Plant-microbe interaction: Relevance for phytoremediation of heavy metals

Abstract The rapid industrialization, mine screening, huge application of chemical fertilizers, sewage sludge, and wastewater irrigation are increasingly stacking up heavy metals into the environment. From the past two decades, phytoremediation becomes an indispensable technology for environmental cleanup of heavy metals and other pollutants because of its cost effectiveness and green approach. In recent years, remediation of polluted metals is implemented by exploring the plant-associated microbes that will accelerate plant growth by producing mineral nutrients or growth-promoting substances in the metal-contaminated soil or by protecting plants from soilborne pathogen by stimulating production of phytohormones, siderophores, and organic acids. Besides, they also modify metal accumulation capacity in plants by synthesizing metal immobilizing substances and metal mobilizing organic acids and biosurfactants. The present work enlightens the potential role of root-associated microorganisms in the remediation of heavy metal–contaminated soils, with an additional discussion on biochemical and molecular mechanisms of plant-microbe interactions.