Unveiling the potential of plant growth promoting rhizobacteria (PGPR) in phytoremediation of heavy metal

Rapid industrialization, modern farming practices, and other human activities are contributing significant amounts of harmful heavy metals to the environment. These metals can accumulate and magnify through food chains, posing substantial risks to human health. Recognizing the global environmental threat and its health implications, researchers have developed cutting-edge methods to address heavy metal contamination. Phytoremediation stands out as the foremost method, offering effectiveness and environmental suitability. Combining plant growth-promoting rhizobacteria (PGPR) with phytoremediation can be a viable option for minimizing contamination. PGPR enhances plant growth and aids in metal cleanup through chemical synthesis, the secretion of chelating agents, redox reactions, and acidification. This review conducted a comprehensive online search across peer-reviewed electronic databases using specific keywords related to PGPR in heavy metal phytoremediation. This review included 129 relevant articles out of the initially identified 187 articles and outcomes were represented with schematic sketches and in-depth tables. The articles selected were focused on the potential of PGPR in phytoremediation, with emphasis on the contribution of rhizo and endophytic bacteria in accelerating the benefits of phytoremediation. There is little information available about the mechanisms involved in plant-PGPR relationships for metal accumulation. The causes and effects of heavy metal toxicity in the environment were examined in this review, along with the usage of PGPR as a different biological strategy to reduce metal contamination and prevent metals from migrating into edible plant parts. Finally, these prospects will provide some perspectives for future studies on these bacteria in agriculture and offer the possibility of major breakthroughs through knowledge expansion and the allocation of trial sites for the transfer of phytoremediation technology to the farmers in a better way. A systematic review of the use of PGPR as an alternative biological approach to reduce metal pressure and its translocation into the edible parts of plants. A basis for developing an integrated approach to phytoremediation of heavy metals. A guideline for future studies on these bacteria in agriculture and offer the possibility of major breakthroughs in phytoremediation technology so that we can offer this to farmers in a better way.