title: Mammalian cytochrome CYP2E1 triggered differential gene regulation in response to trichloroethylene (TCE) in a transgenic poplar.
abstract: Trichloroethylene (TCE) is an important environmental contaminant of soil, groundwater, and air. Studies of the metabolism of TCE by poplar trees suggest that cytochrome P450 enzymes are involved. Using poplar genome microarrays, we report a number of putative genes that are differentially expressed in response to TCE. In a previous study, transgenic hybrid poplar plants expressing mammalian cytochrome P450 2E1 (CYP2E1) had increased metabolism of TCE. In the vector control plants for this construct, 24 h following TCE exposure, 517 genes were upregulated and 650 genes were downregulated over 2-fold when compared with the non-exposed vector control plants. However, in the transgenic CYP2E1 plant, line 78, 1,601 genes were upregulated and 1,705 genes were downregulated over 2-fold when compared with the non-exposed transgenic CYP2E1 plant. It appeared that the CYP2E1 transgenic hybrid poplar plants overexpressing mammalian CYP2E1 showed a larger number of differentially expressed transcripts, suggesting a metabolic pathway for TCE to metabolites had been initiated by activity of CYP2E1 on TCE. These results suggest that either the over-expression of the CYP2E1 gene or the abundance of TCE metabolites from CYP450 2E1 activity triggered a strong genetic response to TCE. Particularly, cytochrome p450s, glutathione S-transferases, glucosyltransferases, and ABC transporters in the CYP2E1 transgenic hybrid poplar plants were highly expressed compared with in vector controls.
authors.affiliation: School of Forest Resources, College of the Environment, University of Washington, Seattle, WA 98195, USA. jwkang75@uw.edu
authors.forename: Jun Won
authors.initials: JW
authors.lastname: Kang
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Wilkerson
authors.forename: Federico M
authors.initials: FM
authors.lastname: Farin
authors.forename: Theo K
authors.initials: TK
authors.lastname: Bammler
authors.forename: Richard P
authors.initials: RP
authors.lastname: Beyer
authors.forename: Stuart E
authors.initials: SE
authors.lastname: Strand
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Doty
mesh_terms: D000818:Animals; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified; D032107:Populus / Q000187:drug effects* / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014241:Trichloroethylene / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D014241:Trichloroethylene; D019392:Cytochrome P-450 CYP2E1