Effect of a short-term salinity stress on the growth, biovolume, toxins, osmolytes and metabolite profiles on three strains of the Dinophysis acuminata-complex (Dinophysis cf. sacculus)
|Author(s)||Gaillard Sylvain1, Réveillon Damien1, Danthu Charline1, Hervé Fabienne1, Sibat Manoella1, Carpentier Liliane1, Hégaret Helene2, Séchet Veronique1, Hess Philipp1|
|Affiliation(s)||1 : IFREMER, DYNECO, Laboratoire Phycotoxines, Rue de l'Ile d'Yeu, F-44000 Nantes, France
2 : Laboratoire des Sciences de l’Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER – Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, Rue Dumont d’Urville, 29280 Plouzané, France
|Source||Harmful Algae (1568-9883) (Elsevier BV), 2021-07 , Vol. 107 , P. 102009 (9p.)|
|Keyword(s)||Dinoflagellates, DMSP, Glycine betaine, Okadaic acid, Pectenotoxins, Proline|
Dinophysis is the main dinoflagellate genus responsible for diarrheic shellfish poisoning (DSP) in human consumers of filter feeding bivalves contaminated with lipophilic diarrheic toxins. Species of this genus have a worldwide distribution driven by environmental conditions (temperature, irradiance, salinity, nutrients etc.), and these factors are sensitive to climate change. The D. acuminata-complex may contain several species, including D. sacculus. The latter has been found in estuaries and semi-enclosed areas, water bodies subjected to quick salinity variations and its natural repartition suggests some tolerance to salinity changes. However, the response of strains of D. acuminata-complex (D. cf. sacculus) subjected to salinity stress and the underlying mechanisms have never been studied in the laboratory. Here, a 24 h hypoosmotic (25) and hyperosmotic (42) stress was performed in vitro in a metabolomic study carried out with three cultivated strains of D. cf. sacculus isolated from the French Atlantic and Mediterranean coasts. Growth rate, biovolume and osmolyte (proline, glycine betaine and dimethylsulfoniopropionate (DMSP)) and toxin contents were measured. Osmolyte contents were higher at the highest salinity, but only a significant increase in glycine betaine was observed between the control (35) and the hyperosmotic treatment. Metabolomics revealed significant and strain-dependent differences in metabolite profiles for different salinities. These results, as well as the absence of effects on growth rate, biovolume, okadaic acid (OA) and pectenotoxin (PTXs) cellular contents, suggest that the D. cf. sacculus strains studied are highly tolerant to salinity variations.