Hormonal and associated metabolic changes in susceptible harvest-ripe grapes under asymptomatic and symptomatic Esca disease

The aim of the study was to study the volatile substances and ellagitannins released to wine by barrels of Quercus pyrenaica (Spanish Oak) in comparison with barrels of Quercus petraea (French Oak) and Quercus alba (American Oak) as well as to determine their sensory impact.

Climate change scenarios suggest an increase in temperatures and an intensification of summer drought. Measuring seasonal plant water status is an essential step in choosing appropriate adaptations to ensure yields and quality of agricultural produce. The water status of grapevines is known to be a key factor for yield, maturity of grapes and wine quality. Several techniques exist to measure the water status of soil and plants, but stem water potential proved to be a simple and precise tool for different plant species.

There is a growing trend on the transition from conventional to agroecological management of vineyards. However, the impact of practices, such as reduced-tillage, organic fertilization and cover crops, is not well-understood regarding the soil microbial diversity, and its relationship with the soil physicochemical properties in the subsurface depth near the rooting zone. Soil bacterial diversity is an important contributor towards plant health, productivity and response to environmental stresses. A field experiment was conducted by sampling subsurface soil bacterial community (NGS and qPCR) near to the root zone of Macabeu and Xarel·lo vineyards, located at the Penedes. 3 organic (ECO) and 3 conventional (CON) vineyards, with more than 10 years of respective management were sampled (n=5 each plot). ECO practices did not affect bacterial and fungal abundance but increased significantly the ammonium oxidizing bacteria and alpha-diversity (Inv.Simpson). Interestingly beta-diversity was significantly affected by the management strategy. ANOSIM-tests revealed a significative effect of the management (ecological vs conventional) and plot, on the soil microbial structure (ASV abundance). Main phyla depicted were Proteobacteria, Actinobacteria and Acidobacteria, whose relative abundances were not affected by the management. EdgeR assay revealed a significant increase of Cyanobacteria and decrease of Gemmatimonadetes and Firmicutes phyla in ECO. Interestingly, the grapevine variety was not correlated with the soil microbial community structure. Mantel-test revealed an important correlation (Spearman) of some physicochemical parameters with the soil microbiota structure, in order of importance: texture, EC, pH Ca/Mg, Mg/P, K+, Mg2+, Ca2+, SO42-, and OM. N-NH4 and NTK, which were higher in the ECO managed soils, did not correlated significantly with the soil microbiome population. The results revealed the importance of combining a deep physicochemical characterization of each replicate with the microbial diversity assessment to gain better insights on the relationship between soil microbiome and vineyard management.

The red Italian variety Nebbiolo (Vitis vinifera L.), used in the production of the prestigious Barolo and Barbaresco wines, is renowned for its aromatic and structural complexity but also for its low color intensity.

Grenache Noir and Syrah are the predominant grape varieties in the French Rhone valley vineyard, and produce wines with well differentiated aromatic notes. This study aimed at investigating the contribution of glycoconjugated precursors to these aromatic specificities, through their analytical profiles and the sensory influence of the odorant compounds they release during wine aging. The aglycones released by enzymatic hydrolysis of glycosidic extracts