title: Expression of deacetylvindoline-4-O-acetyltransferase in Catharanthus roseus hairy roots.
abstract: Madagascar periwinkle [Catharanthus roseus (L.) G Don] is a pantropical plant of horticultural value that produces the powerful anticancer drugs vinblastine and vincristine that are derived from the dimerization of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine. The present study describes the genetic engineering and expression of the terminal step of vindoline biosynthesis, deacetylvindoline-4-O-acetyltransferase (DAT) in Catharanthus roseus hairy root cultures. Biochemical analyses showed that several hairy root lines expressed high levels of DAT enzyme activity compared to control hairy root cultures expressing beta-glucuronidase activity (GUS) activity. Metabolite analysis using high performance liquid chromatography established that hairy root extracts had an altered alkaloid profile with respect to hörhammericine accumulation in DAT expressing lines in comparison to control lines. Further analyses of one hairy root culture expressing high DAT activity suggested that DAT expression and accumulation of hörhammericine (9) were related. It is concluded that expression of DAT in hairy roots altered their MIA profile and suggests that further expression of vindoline pathway genes could lead to significant changes in alkaloid profiles. Evidence is provided that hörhammericine (9) accumulates via a DAT interaction with the root specific minovincinine-19-O-acetyltransferase (MAT) that inhibits the MAT mediated conversion of hörhammericine (9) into 19-O-acetyl-hörhammericine (12).
authors.affiliation: Department of Biological Sciences, Brock University, 500 Glenridge Avenue, St Catharines, ON, Canada L2S 3A1.
authors.forename: Mary
authors.initials: M
authors.lastname: Magnotta
authors.forename: Jun
authors.initials: J
authors.lastname: Murata
authors.forename: Jianxin
authors.initials: J
authors.lastname: Chen
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Luca
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D030008:Catharanthus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D026121:Indole Alkaloids / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D018515:Plant Leaves / Q000201:enzymology; D018517:Plant Roots / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D011804:Quinolines / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D026121:Indole Alkaloids; D011804:Quinolines; D012333:RNA, Messenger; D046948:Secologanin Tryptamine Alkaloids; C009373:tabersonine; D000123:Acetyltransferases