Influence of Glomus intraradices on Cd partitioning in a pot experiment with Medicago truncatula in four contaminated soils

Arbuscular mycorrhizal (AM) fungi are known to have a beneficial effect on host plants growing in metal polluted soils. However, the potential contribution of AM fungi to cadmium (Cd) accumulation in plants is still uncertain and is rarely quantified in the context of phytoremediation. In a pot experiment, we quantified the partitioning of Cd in mycorrhizal (M) or non-mycorrhizal (NM) Medicago truncatula in four soils as a function of Cd availability. AM inoculation with Glomus intraradices increased plant growth and metal accumulation in above-ground biomass, even though Cd concentrations in M plants were lower than in NM plants. AM inoculation also increased the quantity of available Cd and reduced Cd in leachates. Results were consistent and significant in the four tested soils and were not related to Cd availability. Such AM fungi could be a good tool for phytoextraction.