Transgenic plants to improve rhizoremediation of polychlorinated biphenyls (PCBs)

Recent investigations have shown that the three components of the biphenyl dioxygenase and the 2,3-dihydroxybiphenyl dioxygenase can be produced actively in transgenic plants. Both enzymes catalyze critical steps of the bacterial polychlorinated biphenyl (PCB) degrading pathway. On the basis of these observations, optimized plant–microbe bioremediation processes in which transgenic plants would initiate PCB metabolism and release the metabolites for further degradation by rhizobacteria has been proposed. Since this is still a relatively new approach for PCB remediation, its successful application will require efforts first, to engineer improved PCB-degrading enzymes; second, to co-ordinately express these enzymes’ components in plants; and third, to better understand the mechanisms by which plants and rhizobacteria interact to degrade organic pollutants.