OMICS approaches to assess Heterocapsa cf. bohaiensis (dinoflagellate) responses to metal stress
Résumé
Metals are essential for primary production and tropical coastal ecosystems, but can also be toxic in excess. This metal toxicity in marine ecosystems is a growing issue owing to terrestrial runoff and anthropogenic pollution. Dinoflagellates are important primary producers known to biosynthesize metabolites of interest whose production could be affect by metallic stress. Heterocapsa cf. bohaiensis, a newly described dinoflagellate species with haemolytic activity, has been isolated in New Caledonian iron and nickel-rich waters. To decipher H. cf. bohaiensis response to metal stress, we developed metabolomic and transcriptomic approaches combined with physiological studies.
Targeted metabolomic analyses were conducted by UV-visible liquid chromatography to determine pigments composition and by FID-MS gas chromatography to evaluate the fatty acids content. These first data were then compared with untargeted approaches using high-performance liquid chromatography-high resolution mass spectrometry (MS/MS) systems and NMR experiments (1H, 13C and 2D). Finally, comparison of transcriptomes from H. cf. bohaiensis exposed to more or less metal-rich environments will highlight whole cell strategies to cope with metallic stress, thus corroborating metabolomics results and potentially revealing pathways of adaptation to metal-rich waters.
The combination of OMICs studies provides a much-needed global view of molecular processes, which is essential to optimize the production of dinoflagellate metabolites of interest.