Photosystem II (PSII) is a multisubunit protein complex in cyanobacteria, algae and plants that use light energy for oxidation of water and reduction of plastoquinone. The conversion of excitation energy absorbed by chlorophylls into the energy of separated charges and subsequent water-plastoquinone oxidoreductase activity are inadvertently coupled with the formation of reactive oxygen species (ROS). Singlet oxygen is generated by the excitation energy transfer from triplet chlorophyll formed by the intersystem crossing from singlet chlorophyll and the charge recombination of separated charges in the PSII antenna complex and reaction center of PSII, respectively. Apart to the energy transfer, the electron transport associated with the reduction of plastoquinone and the oxidation of water is linked to the formation of superoxide anion radical, hydrogen peroxide and hydroxyl radical. To protect PSII pigments, proteins and lipids against the oxidative damage, PSII evolved a highly efficient antioxidant defense system comprising either a non-enzymatic (prenyllipids such as carotenoids and prenylquinols) or an enzymatic (superoxide dismutase and catalase) scavengers. It is pointed out here that both the formation and the scavenging of ROS are controlled by the energy level and the redox potential of the excitation energy transfer and the electron transport carries, respectively. The review is focused on the mechanistic aspects of ROS production and scavenging by PSII. This article is part of a Special Issue entitled: Photosystem II.

Department of Biophysics Centre of the region Haná for Biotechnological and Agricultural Research Faculty of Science Palacký University Czech Republic

References provided by Crossref.org

A Comprehensive Study of Light Quality Acclimation in Synechocystis Sp. PCC 6803

Genomic capacities for Reactive Oxygen Species metabolism across marine phytoplankton

N6-methyladenosine RNA modification regulates photosynthesis during photodamage in plants

Reactive oxygen species in photosystem II: relevance for oxidative signaling

Tocopherol controls D1 amino acid oxidation by oxygen radicals in Photosystem II

Stem Photosynthesis-A Key Element of Grass Pea (Lathyrus sativus L.) Acclimatisation to Salinity

Formation of α-tocopherol hydroperoxide and α-tocopheroxyl radical: relevance for photooxidative stress in Arabidopsis

Characterization of Protein Radicals in Arabidopsis

Endosymbiotic Evolution of Algae, Secondary Heterotrophy and Parasitism

Mechanism of the Formation of Electronically Excited Species by Oxidative Metabolic Processes: Role of Reactive Oxygen Species

Singlet oxygen imaging using fluorescent probe Singlet Oxygen Sensor Green in photosynthetic organisms

Formation of singlet oxygen by decomposition of protein hydroperoxide in photosystem II

Amino acid oxidation of the D1 and D2 proteins by oxygen radicals during photoinhibition of Photosystem II

Production of Reactive Oxygen Species by Photosystem II as a Response to Light and Temperature Stress

Bcl-2△21 and Ac-DEVD-CHO Inhibit Death of Wheat Microspores

Detection of hydrogen peroxide in Photosystem II (PSII) using catalytic amperometric biosensor

The formation of electronically excited species in the human multiple myeloma cell suspension

Evidence for the involvement of loosely bound plastosemiquinones in superoxide anion radical production in photosystem II

Formation of superoxide anion and carbon-centered radicals by photosystem II under high light and heat stress-EPR spin-trapping study

Evidence on the formation of singlet oxygen in the donor side photoinhibition of photosystem II: EPR spin-trapping study