Role of arbuscular mycorrhizal fungi on the accumulation of radiocaesium by plants
Numerous soils have been contaminated by radiocaesium (Cs) as a result of nuclear weapon testing and accidents at nuclear power-plant facilities. Management of the areas, which have been exposed to either intense or diffuse Cs pollution, has therefore become a major environmental concern.
Strategies orientated toward the use of plants and microorganisms, or both in combination, have been proposed in the recent years as potential players in removing or stabilizing Cs in contaminated soils. Among these microorganisms, arbuscular mycorrhizal (AM) fungi are of particular interest due to their unique position at the soil/root interface and their recognized role in element transport and immobilization.
In the recent years, contradictory results have been published on the impact of AM fungi on Cs accumulation by plants, failing to ascertain whether AM fungi could effectively transport this radionuclide to their host. Therefore, the objective of this work was to determine the role of AM fungi in plant Cs acquisition and accumulation.
Using in vitro compartmented systems, we unambiguously demonstrated that AM fungi could transport Cs to their host, while its accumulation within the extraradical mycelium was rather limited. Our results also suggested that AM fungi could have an effect on Cs distribution within their host. Indeed, it appeared that AM fungi could potentially limit the translocation of Cs from roots to shoot.
However, if the results obtained during this research project have shown that AM fungi could influence the acquisition and accumulation of Cs by plants, their capacity to take part in phytoremediation strategies remains questionable and would need additional investigations.
In particular, attention should be focused on the mechanisms behind Cs transport by AM fungi, their influence on Cs root to shoot translocation and the subsequent validation of the findings obtained to in situ conditions.
School:Université catholique de Louvain
Source Type:Master's Thesis
Keywords:radiocaesium arbuscular mycorrhizal fungi phytoremediation
Date of Publication:01/11/2007