Use of Arbuscular Mycorrhizal Fungi in Remediating Soils Constrained by Metal(loid) Contamination

Some metals(loid)s are micronutrients for plants but could be phytotoxic when present at high concentrations. Some plant species have developed mechanisms to avoid the toxicity that control cell damage, thereby allowing them to perform relatively normally in metabolic, biochemical, and physiological stress under high metals(loid) concentrations. The fundamental mechanisms that are currently identified mainly describe metal(loid) detoxification pathways that ensure that metal(loid)s reach specific sites of action in the plant cell or compartmentalizing them in a cytoplasmic organelle. A rarely studied mechanism is plant symbiosis with soil microorganisms, which has emerged as an essential pathway in metal(loid) tolerance in plant/symbiont interactions. This chapter describes the role of arbuscular mycorrhizal fungi (AMF), a critical soil microsymbiont that helps in the bioremediation of soils with metal(loid)s at a phytotoxic level. The chapter focuses on the mechanisms used by plants in association with AMF to cope with excess metal(loid)s. A particular interest is given to using AMF in phytostabilization and phytoextraction. Finally, using an existing framework for bioremediation of contaminated environments, we discuss the environmental application of the mechanisms involved in metal(loid) detoxification by AMF.