Search Results (692)

Background: Biostimulants naturally improve plant growth, stress tolerance, and nutrient use efficiency and activate defenses by increasing protective metabolites (phenols, anthocyanins) in grapes. In viticulture, especially when using inactive yeasts, they modulate genetic expression and improve the skin resistance, color, and aroma profile of wine grapes in line with sustainable practices. Methods: Two wine grape cultivars, Merlot and Cabernet Sauvignon, were sprayed with the inactive yeast Saccharomyces cerevisiae in a single treatment in pre-veraison or in a double treatment in pre-veraison and veraison. Berry weight, must, total polyphenols, anthocyanins, and mechanical and colorimetric properties were measured on fresh grapes. Results: Two-way ANOVA revealed that titratable acidity (TA), pH, and total polyphenol content (TPC) were not affected, while mean berry weight and anthocyanin content varied by cultivar, treatment, and interaction; total soluble solids (TSS) differed only by cultivar. Inactive yeasts reduced weight in the single-treatment thesis but stabilized it in the double-treatment one; anthocyanins decreased in Cabernet Sauvignon but increased in Merlot. Mechanical and colorimetric analyses showed cultivar-dependent responses, with significant improvements in elasticity, skin thickness, and hue of berries, especially in Merlot when the treatment was applied twice. Conclusions: Inactive yeasts (IYs) showed an effect on the weight of the berries, the anthocyanins, the mechanics, and the color; Merlot significantly improved skin thickness, elasticity, and hue; and Cabernet remained less reactive to treatments. Full article

Rootstocks are widely used in viticulture as an agronomic measure to cope with biotic and abiotic stresses. In winegrapes, the aroma is one of the major factors defining the quality of grape berries and wines. In the present work, the grape aroma and wine aroma of Cabernet Sauvignon (CS) grafted on three rootstocks were investigated to inform the selection of rootstocks to utilize. 1103P, 5A, and SO₄ altered the composition of aromatic volatiles in CS grapes and wines. Among them, 5A and SO₄ had less effect on green leaf volatiles in the berries and wines, while 1103P increased green leaf volatile concentrations, up-regulating VvADH2 expression in both vintages. VvLOXA, VvLOXC, VvHPL1, VvADH1, VvADH2, and VvAAT were co-regulated by vintage and rootstock. Orthogonal partial least squares regression analysis (OPLS-DA) showed that the differential compounds in CS/1103P and CS berries were dominated by green leaf volatiles. Furthermore, the concentrations of 1-hexanol in the CS/1103P wines were significantly higher than in the other treatments in the two vintages. 1103P altered the expression of genes in the LOX-HPL pathway and increased the concentration of grape green leaf volatiles such as 1-hexanol and 1-hexanal, while vine vigor also affected green leaf volatile concentrations, the combination of which altered the aromatic composition of the wine and gave it more green flavors. Full article

Petit Manseng is a variety of Vitis vinifera gaining popularity in Virginia, USA because it consistently produces high quality grapes under variable growing conditions. However, its high sugar and acid levels complicate dry wine production. The goal of this study was to characterize Petit Manseng ripening kinetics from veraison to harvest to identify optimal harvest timing for producing dry white wines, using Chardonnay as a comparator because of its popularity in Virginia, well-known ripening kinetics, and ability to produce high quality dry white wines. A total of 74 samples of Petit Manseng and Chardonnay grapes were collected from five commercial sites over 2 years and evaluated for berry weight, pH, titratable acidity (TA), malic acid, total soluble solids (TSS), glucose, and fructose, with ripening kinetics modeled using segmented regressions. Results indicated that harvest timing and grape variety were the primary factors influencing ripening kinetics. In contrast, growing location and vintage had limited impact. In Chardonnay grapes, TA declined from 21 to 7.1 g/L and TSS increased from 6.1 to 19.5 g/L. In Petit Manseng, TA declined from 25 to 10.8 g/L and TSS increased from 8.0 to 23.6 g/L. Acid depletion plateaued ~2 weeks after sugar accumulation plateaued in Petit Manseng grapes, though the plateaus were similar in Chardonnay grapes. Linear discriminant analysis (LDA) completely separated grapes based on pH or TA vs. sugars, but not malic acid vs. sugars, suggesting that tartaric acid is driving acidity differences between cultivars. These data indicate that regardless of when grapes are harvested, winemakers may need to employ targeted acid management strategies with Petit Manseng because of its ripening kinetics. Full article

This study investigates the roles of grapevine berry inner necrosis virus (GINV) and grapevine yellow speckle viroid 1 (GYSVd1) in regulating the soluble sugar and organic acid metabolism of grape berries and wine. The contents of soluble sugar and organic acid components and the activity and expression levels of critical enzymes of the soluble sugar acid metabolism pathway were measured in ‘Welschriesling’ grape berries and wine carrying the virus GINV, the viroid GYSVd1, and a mixed infection of both GINV and GYSVd1 (GINV + GYSVd1), respectively. The results show that the virus GINV and the viroid GYSVd1 decreased the soluble sugar and increased the organic acid in berries and wine. GINV decreased glucose content and increased malic acid content by regulating AI, NADP-IDH, PEPC, and NAD-MDH activity, as well as VvHT4, VvSWEET10, VvPEPC, and VvMDH expression levels. GYSVd1 decreased glucose content and increased malic acid content by regulating AI and CS activity and VvHT4, VvSWEET15, and VvPEPC expression. The results suggest that the viroid GYSVd1 negatively impacts berries and wine more than the virus GINV. Moreover, in the mixed infection with GINV + GYSVd1, the negative effects of GINV and GYSVd1 on soluble sugars do not seem to be observed. Full article

Anthocyanins are important phenolic compounds in grape skins, affecting the color, oxidation resistance, and aging ability of red wine. In recent years, global warming has had a negative effect on anthocyanin biosynthesis in grape berries. Ethylene serves as a crucial phytohormone regulating the development and ripening processes of fruit; however, the specific molecular mechanism and the regulatory network between ethylene signaling and the anthocyanin biosynthesis pathway remain incompletely understood. In this study, 400 mg/L ethephon (ETH) solution was sprayed onto the surface of grape berries at the lag phase (EL-34), and the changes in anthocyanin-related genes and metabolites were explored through transcriptomic and metabolomic analysis. The results showed that ETH treatment increased Brix and pH in mature berries. In total, 35 individual anthocyanins were detected, in which 21 individual anthocyanins were enhanced by ETH treatment. However, the anthocyanin profile was not affected by exogenous ethylene. Transcriptomics analysis showed that there were a total of 825 and 1399 differentially expressed genes (DEGs) 12 h and 24 h after treatment. Moreover, key structural genes in the anthocyanin synthesis pathway were strongly induced, including VvPAL, VvCHS, VvF3H, VvF3′5′H, VvDFR and VvUFGT. At the maturity stage (EL-38), the expression levels of these genes were still higher in EHT-treated berries than in the control. ETH treatment also influenced the expression of genes related to hormone biosynthesis and signal transduction. The ethylene biosynthesis gene (VvACO), ethylene receptor genes (VvETR2, VvERS1 and VvEIN4), ABA biosynthesis gene (VvNCED2), and ABA receptor gene (VvPYL4) were up-regulated by ETH treatment, while the auxin biosynthesis gene (VvTAA3) and seven genes of the auxin-responsive protein were inhibited by exogenous ethylene. Meanwhile, ETH treatment promoted the expression of the sugar transporter gene (VvEDL16) and two sucrose synthase genes (VvSUS2 and VvSUS6). In EHT-treated berries, 19 MYB and 23 ERF genes were expressed differently compared with the control (p < 0.05). This study provides the theoretical foundation and technical support for the regulation of anthocyanin synthesis in non-climacteric fruit. Full article

The aim of this study was to investigate the effects of the crop load on the berry and wine composition of Marselan grapes. Thus, the appropriate crop load for Marselan wine grapes in Ningxia was determined based on the shoot density and the number of clusters per shoot. Marselan grapes from the Gezi Mountain vineyard, located at the eastern foot of Helan Mountain in the Qingtongxia region of Ningxia, were selected as the research material to conduct a combination experiment with four levels of shoot density and three levels of cluster density. The analysis of the berry and wine chemical composition was combined with a wine sensory evaluation to determine the optimal crop load levels. Crop load regulation significantly affected both the grape berry composition and the basic physicochemical properties of the resulting wine. Low crop loads improved metrics such as the berry weight and soluble solids content. A low shoot density facilitated the accumulation of organic acids, flavonols, and hydroxybenzoic acids in wine. Moderate crop loads were conducive to anthocyanin synthesis—the total individual anthocyanins content in the 10–20 shoots per meter of the canopy treatment group ranged from 116% to 490% of the control group—whereas excessive crop loads hindered its accumulation. Crop load management significantly influenced the aroma composition of wine by regulating the content of sugars, nitrogen sources, and organic acids in grape berries, thereby promoting the synthesis of esters and the accumulation of key aromatic compounds, such as terpenes. This process optimized pleasant flavors, including fruity and floral aromas. In contrast, wines from the high crop load and control treatments contained lower levels of these aroma compounds. Compounds such as ethyl caprylate and β-damascenone were identified as potential quality markers. Overall, the wine produced from vines with a crop load of 30 clusters (15 shoots per meter of canopy, 2 clusters per shoot) received the highest sensory scores. Appropriate crop load management is therefore critical to improving the chemical composition of Marselan wine. Full article

Environmental challenges such as drought, high temperatures, and salinity compromise grapevine physiology, reduce productivity, and negatively affect grape and wine quality. In recent years, foliar applications of biostimulants, antitranspirants, and phytohormones have emerged as promising strategies to enhance stress tolerance in grapevines. This review focuses on the main effects of salinity, drought, and high temperatures and the combined impact of drought and high temperatures on grapevines and examines how foliar applications influence grapevine responses under these specific stress conditions. Synthesizing the recent findings from the last ten years (160 articles), it provides direct insights into the potential of these compounds to alleviate each type of stress, highlighting their effects on grapevine physiology, yield components, and secondary metabolites in berries. While their mechanism of action is not entirely clear and their efficacy can vary depending on the type of compound used and the grapevine variety, most studies report a beneficial effect or no effect on grapevines under abiotic stresses (either single or combined). Future research is necessary to optimize the concentrations of these compounds and determine the appropriate number and timing of applications, particularly under open-field experiments. Additionally, studies should assess the effect of foliar applications under multiple abiotic stress conditions. In conclusion, integrating foliar applications into vineyard management represents a sustainable technique to mitigate abiotic stresses associated with climate change, such as salinity, water deficit, and heat stress, while preserving or enhancing the quality of grapes and wines. Full article

Ripe rot (caused by Colletotrichum species) severely compromises the yield and quality of grapes. Biocontrol approaches, such as antagonistic bacteria, represent an effective strategy to prevent and control grape ripe rot. In this study, 325 strains of Bacillus species were isolated from the rhizosphere soil of healthy grapevine plants. Among them, two strains, LJBA01 and LJBV047, exhibit strong antagonistic effects against C. viniferum, suggesting their potential role as biocontrol agents against grape ripe rot. Treatment with the fermentation broth of these strains significantly reduced disease incidence and lesion diameter in infected grape berries. Whole genome sequencing, combined with morphological characterization and 16S rRNA gene sequence, confirmed LJBA01 as Bacillus amyloliquefaciens and LJBV047 as Bacillus velezensis. Furthermore, GC-MS analysis of volatile compounds in fermentation broth from four strains (LJBA01, LJBV047, LJBS06, and LJBS17) identified 29 potential antimicrobial components. Among these, 2-nonanone and 2-decanol demonstrated highly significant inhibitory effects on C. viniferum. Overall, our research confirmed the potential value of two Bacillus strains as biocontrol bacteria against grape ripe rot. Full article

While resistance or tolerance is a highly sought-after trait in new grape varieties, producing such grapes does not guarantee acceptance in the market. The objective of this study was to explore consumers’ appreciation of a novel tolerant table grape variety by integrating chemical, textural, and sensory analyses with near-infrared (NIR) spectroscopy. To achieve this, we developed multivariate prediction models using artificial neural networks (ANNs) that were applied to the spectra of samples subjected to sensory analysis, allowing us to predict their composition. This approach offers a non-destructive way to conduct sensory analysis, as a single NIR spectrum can assess consumer appreciation and identify the chemical and physical characteristics of each berry. For the grape variety tested, we observed a significant favorable consensus among consumers. Therefore, instead of identifying differences, we focused on determining the optimal maturity ranges that enhance consumer appreciation for this variety. Our findings represent a step toward non-destructive sensory analysis; however, further research is still needed to refine this approach. Full article

Flavonoids play a crucial role in plant development, resistance, and the pigmentation of fruits and flowers. This study aimed to uncover the mechanism of flavonoid biosynthesis and fruit coloring in muscadine grapes. Two muscadine genotypes (Paulk and Supreme) were investigated via metabolomic and transcriptomic analysis during three developmental stages (bunch closure, veraison stage, and ripening stage). A total of 314 flavonoids were identified, with flavones and flavonols being the primary constituents. The contents of many differentially accumulated metabolites (DAMs) were higher at the veraison stage. The total anthocyanin content was upregulated during berry development, with the dominant type of anthocyanidin-3,5-O-diglucoside. Proanthocyanins accumulated higher levels in the ripening stage of Paulk than Supreme. Transcriptomic analyses revealed that over 46% of the DEGs exhibited higher expression levels in the bunch closure stage. Moreover, phenylalanine ammonia-lyase (PAL), cinnamyl 4-hydroxylase (C4H), and coumaryl CoA ligase (4CL) genes were upregulated during berry development, suggesting they promote second metabolites biosynthesis. The upregulation of dihydroflavonol 4-reductase (DFR) and leucoanthocyanin reductase (LAR) may related to the higher levels of PA in Paulk. Anthocyanidin synthase (ANS) and UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT) showed higher expression levels in the ripening stage, which may relate to the accumulation of anthocyanidins. This study provides comprehensive insights into flavonoid metabolism and berry coloration in Vitis rotundifolia. Full article

Excessive shoot vigor in grapevines negatively impacts plant growth and fruit quality, necessitating the use of plant growth regulators (PGRs) for canopy management. This study investigated the effects of mepiquat chloride (MC) and chlormequat chloride (CCC) on shoot growth (including new shoot length, relative chlorophyll content, leaf area, etc.) and fruit quality in Vitis vinifera cv. ‘Shine Muscat’. Different concentrations of MC (100, 300, 500, 700 mg/L) and CCC (100, 300, 500, 700 mg/L) were applied via foliar spraying at multiple stages before flowering. The results demonstrated that both PGRs effectively suppressed shoot elongation, with CCC exhibiting superior inhibitory efficacy compared to MC. However, high concentration of either compound also restricted leaf and cluster development. Optimal treatments MC (500 mg/L) and CCC (100 mg/L) significantly enhanced berry size, soluble solids content (SSC), and solid–acid ratio while maintaining effective shoot control. For practical application, we recommend spraying MC (500 mg/L) or CCC (100 mg/L) during the new shoot growth, flower-cluster separation, and flowering stages of ‘Shine Muscat’ grapevines to improve the new shoot control effect and fruit quality. Full article

Resveratrol is a natural polyphenol found in grapes, berries, and red wine, commonly studied for its biological activity. In vitro research often uses high concentrations of resveratrol applied for short incubation times. However, resveratrol reaches relatively low concentrations in vivo when it is used as a dietary supplement. Therefore, the aim of this study was to investigate the cellular response of cardiomyocytes to low, physiologically relevant concentrations of resveratrol and, in particular, to compare these responses depending on the duration of exposure. Cardiomyocytes were treated with resveratrol for either 1 day, 1 week, or 1 month. Functional assays assessing metabolic activity, cell cycle distribution, and apoptosis intensity were performed, along with analysis of selected pathways at protein levels. The results showed that the cellular response differed markedly depending on the duration of resveratrol treatment. Observed changes indicated alterations in energy metabolism and effects consistent with anti-aging activity. Full article

In the context of increasing consumer demand for high-quality, residue-free fruits and the growing emphasis on sustainable postharvest technologies, identifying effective, eco-friendly treatments to maintain grape quality during storage has become a critical focus in modern viticulture. Over the course of this study, we examined the influence of seaweed extract (derived from Ascophyllum nodosum) and ethanol-based postharvest treatments on the postharvest quality of the ‘Tarsus Beyazı’ grape. The seaweed extract was applied at six specific phenological stages according to the BBCH scale: BBCH 13 (3rd–4th leaf stage, 0.40%), BBCH 60 (first flower sheath opening, 0.50%), BBCH 71 (fruit set, 0.50%), BBCH 75 (chickpea-sized berries, 0.50%), BBCH 81 (start of ripening, 0.60%), and BBCH 89 (harvest maturity, 0.60%). After harvest, grape clusters were subjected to four different postharvest treatments: untreated control, control + ethanol (20% ethanol immersion for 10 s), seaweed extract alone (preharvest applications only), and seaweed extract + ethanol (combining both preharvest and postharvest treatments). Grapes were stored at 0–1 °C and 90–95% RH for three weeks, followed by a shelf-life evaluation period of three days at 20 °C and 60–65% RH. The findings revealed that seaweed treatments, especially when applied during cluster formation and berry development, effectively mitigated physiological deterioration, preserving stem turgidity and enhancing berry firmness. In contrast, ethanol showed variable responses, occasionally exerting negative effects, with only marginal benefits observed when applied at optimal developmental stages. Both the type and timing of application emerged as critical determinants of key quality attributes such as weight loss, decay incidence, and must properties (TSS, pH, TA). Correlation and heat map analyses indicated the interrelationships among these parameters and the differential impacts of treatments. These results suggest that phenological-stage-specific seaweed applications hold significant potential as a sustainable strategy to extend the storage life and maintain the market quality of ‘Tarsus Beyazı’ grapes. Full article

Aroma composition serves as a pivotal quality determinant in table grapes (Vitis vinifera). While the cytochrome P450 enzyme CYP76F14 is implicated in aroma biosynthesis, its functional role in grape berries remains uncharacterized. A comparative analysis of three aroma-distinct cultivars—Muscat type ‘Irsai Oliver’, Neutral type ‘Yanhong’, and Berry-like type ‘Venus Seedless’—revealed cultivar-specific linalool accumulation patterns. ‘Irsai Oliver’ exhibited sustained linalool biosynthesis from the fruit set through to maturity (from Stage 1 to Stage 5), with concentrations peaking at Stage 3 (veraison phase) and remaining elevated until harvest, surpassing the other two cultivars. Transcriptional profiling demonstrated that the CYP76F14 expression exhibited a similar trend with the accumulation of linalool levels, showing a higher expression in ‘Irsai Oliver’ across the developmental stages. A structural analysis identified 12 divergent residues in the ‘Irsai Oliver’ CYP76F14 variant, including E378 and T380 within the conserved substrate recognition site. The site-directed mutagenesis of these residues (CYP76F14-E378G/T380A) reduced the catalytic efficiency by 68–72% compared to the wild-type (in vitro LC-MS/MS assays), confirming their functional significance. This work reveals that cytochrome P450 CYP76F14 mediates the conversion of its substrate linalool in table grape berries, especially of Muscat type grapes, and proposes the CYP76F14 polymorphic variants as molecular markers for aroma-type breeding. The identified catalytic residues (E378/T380) provide targets for enzymatic engineering to modulate the terpenoid profiles in Vitis species. Full article

Climate variability and trends are of increasing concern in grape-growing areas, although each cultivar can respond differently. In order to establish appropriate adaptation measures, it is necessary to know the relationship between climate variables and grape composition for each cultivar. This research attempts to provide information in this regard for the Albillo Mayor variety grown in the Ribera del Duero DO (Spain) and its potential changes under the shared socioeconomic pathways (SSPs) that lead to different radiative forcing targets. The response of this variety was evaluated in two plots during five seasons (2020–2024). For each year, the phenological dates and grape composition (berry weight, pH, titratable acidity, malic acid, alcoholic content, and the total polyphenol index) were evaluated and related to climate variables including maximum and minimum temperature and precipitation and the resulting water availability averaged over different periods within the growing season. Maximum and minimum temperatures in the pre-veraison period led to lower titratable acidity and malic acid, which, in addition, were favored by lower water availability in the same period. These conditions, on the contrary, led to an increase in the probable alcoholic degree, which is associated with a decrease in berry size. In addition, more available water during the ripening period increases the berry weight, which was also negatively affected by the difference between the maximum and minimum temperature in the same period. By 2050, with the predicted decrease in precipitation and increase in temperature, Albillo Mayor may undergo a decrease in acidity >14% and an increase in the probable alcoholic degree of about 5% in the SSP2-4.5 scenario (energy-balanced development, leading to a radiative forcing of 4.5 Wm⁻²), while changes could be up to 1.5 and 1.1 times greater, respectively, in the SSP5-8.5 scenario (heavily reliant in fossil-fueled development, leading to a radiative forcing of 8.5 Wm⁻²). Full article