title: Insight into the role of sugars in bud burst under light in the rose.
abstract: Bud burst is a decisive process in plant architecture that requires light in Rosa sp. This light effect was correlated with stimulation of sugar transport and metabolism in favor of bud outgrowth. We investigated whether sugars could act as signaling entities in the light-mediated regulation of vacuolar invertases and bud burst. Full-length cDNAs encoding two vacuolar invertases (RhVI1 and RhVI2) were isolated from buds. Unlike RhVI2, RhVI1 was preferentially expressed in bursting buds, and was up-regulated in buds of beheaded plants exposed to light. To assess the importance of sugars in this process, the expression of RhVI1 and RhVI2 and the total vacuolar invertase activity were further characterized in buds cultured in vitro on 100 mM sucrose or mannitol under light or in darkness for 48 h. Unlike mannitol, sucrose promoted the stimulatory effect of light on both RhVI1 expression and vacuolar invertase activity. This up-regulation of RhVI1 was rapid (after 6 h incubation) and was induced by as little as 10 mM sucrose or fructose. No effect of glucose was found. Interestingly, both 30 mM palatinose (a non-metabolizable sucrose analog) and 5 mM psicose (a non-metabolizable fructose analog) promoted the light-induced expression of RhVI1 and total vacuolar invertase activity. Sucrose, fructose, palatinose and psicose all promoted bursting of in vitro cultured buds under light. These findings indicate that soluble sugars contribute to the light effect on bud burst and vacuolar invertases, and can function as signaling entities.
authors.affiliation: Agrocampus-Ouest, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France.
authors.forename: Amelie
authors.initials: A
authors.lastname: Rabot
authors.forename: Clemence
authors.initials: C
authors.lastname: Henry
authors.forename: Khaoula
authors.initials: K
authors.lastname: Ben Baaziz
authors.forename: Eric
authors.initials: E
authors.lastname: Mortreau
authors.forename: Wassim
authors.initials: W
authors.lastname: Azri
authors.forename: Jeremy
authors.initials: J
authors.lastname: Lothier
authors.forename: Latifa
authors.initials: L
authors.lastname: Hamama
authors.forename: Rachid
authors.initials: R
authors.lastname: Boummaza
authors.forename: Nathalie
authors.initials: N
authors.lastname: Leduc
authors.forename: Sandrine
authors.initials: S
authors.lastname: Pelleschi-Travier
authors.forename: José
authors.initials: J
authors.lastname: Le Gourrierec
authors.forename: Soulaiman
authors.initials: S
authors.lastname: Sakr
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D003001:Cloning, Molecular; D046508:Culture Techniques / Q000379:methods; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D003624:Darkness; D004789:Enzyme Activation; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D005632:Fructose / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005947:Glucose / Q000494:pharmacology; D007534:Isomaltose / Q000031:analogs & derivatives / Q000494:pharmacology; D008027:Light; D008353:Mannitol / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D027826:Rosa / Q000201:enzymology / Q000235:genetics / Q000528:radiation effects*; D015398:Signal Transduction; D013395:Sucrose / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic; D014617:Vacuoles / Q000201:enzymology / Q000378:metabolism; D043324:beta-Fructofuranosidase / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; C003243:psicose; D005632:Fructose; D008353:Mannitol; D013395:Sucrose; D007534:Isomaltose; D043324:beta-Fructofuranosidase; D005947:Glucose; C008189:isomaltulose