title: Controlled indole-3-acetaldoxime production through ethanol-induced expression of CYP79B2.
abstract: Indole-3-acetaldoxime (IAOx) is a key branching point between primary and secondary metabolism. IAOx serves as an intermediate in the biosynthesis of indole glucosinolates (I-GLSs), camalexin and the plant hormone indole-3-acetic acid (IAA). The cytochrome P450s CYP79B2 and CYP79B3 catalyze the conversion of tryptophan to IAOx. CYP83B1 channels IAOx into I-GLS biosynthesis, CYP71A13 channels IAOx into camalexin biosynthesis, whereas the IAOx-metabolizing enzyme in IAA biosynthesis is not known. In this report, we demonstrate controlled production of I-GLSs by introducing an ethanol (EtOH)-inducible CYP79B2 construct into double (cyp79b2 cyp79b3) or triple (cyp79b2 cyp79b3 cyp83b1) mutant lines. We show EtOH-dependent induction of camalexin and identify a number of candidate IAA homeostasis- or defense-related genes by clustered microarray analysis. The transgenic mutant lines are thus promising tools for elucidating the interplay between primary and secondary metabolism.
authors.affiliation: VKR Research Centre Pro-Active Plants, Department of Plant Biology and Biotechnology, University of Copenhagen, 40 Thorvaldsensvej, 1871, Frederiksberg C, Denmark.
authors.forename: Michael Dalgaard
authors.initials: MD
authors.lastname: Mikkelsen
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Fuller
authors.forename: Bjarne Gram
authors.initials: BG
authors.lastname: Hansen
authors.forename: Majse
authors.initials: M
authors.lastname: Nafisi
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Olsen
authors.forename: Henrik Bjørn
authors.initials: HB
authors.lastname: Nielsen
authors.forename: Barbara Ann
authors.initials: BA
authors.lastname: Halkier
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways; D002853:Chromatography, Liquid; D016000:Cluster Analysis; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005961:Glucosinolates / Q000737:chemistry / Q000378:metabolism; D007210:Indoleacetic Acids / Q000737:chemistry / Q000378:metabolism; D007211:Indoles / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D015394:Molecular Structure; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010091:Oximes / Q000737:chemistry / Q000378:metabolism*; D030821:Plants, Genetically Modified; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism; D000094162:Phytoalexins
chemical_list: D029681:Arabidopsis Proteins; D003577:Cytochrome P-450 Enzyme System; D000431:Ethanol; D005961:Glucosinolates; D007210:Indoleacetic Acids; D007211:Indoles; D010091:Oximes; D013844:Thiazoles; C102405:camalexin; D000094162:Phytoalexins; C467098:indole-3-acetaldoxime; C030737:indoleacetic acid; C530432:cytochrome P-450 79B2 protein, Arabidopsis; C431937:CYP83B1 protein, Arabidopsis; C471054:cytochrome P-450 CYP79B3, Sinapis alba