Metal soil contamination, metallophytes and arbuscular mycorrhizal fungi from South America

Abstract

Heavy metal (HM) soil contamination is an environmental problem since metals can accumulate in the soil and be introduced into the food chain of organisms endangering the quality of the entire ecosystems. A wide diversity of plant species called metallophyte, especially the hyperaccumulator plants, has a great capacity to accumulate HM and can be used to remediate contaminated soil. Phytoremediation is ?the use of plants and associated microorganisms to remove, contain, inactivate, or degrade contaminants.? Several plants can be colonized by arbuscular mycorrhizal (AM) fungi, which tend to be pioneers at contaminated sites, emphasizing their role in the accumulation of and tolerance to metals by plants. Information on metallophytes/hyperaccumulator plants adapted to HM-contaminated soils in South America, and even more their AM fungal status, is quite scarce. This work showed the mycorrhizal status of metallophytes/hyperaccumulator plant species. We especially focused on the relationship between the AM symbiosis with metallophytes in soils contaminated with Cu from Chile and soils contaminated with Pb from Central Argentina. These results should be considered for future phytoremediation strategies based on the selection and utilization of AM fungi species that exhibit tolerance to HM soil contamination.