Clonal selection and vegetative propagation determine low genetic variability in grapevine cultivars, although it is common to observe diverse phenotypes. Environmental signals may induce epigenetic changes altering gene expression and phenotype. The range of phenotypes that a genotype expresses in different environments is known as phenotypic plasticity. DNA methylation is the most studied epigenetic mechanism, but only few works evaluated this novel source of variability in grapevines. In the present study, authors analyzed the effects on phenotypic traits and epigenome of three Vitis vinifera cv. Malbec clones cultivated in two contrasting vineyards of Mendoza, Argentina
Brettanomyces bruxellensis is a wine spoilage yeast known to colonize and persist in production cellars. However, knowledge on the biofilm formation capacity of B. bruxellensis remains limited. The present study investigated the biofilm formation of 11 B. bruxellensis strains on stainless steel coupons after 3 h of incubation in an aqueous solution. FTIR analysis was performed for both planktonic and attached cells, while comparison of the obtained spectra revealed chemical groups implicated in the biofilm formation process.This study represents the first to succeed at applying a non-invasive technique to reveal the metabolic fingerprint implicated in the biofilm formation capacity of B. bruxellensis, underlying the homogenous mechanism within the yeast species.
Vitis vinifera berries are extremely sensitive to infection by the biotrophic pathogen Erysiphe necator causing powdery mildew disease and deleterious effects on grape and wine quality. The combined analysis of the transcriptome and metabolome associated with this common fungal infection has not been previously carried out in any fruit. In order to identify the molecular, hormonal and metabolic mechanisms associated with infection, healthy and naturally infected Carignan berries were collected at two developmental stages: late green (EL33) and early véraison (EL35).
Geographical origin, use of traditional varieties and ancestral viticulture/oenology practices characterize wines classified as Historical Wines of Portugal (HWP). This post reports a study that identifies the authenticity attributes consumers associate with this classification and assesses the relative strength of associations. Compared to Aspirational Explorers, wine connoisseurs emerged as Heritage Gatekeepers, associating origin, cultural heritage, quality, production and at-home consumption more strongly with HWP, and tradition, wine age and out-of-home consumption less strongly. Market recognition of HWP as a novel and distinctive table wine classification, with well-defined and unique attributes, is thus likely to depend on consumers’ general wine knowledge. Related promotional activities targeting wine novices should first focus on educating them on HWP classification, whereas those directed at savvier consumers should emphasize wine authenticity cues instead.
Neurodegenerative diseases pose a major health problem for developed countries. This post reports the results of a study aimed to develop a new antioxidant-enriched drink. The authors found that addition of red grape polyphenols and MecobalActive® to grape juice did not provoke changes in juice organoleptic characteristics, and that the pasteurization process did not greatly affect the levels of flavonoids and vitamin B12. Out of all combinations, grape juice with red grape polyphenols was selected by expert judges. In vivo, oral administration of grape juice supplemented with red grape polyphenols exerted an antioxidant effect in the brain of stressed mice reducing two-fold the expression of genes involved in inflammation and oxidation mechanisms and increasing three-fold the expression of genes related to protection against oxidative stress. In addition, authors found that this drink augmented antioxidant enzyme activity, and prevented lipid peroxidation in the brain. The authors propose supporting the use of this drink by the general population as a new and global strategy for the prevention of neurodegeneration.
The question is “what is normal”? Like many meteorologists and climate scientists, I get asked this question all the time. We typically make statements that describe a certain day, or month, or event, as warmer, colder, more extreme, etc. than average or normal. This is because observing and discussing climate is inherently statistical and requires comparison to baseline periods to make sense of how they relate to our lives. By saying goodbye to 2020 – I think we can all agree it’s more aptly good riddance – we are moving from one decade into another and ushering in a new climate baseline period and new statistics to report from. So, with new climate normal period data being released in many countries worldwide, and the USA last month, I thought it would be worth sharing a little about this process and what it means as we start discussing the “new normal”.
The present post summarizes a review that relates the last decade’s findings on the relationship between phenolics and polysaccharides from grapes, throughout the entire winemaking process up to evaluating the impact of their relationship on the red wine sensory perception. The combination and interconnection of the most recent research studies, from single interactions in model wines to the investigation of the formation of complex macromolecules, brings the perfect story line to relate the relationship between phenolics and polysaccharides from the vineyard to the glass. Grape pectin is highly reactive toward grape and grape derived phenolics. Differences between grape cultivars or changes during grape ripeness will affect the extractability of these compounds into the wines. Therefore, the nature of the grape components will be crucial to understand the subsequent reactions occurring between phenolics and polysaccharide of the corresponding wines. It has been demonstrated that they can form very complex macromolecules which affect wine color, stability and sensory properties.
Grapevine trunk diseases (GTDs) are considered a serious problem to viticulture worldwide. Several GTD fungal pathogens produce phytotoxic metabolites (PMs) that were hypothesized to migrate to the foliage where they cause distinct symptoms. The role of PMs in the expression of Botryosphaeria dieback (BD) symptoms in naturally infected and artificially inoculated wood using molecular and analytical chemistry techniques was investigated. Wood samples from field vines naturally infected with BD and one-year-old vines inoculated with Diplodia seriata, Spencermartinsia viticola and Dothiorella vidmadera were analysed by cultural isolations, quantitative PCR (qPCR) and targeted LC-MS/MS to detect three PMs: (R)-mellein, protocatechuic acid and spencertoxin. (R)-mellein was detected in symptomatic naturally infected wood and vines artificially inoculated with D. seriata but was absent in all non-symptomatic wood. The amount of (R)-mellein detected was correlated with the amount of pathogen DNA detected by qPCR. Protocatechuic acid and spencertoxin were absent in all inoculated wood samples. (R)-mellein may be produced by the pathogen during infection to break down the wood, however it was not translocated into other parts of the vine. The foliar symptoms previously reported in vineyards may be due to a combination of PMs produced and climatic and physiological factors that require further investigation.
Resveratrol (RESV) is one of the most abundant polyphenol-stilbene compounds found in red wine with well-established cardioprotective and antihypertensive effects. Hyperactivity of the sympathoadrenal axis seems to be one of the major contributing factors in the pathogenesis of human essential hypertension. In this study, the long-term RESV treatment prevented the increase of the systolic blood pressure in hypertensive animals, without reversion of cardiac hypertrophy. Data revealed that electrophysiological alterations of the chromaffin cells and in its Ca2+ homeostasis are potential new targets related to the antihypertensive effects of long-term RESV treatment.
“Vino cotto” is a sweet wine, produced according to traditional procedures involving a prolonged fermentation of cooked grape must. It is inserted in the Italian list of traditional food products since 2000 and can be marketed as traditional agrifood product. See more about this wine in this week Science & Wine post.