Review on the Use of Arbuscular Mycorrhizal Fungi in Bioremediation of Heavy Metal Contaminated Soils in the Philippines

Heavy metal (HM) contamination is a global issue characterized by high concentrations of HMs beyond safe and tolerable standards. Plants may receive the brunt of their toxicity due to physiological uptake mechanisms and extreme consequences, leading to plant growth and yield impairment, plant parts system translocation, and eventually plant death. The introduction of these HMs into the food web may occur if not treated. Arbuscular mycorrhizal fungi (AMF) treatment can potentially pose as a biological method to reduce HMs in local terrestrial soils. They are popularly known to enhance plant growth and yield and fortify plant resistance to biotic and abiotic stresses. AMF has also been extensively probed to protect plants against the effects of HM toxicity. Through the systematic collection and summarization of multiple reliable scientific articles, this review reports that AMF are capable of alleviating HMs from the soil through various plant-assisted mechanisms. In this study, information on the current status of HM contamination in the country and the role of AMF as a sustainable tool to address this problem is explored. While increasing metal uptake, they are also able to improve plant metal stress tolerance by acting as a buffer, increasing the “dilution effect,” chelating HMs, and sequestering HM ions in their hyphal cells. In the Philippines, there is little knowledge of the status of HM contamination in the soil, but the majority of the studies reported HM contamination in multiple sites. Therefore, there is a need for the implementation of biological solutions such as the use of AMF, as well as further investigation of the outcomes of this innovation in different laboratory and field conditions.