title: 3,4-Dichloroaniline is detoxified and exported via different pathways in Arabidopsis and soybean.
abstract: The metabolic fate of [UL-14C]-3,4-dichloroaniline (DCA) was investigated in Arabidopsis root cultures and soybean plants over a 48 h period following treatment via the root media. DCA was rapidly taken up by both species and metabolised, predominantly to N-malonyl-DCA in soybean and N-glucosyl-DCA in Arabidopsis. Synthesis occurred in the roots and the respective conjugates were largely exported into the culture medium, a smaller proportion being retained within the plant tissue. Once conjugated, the DCA metabolites in the medium were not then readily taken up by roots of either species. The difference in the routes of DCA detoxification in the two plants could be explained partly by the relative activities of the respective conjugating enzymes, soybean containing high DCA-N-malonyltransferase activity, while in Arabidopsis DCA-N-glucosyltransferase activity predominated. A pre-treatment of plants with DCA increased DCA-N-malonyltransferase activity in soybean but not in Arabidopsis, indicating differential regulation of this enzyme in the two plant species. This study demonstrates that DCA can undergo two distinct detoxification mechanisms which both lead to the export of conjugated metabolites from roots into the surrounding medium in contrast to the vacuolar deposition more commonly associated with the metabolism of xenobiotics in plants.
authors.affiliation: Crop Performance and Improvement Division, Rothamsted Research, Harpenden AL5 2JQ, UK.
authors.forename: Si-Houy
authors.initials: SH
authors.lastname: Lao
authors.forename: Caroline
authors.initials: C
authors.lastname: Loutre
authors.forename: Melissa
authors.initials: M
authors.lastname: Brazier
authors.forename: Julian O D
authors.initials: JO
authors.lastname: Coleman
authors.forename: David J
authors.initials: DJ
authors.lastname: Cole
authors.forename: Robert
authors.initials: R
authors.lastname: Edwards
authors.forename: Frederica L
authors.initials: FL
authors.lastname: Theodoulou
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000814:Aniline Compounds / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D001692:Biological Transport; D001711:Biotransformation; D005964:Glucosyltransferases / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D000814:Aniline Compounds; D029681:Arabidopsis Proteins; C054619:2,4-dichloroaniline; D000217:Acyltransferases; C043371:malonyl-CoA-3,4-dichloroaniline N-malonyltransferase; C477323:3,4-dichloroaniline N-glucosyltransferase; D005964:Glucosyltransferases