SciCombinator

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Concept: Vitis vinifera

468

Chemical analyses of ancient organic compounds absorbed into the pottery fabrics from sites in Georgia in the South Caucasus region, dating to the early Neolithic period (ca. 6,000-5,000 BC), provide the earliest biomolecular archaeological evidence for grape wine and viniculture from the Near East, at ca. 6,000-5,800 BC. The chemical findings are corroborated by climatic and environmental reconstruction, together with archaeobotanical evidence, including grape pollen, starch, and epidermal remains associated with a jar of similar type and date. The very large-capacity jars, some of the earliest pottery made in the Near East, probably served as combination fermentation, aging, and serving vessels. They are the most numerous pottery type at many sites comprising the so-called “Shulaveri-Shomutepe Culture” of the Neolithic period, which extends into western Azerbaijan and northern Armenia. The discovery of early sixth millennium BC grape wine in this region is crucial to the later history of wine in Europe and the rest of the world.

Concepts: Caucasus, Europe, Vitis vinifera, Wine, Turkey, Armenia, Georgia, Azerbaijan

319

Wine grapes present a unique biogeography model, wherein microbial biodiversity patterns across viticultural zones not only answer questions of dispersal and community maintenance, they are also an inherent component of the quality, consumer acceptance, and economic appreciation of a culturally important food product. On their journey from the vineyard to the wine bottle, grapes are transformed to wine through microbial activity, with indisputable consequences for wine quality parameters. Wine grapes harbor a wide range of microbes originating from the surrounding environment, many of which are recognized for their role in grapevine health and wine quality. However, determinants of regional wine characteristics have not been identified, but are frequently assumed to stem from viticultural or geological factors alone. This study used a high-throughput, short-amplicon sequencing approach to demonstrate that regional, site-specific, and grape-variety factors shape the fungal and bacterial consortia inhabiting wine-grape surfaces. Furthermore, these microbial assemblages are correlated to specific climatic features, suggesting a link between vineyard environmental conditions and microbial inhabitation patterns. Taken together, these factors shape the unique microbial inputs to regional wine fermentations, posing the existence of nonrandom “microbial terroir” as a determining factor in regional variation among wine grapes.

Concepts: Bacteria, Biotechnology, Vitis vinifera, Wine, Grape, Vitis, Viticulture, Terroir

301

Climate change is expected to impact ecosystems directly, such as through shifting climatic controls on species ranges, and indirectly, for example through changes in human land use that may result in habitat loss. Shifting patterns of agricultural production in response to climate change have received little attention as a potential impact pathway for ecosystems. Wine grape production provides a good test case for measuring indirect impacts mediated by changes in agriculture, because viticulture is sensitive to climate and is concentrated in Mediterranean climate regions that are global biodiversity hotspots. Here we demonstrate that, on a global scale, the impacts of climate change on viticultural suitability are substantial, leading to possible conservation conflicts in land use and freshwater ecosystems. Area suitable for viticulture decreases 25% to 73% in major wine producing regions by 2050 in the higher RCP 8.5 concentration pathway and 19% to 62% in the lower RCP 4.5. Climate change may cause establishment of vineyards at higher elevations that will increase impacts on upland ecosystems and may lead to conversion of natural vegetation as production shifts to higher latitudes in areas such as western North America. Attempts to maintain wine grape productivity and quality in the face of warming may be associated with increased water use for irrigation and to cool grapes through misting or sprinkling, creating potential for freshwater conservation impacts. Agricultural adaptation and conservation efforts are needed that anticipate these multiple possible indirect effects.

Concepts: Biodiversity, Climate, Vitis vinifera, Wine, Mediterranean climate, Grape, Viticulture

169

BACKGROUND: Vegetative buds provide plants in temperate environments the possibility for growth and reproduction when environmental conditions are favorable. In grapevine, crucial developmental events take place within buds during two growing seasons in consecutive years. The first season, the shoot apical meristem within the bud differentiates all the basic elements of the shoot including flowering transition in lateral primordia and development of inflorescence primordia. These events practically end with bud dormancy. The second season, buds resume shoot growth associated to flower formation and development. Gene expression has been previously monitored at specific stages of bud development but has never been followed along the two growing seasons. RESULTS: Gene expression changes were analyzed along the bud annual cycle at eight different time points. Principal Components Analysis (PCA) revealed that the main factors explaining the global gene expression differences were the processes of bud dormancy and active growth as well as stress responses. Accordingly, non dormant buds showed an enrichment in functional categories typical of actively proliferating and growing cells together with the over abundance of transcripts belonging to stress response pathways. Differential expression analyses performed between consecutive time points indicated that major transcriptional changes were associated to para/endodormancy, endo/ecodormancy and ecodormancy/bud break transitions. Transcripts encoding key regulators of reproductive development were grouped in three major expression clusters corresponding to: (i) transcripts associated to flowering induction, (ii) transcripts associated to flower meristem specification and initiation and (iii) transcripts putatively involved in dormancy. Within this cluster, a MADS-box gene (VvFLC2) and other transcripts with similar expression patterns could participate in dormancy regulation. CONCLUSIONS: This work provides a global view of major transcriptional changes taking place along bud development in grapevine, highlighting those molecular and biological functions involved in the main events of bud development. As reported in other woody species, the results suggest that genes regulating flowering could also be involved in dormancy regulatory pathways in grapevine.

Concepts: DNA, Gene, Gene expression, Cellular differentiation, Plant physiology, Vitis vinifera, Vitis, Vitaceae

165

BACKGROUND: Resveratrol is an important stilbene that benefits human health. However, it is only distributed in a few species including grape and is very expensive. At present, grape has been an important source resveratrol. However, the details are scarce on resveratrol distribution in different Vitis species or cultivars. METHODOLOGYPRINCIPAL FINDING: The composition and content of resveratrols were investigated by HPLC for assessing genotypic variation in berry skins and leaves of 75 grape cultivars, belonging to 3 species and 7 interspecific hybrids. Trans-resveratrol, cis-piceid and trans-piceid were detected in berry skins and leaves, but cis-resveratrol was not. Resveratrol content largely varied with genetic background as well as usage. In most cultivars, total resveratrol including the above three compounds was higher in berry skins than leaves. In berry skins of most cultivars and leaves of almost all cultivars, cis-piceid was the most abundant resveratrol; trans-resveratrol and trans-piceid were minor components. Some specific cultivars were found with extremely high levels of trans-resveratrol, cis- piceid, trans-piceid or total resveratrols in berry skins or leaves. In skins and leaves, rootstock cultivars had a higher content of total resveratrols, and the cultivated European type cultivars and their hybrids with V. labrusca had relatively low totals. There were no significant correlations of the amounts of total resveratrols or any individual resveratrol between berry skins and leaves. All 75 cultivars can be divided into four groups based on the composition of resveratrols and their concentration by principal component analysis. CONCLUSION: Resveratrol content of grape berries and leaves varied largely with their genetic background and usage. Rootstock cultivars had a higher content of total resveratrols than the other germplasm. Total resveratrols were lower in leaves than berry skins in most cultivars. Cis-piceid was the most abundant resveratrol in most cultivars, and trans-res and trans-pd were minor components.

Concepts: Vitis vinifera, Resveratrol, Grape, Vitis, Vitaceae, Vitis riparia, Vitis labrusca, Muscadine

146

Endophytes proved to exert multiple effects on host plants, including growth promotion, stress resistance. However, whether endophytes have a role in metabolites shaping of grape has not been fully understood. Eight endophytic fungal strains which originally isolated from grapevines were re-inoculated to field-grown grapevines in this study, and their effects on both leaves and berries of grapevines at maturity stage were assessed, with special focused on secondary metabolites and antioxidant activities. High-density inoculation of all these endophytic fungal strains modified the physio-chemical status of grapevine to different degrees. Fungal inoculations promoted the content of reducing sugar (RS), total flavonoids (TF), total phenols (TPh), trans-resveratrol (Res) and activities of phenylalanine ammonia-lyase (PAL), in both leaves and berries of grapevine. Inoculation of endophytic fungal strains, CXB-11 (Nigrospora sp.) and CXC-13 (Fusarium sp.) conferred greater promotion effects in grape metabolic re-shaping, compared to other used fungal strains. Additionally, inoculation of different strains of fungal endophytes led to establish different metabolites patterns of wine grape. The work implies the possibility of using endophytic fungi as fine-tuning regulator to shape the quality and character of wine grape.

Concepts: Fungus, Vitis vinifera, Grape, Vitis, Vitaceae, Vitis riparia, Endophyte, Muscadine

142

Phenolic compounds, which are secondary plant metabolites, are considered an integral part of the human diet. Physiological properties of dietary polyphenols have come to the attention in recent years. Especially, proanthocyanidins (ranging from dimers to decamers) have demonstrated potential interactions with biological systems, such as antiviral, antibacterial, molluscicidal, enzyme-inhibiting, antioxidant, and radical-scavenging properties. Agroindustry produces a considerable amount of phenolic-rich sources, and the ability of polyphenolic structures to interacts with other molecules in living organisms confers their beneficial properties. Cocoa wastes and grape seeds and skin byproducts are a source of several phenolic compounds, particularly mono-, oligo-, and polymeric proanthocyanidins. The aim of this work is to compare the phenolic composition of Theobroma cacao and Vitis vinifera grape seed extracts by high pressure liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer and equipped with an electrospray ionization interface (HPLC-ESI-QTOF-MS) and its phenolic quantitation in order to evaluate the proanthocyanidin profile. The antioxidant capacity was measured by different methods, including electron transfer and hydrogen atom transfer-based mechanisms, and total phenolic and flavan-3-ol contents were carried out by Folin-Ciocalteu and Vanillin assays. In addition, to assess the anti-inflammatory capacity, the expression of MCP-1 in human umbilical vein endothelial cells was measured.

Concepts: Nutrition, Mass spectrometry, Catechin, Flavonoid, Vitis vinifera, Resveratrol, Polyphenol antioxidant, Grape seed oil

136

A multiresidue analytical method was developed for grapes for the following 24 plant growth regulators: 1-naphthylacetamide, 2,3,5-triiodobenzoic acid, 2,4,5-T, 2-naphthoxyacetic acid, 3-indolylacetic acid, 4-(3-indolyl)-butyric acid, 4-chlorophenoxyacetic acid, 4-nitrophenol, 6-benzylaminopurine, N6-isopentenyladenine, butralin, chlormequat chloride, chlorphonim-Cl, cloprop, forchlorfenuron, gibberellic acid 3, gibberellic acid 4, gibberellic acid 7, inabenfide, mepiquat chloride, paclobutrazol, prohydrojasmon, thidiazuron and uniconizole-P. The compounds were extracted from grape samples using an extraction method modified from the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method. Liquid chromatography - tandem mass spectrometry was used for the detection and quantification of the compounds. Validation of the method was performed by using recovery studies at both intra-day and inter-day intervals, as well as by evaluation of the matrix effect, limit of quantification, trueness and precision. We used matrix-matched calibrations for the quantification of the compounds, which all resulted in determination coefficients (r2) higher than 0.995. The limit of quantification ranged from 0.1 to 5 ng/mL. Recovery studies using three spiking concentrations at varying levels showed recoveries of 70.2-112.6% and 67.5-101.8% at intra-day and inter-day intervals, respectively. Relative standard deviations were below 20% for the recovery studies. The extraction method were further validated by performing recovery study and matrix effect test in six different grape varieties from Taiwan and the United States and all resulted in comparable results. Application of the established method to 50 grape samples, resulted in the detection of chlormequat chloride and forchlorfenuron residues in the tested grapes. The results of the method validation and real sample analysis shows the extraction method is therefore suitable for routine monitoring of residue in grapes.

Concepts: Mass spectrometry, Analytical chemistry, Vitis vinifera, Gibberellin, Extraction, Grape, Gibberellic acid, 6-Benzylaminopurine

128

Regionally distinct wine characteristics (terroir) are an important aspect of wine production and consumer appreciation. Microbial activity is an integral part of wine production, and grape and wine microbiota present regionally defined patterns associated with vineyard and climatic conditions, but the degree to which these microbial patterns associate with the chemical composition of wine is unclear. Through a longitudinal survey of over 200 commercial wine fermentations, we demonstrate that both grape microbiota and wine metabolite profiles distinguish viticultural area designations and individual vineyards within Napa and Sonoma Counties, California. Associations among wine microbiota and fermentation characteristics suggest new links between microbiota, fermentation performance, and wine properties. The bacterial and fungal consortia of wine fermentations, composed from vineyard and winery sources, correlate with the chemical composition of the finished wines and predict metabolite abundances in finished wines using machine learning models. The use of postharvest microbiota as an early predictor of wine chemical composition is unprecedented and potentially poses a new paradigm for quality control of agricultural products. These findings add further evidence that microbial activity is associated with wine terroir

Concepts: Yeast, Vitis vinifera, Wine, Fermentation, Viticulture, Winemaking, Terroir, Vineyard

28

In order to investigate the effects of cryomaceration and reductive vinification on chemical and physical indices and on antioxidant compounds of Sauvignon blanc wines, four wine-making procedures were applied: traditional white vinification, skin cryomaceration, vinification in a reductive environment, and a combination of the last two procedures. Significant differences were highlighted by both conventional analyses and NMR spectroscopy. The strongest changes were for organic acid concentrations (tartaric, in particular) and phenolic content. Cryomaceration caused a strong precipitation of tartaric acid, which may be desired if grapes have high acidity values. Cryomaceration protected those flavans reactive with vanillin from the action of oxidative enzymes. Vinification in a reductive environment, alone or combined with a cryomaceration step, gave wines with the highest solids content and caused a greater extraction of phenolic compounds from skins compared to traditional winemaking or cryomaceration alone, due to SO(2) solubilisation. Grape oenological expression can be strongly affected by the application of the investigated wine-making procedures.

Concepts: Yeast, Vitis vinifera, Wine, Oenology, Fermentation, Winemaking, Sauvignon blanc, Potassium bitartrate