Use of mycorrhizal fungi for the phytostabilisation of radio-contaminated environment (European project MYRRH): Overview on the scientific achievements

¹ Université Catholique de Louvain, Mycothèque de l'Université Catholique de Louvain (MUCL), Unité de Microbiologie, 3 place Croix du Sud, 1348 Louvain-la-Neuve, Belgium
² LIMOS, UMR 7137 CNRS-UHP Nancy I, Faculté des Sciences, BP. 239, 54506 Vandoeuvre-les-Nancy, Cedex, France
³ Risø National Laboratoty, Plant Research Department, 4000 Roskilde, Denmark
⁴ CEN-SCK, Radiation Protection Research Department, 200 Boeretang, 2400 Mol, Belgium
⁵ Université Catholique de Louvain, Unité des Sciences du Sol, 2/10 place Croix du Sud, 1348 Louvain-la-Neuve, Belgium

Abstract

Because plants significantly affect radionuclides (RN) cycling and further dispersion into the biosphere, it is important to understand the biological factors influencing RN plant uptake, accumulation and redistribution. In this respect, mycorrhizal fungi are of particular interest. The effects of ecto-mycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi on the transport of uranium (U) or radiocaesium (Cs) were investigated both under pot and in vitro culture conditions. Results obtained in vitro demonstrated that AM hyphae can take up and translocate U and Cs towards roots, while this uptake and translocation were not perceptible using pot culture systems with soil. These contrasting results could be due to different experimental conditions, including the K level in the external solution and the bio-availability of Cs. The in vitro studies also indicated that root colonisation by AM fungi might limit U and Cs root transport. Under pot culture conditions, they appeared to significantly reduce root to shoot translocation of U. Under the same conditions, ECM transport of Cs was demonstrated, and appeared to be dependent on fungal species. A better estimation of the potential use of mycorrhizal fungi for the phytoremediation of RN-contaminated areas is now available and will be further discussed.