title: Ultraviolet irradiation induced oxidative stress and response of antioxidant system in an intertidal macroalgae Corallina officinalis L.
abstract: The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L. to different dosages of UV-B irradiation was investigated. Results showed that superoxide dimutase (SOD) and peroxidase (POX) increased and then maintained at a relatively stable level when subjected to UV-B irradiation. Catalase (CAT) activity under medium dosage of UV-B irradiation (Muv) and high dosage of UV-B irradiation (Huv) treatments were significantly decreased. Ascorbate peroxidase (APX) activity first remained unaltered and then increased in Huv treatment. In addition, the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis (PAGE). The activities of some SOD isoforms were altered by UV-B. Two new bands (POX V and POX VII) appeared upon exposure to all three UV-B dosages. CAT III activity was increased by low dosage of UV-B irradiation (Luv), whereas CAT III and CAT IV disappeared when the alga was exposed to Muv and Huv. Two bands of APX (APX VI and APX VII) were increased and a new band (APX X) was observed under Huv exposure. H2O2 and thiobarbituric acid reacting substance (TBARS) increased under Muv and Huv treatments. Overall, UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C. officinalis.
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao 266003, China. lilixianet@126.com
authors.forename: Lixia
authors.initials: L
authors.lastname: Li
authors.forename: Jiqiang
authors.initials: J
authors.lastname: Zhao
authors.forename: Xuexi
authors.initials: X
authors.lastname: Tang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D056890:Eukaryota / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D018384:Oxidative Stress / Q000528:radiation effects*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D055871:Tidal Waves; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D007527:Isoenzymes; D017392:Thiobarbituric Acid Reactive Substances; D006861:Hydrogen Peroxide