title: Leucoanthocyanidin reductase and anthocyanidin reductase gene expression and activity in flowers, young berries and skins of Vitis vinifera L. cv. Cabernet-Sauvignon during development.
abstract: Proanthocyanidins, or condensed tannins, are crucial polyphenolic compounds for grape and wine quality. Recently, significant advances were achieved in understanding the biosynthesis of their main subunits: (+)-catechin and (-)-epicatechin, produced by catalysis of leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR), respectively. Expression studies had been published but no data were available on enzyme activity. In our work, we devised assays to measure LAR and ANR activity and determine their development throughout the growth of flowers, young berries, and skins of Vitis vinifera L. cv. Cabernet-Sauvignon. We also investigated the accumulation of compounds in these tissues and focused on the expression of both the structural genes and the transcription factors involved in regulating them: VvMYB5a and VvMYBPA1. Biosynthetic genes were expressed early and LAR and ANR were already active during flowering and at the beginning of berry growth, as well as during colour-change in skins. The profiles we determined correlated with total tannin, catechin, and epicatechin concentrations. The involvement of VvMYB5a and VvMYBPA1 was confirmed and specific expression patterns were also established for VvLAR transcripts.
authors.affiliation: Université de Bordeaux, UMR 1219 Oenologie, INRA, ISVV, 210 Chemin de Leysotte, CS 58008, 33 140 Villenave D'Ornon, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Gagné
authors.forename: Soizic
authors.initials: S
authors.lastname: Lacampagne
authors.forename: Olivier
authors.initials: O
authors.lastname: Claisse
authors.forename: Laurence
authors.initials: L
authors.lastname: Gény
mesh_terms: D000872:Anthocyanins / Q000378:metabolism; D035264:Flowers / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D005638:Fruit / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D027843:Vitis / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D009247:NADH, NADPH Oxidoreductases