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Two prenyltransferases were located in cell cultures of Vitis vinifera. A geranyl pyrophosphate synthase (EC 2.5.1.1) was associated with plastid-like membranes whereas a farnesyl pyrophosphate synthase (EC 2.5.1.10) was found to be soluble.
Two beta-D-glucopyranosides and two 6-O-beta-D-apiofuranosyl-beta-D-glucopyranosides of (E)-6,9-dihydroxymegastigma-4,7-dien-3-one were isolated from Vitis vinifera cv. Gewürztraminer wine and their structures were established by NMR spectroscopy.
The ultrastructural modification of pollen grains in Vitis vinifera L. variety and hybrids in areas of SO2 atmospheric pollution (the main polluting SO2 usually reaches 2.72 mg/m3), nitrogen oxide, and other gases derived from noniron metal processing factories have been studied. Strains 1001 and 1002, resistant varieties, do not undergo ultrastructural modifications. Neuburger and Issabelle, medium resistant ones, have a heterogeneity in ultrastructural organization from normal forms to forms having both wall covers as well as the main organelles changed.
Aim of the study was to evaluate in vivo antioxidant action of medicinal herb Rhodococcum vitis-idaea (Rh.v) on galactosamine (GalN)-induced rat liver toxicity. The results showed that the hepatotoxicity and oxidative stress induced by GalN (700 mg/kg, s.c.) after 24 h evidenced by an increase in serum alanine aminotransferase and glutathione (GSH) S-transferase activities, and lipid peroxidation in liver homogenate were significantly inhibited, when 10 times diluted Rh.v. extract (5 ml/kg, i.p.) was given to rats 12 and 1 h before GalN treatment demonstrating that the extract of Rh.v is a potent antioxidant and protective against GalN-induced hepatotoxicity. The main antioxidant compound of the herb water extract used in the experiment was determined as arbutin, which possess 8% of dry weight of the herb. The electron spin resonance (ESR) spectrometer analysis revealed that the arbutin isolated from Rh.v exhibited strong superoxide and hydroxyl radical scavenging ability.
Vitis vinifera cell suspensions were used to isolate and characterize the flavonoids (anthocyanins, catechins) and non-flavonoids (stilbenes) found in red wine. Furthermore, we showed that astringin is produced although this stilbene has not previously been reported to be a constituent of V. vinifera or wine. The ability of these compounds to act as radical scavengers was investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical. Antioxidant activities were assessed by their capacity to prevent Fe2+-induced lipid peroxidation in microsomes and their action on Cu2+-induced lipid peroxidation in low-density lipoproteins. The results showed that astringin has an important antioxidant effect similar to that of trans-resveratrol, and a higher radical scavenger activity than the latter. Astringinin appeared to be more active. These data indicate that phenolic compounds (stilbenes, catechins, anthocyanins) exhibit interesting properties which may account in part for the so-called "French paradox," i.e. that moderate drinking of red wine over a long period of time can protect against coronary heart disease.
Three procyanidins, procyanidin B-5 3'-O-gallate, vitisinol, and amurensisin, were isolated from the seeds of Vitis amurensis, whose structures were elucidated on the basis of spectral and chemical evidence. Vitisinol and amurensisin contain a spiro-type biflavanyl linkage and a biphenyl-lactone partial structure, respectively.
The use of plant cell cultures for producing isotopically (13C) labelled phenolic substances is reported. Vitis vinifera cells synthesize high levels of anthocyanins when they are cultured in a polyphenol synthesis-inducing medium. Three major anthocyanin monoglucosides found in red wine were identified in grape cells: cyanidin-3-O-beta-glucoside, peonidin-3-O-beta-glucoside, and malvidin-3-O-beta-glucoside. Kinetic study of the intracellular level of phenylalanine and its metabolites showed that it is preferable to add this precursor to grape cell suspensions after the 5th day of culture, i.e. at the beginning of the exponential growth phase. After adding phenylalanine to the culture medium, its uptake was complete and the accumulation of anthocyanins in grape cells was stimulated. Incorporation of [1-13C]-phenylalanine into anthocyanins was measured by means of 13C satellites in the proton NMR spectrum. The maximal rate of 13C enrichment anthocyanins obtained with this technique reached 65%. The production of 13C labelled phenolic compounds was undertaken in order to investigate their absorption and metabolism in humans.
We have previously reported that sucrose modulates anthocyanin biosynthesis in cell suspension cultures of Vitis vinifera L. The main role of sugar in this response does not seem to be that of general carbohydrate source for the supply of energy. In the present work, a number of pharmacological agents were used to further investigate the components of the signal transduction pathway involved in the induction of anthocyanin biosynthesis by sugar. We found that the phosphorylation of hexose by hexokinase, but not its transport, has to be taken into account for the sucrose signal transduction leading to anthocyanin accumulation. Indeed, 3-O-methylglucose, a glucose analog transported into cells but not phosphorylated by hexokinase, has no effect on anthocyanin production. Mannose mimics the effect of sucrose in grape cells, and mannoheptulose, a specific inhibitor of hexokinase, reduces the accumulation of anthocyanins in response to sucrose. The results with the two latter analogs are discussed. Ca2+ channel blockers, verapamil and LaCl3, which were used to investigate the role of extracellular Ca2+, all inhibited the sugar response. Ca2+ depletion by pretreatment with ethylene glycol bis (beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) also blocked the sugar response, which was partially recovered when Ca2+ was added exogenously after Ca2+ depletion. The use of two potent calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphtalenesulphonamide (W7) and chlorpromazine, showed that calmodulin is involved in the sugar signal transduction. A protein kinase inhibitor, 6-dimethylaminopurine (6-DMAP), and the protein phosphatase inhibitors, endothall and cantharidin, also inhibited the sugar response. The results of the present study suggest the involvement of several components of general signal transduction pathways such as Ca2+, calmodulin, and protein kinases phosphatases in the induction of anthocyanin biosynthesis by sugar.
A disarmed LBA4404 strain of Agrobacterium tumefaciens harboring a binary vector which contained chimeric genes encoding the neomycin phosphotransferase (npt II) and the coat protein (CP) of Arabis mosaic nepovirus (ArMV) was used in co-cultivation experiments with leaf discs of Nicotiana benthamiana and somatic embryos of the grapevine rootstock cultivar Vitis rupestris. Transgenic N. benthamiana expressing the ArMV CP gene were regenerated and six independent lines were characterized. Enzyme-linked immunosorbent assay (ELISA) performed on leaf tissue demonstrated the accumulation of the ArMV CP in five of the six lines analyzed. Immunosorbent electron microscopy (ISEM) studies revealed the presence of virion-like isometric particles (VLPs) reacting to a rabbit antiserum specific to ArMV virions. ArMV-CP expressing transgenic N. benthamiana lines showed protection against ArMV expressed as a delay in infection and a reduction of the percentage of infected plants. Four independent transgenic lines of V. rupestris transformed with the ArMV CP gene were regenerated and characterized. In contrast to N. benthamiana, transgenic V. rupestris did not accumulate the ArMV CP at levels detectable by ELISA and no VLPs could be observed by ISEM. Northern blot analysis showed that the ArMV CP mRNA was expressed at lower level in V. rupestris compared with N. benthamiana. The reason for this difference in transgene expression and/or mRNA stability between grapevine and N. benthamiana is unclear, but the genetic state of the transgene(s) (homozygous in N. benthamiana versus hemizygous in V. rupestris) may have an effect on gene expression.
Three full-length cDNAs (VvAdh1, VvAdh2, and VvAdh3) encoding alcohol dehydrogenases (EC 1.1.1.1) were obtained from grape berries (Vitis vinifera L.) by means of PCR and RACE. Pairwise comparisons at the nucleotide level showed that the three cDNAs displayed strong homology in the coding region, but were highly divergent in the 5' and 3' untranslated regions. VvAdh1 and VvAdh2 corresponded to the two previously characterised Adh genes from grapevine, but VvAdh3 was unrelated to known grapevine Adh sequences. The two first cDNAs presented a single ORF of 380 amino acids, whereas the last one has two additional residues. Moreover, the three encoded polypeptides possessed the 22 residues strictly conserved between Adh from different kingdoms. Expression pattern of the individual isogenes was investigated during fruit development. Specific primers were designed, and quantitative RT-PCR experiments were performed to increase the sensitivity of detecting isogenes with a low expression level. Results presented here revealed different developmental regulation of the three Adh isogenes during fruit ripening. VvAdh1 and VvAdh3 transcripts were temporarily accumulated in young, developing berry, whereas VvAdh2 was overexpressed later in fruit development, from the onset of ripening (véraison). Expression analysis also indicated that VvAdh2 accounted for most of the Adh mRNAs present in berries during development. The increased ADH activity detected in berries correlated with the expression pattern of VvAdh2 transcripts. The VvAdh2 and VvAdh3 encoded enzymes were purified from overexpressing E. coli cells. Comparison of kinetic properties of the two ADH enzymes showed a difference in affinity with either ethanol or acetaldehyde as substrates. Significance of multiple Adh expressed in berries is discussed.
The expression of the UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) gene has been shown to be critical for anthocyanin biosynthesis in the grape berry. Using white cultivars and bud sports with red skin, we examined the expression of seven anthocyanin biosynthetic genes including the UFGT gene and compared the coding/promoter sequences of the UFGT gene. Northern blot analysis showed that the seven anthocyanin biosynthetic genes were expressed coordinately at higher levels in the red-skin sports than in the white-skin progenitors of the sports. It was especially notable that UFGT gene expression was detected only in the red-skin sports and Kyoho. However, there were no differences in either coding or promoter sequences between Italia (Vitis vinifera) and its red-skin sport Ruby Okuyama, or between Muscat of Alexandria (V. vinifera) and the red-skin sport Flame Muscat. From these findings, the phenotypic change from white to red in the sports is thought to be the result of a mutation in a regulatory gene controlling the expression of UFGT.
Activity of three constitutive promoters and enhanced derivatives in transgenic grape (Vitis vinifera L. cv. Thompson Seedless) was characterized using a bifunctional fusion marker containing the enhanced green fluorescent protein (EGFP) and neomycin phosphotransferase (NPTII) genes. Relative differences in transient GFP expression and stable transformation efficiencies were used to compare promoter activity. Expression patterns in transformed somatic embryos revealed that the ACT2 promoter from Arabidopsis thaliana, previously shown to be a strong constitutive promoter in A. thaliana and other species, failed to promote strong expression in grape. In contrast, a promoter isolated from cassava vein mosaic virus (CsVMV) supported high levels of transgene expression equivalent to those achieved using an enhanced double cauliflower mosaic virus (CaMV) 35S promoter. Duplication of the 5'-upstream enhancer region of the CsVMV promoter further enhanced its ability to increase transgene expression. However, the pattern of transgene expression driven by these two viral promoters was significantly different at the whole plant level. The enhanced double CaMV 35S promoter was highly active in most tissues and organs including roots, mature leaves, shoot apices and lateral buds. In contrast, the CsVMV promoter and its double enhancer derivative induced relatively weak expression in these tissues. Our results suggest that activity of the CsVMV promoter, in contrast to the CaMV 35S promoter, was under developmental regulation in transgenic grape plants as compared with the CaMV 35S promoter.
The isolation and NMR spectral data of epifriedelanol from Vitis trifolia are reported. It demonstrated antitumor activity in a potato disc bioassay.
Wild rats and molluscs were examined for Angiostrongylus cantonensis infection on Viti Levu, Fiji. A. cantonensis were recovered from 29.6% (16/54) of Rattus rattus and 59.5% (25/42) of R. exulans. A. cantonensis-like larval nematodes were found in all of four slugs, Laevicaulis alte, and ten of 20 unidentified land snails. The larvae developed to adult A. cantonensis in the pulmonary arteries of laboratory rats 40 to 42 days after ingestion. This is the first record of A. cantonensis in Fiji.
Eight glycosides and a phenylpropanoid glycerol were isolated from Vitis vinifera cv. Gewurztraminer wine, and their structures were elucidated by MS and NMR spectroscopies. cis-1-(5-Ethenyl-5-methyltetrahydrofuran-2-yl)-1-methylethyl O-beta-D-apiofuranosyl-(1-->6)-O-beta-D-glucopyranoside, (E)-3,6, 9-trihydroxymegastigm-7-ene 9-O-beta-D-glucopyranoside, 2-phenylethyl O-beta-D-apiofuranosyl-(1-->6)-O-beta-D-glucopyranoside, and 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]propane-1,3-diol are reported for the first time as wine components.
A reverse phase C(18) HPLC method with potential for high automated throughput has been developed for the quantitative analysis of polymeric procyanidins (tannins) in grape seed extracts. Chromatography gave rise to 13 distinct UV-absorbing peaks with good baseline separation. The UV-absorbing peak eluting last is distinct and therefore easily quantified. Biochemical analyses including ultrafiltration, protein precipitation, and Sephadex LH20 chromatography combined with electrospray mass spectrometric analyses establish that this peak predominantly contains polymeric procyanidins. The polymers, which appear to be galloylated to various degrees and seem to fragment in a characteristic manner during electrospray mass spectrometry, are well separated from catechins and procyanidin oligomers of up to 4 units. The recovery of polymeric grape seed tannins with this HPLC method was 86%, which is similar to the 89% recovery achieved with commercial quebracho tannins. The concentration of tannins in seeds from ripe Vitis vinifera cv. Shiraz grapes ranged from 1360 to 2830 mg/kg of berries.
A method using HPLC analysis has been used to compare the level of resveratrol and its derivatives, piceid, pterostilbene and epsilon-viniferin, in grapevine berries of three Vitis vinifera varieties. The concentration of these compounds has been evaluated in healthy and Botrytis cinerea infected grape clusters, both in natural vineyard conditions and in response to UV elicitation.
Methods based on liquid chromatography-mass spectrometry (LC-MS) and protein trap mass spectrometry (trap-MS) were developed to determine the complement of pathogenesis-related (PR) proteins in grape juice. Trap-MS was superior to LC-MS in terms of simplicity, rapidity, and sensitivity. Proteins with a wide range of masses (13--33 kDa) were found in the juices of 19 different varieties of grape (Vitis vinifera) and were identified as mostly PR-5 type (thaumatin-like) and PR-3 type (chitinases) proteins. Although the PR proteins in juices of grapes are highly conserved, small consistent differences in molecular masses were noted when otherwise identical proteins were compared from different varieties. These differences persisted through different harvest years and in fruits grown in different Australian locations. With the definition of four different masses for PR-5 proteins (range = 21,239--21,272 Da) and nine different masses of PR-3 proteins (range = 25,330--25,631 Da) and using statistical analysis, the methods developed could be used for varietal differentiation of grapes grown in several South Australian locations on the basis of the PR protein composition of the juice. It remains to be seen whether this technology can be extended to grapes grown worldwide and to wine and other fruit-derived products to assist with label integrity to the benefit of consumers.