Molecular diversity of storage glycerolipids in coral–dinoflagellate symbiosis
摘要
Corals form symbiotic relationships with dinoflagellates (Symbiodiniaceae) where lipids play vital metabolic roles. Storage lipids, particularly triacylglycerols (TAG) and monoalkyldiacylglycerols (MADAG), constitute over half of total lipids but remain understudied compared with membrane lipids. The present review summarizes recent data (from 2016 until present) on the molecular species of storage glycerolipids in corals and their endosymbiotic dinoflagellates. The high storage lipid content of corals likely results from their symbiotic relationships with autotrophic organisms. All symbiotic coral species contain an abundance of saturated TAG and MADAG along with molecular species containing polyunsaturated fatty acids (PUFA). These PUFA-rich storage lipids may be associated with the species of their symbiotic dinoflagellates that contain TAG with C16,18,20,22 fatty acids. Seasonal variations mainly have an effect on PUFA-rich molecular species of storage lipids, while bleaching depletes largely saturated molecules. During thermal stress, corals exhibit a conserved utilization hierarchy: the initial consumption of symbiont-derived TAG precedes the host MADAG mobilization which is followed by comprehensive lipid profile rearrangement during recovery. Despite the ecological importance of corals as reef builders and their sensitivity to climate change, the molecular basis of coral’s storage lipids and their symbiotic regulation remains poorly characterized, limiting our understanding of coral resilience mechanisms. This necessitates an integrated lipidomics approach to future studies.