title: Characterization of the safener-induced glutathione S-transferase isoform II from maize.
abstract: The safener-induced maize (Zea mays L.) glutathione S-transferase, GST II (EC 2.5.1.18) and another predominant isoform, GST I, were purified from extracts of maize roots treated with the safeners R-25788 (N,N-diallyl-2-dichloroacetamide) or R-29148 (3-dichloroacetyl-2,2,5-trimethyl-1,3-oxazolidone). The isoforms GST I and GST II are respectively a homodimer of 29-kDa (GST-29) subunits and a heterodimer of 29- and 27-kDa (GST-27) subunits, while GST I is twice as active with 1-chloro-2,4-dinitrobenzene as GST II, GST II is about seven times more active against the herbicide, alachlor. Western blotting using antisera raised against GST-29 and GST-27 showed that GST-29 is present throughout the maize plant prior to safener treatment. In contrast, GST-27 is only present in roots of untreated plants but is induced in all the major aerial organs of maize after root-drenching with safener. The amino-acid sequences of proteolytic fragments of GST-27 show that it is related to GST-29 and identical to the 27-kDa subunit of GST IV.
authors.affiliation: ZENECA Seeds, Bracknell, UK.
authors.forename: D C
authors.initials: DC
authors.lastname: Holt
authors.forename: V J
authors.initials: VJ
authors.lastname: Lay
authors.forename: E D
authors.initials: ED
authors.lastname: Clarke
authors.forename: A
authors.initials: A
authors.lastname: Dinsmore
authors.forename: I
authors.initials: I
authors.lastname: Jepson
authors.forename: S W
authors.initials: SW
authors.lastname: Bright
authors.forename: A J
authors.initials: AJ
authors.lastname: Greenland
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004790:Enzyme Induction; D005982:Glutathione Transferase / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D006540:Herbicides / Q000494:pharmacology*; D007527:Isoenzymes / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010080:Oxazoles / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000201:enzymology*
chemical_list: D000081:Acetamides; D006540:Herbicides; D007527:Isoenzymes; D046911:Macromolecular Substances; D010080:Oxazoles; C092143:3-(dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine; C006284:dichlormid; D005982:Glutathione Transferase