Plant-microbe-metal interactions for heavy metal bioremediation: a review

Considerable amounts of heavy metals have contaminated the soil from potential manmade point and nonpoint sources such as industry, urbanisation and agriculture. In both managed and natural ecosystems, beneficial plant-microbe interactions play a significant role improving the growth and health of plants, and could be applied for improving soil fertility as well as crop productivity. Additionally, plant microbe interactions could be utilised in bioremediation of heavy metal-contaminated soils. The efficiency of phytoremediation can be improved with the aid of plant-growth-promoting bacteria (PGPB), which can change metals to bioavailable and soluble forms. PGPB perform remediation through processes such as production of siderophores, organic acids and biosurfactants, biomethylation, redox processes, phosphorus solubilisation, nitrogen fixation and iron sequestration. These processes improve plant growth and increase plant biomass along with phytoremediation. A crucial solution to the problem of heavy metal contamination might be an appropriate understanding of hyperaccumulator plants and their interaction with microbes. Emerging strategies for either enhancing or reducing the bioavailability of heavy metals in the rhizosphere, such as improving plant establishment, growth and health can significantly accelerate the heavy metal bioremediation process. In this review, we feature the function of PGPB to assist phytoremediation of heavy metals as an eco-friendly and economical approach.

Automated summary

The bio-remediation of heavy metal-contaminated soils through phytoremediation can be assisted by plant growth-promoting bacteria (PGPB), which can enhance the efficiency of remediation by converting metals into bioavailable and soluble forms. This process involves various biochemical processes that promote plant growth and increase biomass.