Exploring the regulatory role of the grapevine MIXTA homologue in cuticle formation and abiotic stress resilience

Among the different management techniques in Viticulture, which have
been developed with the purpose of optimizing the interception of sunlight, the photosynthetic capacity of
the plant and the microclimate of the clusters, especially in varieties that show excess vigor, the management of defoliation presents great importance. The defoliation consists of the removal of leaves that cover or that are in direct contact with the curls, which can cause physical damages in the berries, and aims to balance the relation between part area and number of fruits, providing the aeration and insolation in the interior of the vineyard, as well as reduce the incidence of rot in order to achieve greater efficiency in phytosanitary treatments and quality musts.

The Spotted lanternfly (SLF), first detected in the U.S. in 2014, is an invasive phloem-feeding planthopper that poses a growing threat to grape and wine production in the U.S. In Pennsylvania, where it was first detected, reductions in grapevine production and fruit quality have been reported by commercial growers. Recent advances have begun to elucidate how SLF affects grapevine physiology and resource allocation, but no research has identified how SLF affects wine chemical composition and quality. Documented reductions in fruit sugar allocation due to heavy SLF phloem-feeding may have downstream effects on wine fermentation dynamics. Additionally, secondary metabolic responses stimulated by SLF may also influence berry chemical composition. The present study investigated SLF-mediated effects on wine composition through analysis of the volatile composition of wines produced from white- and red-fruited varieties of different Vitis parentage (e.g., Vitis vinifera vs. interspecific hybrids) following prolonged exposure to adult SLF phloem-feeding.

Free amino acid concentrations in must of 7 Vitis vinifera cultivars (Cabernet Franc, Syrah, Merlot, Montepulciano, Sangiovese, Cesanese d’Affile, Carmenere) grown in the Latium region (Italy) were monitored from 2003 to 2005. The cultivars were located in a homogeneous soil and climatic zone and with the same training system (Cordon Spur).

Lambrusco is a commercially successful sparkling red and rosé wine. With 13.06 million litres sold in 2021 was the second best-selling Italian wine after Chianti. According to National Catalogue of Vine Varieties there are thirteen Lambrusco Varieties with which to date are produced seven PDO wines. Among these, “Lambrusco Salamino di Santa Croce”, “Lambrusco Grasparossa di Castelvetro” and “Lambrusco di Sorbara” are the only ones that can be considered mono-varietal appellations, all located in Modena area. The PDOs contemplate the possibility of producing wines by secondary fermentation either in tank (Charmat method), or in bottle (Classico method). Sur lie is a third method commonly employed for Lambrusco, similar to the Classico method, from which differs for the absence of disgorgement.

Despite their trace concentrations, volatile sulfur compounds (VSCs) are an important category of flavour-active compounds that significantly contribute to desirable or undesirable aromas of many foods and beverages. In wines, VSCs in the form of polyfunctional thiols, notably 3-sulfanylhexan-1-ol (3-SH), 3-sulfanylhexyl acetate (3-SHA), and 4-sulfanyl-4-methyl-pentan-2-one (4-MSP), possess extremely low olfactory thresholds (≈ ng/L) and pleasant “tropical aroma” notes. They have received much attention with respect to their sensory contributions, quantitative occurrences, biogenesis, and thiol management through viticulture and winemaking. However, the fate of these potent volatiles are still not fully understood.