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Phlorotannin and Antioxidant Responses Upon Short‐term Exposure to UV Radiation and Elevated Temperature in Three South Pacific Kelps
Author(s) -
Cruces Edgardo,
Huovinen Pirjo,
Gómez Iván
Publication year - 2011
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2011.01013.x
Subject(s) - photoinhibition , antioxidant , photosynthesis , chemistry , lipid peroxidation , photoprotection , chlorophyll fluorescence , photochemistry , oxidative stress , botany , temperate climate , biophysics , environmental chemistry , biology , biochemistry , photosystem ii
Rapid adjustments of the photosynthetic machinery and efficient antioxidant mechanisms to scavenge harmful ROS are physiologic adaptions exhibited by intertidal seaweeds to persist in temperate regions. This study examines short‐term (3 h) responses of three large kelps from the cold‐temperate coast of Chile, normally adapted to water temperatures <16°C, but exposed abruptly to simultaneous high temperatures and UV radiation during low tide in summer. The kelps were exposed in the laboratory to three temperatures (10, 20 and 28°C) with and without UV radiation, and photochemical reactions, concentration of phlorotannins and antioxidant activity were examined. The exposure to elevated temperature (slightly exacerbated by the presence of UV radiation) decreased photochemical processes (measured as fluorescence kinetics) in the three studied species and increased lipid peroxidation in two of them. The concentration of total soluble phlorotannins was variable and correlated with the antioxidant activity in the presence of UV radiation. Insoluble phlorotannins did not change during the exposure. In all, the downregulation of the photochemical machinery, which was expressed as dynamic photoinhibition, and the rapid induction of soluble phlorotannins triggered by UV radiation minimized the effects of oxidative stress and maintained the operation of photochemical processes during short‐term thermal stress.