title: Identification of a novel hedycaryol synthase gene isolated from Camellia brevistyla flowers and floral scent of Camellia cultivars.
abstract: A novel terpene synthase (Tps) gene isolated from Camellia brevistyla was identified as hedycaryol synthase, which was shown to be expressed specifically in flowers. Camellia plants are very popular because they bloom in winter when other plants seldom flower. Many ornamental cultivars of Camellia have been bred mainly in Japan, although the fragrance of their flowers has not been studied extensively. We analyzed floral scents of several Camellia cultivars by gas chromatography-mass spectrometry (GC-MS) and found that Camellia brevistyla produced various sesquiterpenes in addition to monoterpenes, whereas Camellia japonica and its cross-lines produced only monoterpenes, including linalool as the main product. From a flower of C. brevistyla, we isolated one cDNA encoding a terpene synthase (TPS) comprised of 554 amino acids, which was phylogenetically positioned to a sole gene clade. The cDNA, designated CbTps1, was expressed in mevalonate-pathway-engineered Escherichia coli, which carried the Streptomyces mevalonate-pathway gene cluster in addition to the acetoacetate-CoA ligase gene. A terpene product was purified from recombinant E. coli cultured with lithium acetoacetate, and analyzed by (1)H-nulcear magnetic resonance spectroscopy ((1)H-NMR) and GC-MS. It was shown that a sesquiterpene hedycaryol was produced, because (1)H-NMR signals of the purified product were very broad, and elemol, a thermal rearrangement product from hedycaryol, was identified by GC-MS analysis. Spectroscopic data of elemol were also determined. These results indicated that the CbTps1 gene encodes hedycaryol synthase. Expression analysis of CbTps1 showed that it was expressed specifically in flowers, and hedycaryol is likely to be one of the terpenes that attract insects for pollination of C. brevistyla. A linalool synthase gene, which was isolated from a flower of Camellia saluenensis, is also described.
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Hattan
authors.affiliation: Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Shindo
authors.affiliation: Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan.
authors.forename: Yurica
authors.initials: Y
authors.lastname: Shibuya
authors.affiliation: Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan.
authors.forename: Arisa
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Tagaki
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
authors.forename: Fumina
authors.initials: F
authors.lastname: Ohno
authors.affiliation: Industrial Research Institute of Ishikawa, 2-1 Kuratsuki, Kanazawa, Ishikawa, 920-8203, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ishii
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan. n-misawa@ishikawa-pu.ac.jp.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Misawa
mesh_terms: D000080462:Acyclic Monoterpenes; D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D028244:Camellia / Q000235:genetics / Q000502:physiology*; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D039821:Monoterpenes / Q000378:metabolism; D009812:Odorants / Q000032:analysis*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000032:analysis / Q000378:metabolism
chemical_list: D000080462:Acyclic Monoterpenes; D039821:Monoterpenes; D010940:Plant Proteins; D011994:Recombinant Proteins; D012717:Sesquiterpenes; C018584:linalool; D019883:Alkyl and Aryl Transferases; C000612896:hedycaryol synthase, Camellia brevistyla; C108877:terpene synthase; D003066:Coenzyme A Ligases; C023747:acetoacetyl-CoA synthetase; C033011:elemol
keywords: Camellia; Elemol; Escherichia coli; Hedycaryol; Sesquiterpene synthase