Oxidative stress responses in the marine antarctic diatom Chaetoceros brevis (Bacillariophyceae) during photoacclimation

The enzyme superoxide dismutase (SOD) holds a key position in the microalgal antioxidant network. The present research focused on oxidative stress responses in the Antarctic diatom Chaetoceros brevis F. Schutt during transition to excess (including ultraviolet radiation [UVR]) and limiting irradianc...

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Bibliographic Details
Published in:Journal of Phycology
Main Authors: Janknegt, Paul J., van de Poll, Willem H., Visser, Ronald J. W., Rijstenbil, Jan W., Buma, Anita G. J.
Format: Article in Journal/Newspaper
Language:English
Published: 2008
Subjects:
Antarctic microalgae
malondialdehyde
oxidative stress
photoacclimation
photosystem II efficiency
superoxide dismutase
UV radiation
xanthophyll cycle
UV-B RADIATION
NATURAL PHYTOPLANKTON COMMUNITIES
SOLAR ULTRAVIOLET-RADIATION
SUPEROXIDE-DISMUTASE
DIADINOXANTHIN CYCLE
PLANKTONIC DIATOM
OXYGEN-TOXICITY
PHAEODACTYLUM-TRICORNUTUM
ISOLATED-CHLOROPLASTS
ABSORBING COMPOUNDS
Antarctic
The Antarctic
Antarc*
Online Access:http://hdl.handle.net/11370/f75bdeed-1453-48fe-b51a-0820947d5acf
https://research.rug.nl/en/publications/oxidative-stress-responses-in-the-marine-antarctic-diatom-chaetoceros-brevis-bacillariophyceae-during-photoacclimation(f75bdeed-1453-48fe-b51a-0820947d5acf).html
https://doi.org/10.1111/j.1529-8817.2008.00553.x
Description
Summary:The enzyme superoxide dismutase (SOD) holds a key position in the microalgal antioxidant network. The present research focused on oxidative stress responses in the Antarctic diatom Chaetoceros brevis F. Schutt during transition to excess (including ultraviolet radiation [UVR]) and limiting irradiance conditions. Over a 4 d period, cellular responses of thiobarbituric acid reactive substances (TBARS, a general oxidative stress indicator), SOD activity, photosynthetic and xanthophyll cycle pigments, PSII efficiency, and growth were determined. In addition, oxidative responses were measured during a daily cycle. Changing irradiance conditions significantly affected growth rates of C. brevis. PSII efficiency decreased significantly during periodic excess irradiance and increased under low irradiance conditions. Transition to excess irradiance increased the ratio of xanthophyll to light-harvesting pigments, whereas the opposite was observed for cultures transferred to low irradiance. This acclimation process was completed after 2 d in the new irradiance environment. SOD activity increased significantly after the first day regardless of the new irradiance environment but returned to preexposure values on the fourth day. We hypothesize that SOD activity may be temporarily elevated in C. brevis after irradiance shifts, thereby reducing oxidative stress when photoacclimation is in progress.

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