title: Differential antioxidant response between two Symbiodinium species from contrasting environments.
abstract: High sea surface temperature accompanied by high levels of solar irradiance is responsible for the disruption of the symbiosis between cnidarians and their symbiotic dinoflagellates from the genus Symbiodinium. This phenomenon, known as coral bleaching, is one of the major threats affecting coral reefs around the world. Because an important molecular trigger to bleaching appears related to the production of reactive oxygen species (ROS), it is critical to understand the function of the antioxidant network of Symbiodinium species. In this study we investigated the response of two Symbiodinium species, from contrasting environments, to a chemically induced oxidative stress. ROS produced during this oxidative burst reduced photosynthesis by 30 to 50% and significantly decreased the activity of superoxide dismutase. Lipid peroxidation levels and carotenoid concentrations, especially diatoxanthin, confirm that these molecules act as antioxidants and contribute to the stabilization of membrane lipids. The comparative analysis between the two Symbiodinium species allowed us to highlight that Symbiodinium sp. clade A temperate was more tolerant to oxidative stress than the tropical S. kawagutii clade F. These differences are very likely a consequence of adaptation to their natural environment, with the temperate species experiencing conditions of temperature and irradiance much more variable and extreme.
authors: Université de Liège, InBioS - Animal Physiology, Département de Biologie, Ecologie et Evolution, 4 Chemin de la Vallée, B-4000, Liège, Belgium.
authors: S
authors: S
authors: Roberty
authors: Université Nice Sophia Antipolis, UMR 7138'Evolution Paris Seine', équipe 'Symbiose marine', 06108, Nice Cedex 02, France.|Université Pierre-et-Marie-Curie, UMR 7138 'Evolution Paris Seine', 7, quai Saint-Bernard, 75252, Paris cedex 05, France.|CNRS, UMR 7138 'Evolution Paris Seine', 7, quai Saint-Bernard, 75252, Paris cedex 05, France.
authors: P
authors: P
authors: Furla
authors: Université de Liège, InBioS - Animal Physiology, Département de Biologie, Ecologie et Evolution, 4 Chemin de la Vallée, B-4000, Liège, Belgium.
authors: J-C
authors: JC
authors: Plumier
mesh_terms: D000222:Adaptation, Physiological; D002338:Carotenoids / Q000378:metabolism; D057894:Coral Reefs; D004141:Dinoflagellida / Q000378:metabolism*; D004777:Environment; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature
chemical_list: D017382:Reactive Oxygen Species; D002338:Carotenoids; D013482:Superoxide Dismutase
keywords: coral bleaching; diatoxanthin; menadione sodium bisulfite; oxidative stress; pigments; reactive oxygen species; symbiosis; ubiquitin