Caesium inhibits the colonization of Medicago truncatula by arbuscular mycorrhizal fungi. (March 2015)

• Record Type: Journal Article
• Authors: Wiesel, Lea; Dubchak, Sergiy; Turnau, Katarzyna; Broadley, Martin R.; White, Philip J.
• Is Part Of: Journal of environmental radioactivity. Volume 141(2015:Mar.)
• Page Start: 57
• Page End: 61
• Publication Date: 2015-03
• Subjects: Phytoremediation -- Radiocaesium -- Radiocaesium contamination -- Rhizophagus intraradices -- Safer crop plants; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2014.12.001
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: Contamination of soils with radioisotopes of caesium (Cs) is of concern because of their emissions of harmful β and γ radiation. Radiocaesium enters the food chain through vegetation and the intake of Cs can affect the health of organisms. Arbuscular mycorrhizal (AM) fungi form mutualistic symbioses with plants through colonization of the roots and previous studies on the influence of AM on Cs concentrations in plants have given inconsistent results. These studies did not investigate the influence of Cs on AM fungi and it is therefore not known if Cs has a direct effect on AM colonization. Here, we investigated whether Cs influences AM colonization and if this effect impacts on the influence of Rhizophagus intraradices on Cs accumulation by Medicago truncatula . M. truncatula was grown with or without R. intraradices in pots containing different concentrations of Cs. Here, we present the first evidence that colonization of plants by AM fungi can be negatively affected by increasing Cs concentrations in the soil. Mycorrhizal colonization had little effect on root or shoot Cs concentrations. In conclusion, the colonization by AM fungi is impaired by high Cs concentrations and this direct effect of soil Cs on AM colonization might explain the inconsistent results reported in literature that have shown increased, decreased or unaffected Cs concentrations in AM plants. Highlights: Colonization of plants by arbuscular mycorrhizal fungi is negatively affected by increasing soil caesium concentrations. Shoot caesium concentrations are not influenced by AM fungi at soil caesium concentrations above about 3 μg Cs kg −1 . The direct effect of caesium on AM fungi might impact on the influence of AM fungi on Cs accumulation in plants. This might explain the inconsistent results reported in literature on Cs accumulation in AM plants.