Diversity of leaf functioning under water deficit in a large grapevine panel: high throughput phenotyping and genetic analyses

Aging process is an essential stage in the improvement of wine quality. This process is usually performed by contact with oak wood whose compounds are released and transferred to wine, acquiring typical aging bouquet. Although the use of oak chips is a practice generally accepted as alternative to barrels to shorten aging process, the application of emerging technologies is being unfolded to accelerate this stage.

Ribeira Sacra is a Spanish Denominación de Origen (D.O.) for wines, located in Galicia, NW Spain.

Most grape scion cultivars grown around the world are derived from a single species, Vitis vinifera. Yet, the proportion of interspecific hybrids is increasing for a variety of reasons, including resistance to abiotic stresses such as low temperatures; societal, economic and environmental pressures to reduce pesticide usage; and to add a greater range of flavors to new table grape cultivars.

Considering that global warming is changing berry ripening timing and progression, uncovering the molecular mechanisms and identifying key regulators governing berry ripening could provide important tools in maintaining high quality grapes and wine. NAC (NAM/ATAF/CUC) transcription factors represent an interesting family due to their key role in the developmental processes control, such as fruit-ripening-associated genes expression, and in the regulation of multiple stress responses. Between the 74 NAC family members, we selected 12 of them as putative regulators of berry ripening: NAC01, NAC03, NAC05, NAC11, NAC13, NAC17, NAC18, NAC26, NAC33, NAC37, NAC60 and NAC61.

Sulphur dioxide (SO2) is a well-established preservative in the wine industry. Its ability to act in different stages of the process as an antioxidant and an antiseptic as main characteristics makes it versatile. However, the need for its reduction or even its replacement has been increasing by the regulatory authorities as well as by the final consumer. To understand the impact of SO2 during ageing on volatile organic compounds (VOCs) and amino acids (AAs) profiles, two white wines (one varietal and one blend) were aged under the same conditions, in the presence of different doses of SO2. After fermentation (t=0), 0, 30, 60, 90 and 120 mg/L of SO2 were applied, wines were kept over lees for 3 months (t=3), then were bottled after 3 (t=6) and 9 (t=12) months.