Interactions between arbuscular mycorrhizae and plants in phytoremediation of metal-contaminated soils: A review

Metal contamination in the environment is a global concern due to its high toxicity to living organisms and its worldwide distribution. The principal goal of this review is to examine the current strategies and technologies for the remediation of metal-contaminated soils by metal-accumulating plants and assess the roles of arbuscular mycorrhizal (AM) fungi in remediation of soils under hyperaccumulator or non-accumulator plants. The use of plants to remove metals from the environment or reduce the toxicity, known as phytoremediation, is an environmentally sustainable and low cost remediation technology. The mechanisms of the use of hyperaccumulator plants for phytoremediation included solubilization of the metal in the soil matrix, the plant uptake of the metal, detoxification/chelation and sequestration, and volatilization. Recently, some ecologists have found that phytoremediation with the aids of mycorrhizae can enhance efficiency in the removal of toxic metals. AM fungi can facilitate the survival of their host plants growing on metal-contaminated land by enhancing their nutrient acquisition, protecting them from the metal toxicity, absorbing metals, and also enhancing phytostabilization and phytoextraction. Such information may be useful for developing phytoremediation program at metal-contaminated sites.