Increase in Fruity Ester Production during Spine Grape Wine Fermentation by Goal-Directed Amino Acid Supplementation

The aim of this work was to enhance the levels of fruity esters in spine grape (Vitis davidii Foёx) wine by goal-directed amino acid supplementation during fermentation. HPLC and GC-MS monitored the amino acids and fruity esters, respectively, during alcoholic fermentation of spine grape and Cabernet Sauvignon grape. HPLC was also used to determine the extracellular metabolites and precursors involved in the synthesis of fruity esters. Alanine, phenylalanine, and isoleucine levels in spine grape were less than those in Cabernet Sauvignon. Pearson correlation between amino acid profile and fruity ester content in the two systems indicated that deficiencies in alanine, phenylalanine, and isoleucine levels might have limited fruity ester production in spine grape wine. Supplementation of these three amino acids based on their levels in Cabernet Sauvignon significantly increased fruity ester content in spine grape wine. Interestingly, goal-directed amino acid supplementation might have led to changes in the distribution of carbon fluxes, which contributed to the increase in fruity ester production.

Winemaking in Cold Regions with Buried Viticulture in China

China has a long history of grape cultivation and wine making, and it has grown to be one of the most important countries in terms of grape cultivation, wine production, and wine consumption. According to meteorological and geographical regionalization, China’s wine production area has been divided into 11 regions, the majority of which are located in cold and mid-temperate regions in northern China, where vines must be buried in winter and unearthed in spring. In China, the main cultivated grape varieties are similar, with the red variety accounting for more than 80% of the total, while the white variety represents just 20%. Currently, Cabernet Sauvignon is the most widely planted variety, but Marselan, another red variety, have recently shown good prospects. Wild grape species such as Vitis amurensis, Vitis davidii, and Vitis quinquangularis are widely planted in northern and southern China because of their good resistance to local climate. This chapter highlights some common wild grape varieties in China, as well as the wines made from them. Also, some winemaking pretreatment techniques are reported.

Plasmopara viticola causing downy mildew on Vitis davidii in Korea

Vitis davidii (Rom.Caill.) Foëx, commonly known as spine grape, is a deciduous climber native to China. Its fruits are consumed fresh or used to make wine in South and Central China. In recent years, spine grape has been cultivated in Korea. In July 2020, downy mildew was detected on spine grape vines in Jeongeup (35°42′17″N, 126°54′02″E), Korea, with a disease incidence of 70%. The symptoms appeared as yellowish, brownish, or reddish, vein-limited, poly-angular adaxial leaf spots, correspond to dense, white downy growth abaxially. A representative specimen was deposited in the Kunsan National University Herbarium (KSNUH679). Sporangiophores were tree-like, hyaline, mostly straight, and monopodially branched in orders of three to six; they measured (219.4–)273.2 to 435.1(–546.6) × (4.8–)6.7 to 9.0(–10.0) μm (n = 50). Ultimate branchlets were bi or trifurcate, straight to slightly curved, with truncate or, rarely, a swollen tip and measured 2.9 to 9.7 μm long and 0.8 to 2.5 μm wide at the base (n = 50). Sporangia were hyaline, ovoidal or lemon-shaped; they measured (16.8–)20.0 to 28.8(–34.2) × (11.4–)13.1 to 17.0(–20.1) μm with a length to width ratio of (1.28–)1.46 to 1.78(–2.07) (n = 50). This morphology was as described for Plasmopara viticola (Berk. & M. A. Curtis) Berl. & De Toni (Hall, 1989). Genomic DNA was extracted directly from infected V. davidii leaves. Three regions were PCR-amplified and sequenced: cox2 mtDNA with primers cox2F and cox2-RC4 (Choi et al., 2015), actin with primers pve04815-F and pve04815-R, and beta-tubulin with primers pvc389-F3 and pvc389-R4 (Rouxel et al., 2013). The resulting sequences were deposited in GenBank (accession nos. MT834527 for cox2, MT834525 for actin, and MT834526 for beta-tubulin). A BLASTn search revealed that the Korean sample was identical to P. viticola clade aestivalis originating from Vitis species: MK215072 for cox2 sequence, KY933800 for actin, and MK358393 for beta-tubulin. In all phylogenetic analyses of the three genes (cox2, actin, and beta-tubulin), KSNUH679 came out as phylogenetically place within P. viticola clade aestivalis, which has recently been reported on V. coignetiae and V. ficifolia var. sinuata in Korea (Kim et al., 2019). A pathogenicity test was performed twice by inoculating the leaves of 10 healthy spine grape plants with a sporangial suspension (~1 × 106 sporangia·mL-1) and incubating them in a growth chamber at 25 °C, 12-h day/night cycle, and 90% relative humidity; five non-inoculated plants served as controls. After two weeks, all inoculated plants developed typical downy mildew symptoms could be observed, whereas the controls remained symptomless. Morphology and molecular features confirmed the identity of the pathogen of spine grape to be P. viticola. To the best of our knowledge, this is the first report of downy mildew caused by P. viticola on V. davidii in Korea. Recently, downy mildew outbreaks caused by P. viticola have been recorded in spine grape plantations in southern China (Yi et al., 2019). Considering the potential of spine grape as a novel crop for Korea, P. viticola appears to represent a significant threat to this industry.

Pathogenesis and immune response in resistant and susceptible cultivars of grapevine (Vitis spp.) against Elsinoë ampelina infection

Elsinoë ampelina is the main cause of grape anthracnose, and the majority of grapevine cultivars are susceptible to this fungus. Some Chinese wild grape cultivars are resistant, however. It is therefore apt to compare the pathogenesis and immune responses in susceptible and resistant cultivars of grapevine to explore the detailed molecular and biochemical mechanisms of resistance to this fungus. In this study, ultrastructural and histopathological observations were used to demonstrate the resistance responses to E. ampelina in the resistant Chinese wild cultivar Vitis quinquangularis clone ‘Shang-24’ and the susceptible cultivars Vitis davidii cv. ‘Tangwei’ and Vitis vinifera cv. ‘Thompson Seedless’. Seventy-two hours post-inoculation (hpi) with E. ampelina, brown necrotic spots were clearly visible on the leaves of the susceptible cultivars ‘Tangwei’ and ‘Thompson Seedless.’ The infection was characterized by rapid colonization of the host cells by hyphae and massive spread of the pathogen in the intercellular spaces, ultimately leading to host cell collapse, cuticle dissolution, and extensive hyphal growth. In the resistant clone ‘Shang-24’, the conidia were lysed, a large quantity of electronically dense matter appeared, the hyphal growth was suppressed, and the host cells remained intact. In addition, six genes associated with disease resistance were differentially expressed in the susceptible and resistant cultivars. These disease-related genes were significantly up-regulated following infection with E. ampelina. This study illustrates the differences in infection and colonization of E. ampelina in resistant and susceptible grape leaves.

Targeted Metabolomic and Transcript Level Analysis Reveals Quality Characteristic of Chinese Wild Grapes (Vitis davidii Foex)

Native to China, spine grapes (Vitis davidii Foex) are an important wild grape species. Here, the quality characteristics of one white and three red spine grape clones were evaluated via targeted metabolomic and transcription level analysis. Xiangzhenzhu (XZZ) had the highest soluble sugar and organic acid content. Malvidin-3-acetyl-glucoside and cyanidin-3-glucoside were the characteristic anthocyanins in spine grapes, and significant differences in anthocyanin composition between different clones were detected. Anthocyanins were not detected in Baiyu (BY) grapes. The transcript levels of VdGST, VdF3′H, VdOMT, VdLDOX, and VdUFGT were significantly related to the anthocyanin biosynthesis and proportions. A total of 27 kinds of glycosidically bound volatiles (including alcohols, monoterpenes, esters, aldehydes, ketones, and phenolic acid) were identified in spine grapes, with Gaoshan #4 (G4) and BY grapes having the highest concentrations. The VdGT expression levels were closely related to glycosidically bound volatile concentrations. These results increase our understanding of the quality of wild spine grapes and further promote the development and use of wild grape resources.