Secondary plant metabolites and root exudates: guiding tools for polychlorinated biphenyl biodegradation

Synthetic organic compounds are hallmark of modern society. They are ubiquitous ranging from home, workplace to agriculture industry, which leads to their nonjudicious dispensing into environment. Unfortunately most of them, especially polychlorinated biphenyls (PCBs), are deemed as persistent organic pollutants posing serious health risks to human. Hence, there is an alarming need of phasing out these chemicals and remediating contaminated sites in eco-friendly manner. Phytoremediation has emerged as a highly promising approach which capitalizes on plants and their associated microorganisms for removal of pollutants from targeted sites. Plant root exudations and secondary metabolites efficiently orchestrate selective recruitment of potential PCB-degrading microbial consortia within the rhizosphere and inside plant tissues. Structural analogy between organic contaminants and secondary plant metabolites (SPMEs) renders possible uptake and subsequent degradation of pollutants by microorganisms. Present review is focused on potential role of plant root exudates and SPMEs in structuring and orchestrating remediation of PCBs within rhizosphere and inside plant tissues. Also, recent developments in tools and techniques to study remediation of organic contaminants with special reference to PCBs are addressed

Keywords
Secondary plant metabolites; Persistent organic pollutants; Polychlorinated biphenyls; Biosensor; Rhizoengineering