Effect of symbiosis with arbuscular mycorrhizal fungi on phytoremediation processes in the soils contaminated with heavy metals

Contamination of soil with heavy metals has detrimental effects on ecosystems, because heavy metals accumulated in soil may persist and affect terrestrial ecosystems for a long time. Phytoremediation, as sustainable, low-cost and environmental friendly technology based on the direct use of plants for in situ remediation of contaminated soil, sludges, sediments, and ground water through contaminant removal, degradation or containment, is becoming an important objective in recent plant research. As phytoremediation is a slow process, improvement of efficiency and thus increased stabilization or removal of heavy metals from soils is an important goal. Among biotic factors, the role of soil microorganisms, especially mycorrhizal fungi, on phytoremediation is considerable. As efficiency of plants in phytoremediation process in symbiosis with these soil suitable microorganisms can be increased. So in this review, the contribution of arbuscular mycorrhizal fungi on phytoremediation process in the soils contaminated with heavy metals was considered with regard to the survey and explanation of the results of previous studies. The survey results demonstrated that the potential of arbuscular mycorrhizal fungi to the plant tolerance to heavy metals depends on many factors including plant and fungus species, type and concentration of heavy metals of soil, growth condition of plant, soil properties, age, physiological status and root system of plant.