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

Pavel Pospíšil

doi:10.3389/fpls.2016.01950

Abstract

The effect of various abiotic stresses on photosynthetic apparatus is inevitably associated with formation of harmful reactive oxygen species (ROS). In this review, recent progress on ROS production by photosystem II (PSII) as a response to high light and high temperature is overviewed. Under high light, ROS production is unavoidably associated with energy transfer and electron transport in PSII. Singlet oxygen is produced by the energy transfer form triplet chlorophyll to molecular oxygen formed by the intersystem crossing from singlet chlorophyll in the PSII antennae complex or the recombination of the charge separated radical pair in the PSII reaction center. Apart to triplet chlorophyll, triplet carbonyl formed by lipid peroxidation transfers energy to molecular oxygen forming singlet oxygen. On the PSII electron acceptor side, electron leakage to molecular oxygen forms superoxide anion radical which dismutes to hydrogen peroxide which is reduced by the non-heme iron to hydroxyl radical. On the PSII electron donor side, incomplete water oxidation forms hydrogen peroxide which is reduced by manganese to hydroxyl radical. Under high temperature, dark production of singlet oxygen results from lipid peroxidation initiated by lipoxygenase, whereas incomplete water oxidation forms hydrogen peroxide which is reduced by manganese to hydroxyl radical. The understanding of molecular basis for ROS production by PSII provides new insight into how plants survive under adverse environmental conditions.

Highlights

Photosystem II (PSII) is water-plastoquinone oxidoreductase embedded in the thylakoid membrane that catalyzes light-driven H2O oxidation to O2 and plastoquinone (PQ) reduction to plastoquinol (PQH2; Dau et al, 2012; Vinyard et al, 2013; Nelson and Junge, 2015; Suga et al, 2015; Najafpour et al, 2016)
It has been demonstrated that primary (LOOH) and secondary (LOH, reactive carbonyl species (RCS), and electronically excited species) lipid peroxidation products are formed at high light
The impact of high light on the photosynthetic apparatus is considered to be of particular significance as light reactions of photosynthesis are inhibited prior to other cell functions are impaired

Summary

Introduction

Photosystem II (PSII) is water-plastoquinone oxidoreductase embedded in the thylakoid membrane that catalyzes light-driven H2O oxidation to O2 and plastoquinone (PQ) reduction to plastoquinol (PQH2; Dau et al, 2012; Vinyard et al, 2013; Nelson and Junge, 2015; Suga et al, 2015; Najafpour et al, 2016). Several lines of evidence were provided in the last three decades on the oxidative damage of PSII proteins by ROS under high light (Aro et al, 1993) and high temperature (Yamamoto et al, 2008). Hydrogen peroxide is formed by the one-electron reduction of O2− and the two-electron oxidation of H2O on the PSII electron acceptor and donor sides, respectively (Figure 2).

Results

Conclusion