Affiliation:
1. Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences Xiamen University Xiamen China
2. State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Marine Biology and Fisheries Hainan University Haikou China
3. Department of Marine Sciences University of Connecticut Groton Connecticut USA
4. Laboratory of Marine Biology and Biotechnology Qingdao National Laboratory of Marine Science and Technology Qingdao China
Abstract
AbstractCoral reefs thrive in the oligotrophic ocean and rely on symbiotic algae to acquire nutrients. Global warming is projected to intensify surface ocean nutrient deficiency and anthropogenic discharge of wastes with high nitrogen (N): phosphorus (P) ratios can exacerbate P nutrient limitation. However, our understanding on how symbiotic algae cope with P deficiency is limited. Here, we investigated the responses of a coral symbiotic species of Symbiodiniaceae, Cladocopium goreaui, to P‐limitation by examining its physiological performance and transcriptomic profile. Under P stress, C. goreaui exhibited decreases in algal growth, photosynthetic efficiency, and cellular P content but enhancement in carbon fixation, N assimilation, N:P ratio, and energy metabolism, with downregulated expression of carbohydrate exporter genes. Besides, C. goreaui showed flexible mechanisms of utilizing different dissolved organic phosphorus to relieve P deficiency. When provided glycerol phosphate, C. goreaui hydrolyzed it extracellularly to produce phosphate for uptake. When grown on phytate, in contrast, C. goreaui upregulated the endocytosis pathway while no dissolved inorganic phosphorus was released into the medium, suggesting that phytate was transported into the cell, potentially via the endocytosis pathway. This study sheds light on the survival strategies of C. goreaui and potential weakening of its role as an organic carbon supplier in P‐limited environments, underscoring the importance of more systematic investigation on future projections of such effects.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Hainan Province
Subject
General Environmental Science,Ecology,Environmental Chemistry,Global and Planetary Change