Project description:Grapevine is a commercially important fruit crop that provides berries for direct consumption, juice pressing, drying (raisins), and fermentation to produce wine. The economic value of the crop has encouraged many researchers to study the physiological and molecular basis of berry development, particularly processes that affect wine quality. Post-harvest withering of grapevine berries is used in the production of dessert and fortified wines to alter must quality characteristics and to increase the concentration of simple sugars.
Project description:<p>The composition and changes of the fungal population and of the metabolites present in grapes and in ferments of Vitis vinifera L. cv. Corvina, one of the major components of the Amarone musts, were dissected aiming at the identification of constant characteristics possibly influenced by the productive process. The fungal populations and metabolomic profiles were analyzed in three different vintages. 454-pyrosequencing on the ribosomal ITS1 region has been used to identify the fungal population present in Corvina grapes and fresh must. Samples were also subjected to metabolomics analysis measuring both free volatile compounds and glycosylated aroma precursors through an untargeted approach with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry. Albeit strongly dependent on the climate, both the mycobiota and metabolome of Corvina grapes and fresh musts show some characteristics recursive in different vintages. Such persistent characteristics are likely determined by the method adopted to produce Amarone or other dry wines made from partially dried grapes. In particular, the harsh conditions imposed by the prolonged withering appear to contribute to the shaping of the fungal populations. The fungal genera and metabolites present in different vintages in V. vinifera L. cv. Corvina grapes and fresh musts represent core components of the peculiar technique of production of Amarone. Their identification allows the in-depth understanding and improved control of the process of production of this economically and culturally relevant wine.</p><p><br></p><p><strong>Linked cross omic data sets:</strong></p><p>Meta-taxonomics data associated with this study are available in the European Nucleotide Archive (ENA): accession number <a href='https://www.ebi.ac.uk/ena/browser/view/PRJEB15229' rel='noopener noreferrer' target='_blank'>PRJEB15229</a>.</p>
Project description:The yeast Dekkera bruxellensis is as ethanol tolerant as Saccharomyces cerevisiae and may be found in bottled wine. It causes the spoilage of wine, beer, cider and soft drinks. In wines, the metabolic products responsible for spoilage by Dekkera bruxellensis are mainly volatile phenols. These chemical compounds are responsible for the taints described as ‘‘medicinal’’ in white wines (due to vinyl phenols) and as ‘‘leather’’, ‘‘horse sweat’’ and ‘‘stable’’ in red wines (due to ethyl phenols mainly 4-ethylphenol). Apart from the negative aroma nuances imparted by these yeasts, positive aromas such as ‘smoky’, ‘spicy’ and ‘toffee’ are also cited. Our goal was to identify the impact that the wine spoilage yeast Dekkera bruxellensis has on fermenting S. cerevisiae cells, especially on its gene expression level. To this end we co-inoculated both yeast species at the start of fermentation in a synthetic wine must, using S. cerevisiae-only fermentations without Dekkera bruxellensis as a control. All fermentations were employed in special membrane reactors (1.2 um pore size cut-off) physically separating Dekkera bruxellensis from wine yeast S. cerevisiae. Biomass separation with this membrane was done to abolish the possibility of hybridizing also D. bruxellensis probes on Agilent V2 (8x15K format) G4813 DNA microarrays designed just for S. cerevisiae ORF targets. The 1.2 um pore membrane separating both yeasts allowed the exchange of ethanol, metabolites and sugars during the fermentation.
Project description:In this study, 1H-NMR metabolomics was used to evaluate the effects of using chitosan-genipin (Ch-Ge) films as replacement of sulfur dioxide (SO2) in white wines preservation, to circumvent adverse health consequences caused by SO2 intake, on the final compositional profile of white wines. To do so, differently sized Ch-Ge films (25 and 100 cm2) were tested, as well as SO2-tretment and untreated wines. The obtained data added important knowledge on the potential use of Ch-Ge films, particularly those of higher surface areas, as replacements for the use of SO2 in wine conservation, based on the changes noted in metabolite composition and their putative explanations in terms of wine chemical and biochemical characteristics.
Project description:<p>Cabernet Sauvignon grapes in Chile, mainly grown between the 30 °S and 36 °S, account for more than 30% of Chilean wine production, and yield wines with different characteristics which influence their quality. The aim of this study was to apply an LC-MS based metabolomic protocol to investigate the quality differentiation in a sample set of monovarietal wines from eight valleys covering 679 km of the north-south extension. All samples were produced using a standardized red winemaking process and classified according to a company categorization in two major groups: premium and standard, and each group in two subcategories. The results pointed out that N-containing metabolites (mainly small peptides) are promising biomarkers for quality differentiation. Moreover, the premium wines were characterized by higher amounts of anthocyanins and other glycosylated and acetylated flavonoids, as well as phenolic acids; standard quality wines, on the other hand, presented stilbenoids and sulfonated catabolites of tryptophan and flavanols.</p>
Project description:Background Grapes (Vitis vinifera L.) are economically the most important fruit crop worldwide. However, the complexity of molecular and biochemical events that lead to the onset of ripening of nonclimacteric fruits is not fully understood which is further complicated in grapes due to seasonal and cultivar specific variantion. The Portuguese wine variety Trincadeira gives rise to high quality wines but presents extremely irregular berry ripening among seasons probably due to high susceptibility to abiotic and biotic stresses. Results Ripening of Trincadeira grapes was studied taking into account the transcriptional and metabolic profilings complemented with biochemical data. The mRNA expression profiles of four time points spanning developmental stages from pea size green berries, through veraison and mature berries (EL 32, EL 34, EL 35 and EL 36) and in two seasons (2007 and 2008) were compared using the Affymetrix GrapeGen® genome array containing 23096 probesets corresponding to 18726 unique sequences. Over 50% of these probesets were significantly differentially expressed (1.5 fold) between at least two developmental stages. A common set of modulated transcripts corresponding to 5862 unigenes indicates the activation of common pathways in between years despite the irregular development of Trincadeira grapes. These unigenes were assigned in the functional categories of “metabolism, development”, “cellular process”, “diverse functions”, “regulation overview”, “response to stimulus, stress”, “signaling”, “transport overview”, “xenoprotein, transposable element” and “unknown”. Metabolic profiling using 1H NMR spectroscopy associated to two-dimensional techniques showed the importance of metabolites related to oxidative stress response, amino acid and sugar metabolism as well as secondary metabolism in grape ripening. This information was integrated with transcriptional profiling obtained using genome array and qRT-PCR for five developmental stages (EL 32, EL 34, EL 35, EL 36 and EL 38). Conclusions Altogether the results provide new information regarding the network of events leading to grape ripening as well as highlight features that may be cultivar specific namely in what concerns the role of carbohydrates and growth regulators´ metabolism as well as epigenetic factors and signaling pathways. 4 time points in 2007 season. 3 time points in 2008 season. 3 biological replicates.
Project description:UV radiation (UV) alters secondary metabolism in the skin of Vitis vinifera L. berries, which may affect on the final composition of both, grapes and wines. We compared berry skin transcriptome and phenolic composition between Tempranillo berries grown in the presence or absence of solar UV in a mid-altitude Tempranillo vineyard. By analysing two different ripening degrees, expression of 121 genes was significantly altered. Functional enrichment identified that, principally, secondary metabolism-related transcripts were induced by UV, including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes induction. Concurrently, flavonol accumulation was the most evident impact of UV on the berry skin phenolic composition. Monoterpenoid biosynthetic transcripts were also up-regulated by UV, whereas induction of stilbenoid biosynthetic transcripts and stilbenes accumulation was probably induced by the joint action of UV and other condition under the UV-blocking filter, likely higher temperature. Among regulatory genes, VvMYBF1, VvMYB24 and three bHLH transcription factors were up-regulated by UV. Homologs to Arabidopsis UVR8-dependent UV-B-induced genes were also induced, including VvHY5-1, VvHY5-2 and VvRUP UV-B signalling genes. This suggests that the UV-B-specific signalling pathway is activated in the skin of grapes grown at low-medium altitudes. The biosynthesis and accumulation of UV-absorbing compounds that are appreciated for winemaking were almost specifically triggered, which indicates that viticultural practices increasing solar UV incidence may improve grape features important to wine production.
Project description:Background Grapes (Vitis vinifera L.) are economically the most important fruit crop worldwide. However, the complexity of molecular and biochemical events that lead to the onset of ripening of nonclimacteric fruits is not fully understood which is further complicated in grapes due to seasonal and cultivar specific variantion. The Portuguese wine variety Trincadeira gives rise to high quality wines but presents extremely irregular berry ripening among seasons probably due to high susceptibility to abiotic and biotic stresses. Results Ripening of Trincadeira grapes was studied taking into account the transcriptional and metabolic profilings complemented with biochemical data. The mRNA expression profiles of four time points spanning developmental stages from pea size green berries, through veraison and mature berries (EL 32, EL 34, EL 35 and EL 36) and in two seasons (2007 and 2008) were compared using the Affymetrix GrapeGen® genome array containing 23096 probesets corresponding to 18726 unique sequences. Over 50% of these probesets were significantly differentially expressed (1.5 fold) between at least two developmental stages. A common set of modulated transcripts corresponding to 5862 unigenes indicates the activation of common pathways in between years despite the irregular development of Trincadeira grapes. These unigenes were assigned in the functional categories of “metabolism, development”, “cellular process”, “diverse functions”, “regulation overview”, “response to stimulus, stress”, “signaling”, “transport overview”, “xenoprotein, transposable element” and “unknown”. Metabolic profiling using 1H NMR spectroscopy associated to two-dimensional techniques showed the importance of metabolites related to oxidative stress response, amino acid and sugar metabolism as well as secondary metabolism in grape ripening. This information was integrated with transcriptional profiling obtained using genome array and qRT-PCR for five developmental stages (EL 32, EL 34, EL 35, EL 36 and EL 38). Conclusions Altogether the results provide new information regarding the network of events leading to grape ripening as well as highlight features that may be cultivar specific namely in what concerns the role of carbohydrates and growth regulators´ metabolism as well as epigenetic factors and signaling pathways.
Project description:UV radiation (UV) alters secondary metabolism in the skin of Vitis vinifera L. berries, which may affect on the final composition of both, grapes and wines. We compared berry skin transcriptome and phenolic composition between Tempranillo berries grown in the presence or absence of solar UV in a mid-altitude Tempranillo vineyard. By analysing two different ripening degrees, expression of 121 genes was significantly altered. Functional enrichment identified that, principally, secondary metabolism-related transcripts were induced by UV, including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes induction. Concurrently, flavonol accumulation was the most evident impact of UV on the berry skin phenolic composition. Monoterpenoid biosynthetic transcripts were also up-regulated by UV, whereas induction of stilbenoid biosynthetic transcripts and stilbenes accumulation was probably induced by the joint action of UV and other condition under the UV-blocking filter, likely higher temperature. Among regulatory genes, VvMYBF1, VvMYB24 and three bHLH transcription factors were up-regulated by UV. Homologs to Arabidopsis UVR8-dependent UV-B-induced genes were also induced, including VvHY5-1, VvHY5-2 and VvRUP UV-B signalling genes. This suggests that the UV-B-specific signalling pathway is activated in the skin of grapes grown at low-medium altitudes. The biosynthesis and accumulation of UV-absorbing compounds that are appreciated for winemaking were almost specifically triggered, which indicates that viticultural practices increasing solar UV incidence may improve grape features important to wine production. A total of 12 samples were hybridized. Grape skin RNA from berries ripening under a UV-transmitting filter (FUV+) and a UV-blocking filter (FUV-) was compared. Berry skin of two different ripening stages was analysed on each UV treatment. All samples were harvested simultaneously and a NaCl series was used to select the ripening degree in a non-invasive way. Three biological replicates were analyzed for each sample.