title: Alkaloids in plants and root cultures of Atropa belladonna overexpressing putrescine N-methyltransferase.
abstract: Putrescine N-methyltransferase (PMT) is the first alkaloid-specific enzyme for nicotine and tropane alkaloid formation. The pmt gene from Nicotiana tabacum was fused to the CaMV 35S promoter and integrated into the Atropa belladonna genome. Transgenic plants and derived root cultures were analysed for gene expression and for levels of alkaloids and their precursors. Scopolamine, hyoscyamine, tropine, pseudotropine, tropinone, and calystegines were found unaltered or somewhat decreased in pmt-overexpressing lines compared to controls. When root cultures were treated with 5% sucrose, calystegine levels were elevated in control roots, but were not affected in pmt-overexpressing roots. 1 microM auxin reduced calystegine levels in control roots, while in pmt-overexpressing roots all alkaloids remained unaltered. Expression level of pmt alone is apparently not limiting for tropane alkaloid formation in A. belladonna.
authors.affiliation: Institute of Pharmaceutical Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, D-06120 Halle/Saale, Germany.
authors.forename: Grit
authors.initials: G
authors.lastname: Rothe
authors.forename: Akira
authors.initials: A
authors.lastname: Hachiya
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamada
authors.forename: Takashi
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Birgit
authors.initials: B
authors.lastname: Dräger
mesh_terms: D001532:Atropa belladonna / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D001285:Atropine; D001533:Belladonna Alkaloids / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018745:Genome, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology; D008780:Methyltransferases / Q000235:genetics*; D018517:Plant Roots / Q000201:enzymology*; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012601:Scopolamine / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics; D014326:Tropanes / Q000378:metabolism
chemical_list: D001533:Belladonna Alkaloids; D007210:Indoleacetic Acids; D011993:Recombinant Fusion Proteins; D014326:Tropanes; D001285:Atropine; C005864:tropine; D012601:Scopolamine; D008780:Methyltransferases; C112598:putrescine N-methyltransferase