title: An atypical pattern of accumulation of scopolamine and other tropane alkaloids and expression of alkaloid pathway genes in Hyoscyamus senecionis.
abstract: A cDNA encoding hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11), a bifunctional enzyme catalyzing the last two steps in the scopolamine biosynthetic pathway, was isolated from Hyoscyamus senecionis, a medicinal plant endemic to the Iranian plateau. Expression analysis indicates that Hsh6h is expressed in all tested organs of H. senecionis including roots, rhizomes, leaves, stems and flowers unlike the other tropane alkaloid producing species. In parallel to this, in leaves, levels of scopolamine, the product of H6H, were higher than the substrate hyoscyamine. These data suggest that not only does the conversion of hyoscyamine to scopolamine take place in the root, followed by translocation to aerial parts, but also accumulated hyoscyamine in the aerial parts may be converted to scopolamine by activity of HsH6H. Analysis of expression profiles of putrescine N-methyltransferase and tropinone reductase I and II genes also indicates the organ-independent expression of these genes. Here we also introduce H. senecionis as an important tropane alkaloid producing species with its thick underground parts as a source of hyoscyamine, while its leaves can be considered as a source of scopolamine.
authors.affiliation: Department of Plant Biotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, P.O. Box 9177948978, Mashhad, Iran. es.dehghanshahreza@gmail.com
authors.forename: Esmail
authors.initials: E
authors.lastname: Dehghan
authors.forename: Farajollah
authors.initials: F
authors.lastname: Shahriari Ahmadi
authors.forename: Elnaz
authors.initials: E
authors.lastname: Ghotbi Ravandi
authors.forename: Darwin W
authors.initials: DW
authors.lastname: Reed
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Covello
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Bahrami
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D018076:DNA, Complementary; D015870:Gene Expression; D017343:Genes, Plant; D064692:Hyoscyamine / Q000235:genetics / Q000378:metabolism*; D032304:Hyoscyamus / Q000235:genetics / Q000378:metabolism*; D007492:Iran; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018514:Plant Structures / Q000378:metabolism*; D010946:Plants, Medicinal; D012601:Scopolamine / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D012601:Scopolamine; D006899:Mixed Function Oxygenases; D000429:Alcohol Oxidoreductases; C083753:tropinone reductase; C052273:hyoscyamine (6S)-dioxygenase; D008780:Methyltransferases; C112598:putrescine N-methyltransferase; D064692:Hyoscyamine
keywords: 5-bromo-4-chloro-indolyl-β-d-galactopyranoside; BSTFA; Expression profile; GC; GC–MS; Hyoscyamine 6β-hydroxylase (H6H); Hyoscyamus senecionis; IPTG; MS; Murashige and Skoog; ORF; PMT; Solanaceae; TMCS; TRI; TRII; Tropane alkaloids; X-Gal; bistrimethylsilyltrifluoroacetamide; gas chromatography; gas chromatography–mass spectrometry; isopropyl β-d-1-thiogalactopyranoside; open reading frame; putrescine N-methyltransferase; trimethylchlorosilane; tropinone reductase I; tropinone reductase II