title: Microsomal detoxification enzymes in yam bean [Pachyrhizus erosus (L.) urban].
abstract: Cytochrome P450s and glutathione-S-transferases (GSTs) constitute two of the largest groups of enzyme families that are responsible for detoxification of exogenous molecules in plants. Their activities differ from plant to plant with respect to metabolism and substrate specificity which is one of the reasons for herbicide selectivity. In the tuber forming yam bean, the legume Pachyrhizus erosus, their activities at the microsomal level were investigated to determine the detoxification status of the plant. The breakdown of the herbicide isoproturon (IPU) to two distinct metabolites, 1-OH-IPU and monodesmethyl-IPU, was demonstrated. GST activity was determined with model substrates, but also by the catalysed formation of the fluorescent glutathione bimane conjugate. This study demonstrates for the first time microsomal detoxification activity in Pachyrhizus and the fluorescence image description of microsomal GST catalysed reaction in a legume.
authors.affiliation: Institute of Soil Ecology, GSF--National Research Centre for Environment and Health, D-85764 Neuherberg, Germany.
authors.forename: Ebenezer J D
authors.initials: EJ
authors.lastname: Belford
authors.forename: Ulrike
authors.initials: U
authors.lastname: Dörfler
authors.forename: Andreas
authors.initials: A
authors.lastname: Stampfl
authors.forename: Peter
authors.initials: P
authors.lastname: Schröder
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D006540:Herbicides / Q000493:pharmacokinetics; D008658:Inactivation, Metabolic / Q000502:physiology; D007700:Kinetics; D008856:Microscopy, Fluorescence; D008861:Microsomes / Q000201:enzymology*; D029905:Pachyrhizus / Q000201:enzymology*; D010671:Phenylurea Compounds / Q000493:pharmacokinetics; D010936:Plant Extracts / Q000302:isolation & purification / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology
chemical_list: D006540:Herbicides; D010671:Phenylurea Compounds; D010936:Plant Extracts; C028904:isoproturon; D003577:Cytochrome P-450 Enzyme System; D005982:Glutathione Transferase