title: Abiotic stresses differentially affect the expression of O-methyltransferase genes related to methoxypyrazine biosynthesis in seeded and parthenocarpic fruits of Vitis vinifera (L.).
abstract: MPs (3-alkyl-2-methoxypyrazines) are grape-derived aroma compounds that are associated with detrimental herbaceous flavours in some wines. It is well known that several viticultural and environmental parameters can modulate MP concentrations in grapes, although comprehensive molecular studies have not been conducted in this field. Although the biosynthesis pathway of MPs has not been fully elucidated, four Vitis vinifera O-methyltransferase genes (VvOMT1-4) have been related to be involved in MP biosynthesis. We assessed whether different abiotic stresses induction have an impact on MP levels in grapes and wines from seeded and parthenocarpic fruits. Our results show that the timing of VvOMT3 expression is associated with the period of MPs accumulation in seeded fruits during both abiotic stresses, whereas no association was found in parthenocarpic fruits. These results are discussed in the context of how different viticultural practices can modulate VvOMT gene expression, which has a direct impact on MPs levels in wines.
authors: Centro Tecnológico de la Vid y el Vino, Facultad de Ciencias Agrarias, Universidad de Talca, Chile. Electronic address: jvallarino@utalca.cl.
authors: José G
authors: JG
authors: Vallarino
authors: Centro de Estudios Avanzados en Fruticultura (CEAF), CONICYT-Regional, GORE-O'higgins, R08i1001 Rengo, Chile.
authors: Felipe
authors: F
authors: Gainza-Cortés
authors: Centro Tecnológico de la Vid y el Vino, Facultad de Ciencias Agrarias, Universidad de Talca, Chile.
authors: Claudio
authors: C
authors: Verdugo-Alegría
authors: Instituto de Biología Vegetal y Biotecnología, Universidad de Talca, Talca, Chile.
authors: Enrique
authors: E
authors: González
authors: Centro Tecnológico de la Vid y el Vino, Facultad de Ciencias Agrarias, Universidad de Talca, Chile.
authors: Yerko M
authors: YM
authors: Moreno
mesh_terms: D053898:Biosynthetic Pathways; D005421:Flavoring Agents / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011719:Pyrazines / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D027843:Vitis / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D014920:Wine / Q000032:analysis
chemical_list: D005421:Flavoring Agents; D010940:Plant Proteins; D011719:Pyrazines; D008780:Methyltransferases
keywords: Abiotic stress; Methoxypyrazine; Methyltransferase; Parthenocapy; Vitis vinifera; VvOMT; Wine flavour