title: Interplay of sugar, light and gibberellins in expression of Rosa hybrida vacuolar invertase 1 regulation.
abstract: Our previous findings showed that the expression of the Rosa hybrida vacuolar invertase 1 gene (RhVI1) was tightly correlated with the ability of buds to grow out and was under sugar, gibberellin and light control. Here, we aimed to provide an insight into the mechanistic basis of this regulation. In situ hybridization showed that RhVI1 expression was localized in epidermal cells of young leaves of bursting buds. We then isolated a 895 bp fragment of the promoter of RhVI1. In silico analysis identified putative cis-elements involved in the response to sugars, light and gibberellins on its proximal part (595 bp). To carry out functional analysis of the RhVI1 promoter in a homologous system, we developed a direct method for stable transformation of rose cells. 5' deletions of the proximal promoter fused to the uidA reporter gene were inserted into the rose cell genome to study the cell's response to exogenous and endogenous stimuli. Deletion analysis revealed that the 468 bp promoter fragment is sufficient to trigger reporter gene activity in response to light, sugars and gibberellins. This region confers sucrose- and fructose-, but not glucose-, responsive activation in the dark. Inversely, the -595 to -468 bp region that carries the sugar-repressive element (SRE) is required to down-regulate the RhVI1 promoter in response to sucrose and fructose in the dark. We also demonstrate that sugar/light and gibberellin/light act synergistically to up-regulate β-glucuronidase (GUS) activity sharply under the control of the 595 bp pRhVI1 region. These results reveal that the 127 bp promoter fragment located between -595 and -468 bp is critical for light and sugar and light and gibberellins to act synergistically.
authors.affiliation: Agrocampus-Ouest, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France These authors contributed equally to this work.
authors.forename: Amélie
authors.initials: A
authors.lastname: Rabot
authors.affiliation: Université de Poitiers, UMR 7267 CNRS/Université de Poitiers Écologie et Biologie des Interactions, équipe Physiologie Moléculaire du Transport des Sucres chez les végétaux, 3 rue Jacques Fort, B31, 86 000 Poitiers, France These authors contributed equally to this work. Present address: INRA, Institut Jean Pierre Bourgin, UMR 1318, F-78026 Versailles, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Portemer
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: Thomas
authors.initials: T
authors.lastname: Péron
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: Eric
authors.initials: E
authors.lastname: Mortreau
authors.affiliation: Université d'Angers, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Leduc
authors.affiliation: Agrocampus-Ouest, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France Université d'Angers, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France INRA, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49071 Beaucouzé, France.
authors.forename: Latifa
authors.initials: L
authors.lastname: Hamama
authors.affiliation: Université de Poitiers, UMR 7267 CNRS/Université de Poitiers Écologie et Biologie des Interactions, équipe Physiologie Moléculaire du Transport des Sucres chez les végétaux, 3 rue Jacques Fort, B31, 86 000 Poitiers, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Coutos-Thévenot
authors.affiliation: Université de Poitiers, UMR 7267 CNRS/Université de Poitiers Écologie et Biologie des Interactions, équipe Physiologie Moléculaire du Transport des Sucres chez les végétaux, 3 rue Jacques Fort, B31, 86 000 Poitiers, France.
authors.forename: Rossitza
authors.initials: R
authors.lastname: Atanassova
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: Soulaiman
authors.initials: S
authors.lastname: Sakr
authors.affiliation: Université d'Angers, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, F-49045 Angers, France jose.gentilhomme@univ-angers.fr.
authors.forename: José
authors.initials: J
authors.lastname: Le Gourrierec
mesh_terms: D001483:Base Sequence; D050260:Carbohydrate Metabolism; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D005875:Gibberellins / Q000378:metabolism*; D008027:Light; D008969:Molecular Sequence Data; D027826:Rosa / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000528:radiation effects; D014617:Vacuoles / Q000201:enzymology*; D043324:beta-Fructofuranosidase / Q000378:metabolism*
chemical_list: D018744:DNA, Plant; D005875:Gibberellins; D043324:beta-Fructofuranosidase
keywords: Gibberellins; Light; Promoter; Rosa hybrida; Sugar; Vacuolar invertase