| Title: | Allelopatic effects of cyanobacteria extracts containing microcystins on Medicago sativa-Rhizobia symbiosis |
| Author(s): | El Khalloufi F; Oufdou K; Lahrouni M; El Ghazali I; Saqrane S; Vasconcelos V; Oudra B; |
| Address: | "Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakech, Morocco" |
| DOI: | 10.1016/j.ecoenv.2010.10.006 |
| ISSN/ISBN: | 1090-2414 (Electronic) 0147-6513 (Linking) |
| Abstract: | "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 mug 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 mug 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" |
| Keywords: | Agricultural Irrigation Eutrophication Medicago sativa/*drug effects/microbiology/physiology Microcystins/*toxicity Microcystis/*growth & development Oxidative Stress Pheromones/*toxicity Rhizobiaceae/*drug effects/physiology Symbiosis/*drug effects; |
| Notes: | "MedlineEl Khalloufi, Fatima Oufdou, Khalid Lahrouni, Majida El Ghazali, Issam Saqrane, Sanaa Vasconcelos, Vitor Oudra, Brahim eng Research Support, Non-U.S. Gov't Netherlands 2010/10/30 Ecotoxicol Environ Saf. 2011 Mar; 74(3):431-8. doi: 10.1016/j.ecoenv.2010.10.006. Epub 2010 Oct 27" |
