title: Microbiote shift in the Medicago sativa rhizosphere in response to cyanotoxins extract exposure.
abstract: The bloom-containing water bodies may have an impact due to cyanotoxins production on other microorganisms and aquatic plants. Where such water is being used for crops irrigation, the presence of cyanotoxins may also have a toxic impact on terrestrial plants and their rhizosphere microbiota. For that purpose, PCR-based 454 pyrosequencing was applied to phylogenetically characterize the bacterial community of Medicago sativa rhizosphere in response to cyanotoxins extract. This analysis revealed a wide diversity at species level, which decreased from unplanted soil to root tissues indicating that only some populations were able to compete for nutrients and niches in this selective habitat. Gemmatimonas, Actinobacteria, Deltaproteobacteria and Opitutae mainly inhabited the bulk soil, whereas, the root-adhering soil and the root tissues were inhabited by Gammaproteobacteria and Alphaproteobacteria. The proportion of these populations fluctuated in response to cyanotoxins extract exposure. Betaproteobacteria proportion increased in the three studied compartments, whereas Gammaproteobacteria proportion decreased except in the bulk soil. This study revealed the potential toxicity of cyanotoxins extract towards Actinobacteria, Gemmatimonas, Deltaproteobacteria, and Gammaproteobacteria, however Clostridia, Opitutae and bacteria related with Betaproteobacteria, were stimulated denoting their tolerance. Altogether, these data indicate that crop irrigation using cyanotoxins containing water might alter the rhizosphere functioning.
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France; Laboratory of Biology and Biotechnology of Microorganisms, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco; University Hassan 1st. Polydisciplinary Faculty of Khouribga, BP. 145, 25000 Khouribga, Morocco.
authors.forename: Fatima
authors.initials: F
authors.lastname: El Khalloufi
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco.
authors.forename: Khalid
authors.initials: K
authors.lastname: Oufdou
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Bertrand
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco.
authors.forename: Majida
authors.initials: M
authors.lastname: Lahrouni
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco.
authors.forename: Brahim
authors.initials: B
authors.lastname: Oudra
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ortet
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Barakat
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Heulin
authors.affiliation: CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem (LEMiRE), 13108, Saint Paul-Lez-Durance, France; CNRS, BVME UMR 7265, ECCOREV FR 3098, 13108, Saint Paul-Lez-Durance, France; Aix Marseille Université, 13284 Marseille Cedex 07, France. Electronic address: wafa.achouak@cea.fr.
authors.forename: Wafa
authors.initials: W
authors.lastname: Achouak
mesh_terms: D001427:Bacterial Toxins / Q000633:toxicity*; D018556:Crops, Agricultural; D000455:Medicago sativa / Q000382:microbiology*; D064307:Microbiota / Q000187:drug effects; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D058441:Rhizosphere; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D001427:Bacterial Toxins; D012989:Soil Pollutants
keywords: Cyanobacterial bloom; Cyanotoxins; Medicago sativa; Pyrosequencing; Rhizosphere; Soil