OXIDATIVE STRESS RESPONSES IN THE MARINE ANTARCTIC DIATOM CHAETOCEROS BREVIS (BACILLARIOPHYCEAE) DURING PHOTOACCLIMATION(1)
| Autor: | Paul J. Janknegt, Anita G. J. Buma, Willem H. van de Poll, Jan W. Rijstenbil, Ronald J. W. Visser |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Irradiance Plant Science Aquatic Science Biology Malondialdehyde biology.organism_classification medicine.disease_cause Acclimatization Superoxide dismutase chemistry.chemical_compound chemistry Xanthophyll Botany TBARS biology.protein medicine Phaeodactylum tricornutum Food science Oxidative stress |
| Zdroj: | Journal of phycology. 44(4) |
| ISSN: | 0022-3646 |
| Popis: | 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 ultra- violet radiation (UVR)) and limiting irradiance con- ditions. 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 irradi- ance 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 com- pleted 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 tem- porarily elevated in C. brevis after irradiance shifts, thereby reducing oxidative stress when photoaccli- mation is in progress. |
| Databáze: | OpenAIRE |
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