RESUMO
Dry yeast extracts (DYE) are applied to vineyards to improve aromatic and secondary metabolic compound content and wine quality; however, systematic information on the underpinning molecular mechanisms is lacking. This work aimed to unravel, through a systematic approach, the metabolic and molecular responses of Sauvignon Blanc berries to DYE treatments. To accomplish this, DYE spraying was performed in a commercial vineyard for two consecutive years. Berries were sampled at several time points after the treatment, and grapes were analyzed for sugars, acidity, free and bound aroma precursors, amino acids, and targeted and untargeted RNA-Seq transcriptional profiles. The results obtained indicated that the DYE treatment did not interfere with the technological ripening parameters of sugars and acidity. Some aroma precursors, including cys-3MH and GSH-3MH, responsible for the typical aromatic nuances of Sauvignon Blanc, were stimulated by the treatment during both vintages. The levels of amino acids and the global RNA-seq transcriptional profiles indicated that DYE spraying upregulated ROS homeostatic and thermotolerance genes, as well as ethylene and jasmonic acid biosynthetic genes, and activated abiotic and biotic stress responses. Overall, the data suggested that the DYE reduced berry oxidative stress through the regulation of specific subsets of metabolic and hormonal pathways.
RESUMO
Irrigating vineyard soils can affect grapevine water potential, nutritional status, and must composition. This study aimed to evaluate leaf water potential, nutritional status, and must composition in cv. 'Pinot Nero' grapevines grown with and without irrigation. The experiment was conducted at a commercial vineyard of 'Pinot Nero' 828 grafted on SO4 rootstock, established in 2002 in Trento, Northern Italy. The treatments were irrigated (I) and non-irrigated (NI) throughout the 2013 crop season. The criteria evaluated were the water potential of the leaves, total nutrient content in the leaves and berries, and weight of 100 berries, as well as the total soluble solids content, pH, and total titratable acidity of the must. Despite providing a less negative water potential for the grapevine leaves, irrigation did not affect the nutritional status or must composition, and it only slightly interfered with berry nutrient content. .
A irrigação em solos de vinhedos pode afetar o potencial hídrico da videira, o estado nutricional e a composição do mosto. O trabalho objetivou avaliar o potencial de água em folhas, o estado nutricional e a composição do mosto, em videiras da cv. 'Pinot Nero', cultivadas com e sem irrigação. O experimento foi conduzido em um vinhedo comercial de 'Pinot Nero' 828, enxertada sobre o porta enxerto SO4, implantado em 2002 em Trento, Norte da Itália. Os tratamentos foram com irrigação (I) e sem irrigação (SI) ao longo da safra de 2013. Avaliou-se o potencial hídrico das folhas, o teor total de nutrientes em folhas e bagas, a massa de 100 bagas e, no mosto, foram avaliados o teor de sólidos solúveis totais, pH e acidez total titulável. A irrigação, apesar de proporcionar potencial de água menos negativo nas folhas da videira, não afetou o estado nutricional, a composição do mosto e pouco interferiu no teor de nutrientes na baga.
