Protective Role of Native Rhizospheric Soil Microbiota Against the Exposure to Microcystins Introduced into Soil-Plant System via Contaminated Irrigation Water and Health Risk Assessment.


Redouane EM(1), Lahrouni M(2), Martins JC(3), El Amrani Zerrifi S(1), Benidire L(4), Douma M(5), Aziz F(1)(6), Oufdou K(7), Mandi L(1)(6), Campos A(3), Vasconcelos V(3)(8), Oudra B(1).
Author information:
(1)Water, Biodiversity and Climate change Laboratory, Department of Biology, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco.
(2)Bioactives, Health and Environement Laboratory, "Biology, Environement & Health" Research Unit, Department of Biology, Faculty of Sciences and technology, Moulay Ismail University, B.P. 509 Boutalamine, Errachidia 52000, Morocco.
(3)CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de MatosMatosinhos, 4450-208 Matosinhos, Portugal.
(4)Plant Biotechnology Laboratory "BiotecV", Ibn Zohr University, Laayoune Higher School of Technology, 25 Mars P.B. 3007, Laayoune 70000, Morocco.
(5)Laboratory of Chemistry, Modeling and Evironmental Sciences, Polydisciplinary Faculty of Khouribga
(F.P.K), Sultan Moulay Slimane University, P.B. 145, Khouribga 25000, Morocco.
(6)National Center for Studies and Research on Water and Energy
(CNEREE), Cadi Ayyad University, B.P. 511, Av. Abdelkrim Elkhattabi, Marrakech 40000, Morocco.
(7)Laboratory of Microbial Biotechnologies, Agrosciences and Environment
(BioMAgE) Department of Biology, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco.
(8)Departament of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.


Microcystins (MCs) produced in eutrophic waters may decrease crop yield, enter food chains and threaten human and animal health. The main objective of this research was to highlight the role of rhizospheric soil microbiota to protect faba bean plants from MCs toxicity after chronic exposure. Faba bean seedlings were grown in pots containing agricultural soil, during 1 month under natural environmental conditions of Marrakech city in Morocco (March-April 2018) and exposed to cyanobacterial extracts containing up to 2.5 mg·L-1 of total MCs. Three independent exposure experiments were performed (a) agricultural soil was maintained intact "exposure experiment 1"; (b) agricultural soil was sterilized "exposure experiment 2"; (c) agricultural soil was sterilized and inoculated with the rhizobia strain Rhizobium leguminosarum RhOF34 "exposure experiment 3". Overall, data showed evidence of an increased sensitivity of faba bean plants, grown in sterilized soil, to MCs in comparison to those grown in intact and inoculated soils. The study revealed the growth inhibition of plant shoots in both exposure experiments 2 and 3 when treated with 2.5 mg·L-1 of MCs. The results also showed that the estimated daily intake (EDI) of MCs, in sterilized soil, exceeded 2.18 and 1.16 times the reference concentrations (0.04 and 0.45 µg of microcysin-leucine arginine (MC-LR). Kg-1 DW) established for humans and cattle respectively, which raises concerns about human food chain contamination.