Inoculation with arbuscular mycorrhizal fungi can increase the concentration of PFAS compounds in cereal crops

Abstract

Contamination of agricultural soils with per and poly-fluoroalkyl substances (PFAS) is now widespread and common throughout the world due to management practices such as biosolid application. Crop and pasture plants can readily take up and accumulate PFAS in their tissues, which eventually ends up in food products or livestock feed and presents health issues. We investigated whether arbuscular mycorrhizal (AM) fungi in the soil affect plant PFAS uptake in three important cereal crop species (barley, bread wheat, durum wheat), using a combination of soils that were artificially-spiked or naturally contaminated with PFAS. Spiking soil with PFAS did not interfere with AM colonisation of roots, nor did it detrimentally affect plant biomass. However, the shoots of all three plant species accumulated high concentrations of multiple short- and long-chain PFAS compounds. Inoculation with AM fungi led to increased concentration of all measured PFAS compounds in durum wheat shoots and several compounds in barley shoots, with no effect on any compounds in bread wheat shoots. The effect of AM fungal colonisation on PFAS concentrations in cereal plants is highly dependent on the nature of the soil PFAS contamination (i.e., the concentration and speciation) and the host plant species. It remains to be investigated whether AM fungi can directly take up PFAS from the soil.