Effects of temperature and different nitrogen sources on Cladocopium goreaui
Yulin Huang 1, Senjie Lin 1,2
1. College of Ocean and Earth Sciences, Xiamen University, China
2. State Key Laboratory of Marine Environmental Science (Xiamen University)
The efficient nitrogen cycling between corals and their symbiotic algae Symbiodiniaceae allows coral reefs to flourish in tropical waters that are mostly nutrient-poor (especially nitrogen limited). Though studies have found that elevated ocean temperature could destruct this fragile symbiotic relationship and cause mass coral bleaching, it remains unknown how thermal stress can effect nitrogen utilization by Symbiodiniaceae and nitrogen cycling within the holobiont. In this study, physiological responses of symbiodiniaceae Cladocopium goreaui to temperatures (25˚C and 31˚C) when supplied with different nitrogen sources (ammonium, nitrate, and urea) were investigated. The results showed that population growth of C. goreaui was markedly suppressed under high temperature. Cell size increased under high temperature, along with higher cellular chlorophyll α content, cellular carbon and nitrogen content. C. goreaui cells fixed nitrogen more rapidly when suppled with ammonium rather than urea or nitrate.
Keywords：Symbiodiniaceae, heat stress, nitrogen nutrient uptake.
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