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

Paul J. Janknegt*, Willem H. van de Poll, Ronald J. W. Visser, Jan W. Rijstenbil, Anita G. J. Buma

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

41 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)957-966
Number of pages10
JournalJournal of Phycology
Volume44
Issue number4
DOIs
Publication statusPublished - Aug-2008

Keywords

  • 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

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