No Significant Contribution of Arbuscular Mycorrhizal Fungi to Transfer of Radiocesium from Soil to Plants
AUTOR(ES)
Joner, E. J.
FONTE
American Society for Microbiology
RESUMO
The diffuse pollution by fission and activation products following nuclear accidents and weapons testing is of major public concern. Among the nuclides that pose a serious risk if they enter the human food chain are the cesium isotopes 137Cs and 134Cs (with half-lives of 30 and 2 years, respectively). The biogeochemical cycling of these isotopes in forest ecosystems is strongly affected by their preferential absorption in a range of ectomycorrhiza-forming basidiomycetes. An even more widely distributed group of symbiotic fungi are the arbuscular mycorrhizal fungi, which colonize most herbaceous plants, including many agricultural crops. These fungi are known to be more efficient than ectomycorrhizas in transporting mineral elements from soil to plants. Their role in the biogeochemical cycling of Cs is poorly known, in spite of the consequences that fungal Cs transport may have for transfer of Cs into the human food chain. This report presents the first data on transport of Cs by these fungi by use of radiotracers and compartmented growth systems where uptake by roots and mycorrhizal hyphae is distinguished. Independent experiments in three laboratories that used different combinations of fungi and host plants all demonstrated that these fungi do not contribute significantly to plant uptake of Cs. The implications of these findings for the bioavailability of radiocesium in different terrestrial ecosystems are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=525231Documentos Relacionados
- Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil
- Response of Sesbania grandiflora to Inoculation of Soil with Vesicular-Arbuscular Mycorrhizal Fungi †
- Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation
- Arbuscular mycorrhizal fungi and dark septate fungi in plants associated with aquatic environments
- Effect of arbuscular mycorrhizal fungi on young vines in copper-contaminated soil