title: Enhanced accumulation of atropine in Atropa belladonna transformed by Rac GTPase gene isolated from Scoparia dulcis.
abstract: Leaf tissues of Atropa belladonna were transformed by Sdrac2, a Rac GTPase gene, that is isolated from Scoparia dulcis, and the change in atropine concentration of the transformants was examined. Re-differentiated A. belladonna overexpressing Sdrac2 accumulated considerable concentration of atropine in the leaf tissues, whereas the leaves of plants transformed by an empty vector accumulated only a very low concentration of the compound. A. belladonna transformed by CASdrac2, a modified Sdrac2 of which translate was expected to bind guanosine triphosphate (GTP) permanently, accumulated very high concentrations of atropine (approximately 2.4-fold excess to those found in the wild-type plant in its natural habitat). In sharp contrast, the atropine concentration in transformed A. belladonna prepared with negatively modified Sdrac2, DNSdrac2, expected to bind guanosine diphosphate instead of GTP, was very low. These results suggested that Rac GTPases play an important role in the regulation of secondary metabolism in plant cells and that overexpression of the gene(s) may be capable of enhancing the production of natural products accumulated in higher plant cells.
authors.affiliation: Laboratory of Medicinal Bio-resources, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan.
authors.forename: Kyouhei
authors.initials: K
authors.lastname: Asano
authors.forename: Jung-Bum
authors.initials: JB
authors.lastname: Lee
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Yamamura
authors.forename: Fumiya
authors.initials: F
authors.lastname: Kurosaki
mesh_terms: D001532:Atropa belladonna / Q000235:genetics* / Q000254:growth & development; D001285:Atropine / Q000235:genetics / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006153:Guanosine Diphosphate / Q000235:genetics / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics; D030821:Plants, Genetically Modified; D036721:Scoparia / Q000235:genetics*
chemical_list: D006153:Guanosine Diphosphate; D001285:Atropine; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases