Arbuscular Mycorrhizal Fungi as Potential Agents in Ameliorating Heavy Metal Stress in Plants

Abstract

Heavy metal accumulation in plants is a severe environmental problem, rising at an expeditious rate. Heavy metals such as cadmium, arsenic, mercury and lead are known environmental pollutants that exert noxious effects on the morpho-physiological and biological attributes of a plant. Due to their mobile nature, they have become an extended part of the food chain and affect human health. Arbuscular mycorrhizal fungi ameliorate metal toxicity as they intensify the plant’s ability to tolerate metal stress. Mycorrhizal fungi have vesicles, which are analogous to fungal vacuoles and accumulate massive amount of heavy metals in them. With the help of a pervasive hyphal network, arbuscular mycorrhizal fungi help in the uptake of water and nutrients, thereby abating the use of chemical fertilizers on the plants. They also promote resistance parameters in the plants, secrete a glycoprotein named glomalin that reduces the metal uptake in plants by forming glycoprotein–metal complexes, and improve the quality of the soil. They also assist plants in phytoremediation by increasing the absorptive area, increase the antioxidant response, chelate heavy metals and stimulate genes for protein synthesis that reduce the damage caused by free radicals. The current manuscript focuses on the uptake of heavy metals, accumulation, and arbuscular mycorrhizal impact in ameliorating heavy metal stress in plants.

Phytoremediation of a Highly Arsenic Polluted Site, Using Pteris vittata L. and Arbuscular Mycorrhizal Fungi

“…These results are in agreement with other works [ 15 , 48 , 49 , 50 ] demonstrating that phytoremediation can be increased by inoculating P. vittata with selected AMF. In fact, AMF play a key role in the mobilization/immobilization of metal ions and could alter their availability to plants [ 21 ]. AMF may lead to protective effects through changes in metals solubility mediated by changes in the soil solution pH, or by immobilizing heavy metals in and on fungal biomass [ 51 ] Moreover, ferns inoculated with the AMF Funneliformis mosseae exhibited higher activities of antioxidant enzymes [ 49 ] and up-regulation of multiple forms of glyceraldehyde-3-36 phosphate dehydrogenase, and other enzymes playing a central role of glycolytic enzymes in arsenic metabolism [ 18 ].…”

“…Arbuscular mycorrhizal fungi (AMF) are symbiotic microscopic fungi belonging to the Glomeromycotina, subphylum of phylum Mucoromycota [ 20 ], able to positively influence plant performance in many ways, including by enhancement of heavy metal/metalloid stress tolerance [ 21 ]. AMF colonize the roots of most terrestrial plants [ 22 ], including ferns; once the symbiosis is established, they improve plant nutrition [ 23 ], modify root architecture [ 24 ], and promote plant tolerance or resistance to pathogens [ 25 , 26 , 27 ], drought [ 28 ], and salinity [ 29 ].…”

“…AMF colonize the roots of most terrestrial plants [ 22 ], including ferns; once the symbiosis is established, they improve plant nutrition [ 23 ], modify root architecture [ 24 ], and promote plant tolerance or resistance to pathogens [ 25 , 26 , 27 ], drought [ 28 ], and salinity [ 29 ]. During phytoremediation, the use of AMF could positively affect the plant growth, mitigating the adverse effects of heavy metals and As or influencing their absorption, accumulation, and translocation [ 21 , 30 ].…”

Bioactive Compounds of Edible Fruits with Their Anti-Aging Properties: A Comprehensive Review to Prolong Human Life

“…Overproduction of ROS in the human body damages diverse biomolecules via redox reactions and leads to cellular damage, mutation, cell death, and aging [ 40 , 41 , 42 , 43 ]. ROS are also implicated in several chronic illnesses and other age-related disorders.…”

Effect of Arbuscular Mycorrhiza Fungal Inoculation on Growth of Tropical Tree Species under Nursery and Post-Opencast Bauxite Mining Field in Bintan Island, Indonesia

“…Aluminum was determined in the formation of High-Grade Al Deposits of the Dopolan Karst Type Bauxite, Iran [38] while pollutant of arsenic, lead, and copper were also detected in bauxite mining soil from Bintan Island, Indonesia [39]. AM fungi ameliorate metal toxicity as they intensify the plant's ability to tolerate metal stress [40]. Agus et al [41] reported that fast-growing legume species of Pongamia pinnata and AM fungi application can not only increase nutrient contents of post-coal mining soil but also increases iron absorption, which is mostly accumulated in the root system.…”