Singlet oxygen oxidation products of carotenoids, fatty acids and phenolic prenyllipids.

Singlet oxygen (O) is the major reactive oxygen species ROS causing photooxidative stress in plants which is formed predominantly in the reaction center of photosystem II during photosynthesis. To avoid deleterious effects of O oxygen on photosynthetic membrane components, plant synthesize a variety of O quenchers of lipophilic character, such as carotenoids or phenolic prenyllipids (tocopherols, plastochromanol-8, plastoquinol). In the process of chemical quenching of O by the antioxidants, both short-lived products, such as oxidized carotenoids, or relative long-lived compounds, such as oxidized phenolic prenyllipids are formed. The other target of O are unsaturated fatty acids of membrane lipids that undergo peroxidation as a result of the reaction. Some of the O oxidation products, like β-cyclocitral can be components of O-signallingsignaling pathway leading to acclimatory responses of plants, while some others further fulfill antioxidant functions, like hydroxy-plastochromanol or hydroxy-plastoquinol. As most of the O oxidation products are specific compounds formed only as a results of O action, they can be very useful, specific molecular markers of O-dependent oxidative stress in vivo.

Copyright © 2021 Elsevier B.V. All rights reserved.