the EPR signals from the manganese cluster and YD reveal a light-adaptation process of Photosystem II
By exposing photosystem II (PSII) samples to an incrementing number of excitation flashes at room temperature, followed by freezing, we could compare the Mn-derived multiline EPR signal from the S-2 oxidation state as prepared by 1, 5, 10, and 25 flashes of light. While the S-2 multiline signals exhibited by these samples differed very little in spectral shape, a significant increase of the relaxa