title: RhVI1 is a membrane-anchored vacuolar invertase highly expressed in Rosa hybrida L. petals.
abstract: Invertases are a widespread group of enzymes that catalyse the conversion of sucrose into fructose and glucose. Plants invertases and their substrates are essential factors that play an active role in primary metabolism and in cellular differentiation and by these activities they sustain development and growth. Being naturally present in multiple isoforms, invertases are known to be highly differentiated and tissue specific in such a way that every isoform is characteristic of a specific part of the plant. In this work, we report the identification of the invertase RhVI1 that was found to be highly expressed in rose petals. A characterization of this protein revealed that RhVI1 is a glycosylated membrane-anchored protein associated with the cytosolic side of the vacuolar membrane which occurs in vivo in a monomeric form. Purification yields have shown that the levels of expression decreased during the passage of petals from buds to mature and pre-senescent flowers. Moreover, the activity assay indicates RhVI1 to be an acidic vacuolar invertase. The physiological implications of these findings are discussed, suggesting a possible role of this protein during anthesis.
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, Viale S. Ignazio da Laconi 13, 09123 Cagliari, Italy.
authors.forename: Domenica
authors.initials: D
authors.lastname: Farci
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, Viale S. Ignazio da Laconi 13, 09123 Cagliari, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Collu
authors.affiliation: European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kirkpatrick
authors.affiliation: Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari,Cittadella Universitaria di Monserrato, SS554, 09042 Monserrato, Cagliari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Esposito
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, Viale S. Ignazio da Laconi 13, 09123 Cagliari, Italy dario.piano@unica.it dario.piano@yahoo.it.
authors.forename: Dario
authors.initials: D
authors.lastname: Piano
mesh_terms: D002850:Chromatography, Gel; D035264:Flowers / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D027826:Rosa / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*; D043324:beta-Fructofuranosidase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020033:Protein Isoforms; D043324:beta-Fructofuranosidase
keywords: Anthesis; bud; glycosylation; rose petals; senescence; sucrose; vacuolar invertases.