Effect of arbuscolar mycorrhizae and phosphorous on arsenic availability in a contaminated soil

Since 7th–6th centuries BC, southern Tuscany (Italy) has been characterized by intensive mining and smelting activity, resulting in a huge release of As to the surrounding soil, where plant cultivation is diffused. It has been demonstrated that phosphate and arbuscular mycorrhizal (AM) fungi are able to enhance the tolerance of plants to soil contamination by As, generally decreasing its concentration in the plant tissues. In this work, maize plant was chosen to assess the As availability and plant accumulation and translocation in relation to mycorrhizal inoculation and phosphorus application as it is one of the most representative crop from southern Tuscany. We found that in maize plant, accumulation of As is mainly regulated at root level, where concentration is higher. The labile fraction of arsenic in the examined soil is low and it may change if AM or phosphorus are applied, as suggested by DGT analysis. AM and fertilizer modified differently As mobilization and plant uptake, but the effect of P was much more evident.