title: Metabolic engineering of plant alkaloid biosynthesis.
abstract: Plant alkaloids, one of the largest groups of natural products, provide many pharmacologically active compounds. Several genes in the biosynthetic pathways for scopolamine, nicotine, and berberine have been cloned, making the metabolic engineering of these alkaloids possible. Expression of two branching-point enzymes was engineered: putrescine N-methyltransferase (PMT) in transgenic plants of Atropa belladonna and Nicotiana sylvestris and (S)-scoulerine 9-O-methyltransferase (SMT) in cultured cells of Coptis japonica and Eschscholzia californica. Overexpression of PMT increased the nicotine content in N. sylvestris, whereas suppression of endogenous PMT activity severely decreased the nicotine content and induced abnormal morphologies. Ectopic expression of SMT caused the accumulation of benzylisoquinoline alkaloids in E. californica. The prospects and limitations of engineering plant alkaloid metabolism are discussed.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: A
authors.initials: A
authors.lastname: Hachiya
authors.forename: K
authors.initials: K
authors.lastname: Tamura
authors.forename: K B
authors.initials: KB
authors.lastname: Choi
authors.forename: T
authors.initials: T
authors.lastname: Morishige
authors.forename: H
authors.initials: H
authors.lastname: Fujimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering; D007546:Isoquinolines / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D009538:Nicotine / Q000737:chemistry / Q000378:metabolism; D059828:Plant Cells; D010940:Plant Proteins / Q000032:analysis; D010944:Plants / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000032:analysis; D014170:Transformation, Genetic
chemical_list: D000470:Alkaloids; D007546:Isoquinolines; D010940:Plant Proteins; D018749:RNA, Plant; D009538:Nicotine; D008780:Methyltransferases; C093217:S-adenosyl-L-methionine - scoulerine-9-O-methyltransferase; C112598:putrescine N-methyltransferase