Abstract

A Metabolomics Approach to Understanding Thermally-induced Coral Bleaching

Simon Davy, Associate Professor, Head of School, Victoria University of Wellington

Coral reefs are under threat from rising seawater temperatures, as a result of the thermal dysfunction of the cnidarian-dinoflagellate symbiosis that underlies their success (i.e. coral bleaching). Metabolomics offers a powerful means of elucidating the impacts of thermal stress on inter-partner nutritional exchange in this symbiosis and the downstream impacts on the metabolite profile. We analysed (via GC-MS) free metabolite pools and associated pathway fluxes in both the animal and algal fractions of the sea anemone Aiptasia sp., a widely used model organism for the study of cnidarian-dinoflagellate symbiosis, when under thermal stress. In the dinoflagellate symbionts we observed increased pools of saturated fatty acids, proteinogenic amino acids and TCA cycle intermediates. In the cnidarian host we observed increased pools of saturated and monounsaturated fatty acids, TCA cycle intermediates, the antioxidant glutathione, and a range of amino acids; we also observed reduced pools of polyunsaturated fatty acids and some other amino acids. We will outline what these changes tell us in terms of metabolic fluxes through the symbiosis, and describe our ongoing application of metabolomic methods to the study of climate change impacts on the world’s threatened coral reefs.