Influence of arbuscular mycorrhizal fungi on the uptake and accumulation of radiocesium by plants and on its redistribution between plants
(2009)
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- Authors
- Supervisors
- Declerck, Stéphane
- Abstract
- (en) Radiocesium (Cs) is released in the environment from weapon testing and accidents such as the Chernobyl catastrophe. As this radio-pollutant remains in the soil, it can be taken up by plants. This uptake is facilitated by its chemical similarity with potassium (K), which contributes to its easy entry into the food chain. Fungi, and more specifically arbuscular mycorrhizal (AM) fungi, can play an important role in the biogeochemical cycling of Cs. AM fungi were also recently shown to have a capacity to take up and transport Cs to their host plants. Although this finding could help in the elaboration of remediation techniques, many factors remain to be explored: the influence of other elements on the fungal Cs transport, the effects of AM fungi on plant Cs accumulation and the role of AM fungi in its redistribution between plants were never investigated. Therefore, different variations of recently developed in vitro culture systems were used to determine: 1) the impact of increasing concentrations of K on a) Cs transport of extraradical mycelium combined with phosphorus (P) and b) Cs accumulation in mycorrhizal and non-mycorrhizal Medicago truncatula plants; 2) the possibility of an exclusively hyphae-mediated Cs-transport between plants. The results showed that both K and P had an effect on the transport of Cs of AM fungi: K decreased this transport, while the opposite was observed for P. In mycorrhizal plants Cs uptake decreased, regardless of the concentration of K. Moreover, AM fungi were found to transfer Cs between plants through a common mycorrhizal network. These findings support the hypothesis of similar uptake mechanisms of K and Cs in AM fungi, supplying important details for the elaboration of remediation methods. In addition, the direct hyphal transfer of Cs between plants could be ascertained, which greatly improves our understanding on the role of AM fungi in Cs redistribution in plant communities.
- Affiliations
Citations
Gyuricza, V. (2009). Influence of arbuscular mycorrhizal fungi on the uptake and accumulation of radiocesium by plants and on its redistribution between plants. https://hdl.handle.net/2078.5/46375