Physiological changes induced by sodium chloride stress in Aphanizomenon gracile, Cylindrospermopsis raciborskii and Dolichospermum sp
| Autor: | Fabienne Hervé, Georges-Augustin Rovillon, Elise Robert, Emilie Houliez, Enora Briand, Amandine M.N. Caruana, Agata Zykwinska, Florent Malo, Laëtitia Marchand |
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| Přispěvatelé: | Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG], Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER], Dynamiques des Écosystèmes Côtiers [DYNECO], Laboratoire Phycotoxines [PHYC], Etude longitudinale française depuis l'enfance (UMS : Ined-Inserm-EFS) [ELFE], Microbiologie Aliment Santé Environnement [MASAE] |
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
Cyanobacteria Paralytic shellfish toxins Sodium chloride Cyanotoxins Plant Science Sodium Chloride 010501 environmental sciences Aquatic Science 01 natural sciences Algal bloom Cylindrospermopsis raciborskii Phycocyanin Botany Animals Aphanizomenon Ecosystem 0105 earth and related environmental sciences Saxitoxins Harmful algal bloom biology Brackish water Chemistry 010604 marine biology & hydrobiology biology.organism_classification Polyhaline Salinity Osmoprotectant Cylindrospermopsis |
| Zdroj: | Harmful Algae (1568-9883) (Elsevier BV), 2021-03, Vol. 103, P. 102028 (17p.) |
| ISSN: | 1568-9883 |
| Popis: | Due to anthropogenic activities, associated with climate change, many freshwater ecosystems are expected to experience an increase in salinity. This phenomenon is predicted to favor the development and expansion of freshwater cyanobacteria towards brackish waters due to their transfer along the estuarine freshwater-marine continuum. Since freshwater cyanobacteria are known to produce toxins, this represents a serious threat for animal and human health. Saxitoxins (STXs) are classified among the most powerful cyanotoxins. It becomes thus critical to evaluate the capacity of cyanobacteria producing STXs to face variations in salinity and to better understand the physiological consequences of sodium chloride (NaCl) exposure, in particular on their toxicity. Laboratory experiments were conducted on three filamentous cyanobacteria species isolated from brackish (Dolichospermum sp.) and fresh waters (Aphanizomenon gracile and Cylindrospermopsis raciborskii) to determine how salinity variations affect their growth, photosynthetic activity, pigment composition, production of reactive oxygen species (ROS), synthesis of compatible solutes and STXs intracellular quotas. Salinity tolerance was found to be species-specific. Dolichospermum sp. was more resistant to salinity variations than A. gracile and C. raciborskii. NaCl variations reduced growth in all species. In A. gracile, carotenoids content was dose-dependently reduced by NaCl. By contrast, in C. raciborskii and Dolichospermum sp., variations in carotenoids content did not show obvious relationships with NaCl concentration. While in Dolichospermum sp. phycocyanin and phycoerythrin increased within the first 24 h exposure to NaCl, in both A. gracile and C. raciborskii, these pigments decreased proportionally to NaCl concentration. Low changes in salinity did not impact STXs production in A. gracile and C. raciborskii while higher increase in salinity could modify the toxin profile and content of C. raciborskii (intracellular STX decreased while dc-GTX2 increased). In estuaries, A. gracile and C. raciborskii would not be able to survive beyond the oligohaline area (i.e. salinity > 5). Conversely, in part due to its ability to accumulate compatible solutes, Dolichospermum sp. has the potential to face consequent salinity variations and to survive in the polyhaline area (at least up to salinity = 24). |
| Databáze: | OpenAIRE |
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