Phytoplankton growth and potential cyanotoxin production differ in response to nitrogen and phosphorus amendments in late summer communities from Kabetogama Lake (Minnesota, United States)
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Le résumé fourni par la source
Abstract Cyanotoxins such as microcystin (MC), cylindrospermopsin, and saxitoxin are secondary metabolites that are rich in nitrogen (N). Most cyanobacteria grow best on reduced inorganic N (ammonium, NH 4 ), but when NH 4 is absent, cyanobacteria can activate physiological pathways to process other N forms (e.g., nitrate; NO 3 ). Studies on some cyanobacterial cultures have indicated that expression of N stress response genes is associated with MC gene expression. If accurate, NH 4 additions could reduce N stress and therefore cyanotoxin production. Lakes experiencing changes in N form and supply could thus experience changes in cyanobacterial toxicity independent of shifts in abundance. We performed nutrient amendments on phytoplankton communities from Kabetogama Lake (Minnesota, United States) over 2 years (four experiments total), to assess the role of N and phosphorus amendments on growth and toxicity of phytoplankton. Natural communities were collected during cyanobacterial blooms and exposed to short laboratory experiments with amendments of NH 4 , NO 3 , orthophosphate, or a combination of all three. In three of four experiments, biomass responses were consistent with N‐limitation based on chlorophyll a or biovolume estimates. In experiments with evidence for N‐limited growth, MC gene expression was lower in NH 4 treatments than in the control in 2021 but higher than in the control in 2022. The proportion of heterocytes (specialized cells for N fixation) was positively correlated with MC gene expression. These experiments reinforce the strong connection between N physiology and MC gene expression, but variation in taxonomic composition within genera or even species remains a possible cause of inconsistency in whole‐community responses.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Phytoplankton growth and potential cyanotoxin production differ in response to nitrogen and phosphorus amendments in late summer communities from Kabetogama Lake (Minnesota, United States)
- Date Crossref
- 02/05/2026
- Éditeur
- Wiley
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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United States Geological Survey pays non établi dans la noticeOrganisme public
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Upper Midwest Environmental Sciences Center pays non établi dans la noticeStructure de recherche
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Voyageurs National Park pays non établi dans la noticeInstitution
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University of Kansas pays non établi dans la noticeUniversité ou école supérieure
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Indiana Geological and Water Survey pays non établi dans la noticeStructure de recherche
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Illinois Environmental Protection Agency pays non établi dans la noticeOrganisme public
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Environmental Protection Agency pays non établi dans la noticeOrganisme public
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U.S. Geological Survey Upper Midwest Water Science Center St. Paul Minnesota USA pays non établi dans la noticeInstitution
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Algal and Other Environmental Toxins Laboratory Lawrence Kansas USA US Geological Survey Kansas Water Science Center pays non établi dans la noticeStructure de recherche
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U.S. Geological Survey Ohio‐Kentucky‐Indiana Water Science Center Columbus Ohio USA pays non établi dans la noticeInstitution
United States Geological Survey, Upper Midwest Environmental Sciences Center et Voyageurs National Park, avec 7 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.