BACKGROUND AND AIMS: Rotundone, a potent aroma compound responsible for peppery aroma and flavour in Shiraz, was detected recently in Vitis vinifera L. cv. Duras wines. In 2011 and 2012, two separate ...experiments were carried out to determine the effect of ripeness and viticultural techniques on rotundone concentration in Duras wine. METHODS AND RESULTS: Rotundone was measured in wines prepared by microvinification techniques (1 L Erlenmeyer). Accumulation of this compound in wines depended on vintage conditions and the degree of ripening, such that a higher concentration of rotundone was reached 44 days after mid‐veraison. Application of exogenous jasmonic acid and grape thinning did not significantly affect rotundone concentration, whereas leaf removal strongly reduced rotundone concentration. Wine from the irrigated treatment had a higher concentration of rotundone, and in most cases, vine water status over the veraison–harvest period was identified as a key variable that was well correlated with observed intraplot variability. CONCLUSIONS: These findings confirm that some common viticultural practices can be used to manipulate the peppery character in red wine. SIGNIFICANCE OF THE STUDY: Our results may assist grape growers to produce Duras, Shiraz and other cultivars where rotundone makes an important contribution to wine aroma.
(
) is a herbaceous plant, cultivated worldwide and known for its biological benefits. The aim of this study is the investigation of the chemical composition as well as the determination of the ...biological potential of different grape stem extracts obtained by maceration and accelerated solvent extraction (ASE). The HPLC analysis of the tested extracts led to the identification of 28 compounds of which 17 were identified for the first time in grape plants, in addition to seven revealed in the stem part for the first time. Twenty-nine volatile molecules have been detected by GC-MS in the grape stem part; among them seven were identified for the first time in the grape plant. For the biological analysis, the ethyl acetate extract (EtOAc) obtained by maceration showed a significant potential regarding antioxidant activity (IC
= 42.5 µg/mL), anti-Alzheimer (IC
= 14.1 µg/mL), antidiabetic (IC
= 13.4 µg/mL), cytotoxic with HCT-116 (IC
= 12.5 µg/mL), and anti-inflammatory (IC
= 26.6 µg/mL) activities, as well as showing the highest polyphenol content (207.9 mg GAE/g DW).
The grapevine trunk-disease complex limits vineyard longevity in all major grape-growing regions. Although trunk diseases have been distinguished based on etiologies (e.g., Botryosphaeria-, Eutypa-, ...and Phomopsis dieback, Esca) and causal agents, mixed infections of trunk pathogens and other wood-colonizing fungi are frequent in grapevines. These diverse fungal communities in grapevine span four classes in the Pezizomycotina (Ascomycota) and 10 genera in the Hymenochaetales (Basidiomycota). Traditional identification based on morphology is largely untenable because of overlap in colony characteristics or spore dimensions, or lack of sporulation in culture. When based on DNA sequencing, searches of uncurated, public molecular databases can lead to misidentifications. The new molecular database TrunkDiseaseID.org is populated with accurate rDNA ITS sequences from 250 + isolates (pathogens and saprobes) and secondary DNA barcodes for delineating closely related species. Currently, no such comprehensive database exists for grapevine wood-colonizing fungi. In addition to ITS and secondary barcode sequences, this database provides a scientific reference, origin, and ecological status for each isolate, to aid diagnosticians in communicating results and recommendations to growers. Outreach through the National Plant Diagnostic Network and the US Department of Agriculture's Identification Technology Program will connect diagnosticians to this new database for grape.
•Grapevine trunk diseases are caused by diverse fungal communities.•Mixed infections confound culture-based identification.•Searches of uncurated, public molecular databases can lead to misidentifications.•To aid diagnosticians, we developed a molecular database, TrunkDiseaseID.org.•The ecological status of each species conveys level of disease risk to growers.
Grape skin color is among the most important qualitative traits on which selection is based in wine and table grape breeding programmes. Skin color is determined by the quantity and composition of ...anthocyanins. In prior work on cultivated forms, it was shown that polymorphisms in the grape transcription factor family VvMYBA are responsible for anthocyanin content variation in the berries of cultivated grapevine (Vitis vinifera subsp. vinifera). Wild grapevine (V. vinifera subsp. sylvestris) is the ancestor of the cultivated V. vinifera subsp. sativa and has black-colored berries. The purpose of this study was to determine how the VvmybA1 and VvmybA2 polymorphisms emerged and affected the genetic diversity of wild grapevines in the Mediterranean basin by examining samples from the Iberian Peninsula, Italian Peninsula and Caucasian region. Our observations provide evidence that variation in the two transcriptional regulators generated a novel allele series via length polymorphisms in VvmybA1 and a point mutation in VvmybA2, which is lacking in cultivated grapevine. Further, correlation was detected between allele composition and anthocyanin contents. According to polymorphisms in both VvMYBA genes at the color locus, we were able to identify several haplotypes. The most ancestral haplotype (HapN) was found in wild grapevine in the western Mediterranean region and corresponded to wine grape cultivars, whereas recent haplotypes were detected in eastern regions. These eastern zones showed the most diverse haplotypes, which appeared in table cultivars where intense breeding practices may have replaced the original haplotype diversity. These findings provide information about the evolution of grapes since their domestication and have direct implications for wine quality.
Despite the numerous beneficial properties and uses of chitosan in agriculture, the molecular mechanisms behind its elicitation potential are still unclear. This study aimed at understanding the ...effect of chitosan application in the levels of phenolic compounds of
L. red grapes berry skin (cv. Tinto Cão) during veraison. Grapevines were treated with chitosan (0.01% in 0.01% acetic acid) while control grapevines were sprayed with 0.01% acetic acid. Results showed that several monomeric anthocyanins increased significantly in berry skins after treatment with chitosan. Additionally, Catechin, Rutin and Querecetin-3-
-galactoside were also recorded in higher amount upon chitosan treatment. Besides modulating the phenolic content, chitosan treatment also induced modifications in several target genes encoding key enzymes and transporters involved in secondary metabolic pathways. For instance, the genes
,
,
,
,
,
,
,
were upregulated in leaves and berry skins at veraison cessation in response to chitosan treatment. Overall, the results demonstrated that chitosan has a stimulatory effect on the accumulation of phenolic compounds, including anthocyanins, mediated by modifications in the transcription of key genes involved in their biosynthesis and transport in grape berries.
SUMMARY
To understand how grapevine sinks compete with each other during water stress and subsequent rehydration, carbon (C) allocation patterns in drought‐rehydrated vines (REC) at the beginning of ...fruit ripening were compared with control vines maintained under drought (WS) or fully irrigated (WW). In the 30 days following rehydration, the quantity and distribution of newly fixed C between leaves, roots and fruits was evaluated through 13CO2 pulse‐labeling and stable isotope ratio mass spectrometry. REC plants diverted the same percentage of fixed C towards the berries as the WS plants, although the percentage was higher than that of WW plants. Net photosynthesis (measured simultaneously with root respiration in a multichamber system for analysis of gas exchange above‐ and below‐ground) was approximately two‐fold greater in REC compared to WS treatment, and comparable or even higher than in WW plants. Maximizing C assimilation and delivery in REC plants led to a significantly higher amount of newly fixed C compared to both control treatments, already 2 days after rehydration in root, and 2 days later in the berries, in line with the expression of genes responsible for sugar metabolism. In REC plants, the increase in C assimilation was able to support the requests of the sinks during fruit ripening, without affecting the reserves, as was the case in WS. These mechanisms clarify what is experienced in fruit crops, when occasional rain or irrigation events are more effective in determining sugar delivery towards fruits, rather than constant and satisfactory water availabilities.
Significance Statement
In the rehydration phases following a period of drought, the strength of fruit carbon sinks inherited from the previous period of stress persists in grapevines, combined with a decisive photosynthetic recovery. These phases become the key moments in the life of fruit plants, especially if they coincide with the ripening phase of the fruit.
Background: Vitis vinifera is known for its antimicrobial activity; however, the hepatoprotective activity of aqueous extracts of aerial parts has also been reported, but the nephroprotective and ...hepatoprotective activity of ethanolic extracts have not yet been evaluated. Objective: To evaluate Vitis vinifera's hepatoprotective and nephroprotective activities against CCl4-induced toxicity in rats. Methods: Two doses of ethanolic extract of Vitis vinifera (100 and 200 mg/kg/day) were evaluated and compared with silymarin 100 mg/kg. Biochemical blood parameters like aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), Gamma-glutamyltranspeptidase (GGT), bilirubin, urea, uric acid, total protein and creatinine, and histopathologic changes of liver and kidney were studied and evaluated. Results: Vitis vinifera reduced the elevated blood levels of ALT, AST, ALP, urea, and creatinine, with the ethanol extract to 200 mg/kg/day being more effective. The histopathologic evaluation suggested that Vitis vinifera decreased hepatic and renal necrosis induced by CCl4. The more significant dose resulted in reductions in AST, ALT, GGT, ALP, and bilirubin of 54, 27, 56, 36, and 17%, respectively. Ethanolic extract 200 mg/kg/day also shows a reduction in elevated levels of Creatinine, Urea, Uric Acid, and Total Protein by 61%, 58%, 29%, and 9%, respectively. Conclusion: Hepatoprotective and nephroprotective activities of ethanol extract of Vitis vinifera were demonstrated, with ethanol extract to 200 mg/kg/day being the most effective. This presents scientific evidence for using medicinal plants such as Vitis vinifera in managing liver and kidney disorders.
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