Allelopatic effects of cyanobacteria extracts containing microcystins on Medicago sativa-Rhizobia symbiosis

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Fatima El Khalloufi (Author) Other; Khalid Oufdou (Author) Other; Majida Lahrouni (Author) Other; Issam El Ghazali (Author) Other; Sanaa Saqrane (Author) Other; Vitor Vasconcelos (Author) FCUP; Brahim Oudra (Author) Other

Journal

Title: Ecotoxicology and Environmental Safety

Vol. 74

Pages: 431-438

ISSN: 0147-6513

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 36 Citations

Scopus - 41 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-002-TXZ

DOI: 10.1016/j.ecoenv.2010.10.006

Abstract (EN): The eutrophication of water leads to massive blooms of cyanobacteria potentially producers of highly toxic substances: cyanotoxins, especially microcystins (MC). The contamination of water used for irrigation by these toxins, can cause several adverse effects on plants and microorganisms. In this work, we report the phytotoxic effects of microcystins on the development of symbiosis between the leguminous plant Medicago sativa (Alfalfa) and rhizobia strains. The exposure of rhizobial strains to three different concentrations 0.01, 0.05 and 0.1 mu g MC ml(-1) led to decrease on the bacteria growth. The strains of rhizobia Rh L1, Rh L2, Rh L3 and Rh L4 reduced their growth to, respectively, 20.85%, 20.80%, 33.19% and 25.65%. The chronic exposure of alfalfa seeds and seedlings to different MC concentrations affects the whole stages of plant development. The germination process has also been disrupted with an inhibition, which reaches 68.34% for a 22.24 mu g MC ml(-1). Further, seedlings growth and photosynthetic process were also disrupted. The toxins reduced significantly the roots length and nodule formation and leads to an oxidative stress. Thus, the MCs contained in lake water and used for irrigation affect the development of symbiosis between M. sativa and Rhizobia.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8