Coral bleaching has a profound impact on the health and function of reef ecosystems, but the metabolomic effects of coral bleaching are largely uncharacterized. Here, untargeted metabolomics was used to analyse pairs of adjacent Montipora capitata corals that had contrasting bleaching phenotypes during a severe bleaching event in 2015. When these same corals were sampled four years later while visually healthy, there was a strong metabolomic signature of bleaching history. This was primarily driven by betaine lipids from the symbiont, where corals that did not bleach were enriched in saturated lyso-betaine lipids. Immune modulator molecules were also altered by bleaching history in both the coral host and the algal symbiont, suggesting a shared role in partner choice and bleaching response. Metabolomics from a separate set of validation corals was able to predict the bleaching phenotype with 100% accuracy. Experimental temperature stress induced phenotype-specific responses, which magnified differences between historical bleaching phenotypes. These findings indicate that natural bleaching susceptibility is manifested in the biochemistry of both the coral animal and its algal symbiont. This metabolome difference is stable through time and results in different physiological responses to temperature stress. This work provides insight into the biochemical mechanisms of coral bleaching and presents a valuable new tool for resilience-based reef restoration.

珊瑚白化对珊瑚礁生态系统的健康和功能有着深远的影响，但珊瑚白化的代谢组学效应在很大程度上是未知的。在这里，非靶向代谢组学被用来分析成对的相邻的Montipora capita在 2015 年一次严重的白化事件中，珊瑚具有截然不同的漂白表型。当这些相同的珊瑚在四年后在视觉健康的情况下被采样时，有一个强烈的漂白历史的代谢组学特征。这主要是由共生体中的甜菜碱脂质驱动的，其中没有漂白的珊瑚富含饱和溶血甜菜碱脂质。珊瑚宿主和藻类共生体的漂白历史也改变了免疫调节剂分子，这表明在伙伴选择和漂白反应中有共同作用。来自一组单独的验证珊瑚的代谢组学能够以 100% 的准确度预测漂白表型。实验温度应激诱导表型特异性反应，这放大了历史漂白表型之间的差异。这些发现表明，自然漂白敏感性体现在珊瑚动物及其藻类共生体的生物化学中。这种代谢组差异随着时间的推移是稳定的，并导致对温度应激的不同生理反应。这项工作提供了对珊瑚白化的生化机制的深入了解，并为基于恢复力的珊瑚礁恢复提供了一个有价值的新工具。