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International audience; The composition of steroids and triterpenoids in the leaves of eight grapevine species was analyzed in order to assess phenotypic differences. Four wild species (Vitis aestivalis Michx., Vitis labrusca L., Vitis riparia Michx., and Vitis vinifera subsp. sylvestris (Gmelin) Hegi) and four domesticated (Vitis vinifera cultivars: Cabernet Sauvignon, Gamay, Marselan, and Merlot) were studied. Although the main profiles of steroids and triterpenoids were similar in all analyzed extracts, remarkable quantitative differences in the content of these compounds in Vitis spp. leaves were demonstrated by GC–MS/FID analysis. The analyzed Vitis plants differed in the level of sterols, i.e. cholesterol (1), campesterol (2), stigmasterol (3), clionasterol (4) (exclusively in V. vinifera subsp. sylvestris (Gmelin) Hegi), sitosterol (5), and their amount was generally higher in wild grapevines. The predominance of pentacyclic triterpenoids of ursane-, oleanane-, lupane- and friedooleanane (taraxerane)-type skeletons depended on the studied cultivar/variety. Taraxerol (7) may be considered as a biomarker compound of V. vinifera leaves. The obtained data supplement information about biochemical diversity of Vitis genus and despite small qualitative differences allow species discrimination considering phylogenetic relationships confirmed by HCPC analysis. Differences between wild and cultivated grapevines in steroid and triterpenoid profiles may be connected to the domestication process.

The Vitis aestivalis -derived ‘Norton’ is one of the very few commercial red grape varieties that can be grown in regions with high disease pressure and cold temperatures in winter and spring where V. vinifera is difficult to grow. This study began with the objectives of generating interspecific hybrids of Norton and V. vinifera (Cabernet Sauvignon, Pinot Noir, Syrah, and Merlot) in order to combine the disease resistance and cold hardiness characters of V. aestivalis with the excellent wine quality of V. vinifera . Norton grapes were also crossed with the Vitis interspecific hybrid ‘Vignoles’ for the same reason. The true hybrids obtained from all of the crosses were identified using microsatellite markers. A high percentage of hybrids (70–92%) were obtained in all crosses except Norton × Merlot (17%). Results demonstrate the reliability of SSR markers for Norton-based interspecific hybrid identification.

Non-expressor of pathogenesis-related genes 1 (NPR1) plays a significant role in the defense responses of plants to pathogens by regulating the expression of defense-related genes. In the present study, we isolated two NPR1 genes from Vitis aestivalis cv. Norton and Vitis vinifera cv. Cabernet Sauvignon, which were referred to as VaNPR1.1 and VvNPR1. 1-CS, respectively. They encode a protein of 584 amino acids with a predicted molecular weight of 64.8 kDa and a theoretical isoelectric point (pI) of 5.74. The predicted amino acid sequences of VaNPR1.1 and VvNPR1.1-CS differ by only one amino acid. Over-expression of VaNPR1.1 gene in Arabidopsis npr1-1 mutant plants restores the transcriptional expression of AtPR-1 gene, though not to the full scale. This result demonstrated that a grapevine VaNPR1.1 possesses a similar function to the Arabidopsis NPR1 in the regulation of defense-related genes. Over-expression of VaNPR1.1 in transgenic Arabidopsis plant increased tolerance to salinity, but had no effect on the drought tolerance. We conclude that VaNPR1.1 is a functional ortholog of AtNPR1 and also involved in grapevine's response to the salt stress.

Three wine grapes, Norton ( Vitis aestivalis ), Cabernet Franc clone1, and Cabernet Franc clone313 ( Vitis vinifera ), collected from a Virginia vineyard were evaluated and compared for their antioxidant properties and phenolic profile. All grape extracts exerted remarkable antioxidant activities. Their oxygen radical absorbance capacity (ORAC) values were not significantly different from one another, ranging from 22.9 to 26.7 μmol TE/g of fresh weight. The Cabernet Franc clone1 had the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH ) radicals scavenging activity (8.8 μmol TE/g) compared to the Norton or Cabernet Franc clone313 grape extracts (7.9 μmol TE/g and 5.4 μmol TE/g, respectively). The Norton grape contained significantly higher total phenolic, anthocyanin, and flavonoid content than the Cabernet Franc grapes ( p

A total of 19 compounds were isolated from the leaves of five North American members of the genus Vitis The flavonoid data indicate three distinct chemical groups: one producing flavonols, flavones and C-glycosylflavones (V. aestivalis and V. cinerea var. cinerea, one producing fiavonols and flavones (V. cinerea ver. floridana) and one producing only fiavonols ( V. vulpina and V. riparia). The fiavonoid complements of the taxa are extremely useful in taxon delimitation and in suggesting systematic relationships.