Species-specific variation in the metabolomic profiles of Acropora hyachintus and Acropora millepora mask acute temperature stress effects in adult coral colonies.

Coral reefs are suffering unprecedented declines in health state, on a global scale. Some researchers suggested that human assisted evolution (HAE) or assisted gene flow (AGF) may be necessary in order to effectively restore reefs and pre-condition them ready for the change in climate. To fully deploy such approaches, an omic-scale understanding of proposed transplanted corals would ensure desirable end benefits are achieved i.e. increased thermal resilience in the long term. To date, however, there is a dearth of research, particularly with regards to basic metabolomics understanding within Scleractinian corals. Here, the metabolomic profiles (measured using 1H nuclear magnetic resonance (1H NMR) spectroscopy and ultra-high-performance liquid chromatography-mass spectrometry (LC-MS)), of two dominant reef building corals, <i>Acropora hyacinthus</i> and <i>A. millepora,</i> from two distinct geographical locations (Australia, Great Barrier Reef and Singapore), were assessed. We explored how an acute temperature stress shifted the corals baseline metabolomic profile (an increase of 3.25^◦C ± 0.28 from ambient, control levels over 28 days). Regardless of profiling method utilised, metabolomic signatures of coral colonies were significantly distinct between coral species, a result supporting previous work undertaken. Interestingly, this strong species-specific metabolomic signature appeared to mask any differences resulting from the heat stress. This indicates that metabolomics may not be the most sensitive tool for use in studies assessing heat stress and/or adult colonies are not plastic in their metabolomic response to short stress events. That said, it is likely not that simple and further research is urgently needed in order to decouple the cause of this masked metabolomic signature with regard to a corals response to a changing climate.

全球范围内，珊瑚礁的健康状况正经历前所未有的衰退。部分研究者提出，为有效恢复珊瑚礁并使其预先适应气候变化，人类辅助进化（human assisted evolution, HAE）或辅助基因流动（assisted gene flow, AGF）或许是必要手段。

要全面应用这类干预手段，需对拟移植珊瑚开展组学尺度的解析，以确保实现理想的最终效益——即长期提升珊瑚的热耐受性。然而迄今为止，相关研究仍较为匮乏，尤其是关于石珊瑚（Scleractinian corals）的基础代谢组学研究。

本研究针对来自两个不同地理区域（澳大利亚大堡礁与新加坡）的两种造礁优势珊瑚——鹿角杯形珊瑚（*Acropora hyacinthus*）与多孔鹿角珊瑚（*A. millepora*）——的代谢组学特征进行了评估。本次检测采用了氢核磁共振（1H nuclear magnetic resonance, 1H NMR）光谱法与超高效液相色谱-质谱联用（ultra-high-performance liquid chromatography-mass spectrometry, LC-MS）两种技术。我们探究了急性温度胁迫（在28天内较环境对照温度升高3.25±0.28℃）如何改变珊瑚的基础代谢组学特征。

无论采用哪种代谢组学分析方法，不同珊瑚物种的菌落代谢组学特征均存在显著差异，这一结果与既往相关研究结论一致。有趣的是，这种强烈的物种特异性代谢组学特征似乎掩盖了热胁迫所带来的所有差异。这表明，代谢组学或许并非评估热胁迫效应的最灵敏工具，抑或是成年珊瑚菌落对短期胁迫的代谢响应不具备可塑性。

不过，实际情况可能并非如此简单，亟需开展进一步研究，以厘清这种被掩盖的代谢组学特征与珊瑚应对气候变化响应之间的内在关联。