Search Results (1,454)

PIWI, from the German word Pilzwiderstandsfähig, meaning “fungus-resistant”, refers to grapevine cultivars bred for resistance to fungal pathogens such as Erysiphe necator (the causal agent of powdery mildew) and Plasmopara viticola (the causal agent of downy mildew), two major diseases in viticulture. These varieties are typically developed through traditional breeding, often crossbreeding European Vitis vinifera with American or Asian species that carry natural disease resistance. This study investigates the transcriptional profiles of exocarp tissues in mature berries from four PIWI grapevine varieties compared to their elite parental counterparts using RNA-seq analysis. We performed RNA-seq on four PIWI varieties (two red and two white) and their noble parents to identify differential gene expression patterns. Comprehensive analyses, including Differential Gene Expression (DEGs), Gene Set Enrichment Analysis (GSEA), Weighted Gene Co-expression Network Analysis (WGCNA), and tau analysis, revealed distinct gene clusters and individual genes characterizing the transcriptional landscape of PIWI varieties. Differentially expressed genes indicated significant changes in pathways related to organic acid metabolism and membrane transport, potentially contributing to enhanced resilience. WGCNA and k-means clustering highlighted co-expression modules linked to PIWI genotypes and their unique tolerance profiles. Tau analysis identified genes uniquely expressed in specific genotypes, with several already known for their defense roles. These findings offer insights into the molecular mechanisms underlying grapevine resistance and suggest promising avenues for breeding strategies to enhance disease resistance and overall grape quality in viticulture. Full article

Yeasts play an essential role in the aroma and sensory profiles of wines. Spontaneous fermentations were carried out at the newly built winery of Granxa D’Outeiro. Yeasts were isolated from must at different stages of fermentation. Colonies belonging to Saccharomyces cerevisiae were characterised at the strain level by mtDNA-RFLPs. General chemical parameters and aroma profiles of the wines were determined using official OIV methodology and GC-MS analysis, respectively. The diversity of S. cerevisiae per fermentation ranged from 5 to 13 different strains depending on the grapevine variety. Out of 24 strains, strain B was the dominant yeast in most fermentations at different proportions, but strains D, E, and H also reached up to 25% of the total population in some fermentations. The yeast diversity was higher in the Lado fermentation than in those containing Treixadura. The chemical compositions of the wines revealed differences among them, with Loureira and Albariño wines showing the highest content of volatile compounds. The evaluation of their technological properties revealed the oenological potential of some strains of S. cerevisiae. The strains showing the best scores were selected to be used in future vintages to enhance the typicality of wines in the Granxa D’Outeiro winery. Full article

The grapevine fleck virus (GFkV) is a ubiquitous grapevine-infecting virus found worldwide, is associated with the grapevine fleck complex, and is often found in mixed infections with viruses of the grapevine leafroll complex and/or vitiviruses. Although GFkV has been studied for a long time, limited sequence information is available in the public databases. In this study, the GFkV sequence data available in GenBank and data generated at the Foundation Plant Services, University of California, Davis, were used to perform nucleotide sequence comparisons, construct a phylogenetic tree, and develop a new RT-qPCR assay. Sequence comparisons showed high genetic diversity among the GFkV isolates, and the phylogenetic analyses revealed a new group comprised of GFkV isolates identified in the present study. A new assay, referred to as GFkV-CP, was designed and validated using an existing GFkV positive control together with 11 samples known to be infected with combinations of different marafiviruses and maculaviruses but not GFkV. In addition, the newly designed assay was used in a field survey to screen grapevines from diverse geographical locations that are maintained at the United States Department of Agriculture (USDA) National Clonal Germplasm Repository (NCGR) in Winters, CA. Full article

The formation of seedless traits is regulated by multiple factors. AGLs, which belong to the MADS-box family, were reported to be important regulators in this process; however, the underlying mechanism remains elusive. Here, we identified the VvAGL sub-family genes during the seed abortion process in seedless grapevine cv. ‘JingkeJing’ and found 40 differentially expressed VvAGL members and 1069 interacting proteins in this process. Interestingly, almost all members and their interacting proteins involved in the tryptophan metabolic pathway (K14486) and participated in the phytohormone signalling (KO04075) pathway, including the growth hormone (IAA), salicylic acid (SA), abscisic acid (ABA), cytokinin (CTK), and ethylene signalling pathways. The promoters of AGL sub-family genes contain cis-elements in response to hormones such as IAA, ABA, CTK, SA, and ETH, implying that they might respond to multi-hormone signals and involve in hormone signal transductions. Further expression analysis revealed VvAGL6-2, VvAGL11, VvAGL62-11, and VvAGL15 had the highest expression at the critical period of seed abortion, and there were positive correlations between ETH-VvAGL15-VvAGL6-2, ABA-VvAGL80, and SA-VvAGL62 in promoting seed abortion but negative feedback between IAA-VvAGL15-VvAGL6-2 and CTK-VvAGL11. Furthermore, many genes in the IAA, ABA, SA, CTK, and ETH pathways had a special expressional pattern in the seed, whereby we developed a regulatory network mediated by VvAGLs by responding to multihormonal crosstalk during grape seed abortion. Our findings provide new insights into the regulatory network of VvAGLs in multi-hormone signalling to regulate grape seed abortion, which could be helpful in the molecular breeding of high-quality seedless grapes. Full article

Aiming at the problem of the low rate of resource utilization of large amounts of grape branch pruning and the high cost of leaving the garden, we design a kind of grape branch picking and crushing collection machine that integrates the collection of strips, the picking up, crushing, and collecting operations. The crushing and collecting parts of the machine are simulated, analyzed, and tested. Using the method of numerical simulation, combined with the results of the pre-branch material properties measurement, the branch crushing process is simulated based on LS-DYNA software. Our analysis found that in the branch destruction process, not only does knife cutting exist, but the bending fracture of the opposite side of the cutting place also exists. With the increase in the knife roller speed, the cutting resistance of the tool increases, reaching 2690 N at 2500 r/min. In the cutting simulation under different tool edge angles, the cutting resistance of the tool is the smallest when the edge angle is 55°, which is 1860 N, and this edge angle is more suitable for branch crushing and cutting. In the cutting simulation under different cutting edge angles, the cutting resistance of the tool is the smallest when the edge angle is 55°, which is 1860 N, and this edge angle is more suitable for branch crushing and cutting. Using Fluent software to analyze the characteristics of the airflow field of the pulverizing device, it was found that with the increase in the knife roller speed, the inlet flow and negative pressure of the pulverizing chamber increase. When the knife roller speed is 2500 r/min, the inlet flow rate and negative pressure are 1.92 kg/s and 37.16 Pa, respectively, which will be favorable to the feeding of the branches, but the speed is too high and will also lead to the enhancement of the vortex in some areas within the pulverizing device, which will in turn affect the feeding of the branches as well as the throwing out of pulverized materials. Therefore, the speed range of the pulverizing knife roller was finally determined to be 1800~2220 r/min. Based on the ANSYS/Model module modal analysis of the crushing knife roller, the knife roller of the first six orders of the intrinsic frequency and vibration pattern, the crushing knife roller of the lowest order had a modal intrinsic frequency of 137.42 Hz, much larger than the crushing knife roller operating frequency of 37 Hz, above which the machine will not resonate during operation. The research results can provide a theoretical basis and technical support for other similar crops to be crushed and collected. Full article

The advent of Clustered Regularly Interspaced Palindromic Repeat (CRISPR)/CRISPR-associated (Cas) proteins as a revolutionary innovation in genome editing has greatly promoted targeted modification and trait improvement in most plant species. For grapevine (Vitis vinifera L.), a perennial woody plant species, CRISPR/Cas genome editing is an extremely promising technique for genetic improvement in a short period. Advances in grapevine genome editing have been achieved by using CRISPR technology in recent years, which promises to accelerate trait improvement in grapevine. In this review, we describe the development and advances in CRISPR/Cas9 and its orthologs and variants. We summarize the applications of genome editing in grapevine and discuss the challenges facing grapevine genome editing as well as the possible strategies that could be used to improve genome editing in grapevine. In addition, we outline future perspectives for grapevine genome editing in a model system, precise genome editing, accelerated trait improvement, and transgene-free genome editing. We believe that CRISPR/Cas will play a more important role in grapevine genome editing, and an exciting and bright future is expected in this economically significant species. Full article

Continuous efforts are required to find ways to protect crop production against the toxicity of petroleum hydrocarbons, such as diesel, and contamination of soils. There is a need for identification of candidate plants that are tolerant to diesel toxicity that might also have the potential for remediation of diesel-contaminated soils. In this study, petunia, a popular ornamental plant and a model experimental plant in research on phytoremediation of environmental pollutants, was used to evaluate a novel method for rapidly assessing diesel toxicity based on the tolerance of shoots generated through in vitro plant cell culture selection. Petunia shoot lines (L1 to L4) regenerated from diesel-treated callus were compared with those from non-diesel-treated callus (control). Significant morphological differences were observed among the tested lines and control, notably with L1 and L4 showing superior growth. In particular, L4 exhibited remarkable adaptability, with increased root development and microbial counts in a diesel-contaminated potting mix, suggesting that the shoots exhibited enhanced tolerance to diesel exposure. Here, this rapid bioassay has been shown to effectively identify plants with varying levels of tolerance to diesel toxicity and could therefore assist accelerated selection of superior plants for phytoremediation. Further research is needed to understand the genetic and physiological mechanisms underlying tolerance traits, with potential applications beyond petunias to other environmentally significant plants. Full article

Fruit crops under soil conservational management might sequester carbon (C) in soils and mitigate greenhouse gases emissions. Using grape pomace residues as soil amendment holds promise for sustainable viticulture. However, its actual capability to increase soil organic carbon (SOC) and nitrogen (N) is unknown, especially in subtropical climates. This research aims to investigate whether grape pomace compost and vermicompost can increase SOC, total N (TN), and C and N stocks in subtropical vineyards. Two vineyards located in Veranópolis, in South Brazil, one cultivated with ‘Isabella’ and the other with ‘Chardonnay’ varieties, were annually amended with these residues for three years. We quantified SOC and TN in each condition in different soil layers, as well as C and N content in two different granulometric fractions: mineral-associated organic matter (MAOM) and particulate organic matter (POM). C and N stocks were also calculated. Despite potential benefits, neither treatment enhanced SOC, its fractions, or C stocks. In fact, vermicompost was rapidly mineralized and depleted SOC and its fractions in the 0.0 to 0.05 m layers of the ‘Isabella’ vineyard. Our findings indicate that the tested grape pomace residues were unable to promote C sequestration in subtropical vineyards after a three-year period. Full article

Mechanisms underlying grapevine responses to water(-deficient) stress (WS) are crucial for viticulture amid escalating climate change challenges. Reanalysis of previous transcriptome data uncovered disparities among isohydric and anisohydric grapevine cultivars in managing water scarcity. By using a self-organizing map (SOM) transcriptome portrayal, we elucidate specific gene expression trajectories, shedding light on the dynamic interplay of transcriptional programs as stress duration progresses. Functional annotation reveals key pathways involved in drought response, pinpointing potential targets for enhancing drought resilience in grapevine cultivation. Our results indicate distinct gene expression responses, with the isohydric cultivar favoring plant growth and possibly stilbenoid synthesis, while the anisohydric cultivar engages more in stress response and water management mechanisms. Notably, prolonged WS leads to converging stress responses in both cultivars, particularly through the activation of chaperones for stress mitigation. These findings underscore the importance of understanding cultivar-specific WS responses to develop sustainable viticultural strategies in the face of changing climate. Full article

Fungi infection, especially derived from Plasmopara viticola, causes severe grapevine economic losses worldwide. Despite the availability of chemical treatments, looking for eco-friendly ways to control Vitis vinifera infection is gaining much more attention. When a plant is infected, multiple disease-control molecular mechanisms are activated. PRRs (Pattern Recognition Receptors) and particularly RLKs (receptor-like kinases) take part in the first barrier of the immune system, and, as a consequence, the kinase signaling cascade is activated, resulting in an immune response. In this context, discovering new lectin-RLK (LecRLK) membrane-bounded proteins has emerged as a promising strategy. The genome-wide localization of potential LecRLKs involved in disease defense was reported in two grapevine varieties of great economic impact: Chardonnay and Pinot Noir. A total of 23 potential amino acid sequences were identified, exhibiting high-sequence homology and evolution related to tandem events. Based on the domain architecture, a carbohydrate specificity ligand assay was conducted with docking, revealing two sequences as candidates for specific Vitis vinifera–Plasmopara viticola host–pathogen interaction. This study confers a starting point for designing new effective antifungal treatments directed at LecRLK targets in Vitis vinifera. Full article

Warming and drying trends in the Mediterranean Basin exacerbate regional water scarcity and threaten agricultural production, putting global food security at risk. This study aimed to review the most significant research on future water availability for the Mediterranean agricultural sector under climate change (CC) scenarios published during 2009–2024. Two searches were performed in the Scopus and Web of Science databases, to which previously identified significant studies from different periods were also added. By applying a methodology duly protocoled in the PRISMA2020-based guideline, a final number of 44 particularly relevant studies was selected for review. A bibliometric analysis has shown that most of the published research was focused on Southwestern European countries (i.e., Spain, Italy, Portugal) and grapevine and olive tree crops. Overall, the reviewed studies state that future Mediterranean water reserves may not meet agricultural water demands, due to reduced reservoir inflows and higher irrigation demands under future CC and socioeconomic scenarios. Regarding adaptation measures to improve water-use management in agriculture, the majority of the reviewed studies indicate that the use of integrated modelling platforms and decision–support systems can significantly contribute to the development and implementation of improved water/land-management practices. Full article

Ceresini treehoppers are present in northern California vineyard ecosystems, including the closely related Spissistilus and Tortistilus (Hemiptera: Membracidae). These membracids are not direct pests of wine grapes, but S. festinus is a vector of grapevine red blotch virus (GRBV). No information is available on the ability of Tortistilus spp. to transmit GRBV. In this study, Tortistilus were collected on yellow panel cards across 102 vineyard sites and surrounding areas in Napa Valley, California, USA in 2021–2023. Specimens were morphotyped, sexed and tested for GRBV ingestion and acquisition by multiplex PCR or qPCR. Phylogenetic analysis of the partial sequence of mt-COI and ITS gene fragments of a subset of 40 Tortistilus specimens revealed clustering in a monophyletic clade with T. wickhami with the former barcode sequence. Only 6% (48/758) of the T. wickhami tested positive for GRBV, but none of the heads with salivary glands (0%, 0/50) of the dissected specimens tested positive for GRBV, indicating no virus acquisition. In contrast, half of the dissected heads with salivary glands of S. festinus (52%, 12/23), from the same collection vineyard sites, tested positive for GRBV. Together, our findings confirmed the presence of T. wickhami in northern California vineyards and suggested a dubious role of this treehopper as a vector of GRBV. Full article

Phosphate fertilizers are applied to the soil surface, especially in vineyards in production in subtropical regions. Nowadays, phosphorus (P) is not incorporated into the soil to avoid mechanical damage to the root system in orchards. However, over the years, successive surface P applications can increase the P content only in the topsoil, maintaining low P levels in the subsurface, which can reduce its use by grapevines. For this reason, there is a need to propose strategies to increase the P content in the soil profile of established orchards. The study aimed to evaluate the effect of management strategies to (i) increase the P content in the soil profile; (ii) enhance the grape production; and (iii) maintain the grape must composition. An experiment on the ‘Pinot Noir’ grape in full production was carried out over three crop seasons. The treatments were without P application (C), P on the soil surface without incorporation (SP), P incorporated at 20 cm (IP20), P incorporated at 40 cm (IP40), and twice the P dose incorporated at 40 cm (2IP40). The P concentration in leaves at flowering and veraison, P content in the soil, grape production and its components, and chemical parameters of the grape must (total soluble solids, total polyphenols, total titratable acidity, total anthocyanins, and pH) were evaluated. The P concentration in leaves did not differ among the P application modes. The application of P associated with soil mobilization, especially at 20 cm depth, increased grape production. The P application modes did not affect the values of the chemical parameters of the grape must except for the total anthocyanins, which had the highest values when the vines were subjected to 2IP40. Finally, the P application and incorporation into the soil profile was an efficient strategy for increasing the grape production in full production vineyards. Full article

An urgent challenge posed by climate change in warm grapevine-growing areas is accelerated ripening, which leads to rapid sugar accumulation while phenolics and aroma traits lag behind. Techniques that enable selectively delaying the sugar accumulation process without affecting the accumulation of secondary metabolites are essential. This study aimed to evaluate the effects of apical-to-cluster defoliation, manually applied in 2019 at the onset of veraison (D₁) or 20 days later (D₂), which removed about 30–40% of the pending total leaf area without altering the cluster microclimate compared with a non-defoliated control (C). Ripening trends, vegetative growth, yield components, and the final grape and wine composition, as well as wine sensorial attributes, were assessed. Although both treatments significantly lowered the final leaf area-to-yield ratio (0.80–0.90 m²/kg) compared with the 1.35 m²/kg recorded in the C vines, only D₁ reduced the final total soluble solids (TSS) at harvest (2 °Brix less than C). However, the total anthocyanins were similarly limited, and titratable acidity (TA) did not differ from the C vines. The D₁ wine was deemed similar to that made from control plants. Conversely, D₂ failed to delay ripening, yet the D₂ wine was deemed superior in terms of olfactory intensity, body, fruitiness, balance, and overall preference. Although the study was conducted over a single season, the results are robust enough to conclude that the timing of defoliation—i.e., the level of TSS concurrently reached by the C treatment—is crucial to achieving specific effects. Early defoliation appears valid for postponing ripening into a cooler period, making it quite interesting in warm–hot areas with a very long growing season; a much later defoliation, likely due to the interaction between mean canopy age and more light filtering from above the cluster zone, can elevate the quality of and appreciation for the final wine. Full article

In grape (Vitis vinifera L.) cultivation, high temperatures (HTs) usually reduce the accumulation of anthocyanins. In order to elucidate the regulatory mechanism of anthocyanin biosynthesis under high-temperature environments, we investigated the effects of HT stress at veraison (5% coloring of grape ears) on fruit coloration and anthocyanin biosynthesis in ‘Summer Black’ (XH) and ‘Flame seedless’ (FL) grapevines. Compared to the control group (35 °C), the total anthocyanin content of XH and FL grapes subjected to a high-temperature (HT) treatment group (40 °C) decreased significantly as the HT treatment continued, but showed an upward trend with fruit development. However, the concentration of procyanidins increased significantly following HT treatment but decreased with fruit development. Nonetheless, FL grapes showed some resistance to the HT condition, producing anthocyanin content at ripeness comparable to the control group, demonstrating a greater adaptability to HT conditions than XH grapes. Based on the CIRG index, at stage S4, the fruit of FL was classified as dark red, while XH was classified as blue-black in the control group. Anthocyanin-targeted metabonomics identified eight different types of anthocyanins accumulating in the peels of XH and FL grapes during ripening, including cyanidins, delphinidins, malvidins, pelargonidins, peonidins, petunidins, procyanidins, and flavonoids. Malvidins were the most abundant in the two grape varieties, with malvidin-3-O-glucoside being more sensitive to high temperatures. HT treatment also down-regulated the expression of structural genes and regulators involved in the anthocyanin synthesis pathways. We used the WGCNA method to identify two modules that were significantly correlated with total anthocyanin and procyanidin contents. Among them, MYBCS1, bHLH137, WRKY65, WRKY75, MYB113-like, bZIP44, and GST3 were predicted to be involved in grape anthocyanin biosynthesis. In conclusion, this study conducted in-depth research on the HT inhibition of the biosynthesis of anthocyanins in XH and FL grapes, for reference. Full article