Characterization of Brettanomyces bruxellensis biofilm, a resistance strategy to persist in wine-related environments

The aim of this study was to evaluate the effects of different soil types on the chemical composition of Mediterranean red wines, through untargeted and targeted 1H-NMR metabolomics. One milliliter of raw wine was analyzed by means of a Bruker Avance II 400 spectrometer operating at 400.15 MHz. The spectra were recorded by applying the NOESYGPPS1D pulse sequency, to achieve water and ethanol signals suppression. No modification of the pH was performed to avoid any chemical alteration of the matrix. The generation of input variables for untargeted analysis was done via bucketing the spectra. The resulting dataset was preprocessed prior to perform unsupervised PCA, by means of MetaboAnalyst web-based tool suite. The identification of compounds for the targeted analysis was performed by comparison to pure compounds spectra by means of SMA plug-in of MNova 14.2.3 software. The dataset containing the concentrations (%) of identified compounds was subjected to one-way analysis of variance (ANOVA) to highlight significant differences among the wines. The untargeted analysis, carried out through the PCA, revealed a clear differentiation among the wines. The fragments of the spectra contributing mostly to the separation were attributed to flavonoids, aroma compounds and amino acids. The targeted analysis leaded to the identification of 68 compounds, whose concentrations were significant different among the wines. The results were related to soils physical-chemical analysis and showed that: 1) high concentrations of flavan-3-ols and flavonols are correlated with high clay content in soils; 2) high concentrations of anthocyanins, amino acids, and aroma compounds are correlated with neutral and moderately alkaline soil pH; 3) low concentrations of flavonoids and aroma compounds are correlated with high soil organic matter content and acidic pH. The 1H-NMR metabolomic analysis proved to be an excellent tool to discriminate between wines originating from grapes grown on different soil types and revealed that soils in the Mediterranean area exert a strong impact on the chemical composition of the wines.

In the O Ribeiro Denomination of Origin, there is a winemaking tradition of growing vines under a high-density plantation framework (8,920 vines/ha) and maintaining its vegetative cycle under rainfed conditions.
Currently, viticulture is advancing to plantation frames in which the density is considered medium (5,555 vines/ha), thus allowing mechanized work to be carried out for vineyard management operations. Although, the application of irrigation applied proportionally to the needs of the vegetative cycle of the vine, is a factor that increasingly helps a good development of the vine compared to the summer period, with increasingly uncertain weather forecasts.

to maintain viticulture under global warming conditions, it is important to carefully select the appropriate genotypes for each vine-growing region and develop cultivars that are drought resistant. this ability is highly dependent on hydraulic traits, which are dynamic and vary according to the vine’s developmental stage and climatic conditions. this framework steadily enhances our understanding of the differences in drought resistance among vitis genotypes. however, there is still a need to comprehensively grasp the intra-specific variability, particularly between oenological and table grape cultivars.

It is a well-established fact that premature oxidation is noxious for wine aromatic quality and longevity. Although some oxidation-related aroma molecules have been previously identified, there are not works carrying out systematic research about the changes in the profiles of odour-active volatiles during wine oxidation.

Ectopic RNA application for plant defense faces challenges in tree crops, including size, diffusion, and stability of active compounds such as ribonucleoproteins and nucleic acids. While existing strategies involve expressing dsRNA in transgenic plants targeting pathogens, our research strives to develop a transient RNAi system based on Spray-Induced Gene Silencing (SIGS). This approach aims to circumvent legal barriers and public concerns associated with genetically modified organisms (GMOs). Our strategy integrates SIGS with branched polyethyleneimine-functionalized Carbon Dots (bPEI-CDs) as nanocarriers, effectively addressing unique delivery challenges in plant defense as RNA stability and uptake enhancement