Meeting Abstract

P3.207  Sunday, Jan. 6  Exploring physiological effects of temperature sensor activation in Symbiodinium DIAZ-ALMEYDA, E*; MEDINA, M; IGLESIAS-PRIETO, R; University of California Merced; Unidad Academica Puerto Morelos, UNAM; University of California Merced ediaz-almeyda@ucmerced.edu

Symbiodinium is a genus of dinoflagellates that lives in symbiosis with a variety of marine invertebrates, and other eukaryote groups including corals. Rising temperatures due to climate change cause the breakdown of this symbiosis, in a phenomenon designated as coral bleaching. This phenomenon threatens coral reefs on a global scale. It has been proposed that the dinoflagellates are the most temperature sensitive component of the symbiosis and therefore responsible for the fragility of reefs. TRP channels have been identified as temperature sensors in a variety of organisms, but it’s role has not been explored in the context of climate change in symbiotic dinoflagellates. These channels can be activated by increases in temperature or by exposing the cells to capsaicin. In order to test if a temperature increases have similar effect as the chemical activation of the TRP channel, here we characterize the physiological responses of Symbiodinium cultures exposed to 100uM of capsaicin. Changes in growth rate relative to the control (no capsaicin) were observed. Non-significant changes were observed in the quantum yield of charge separation (Fv/Fm). A decrease in the oxygen production was measured with the presence of capsaicin. Ultra-structural changes were observed under fluorescent microscopy. Collectively, our results suggest that capsaicin has a different physiological effect than those observed in thermally stressed algal cultures.