Light-induced damage of the photosynthetic apparatus in plants is an important phenomenon that primarily affects the photosystem II complex. Here, we propose a new model of photoinhibition in which charge recombination processes have a double-faced role: first, photodamage is induced by singlet oxygen, which is produced via interaction with the triplet reaction center chlorophyll (3P680) arising from the recombination of the charge-separated state between P680 and the pheophytin electron acceptor (3[P680+Phe-]). Second, photoprotection is provided by competition between 3[P680+Phe-] formation and direct recombination of the 1[P680+Phe-] and P680+QA- states. The efficiency of these two pathways is under control of the redox potential of the Phe and QA electron acceptors, which is utilized during adaptation to high light conditions.
ASJC Scopus subject areas
- Plant Science