Dual urea utilization enzyme systems in Symbiodiniaceae coral symbionts under warming

BACKGROUND: Urea has been shown to be important as a nitrogen (N) nutrient for coral holobionts, but the mechanism underpinning urea utilization by symbiotic algae is not fully understood. In this study, we investigated the molecular pathways underlying urea utilization in the Symbiodiniaceae family and the responses of these pathways to different N-nutrient conditions and heat stress through comprehensive genomic screening, multi-omics analysis and stable isotope pulse-chase experiments. RESULTS: uptake. Omics analyses suggest that responses to different nitrogen, light, and temperature conditions were more likely mediated by UAL. CONCLUSIONS: This study reveals two distinct urea utilization systems in the coral ecosystem and their differential responses to warming, highlighting the importance of urea as N-nutrient when facing global warming.