title: Molecular evolution of N-methylputrescine oxidase in tobacco.
abstract: Biosynthesis of nicotine in tobacco requires N-methylputrescine oxidase (MPO), which belongs to the copper-containing amine oxidase superfamily. Previous studies identified tobacco MPO1 and its close homolog NtDAO1 (formerly called MPO2), of which MPO1 has been shown preferentially to oxidize N-methylated amines. We show here that NtDAO1, as well as a homologous Arabidopsis diamine oxidase (DAO), accept non-N-methylated amines more efficiently than their corresponding N-methylated amines. MPO1 is coordinately regulated with other nicotine biosynthesis genes with regard to COI1-MYC2-dependent jasmonate induction and its dependence on nicotine-specific ERF transcription factors, whereas NtDAO1 is constitutively expressed at low basal levels in tobacco plants. Both MPO1 and NtDAO1 are targeted to peroxisomes by their C-terminal motifs, and the peroxisomal localization of MPO1 is required for it to function in nicotine biosynthesis in jasmonate-elicited cultured tobacco cells. Restricted occurrence of the MPO subfamily in Nicotiana and Solanum indicates that, during the formation of the Solanaceae, MPO has evolved from a DAO, which functions in polyamine catabolism within peroxisomes, by optimizing substrate preference and gene expression patterns to be suitable for alkaloid formation.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192 Japan.
authors.forename: Maliwan
authors.initials: M
authors.lastname: Naconsie
authors.forename: Keita
authors.initials: K
authors.lastname: Kato
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Shoji
authors.forename: Takashi
authors.initials: T
authors.lastname: Hashimoto
mesh_terms: D000470:Alkaloids / Q000032:analysis / Q000378:metabolism; D006631:Amine Oxidase (Copper-Containing) / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D003517:Cyclopentanes / Q000378:metabolism; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D009538:Nicotine / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D020675:Peroxisomes / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D021381:Protein Transport; D011700:Putrescine / Q000378:metabolism*; D034622:RNA Interference; D011994:Recombinant Proteins; D013379:Substrate Specificity; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology* / Q000235:genetics
chemical_list: D000470:Alkaloids; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011994:Recombinant Proteins; D009538:Nicotine; C011006:jasmonic acid; D006631:Amine Oxidase (Copper-Containing); D011700:Putrescine
keywords: Diamine oxidase; Nicotine; Peroxisomes; Putrescine; Tobacco