Back to Search
Start Over
Inhibition of photosynthetic CO2 fixation in the coral Pocillopora damicornis and its relationship to thermal bleaching
- Source :
- Journal of Experimental Biology.
- Publication Year :
- 2014
- Publisher :
- The Company of Biologists, 2014.
-
Abstract
- Two inhibitors of the Calvin-Benson cycle (glycolaldehyde, GA, and potassium cyanide, KCN) were used in cultured Symbiodinium cells and in nubbins of the coral Pocillopora damicornis to test the hypothesis that inhibition of the Calvin-Benson cycle triggers coral bleaching. Inhibitor concentration range-finding trials aimed to determine the appropriate concentration to generate inhibition of the Calvin-Benson cycle, but avoid other metabolic impacts to the symbiont and the animal host. Both 3 mM GA and 20 μM KCN caused minimal inhibition of host respiration, but did induce photosynthetic impairment, measured by a loss of photosystem II function and oxygen production. GA did not affect the severity of bleaching, nor induce bleaching in the absence of thermal stress, suggesting inhibition of the Calvin-Benson cycle by GA does not initiate bleaching in P. damicornis. In contrast, KCN did activate a bleaching response through symbiont expulsion, which occurred in the presence and absence of thermal stress. While KCN is an inhibitor of the Calvin-Benson cycle, it also promotes reactive oxygen species formation, and it is likely that this was the principal agent in the coral bleaching process. These findings do not support the hypothesis that temperature-induced inhibition of the Calvin-Benson cycle alone induces coral bleaching.
- Subjects :
- Photoinhibition
biology
Physiology
Coral bleaching
Carbon fixation
Potassium cyanide
food and beverages
Pocillopora damicornis
Aquatic Science
biology.organism_classification
Photosynthesis
Symbiodinium
chemistry.chemical_compound
chemistry
Insect Science
Botany
Biophysics
Animal Science and Zoology
Light-independent reactions
Molecular Biology
Ecology, Evolution, Behavior and Systematics
Subjects
Details
- ISSN :
- 14779145 and 00220949
- Database :
- OpenAIRE
- Journal :
- Journal of Experimental Biology
- Accession number :
- edsair.doi...........575aa6f032b302ff5f246ccac95bf97a