Phytoaccumulation of coplanar PCBs by Arabidopsis thaliana

摘要

The stability and hydrophobic nature of poly-chlorinated biphenyls (PCBs) make them a persistent environmental hazard; thus, the environmental pollution level of PCBs has been kept high for a long time (Ohsaki et al., 1995, 1997; Kurokawa et al., 1996; Soong et al., 1997). Among PCBs, the environmental toxicity of coplanar PCBs (Co-PCBs) is becoming more severe especially in Japan. To clean up the polluted environment, phytoremediation is expected to solve the environmental pollution problem. We have been studying the utilization of genetically engineered plants to monitor or remedy the environment polluted by harmful organic compounds, particularly by Co-PCBs (Sonoki et al., 2000, 2001). There are some reports on the metabolism of PCBs by plants; however, few reports referred to the precise analysis of Co-PCB congeners accumulated in plants (Groeger and Fletcher, 1988; Lee and Fletcher, 1992; Mackova et al., 1997; Macek et al., 2000). In this study, we investigated the accumulation of 11 congeners of Co-PCB by the plant, Arabidopsis thaliana (Brassicaceae), using high-resolution GC-MS. As a result, it was found that the accumulation rate greatly depended on the chlorination rate of Co-PCBs. Lower chlorinated Co-PCBs were accumulated much more than higher chlorinated Co-PCBs, and the non-ortho Co-PCBs were less accumulated than ortho congeners.