title: Occurrence of a number of enzymes involved in either gluconeogenesis or other processes in the pericarp of three cultivars of grape (Vitis vinifera L.) during development.
abstract: It is uncertain whether the enzymes pyruvate orthophosphate dikinase (PPDK) or isocitrate lyase (ICL) are present in the pericarp of grape, in which they could function in gluconeogenesis. The occurrence of these and other enzymes was investigated in the pericarp of three cultivars of grape (Vitis vinifera L.). In particular, the abundance of the enzymes aldolase, glutamine synthase (GS), acid invertase, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPC), PPDK and ICL were determined during the development of the pericarp of the cultivars Cabernet Sauvignon, Chardonnay and Zibibbo. PPDK and ICL were not detected at any stage of development. Each of the other enzymes showed different changes in abundance during development. However, for a given enzyme its changes in abundance were similar in each cultivar. In the ripe pericarp of Cabernet Sauvignon, PEPC, cytosolic GS and aldolase were equally distributed between the vasculature and parenchyma cells of the flesh and skin. The absence or very low abundance of PPDK provides strong evidence that any gluconeogenesis from malate utilises phosphoenolpyruvate carboxykinase (PEPCK). The absence or very low abundance of ICL in the pericarp precludes any gluconeogenesis from ethanol.
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno, 74, 06121, Perugia, Italy. Electronic address: franco.famiani@unipg.it.
authors.forename: Franco
authors.initials: F
authors.lastname: Famiani
authors.affiliation: Istituto di Biologia Agroambientale e Forestale, CNR, Viale Marconi, 2, 05010, Porano TR, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Moscatello
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno, 74, 06121, Perugia, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Ferradini
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno, 74, 06121, Perugia, Italy.
authors.forename: Tiziano
authors.initials: T
authors.lastname: Gardi
authors.affiliation: Istituto di Biologia Agroambientale e Forestale, CNR, Viale Marconi, 2, 05010, Porano TR, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Battistelli
authors.affiliation: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno, 74, 06121, Perugia, Italy. Electronic address: rob.walker@talktalk.net.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Walker
mesh_terms: D005638:Fruit / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005943:Gluconeogenesis / Q000235:genetics / Q000502:physiology; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D027843:Vitis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D010730:Phosphoenolpyruvate Carboxylase; D019764:Phosphoenolpyruvate Carboxykinase (ATP)
keywords: Aldolase; Glutamine synthase; Invertase; Isocitrate lyase; Pyruvate orthophosphate dikinase; Seed; Storage proteins