Arbuscular mycorrhizal fungi as a potential tool for bioremediation of heavy metals in contaminated soil

Human activities have introduced large amounts of heavy metals into natural ecosystems in recent years. As a result, the accumulation of heavy metals and metalloids in plants, animals, and humans, which may have caused some health problems. Chemical and physical methods can remove the heavy metal in contaminated soil, but both are very expensive and ineffective. Arbuscular Mycorrhizal Fungi (AMF) are mutualistic symbionts in most plant roots. Furthermore, AMF are the essential mycorrhizae for phytoremediation, and the extensive hyphal network of them can increase the uptake of micro and macronutrients, water and heavy metals from the soil. However, AMF hyphae colonized in plant roots have an ability for compartmentalizing heavy metals inside plant roots. Furthermore, AMF hyphae are capable of secreting a glycoprotein, named glomalin, which can bind heavy metals and subsequently remove heavy metals absorbed by the plants from contaminated soil. Glomalin can develop the properties and structure of the soil, which helps to enhance soil fertility. This paper presents the role of AMF in the ecosystems and as potential tools for bioremediation of heavy metals in the soil.