Effect of copper on in vivo fate of BDE-209 in pumpkin

A 60-day growth chamber experiments were performed to investigate the effect of Cu stress on the uptake, translocation and metabolism of decabromodiphenyl ether (BDE-209) by pumpkin. A total of nine debrominated metabolites (de-PBDEs), two hydroxylated PBDEs (OH-PBDEs) and one methoxylated PBDEs (MeO-PBDEs) were detected in the tested plants. Concentrations of the total debrominated, hydroxylated or methoxylated metabolites generally followed the order of roots > stems > leaves, and de-PBDEs > OH-PBDEs > MeO-PBDEs. These results indicate that metabolism occurred preferentially in roots than in stems and leaves. The addition of moderate dosage of Cu (50 mg/kg) resulted in increment in OH-PBDE concentrations in plant tissues, whereas higher concentrations of Cu could inhibit uptake and metabolism of BDE-209. No in vivo mineralization of BDE-209 was detected in the plants. These results provide valuable information about the behavior of BDE-209 in plant tissues under heavy metal exposure.