title: The gentio-oligosaccharide gentiobiose functions in the modulation of bud dormancy in the herbaceous perennial Gentiana.
abstract: Bud dormancy is an adaptive strategy that perennials use to survive unfavorable conditions. Gentians (Gentiana), popular alpine flowers and ornamentals, produce overwintering buds (OWBs) that can persist through the winter, but the mechanisms regulating dormancy are currently unclear. In this study, we conducted targeted metabolome analysis to obtain clues about the metabolic mechanisms involved in regulating OWB dormancy. Multivariate analysis of metabolite profiles revealed metabolite patterns characteristic of dormant states. The concentrations of gentiobiose [β-D-Glcp-(1→6)-D-Glc] and gentianose [β-D-Glcp-(1→6)-D-Glc-(1→2)-d-Fru] significantly varied depending on the stage of OWB dormancy, and the gentiobiose concentration increased prior to budbreak. Both activation of invertase and inactivation of β-glucosidase resulted in gentiobiose accumulation in ecodormant OWBs, suggesting that gentiobiose is seldom used as an energy source but is involved in signaling pathways. Furthermore, treatment with exogenous gentiobiose induced budbreak in OWBs cultured in vitro, with increased concentrations of sulfur-containing amino acids, GSH, and ascorbate (AsA), as well as increased expression levels of the corresponding genes. Inhibition of GSH synthesis suppressed gentiobiose-induced budbreak accompanied by decreases in GSH and AsA concentrations and redox status. These results indicate that gentiobiose, a rare disaccharide, acts as a signal for dormancy release of gentian OWBs through the AsA-GSH cycle.
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan h-takahashi@ibrc.or.jp.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imamura
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
authors.forename: Naotake
authors.initials: N
authors.lastname: Konno
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Takeda
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Okinawa 903-0213, Japan.
authors.forename: Teruko
authors.initials: T
authors.lastname: Konishi
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishihara
authors.affiliation: Institute of Environmental Science and Technology, Saitama University, Sakura-Ku, Saitama City, Saitama 338-8570, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Uchimiya
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D050260:Carbohydrate Metabolism / Q000187:drug effects / Q000235:genetics; D004187:Disaccharides / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D030012:Gentiana / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005978:Glutathione / Q000378:metabolism; D006593:Hexokinase / Q000235:genetics / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D055442:Metabolome / Q000235:genetics; D055432:Metabolomics / Q000379:methods*; D008969:Molecular Sequence Data; D010733:Phosphoglucomutase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D043324:beta-Fructofuranosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D000596:Amino Acids; D004187:Disaccharides; D010940:Plant Proteins; D006593:Hexokinase; D043324:beta-Fructofuranosidase; D010733:Phosphoglucomutase; D005978:Glutathione; C100052:gentiobiose; D001205:Ascorbic Acid