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, Acropora hyacinthus and A. millepora, 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.