Accumulation, distribution and transformation of DDT and PCBs by Phragmites australis and Oryza sativa L.: II. Enzyme study
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Two wetland plant species, Phragmites australis and Oryza sativa, were grown in a glasshouse under hydroponics conditions. Enzyme extracts from different parts of the plants were used to determine the transformation rate of o,p′-DDT, p,p′-DDT and PCBs. The organic pollutants were directly spiked into the enzyme extracts, and samples were collected every 30 min and analyzed with a GC-ECD. Root extracts of P. australis readily degraded and transformed DDT and some PCB congeners with a low degree of chlorination. In contrast, crude extracts of O. sativa showed no appreciable degradation or transformation of DDT or PCBs. Inhibition studies indicated that the degradation and transformation of both DDT and PCBs by P. australis enzymes were partly mediated by peroxidase and the plant P-450 system. PCBs with a high degree of chlorination were highly resistant to transformation or degradation by plant enzymes. Both wetland plant species accumulated substantial quantities of the persistent organic chemicals but had different degradation capacities. The enzyme systems in P. australis were much more effective that those in rice in the degradation and transformation of the organic pollutants.
KeywordsDDT PCBs persistent organic chemicals phytoremediation Phragmites australis Oryza sativa
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This research was supported by the Central Allocation Group Research, University Grants Committee, Hong Kong (Code No: HKBU-2/00C).
- Briggs GG, Bromilow RH, Evans AA, 1982 Relationship between lipophilicity and root uptake and translocation of non-ionized chemicals by barley Pestic Sci Technol 29:1581–1585Google Scholar
- Dunlup TR, 1981 DDT: Scientists, Citizens, and Public Policy. Princeton, NJ: Princeton University PressGoogle Scholar
- Meagher RB, 2000 Phytoremediation of toxic elemental and organic pollutants Plant Biol. 3:153–162Google Scholar
- Ritter L, Solomon KR, Forget J. 1995 Persistent Organic Pollutants: An Assessment Report on DDT, Aldrin, Dieldrin, Endrin, Chlordane, Heptachlor, Hexachlorobenzene, Mirex, Toxaphene, Polychlorinated Biphenyls, Dioxins, and Furans. International Programme on Chemical Safety (IPCS) Google Scholar
- Sandermann H, 1994 Higher plant metabolism of xenobiotics: the ‘green-liver’ concept Pharmacogenetics 4:225–241Google Scholar
- Smith AG, 1991 Chlorinated hydrocarbon insecticides.In: Hayes WJ, Laws ER, eds Handbook of Pesticides Toxicology, San Diego, New York: Academic Press Inc., 731–915Google Scholar
- Stiborova M, Anzenbacher P, 1991 What are the principal enzymes oxidising the xenobiotics in plants? Cytochromes P-450 or peroxidases? Gen Physiol Biophys 10:209–216Google Scholar
- WHO 1989 DDT and its Derivatives – Environmental Aspects. Environmental Health Criteria 83. WHO European Centre for Environment and Health International Programme on Chemical Safety, Geneva, Switzerland Google Scholar