title: The involvement of the antioxidant system in protection of desert cyanobacterium Nostoc sp. against UV-B radiation and the effects of exogenous antioxidants.
abstract: In this study, we found that UV-B radiation decreased photosynthetic activity and boosted lipid peroxidation of desert Nostoc sp., and exogenous chemicals (ascorbate acid (ASC), N-acetylcysteine (NAC), and sodium nitroprusside (SNP)) had obvious protective effects on photosynthesis and membranes under UV-B radiation. High-concentration SNP boosted the activities of antioxidant enzymes, but low-concentration SNP reduced the activities of antioxidant enzymes. Both NAC and ASC treatments of cells decreased activities of antioxidant enzymes. The results suggested that those chemicals possibly had different mechanisms of protection of algae cells against UV-B radiation. SNP might play double roles as a signal molecule in the formation of algae cell protection of Photosystem II under UV-B radiation and as a (reactive oxygen species) scavenger, while NAC and ASC might function as antioxidant reagents or precursors of other antioxidant molecules, which could protect cells directly against ROS initiated by UV-B radiation.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
authors.forename: Gaohong
authors.initials: G
authors.lastname: Wang
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.forename: Lanzhou
authors.initials: L
authors.lastname: Chen
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Hu
authors.forename: Delu
authors.initials: D
authors.lastname: Zhang
authors.forename: Yongding
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology*; D003889:Desert Climate; D046937:Nostoc / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D010788:Photosynthesis / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants