title: Implications of mycosporine-like amino acid and antioxidant defenses in UV-B radiation tolerance for the algae species Ptercladiella capillacea and Gelidium amansii.
abstract: Ultraviolet-B (UV-B) radiation (0.5, 1.0, 1.5, and 3.0Wm(-2)) induced higher H(2)O(2) production and lipid peroxidation in alga Gelidium amansii inhabiting in lower subtidal regions than upper subtidal alga Ptercladiella capillacea. Compared to G. amansii, mycosporine-like amino acid (MAA) concentration in P. capillacea was higher and can be increased by 0.5-1.0Wm(-2) UV-B, while carotenoid concentration was lower but also increased by 1.5-3.0Wm(-2) UV-B. UV-B increased ascorbate concentration, but to a higher degree in P. capillacea. UV-B decreased glutathione concentration, but to a higher degree in G. amansii. UV-B increased ascorbate peroxidase (APX) and glutathione reductase (GR) activities in P.capillacea but decreased them in G. amansii. UV-B increased superoxide dismutase and catalase activities, but to a higher degree in G. amansii. So, G. amansii suffered greater oxidative stress from UV-B radiation. P. capillacea can effectively reduce UV-B sensitivity by increasing sunscreen ability and antioxidant defense capacity.
authors.affiliation: Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung, Taiwan 80424, Republic of China. tmlee@mail.nsysu.edu.tw
authors.forename: Tse-Min
authors.initials: TM
authors.lastname: Lee
authors.forename: Chia-Tai
authors.initials: CT
authors.lastname: Shiu
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D000461:Rhodophyta / Q000201:enzymology / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D004798:Enzymes; D017392:Thiobarbituric Acid Reactive Substances; D002338:Carotenoids; D006861:Hydrogen Peroxide