Berries Of Vitis Vinifera Research Articles

Characterization of a putative grapevine Zn transporter, VvZIP3, suggests its involvement in early reproductive development in Vitis vinifera L

BackgroundZinc (Zn) deficiency is one of the most widespread mineral nutritional problems that affect normal development in plants. Because Zn cannot passively diffuse across cell membranes, it must be transported into intracellular compartments for all biological processes where Zn is required. Several members of the Zinc-regulated transporters, Iron-regulated transporter-like Protein (ZIP) gene family have been characterized in plants, and have shown to be involved in metal uptake and transport. This study describes the first putative Zn transporter in grapevine. Unravelling its function may explain an important symptom of Zn deficiency in grapevines, which is the production of clusters with fewer and usually smaller berries than normal.ResultsWe identified and characterized a putative Zn transporter from berries of Vitis vinifera L., named VvZIP3. Compared to other members of the ZIP family identified in the Vitis vinifera L. genome, VvZIP3 is mainly expressed in reproductive tissue - specifically in developing flowers - which correlates with the high Zn accumulation in these organs. Contrary to this, the low expression of VvZIP3 in parthenocarpic berries shows a relationship with the lower Zn accumulation in this tissue than in normal seeded berries where its expression is induced by Zn. The predicted protein sequence indicates strong similarity with several members of the ZIP family from Arabidopsis thaliana and other species. Moreover, VvZIP3 complemented the growth defect of a yeast Zn-uptake mutant, ZHY3, and is localized in the plasma membrane of plant cells, suggesting that VvZIP3 has the function of a Zn uptake transporter.ConclusionsOur results suggest that VvZIP3 encodes a putative plasma membrane Zn transporter protein member of the ZIP gene family that might play a role in Zn uptake and distribution during the early reproductive development in Vitis vinifera L., indicating that the availability of this micronutrient may be relevant for reproductive development.

Overwintering and presence of Colletotrichum acutatum (ripe rot) on mummified bunches, dormant wood, developing tissues and mature berries of Vitis vinifera

Colletotrichum acutatum , the casual agent of ripe rot in tropical and sub-tropical grape growing regions of Australia, affects crop yield and wine quality. To elucidate the epidemiology of the fungus, its presence was studied on shoots, pea sized and mature berries, mummified bunches, spurs and canes during two consecutive growing seasons and one winter season. The presence of C. acutatum was analysed by both traditional and real-time PCR methods. A protocol was developed to achieve PCR amplification for fungal DNA extracted from 'difficult' wood samples. C. acutatum was detected on mature berries, mummified berries, the peduncles of mummified berries, winter spurs and canes but not on the remaining analysed tissues. Thus the fungus overwinters on Vitis vinifera plant tissues and the conidia on spurs and dormant wood are likely to be the most important source of primary inoculum for the next growing season.

Study of content and composition of anthocyanins in selected plants species

Anthocyanins are heteroglycosides composed of aglycone – anthocyanidine and sugar moiety. They are the final product of flavonoid production in secondary metabolism of plant cells. They are characteristic with antioxidant effects, through which they have positive effect on human organism. There is a large number of anthocyanidins, out of which only six are of the greatest importance, those with hydroxylic group at C-3 location. They are cyanidine, pelargonidine, peonidine, delfinidine, petunidine, malvidine. These are present in large amounts in plant species Vitis vinifera L., Vaccinum corymbosum L. and Sambucus nigra L. In the berries of Vitis vinifera they are accumulated in hypodermal cell layer of peel, or in the pulp of some cultivars. Except for pelargonidine, it contains all important anthocyanidines, with predomination of malvidine. Total content of anthocyanins in fresh berries ranged from 0,50 to 4,99g.kg-1 and in peels from 20,7 to 66,6mg.g-1 of peels dry matter. In the anthocyanins of Vaccinum corymbosum there were identified cyanidine, delphinidine, malvidine and peonidine. Their total content varies significantly depending on variety. Total determined content of anthocyanins ranged from 290,16 to 1343,08mg.dm-3. Sambucus nigra contains five important anthocyanidines: cyanidine 3-sambubiosid-5-glucoside, cyanidine 3,5 diglucoside, cyanidine 3-sambubioside, cyanidine 3-glucoside and cyanidine 3-rutinoside. The content of identified anthocyanins in fruits of this species ranges from 602,9 to 1265,3mg.100g-1. The amount of accumulated anthocyanins pigments depends on variety, ecological conditions standard of agricultural technology, and particularly on the temperature and solar radiation.

Characterization of Botrytis cinerea Isolates Present in Thompson Seedless Table Grapes in the Central Valley of Chile.

Botrytis cinerea isolates from flowers and berries of Vitis vinifera 'Thompson seedless' (grapevine) were characterized in terms of two transposable elements (TEs) Boty and Flipper, random amplified polymorphic DNA (RAPD), infection levels, and resistance to iprodione. The isolates were collected from grapevines under fungicide programs of variable numbers of iprodione applications, and replicated in three Chilean Central Valley locations. Recovery was repeated from clusters collected at four phenological stages. Highest infection levels were found at bloom. Fungicide programs including one iprodione application or a combination of other fungicides were most effective for reducing gray mold symptoms. A total of 457 isolates collected from fungicide programs including only one iprodione application, and the control program, were tested for the presence of TEs. In all locations and during all phenological stages, transposa isolates (containing both TEs) were most common, followed by Boty. Vacuma isolates (containing neither TE) were identified at very low levels in two locations and only in the control treatment, and isolates with only Flipper were not detected at any time or location. Vacuma and Boty isolates were all sensitive to iprodione, while transposa isolates showed a wide range of resistance. Based on response to iprodione, the presence of TEs, and presence of vegetative-incompatibility alleles (Bc-hch), the isolates studied belong to B. cinerea Group II, a phylogenetic species within B. cinerea. Hierarchical analysis of molecular variance and genetic diversity analyses of the RAPD genotypes showed a genetic differentiation linked to location, but it was not related to geographic distance. Moreover, a genetic differentiation related to the phenological stage of grapes was also detected.

Ripe rot of south-eastern Australian wine grapes is caused by two species of Colletotrichum: C. acutatum and C. gloeosporioides with differences in infection and fungicide sensitivity

Background and Aims: Ripe rot of grapes is widespread in subtropical vineyards of south-eastern Australia. We aimed to re-evaluate the causative agent(s), berry susceptibility, fungicide sensitivity and differences in histopathology. Methods and Results: Both Colletotrichum acutatum and C. gloeosporioides were shown to be responsible for ripe rot in three vineyards surveyed in the Hastings Valley, NSW in 2007 and 2009. Observation on detached berries of Vitis vinifera (cv. Cabernet Sauvignon and Chardonnay) revealed that C. acutatum had a faster infection rate than C. gloeosporioides. C. acutatum also formed appressoria and penetrated grape tissue faster than C. gloeosporioides, which produced longer hyphae on the berry surface before penetration. Both C. acutatum and C. gloeosporioides produced acervuli 48 h after inoculation. In contrast, spore germination rates and growth rates on potato dextrose agar were greater for C. gloeosporioides. The two species differed in their sensitivity to the fungicides benomyl, captan and triadimenol. C. acutatum was significantly more sensitive to captan and triadimenol, whereas C. gloeosporioides was more sensitive to benomyl. Conclusions: Both C. acutatum and C. gloeosporioides cause ripe rot of wine grapes in Australia. Subtle differences in the infection process may explain the relative prevalence of the two species. Significance of the Study: This study confirms the involvement of C. acutatum and C. gloeosporioides in ripe rot of grapes in Australia. Knowledge of growth characteristics and fungicide sensitivity of ripe rot pathogens should aid disease management strategies.

Proteomic Analysis of Grape Berry Cell Cultures Reveals that Developmentally Regulated Ripening Related Processes Can Be Studied Using Cultured Cells

BackgroundThis work describes a proteomics profiling method, optimized and applied to berry cell suspensions to evaluate organ-specific cultures as a platform to study grape berry ripening. Variations in berry ripening within a cluster(s) on a vine and in a vineyard are a major impediment towards complete understanding of the functional processes that control ripening, specifically when a characterized and homogenous sample is required. Berry cell suspensions could overcome some of these problems, but their suitability as a model system for berry development and ripening needs to be established first.Methodology/Principal FindingsIn this study we report on the proteomic evaluation of the cytosolic proteins obtained from synchronized cell suspension cultures that were established from callus lines originating from green, véraison and ripe Vitis vinifera berry explants. The proteins were separated using liquid phase IEF in a Microrotofor cell and SDS PAGE. This method proved superior to gel-based 2DE. Principal component analysis confirmed that biological and technical repeats grouped tightly and importantly, showed that the proteomes of berry cultures originating from the different growth/ripening stages were distinct. A total of twenty six common bands were selected after band matching between different growth stages and twenty two of these bands were positively identified. Thirty two % of the identified proteins are currently annotated as hypothetical. The differential expression profile of the identified proteins, when compared with published literature on grape berry ripening, suggested common trends in terms of relative abundance in the different developmental stages between real berries and cell suspensions.ConclusionsThe advantages of having suspension cultures that accurately mimic specific developmental stages are profound and could significantly contribute to the study of the intricate regulatory and signaling networks responsible for berry development and ripening.

Proteomic analysis of the effects of ABA treatments on ripening Vitis vinifera berries.

The control of ripening of the non-climacteric grapevine fruit is still a matter of debate, but several lines of evidence point to an important role for the hormone abscisic acid (ABA). The effects of ABA treatments on Cabernet Sauvignon berries before and at véraison were studied using a 2-DE proteomic approach. Proteins from whole deseeded berries (before véraison) and berry flesh and skin (at véraison) treated with 0.76 mM ABA and collected 24 h after treatment were separated and analysed. A total of 60 protein spots showed significant variations between treated and control berries, and 40 proteins, mainly related to general metabolism and cell defence, were identified by LC MS/MS. Our results show that ABA acts mainly through the regulation of mostly the same proteins which are involved in the ripening process, and that several of these changes share common elements with the ABA-induced responses in vegetative tissues.

Different Anthocyanin Profiles of the Skin and the Pulp of Yan73 (Muscat Hamburg × Alicante Bouschet) Grape Berries

Yan73 is a “teinturier” red wine variety cultivated in China and used in winemaking to strengthen red wine color. Here, the anthocyanin profile in both the skin and pulp of this grape variety was analyzed by HPLC-MS. The results showed that 18 anthocyanins were detected in both the skin and the pulp, and pelargonidin-3-O-glucoside, an anthocyanin compound hardly detected in most other Vitis vinifera berries, was found. However, the contents of individual anthocyanins in the skin and the pulp were significantly different. Compared with the skin, the pulp exhibited much lower ratio of 3’,5’-substituted to 3’-substituted anthocyanins and much higher ratio of methoxylation of anthocyanin B-ring to non methoxylation, and with regard to the aromatic acylated and aliphatic acylated anthocyanins, both their contents in the skin are higher than in the pulp. The findings will provide some new insight for the tissue-specific expression and regulation of the genes involving in anthocyanin biosynthesis in grape berries.

Role of Glycosidic Aroma Precursors on the odorant profiles of Grenache noir and Syrah Wines from the Rhone valley. Part 1: sensory study

<p style="text-align: justify;"><strong>Aims</strong>: The aim of this study was to demonstrate the impact of the volatile compounds, arising from glycosidic precursors contained in the berries of Vitis vinifera L.cv Syrah and Grenache noir varieties, on wine aromas from these varieties.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The sensory analysis was used to compare Grenache noir and Syrah wines. The role played by the glycosidic precursors on the future odorant profile of the wines from both varieties was demonstrated in an experiment by increasing their natural content in glycosides. Then, odorant compounds were generated by aging treatments, heating at 45 °C for 3 weeks, preceded or not by enzyme addition, or natural aging for 18 months. The wines were then submitted to a selected and trained panel. Samples were compared using triangular test. Furthermore, a quantitative descriptive analysis was carried out to determine the aroma attributes describing and discriminating the wines from the two varieties.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The glycoconjugates increased the global aromatic complexity, and enhanced the fruity aromas in Grenache wines and the leather or olive aromas in Syrah wines. The use of glycosidase enzymes led to a stewed fruit character in Grenache wines, whereas in Syrah wines, the samples enriched with glycosides differed according to the « terroir ».</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: This study showed the impact of the glycosidic fraction of the grapes on the varietal aroma of wines. Furthermore, comparisons of the results obtained by both aging techniques highlight the experimental interest of the aging model but also its limits.</p>

Anthocyanins, flavonols and hydroxycinnamates: an attempt to use them to discriminate Vitis vinifera L. cv ‘Barbera’ clones

Anthocyanin and flavonol profiles of Vitis vinifera berry skin have been diffusely studied in past years to identify the effects exerted by climate, environment and cultural practices on their biosynthesis. They have also been used for chemotaxonomic purposes with the aim of classifying grape varieties. Hydroxycinnamates and phenolic acids are the most important group of non-flavonoid phenols in grapes and wines. In the present work six ‘Barbera’ clones were grown in the same site to evaluate the influence of two seasons on the accumulation of flavonoids and hydroxycinnamates at maturity. Berry skins were extracted in an ethanolic buffer and flavonoids and hydroxycinnamates were separated by HPLC. Two principal component analysis (PCA) models were built to identify phenolic parameters exploitable to classify clones. The PCA scores were taken further to perform discriminant analysis to evaluate the degree of classification possible. A significant seasonal variability was observed for most phenolic features, whereas some parameters such as total anthocyanin expressed on a per berry basis, the sum of tri-hydroxylated anthocyanin percentages, the percentages of kaempferol glucuronide and the total hydroxycinnamate content were stable over the seasons. The percentage of individual anthocyanin alone, not associated with maturity data, was not effective in classifying clones; in association with maturity data it allowed to discriminate clones, similarly to what it was previously assessed for classifying varieties. The results indicated that LDA models developed on the PCA scores including maturity data correctly classified 75% of clones.

Resveratrol exhibits a strong cytotoxic activity in cultured cells and has an antiviral action against polyomavirus: potential clinical use

BackgroundResveratrol is a non flavonoid polyphenol compound present in many plants and fruits and, at especially high concentrations, in the grape berries of Vitis vinifera. This compound has a strong bioactivity and its cytoprotective action has been demonstrated, however at high concentrations the drug exhibits also an effective anti-proliferative action. We recently showed its ability to abolish the effects of oxidative stress in cultured cells. In this work we assayed the bioactivity of resveratrol as antiproliferative and antiviral drug in cultured fibroblasts. Studies by other Authors showed that this natural compound inhibits the proliferation of different viruses such as herpes simplex, varicella-zoster and influenza A. The results presented here show an evident toxic activity of the drug at high concentrations, on the other hand at sub-cytotoxic concentrations, resveratrol can effectively inhibit the synthesis of polyomavirus DNA. A possible interpretation is that, due to the damage caused by resveratrol to the plasma membrane, the transfer of the virus from the endoplasmic reticulum to the nucleus, may be hindered thus inhibiting the production of viral DNA.MethodsThe mouse fibroblast line 3T6 and the human tumor line HL60 were used throughout the work. Cell viability and vital cell count were assessed respectively, by the MTT assay and Trypan Blue staining. Cytotoxic properties and evaluation of viral DNA production by agarose gel electrophoresis were performed according to standard protocols.ResultsOur results show a clear dose dependent both cytotoxic and antiviral effect of resveratrol respectively at high and low concentrations. The cytotoxic action is exerted towards a stabilized cell-line (3T6) as well as a tumor-line (HL60). Furthermore the antiviral action is evident after the phase of virion entry, therefore data suggest that the drug acts during the synthesis of the viral progeny DNA.ConclusionResveratrol is cytotoxic and inhibits, in a dose dependent fashion, the synthesis of polyomavirus DNA in the infected cell. Furthermore, this inhibition is observed at non cytotoxic concentrations of the drug. Our data imply that cyto-toxicity may be attributed to the membrane damage caused by the drug and that the transfer of polyomavirus from the endoplasmic reticulum to the cytoplasm may be hindered. In conclusion, the cytotoxic and antiviral properties of resveratrol make it a potential candidate for the clinical control of proliferative as well as viral pathologies.

Identification and Quantification of Phenolic Compounds in Grapes by HPLC-PDA-ESI-MS on a Semimicro Separation Scale

Reversed phase high performance liquid chromatography (RP-HPLC) on a semimicro separation scale was employed to develop a straightforward method for the simultaneous separation, identification, and quantification of phenolic compounds occurring in whole berries of Vitis vinifera, which comprise phenolic acids, flavonols, catechins, stilbenes, and anthocyanins. A C-18 narrow bore column of 150 x 2.0 mm I.D. and a semimicro photodiode array detector (PDA) cell of 2.5 microL, in conjunction with a mass spectrometry detector equipped with an electrospray ionization source (ESI-MS) to confirm peak identification, were employed. The C-18 narrow bore column was eluted by a multisegment gradient of increasing concentration of acetonitrile in water-formic acid solution that was optimized on the basis of the results of a study carried out to evaluate the influence of mobile phase composition and gradient shape on separation performance and detection sensitivity by ESI-MS. The identification of individual phenolic compounds was performed on the basis of their retention times and both UV-visible and mass spectra, acquired by a mass spectrometer (MS) equipped with an electrospray ionization (ESI) source, employed in conjunction with the PDA detector. Libraries comprising retention times, UV-visible, and mass spectra for major phenolic compounds expected in grape berries were made by subjecting solutions of each phenolic standard to the optimized RP-HPLC method. Quantification of individual compounds was performed by the external standard method using a six point regression graph of the UV-visible absorption data collected at the wavelength of maximum absorbance of each analyte determined by the PDA spectra. The RP-HPLC method was validated in terms of linearity of calibration graphs, limits of detection, limits of quantification, repeatability, and accuracy, which was evaluated by a recovery study. The developed method was successfully applied to identify the phenolic compounds occurring in the whole berries of nine red and one white grape of different varieties of Vitis vinifera, comprising some autochthonous varieties of south Italy such as Aglianico, Malvasia Nera, Uva di Troia, Negroamaro, Primitivo, and Susumaniello. Large differences in the content of phenolic compounds was found in the investigated grape varieties. As expected, only glycosilated flavonols were quantified, and the total amount of these compounds was higher in the whole berries of red grapes than in the white Moscato, where the most abundant phenolic compound was quercetin 3-O-glucoside. In almost all samples, the most and least abundant anthocyanins were malvidin 3-O-glucoside and cyanidin 3-O-glucoside, respectively, with the exception of Uva di Troia where the least abundant anthocyanin was delphinidin 3-O-glucoside.

Evidence for a putative flavonoid translocator similar to mammalian bilitranslocase in grape berries (Vitis vinifera L.) during ripening

During maturation, Vitis vinifera berries accumulate a large amount of several anthocyanins in the epidermal tissue, whereas their precursors and intermediates are ubiquitously synthesized within the fruit. Up to date, several mechanisms of flavonoid transport at subcellular level have been hypothesized, but it is not possible to identify a general model applicable in every plant tissue and organ. Recently, a putative anthocyanin carrier, homologue to mammalian bilitranslocase (BTL) (TC 2.A.65.1.1), was found in Dianthus caryophyllus petal microsomes. In the present paper, an immunohistochemical and immunochemical analysis, using an antibody raised against a BTL epitope, evidences the expression and function of such a transporter in V. vinifera berries (cv. Merlot). Specific localisations of the putative carrier within berry tissues together with expression changes during different developmental stages are shown. Water stress induces an increase in protein expression in both skin and pulp samples. A bromosulfalein (BSP) uptake activity, inhibitable by the BTL antibody, is detected in berry mesocarp microsomes, with K (m) = 2.39 microM BSP and V (max) = 0.29 micromol BSP min(-1) mg(-1) protein. This BSP uptake is also competitively inhibited by quercetin (K (i) = 4 microM). A putative role for this carrier is discussed in relation to the membrane transport of secondary metabolites.

Direct measurement of hydraulic properties in developing berries of Vitis vinifera L. cv Shiraz and Chardonnay

Berries of Vitis vinifera L. cv Shiraz can undergo weight loss during later stages of ripening. Existing published views on how weight loss occurs are based on changes in capacity of the vascular system to import water during development (McCarthy and Coombe, Australian Journal of Grape and Wine Research, 5, 17–21, 1999). One important element of these views is the proposed cessation of water flow through the xylem after veraison. We have now measured the water flow into berries of Shiraz and Chardonnay as they develop using the pressure probe and the high pressure flow meter (HPFM). The pressure probe connected to the pedicel of individual berries provided measurements of single berry hydraulic conductance. By systematic excision of tissue segments of the berry and pedicel we determined where in the pathway hydraulic conductance changed during development. The HPFM was used on whole bunches showing that berries (including pedicels) represent parallel high hydraulic resistances and that the hydraulic resistance of the bunch axis was rather small. The hydraulic conductance per berry could be determined from excision experiments. There was close agreement between the pressure probe and HPFM measurements. Both showed a ten-fold reduction in hydraulic conductance of whole berries from veraison to full ripeness. Shiraz had hydraulic conductances that were 2- to 5-fold higher than those for Chardonnay. Shiraz maintained a higher hydraulic conductance past 90 days after flowering than Chardonnay. The decrease in hydraulic conductance occurred in both the distal and proximal parts of the berry for both varieties. The pressure probe also provided measurements of the xylem pressure that non-transpiring berries could develop. These pressures were –0.2 to –0.1 MPa until veraison and increased to zero when the juice osmotic potential reached about –3 MPa in Chardonnay and –4 MPa in Shiraz. The results suggest values of the reflection coefficient of the osmotic barrier around the xylem vessels of about 0.1–0.2 at veraison decreasing to 0 at harvest. It is suggested that in addition to changes in xylem anatomy, aquaporins in berry membranes may play a role in regulating hydraulic conductance. Water movement from the berry back to the parent vine via the xylem (backflow) may be an important component of berry weight loss in Shiraz, particularly if the phloem ceases functioning at high osmotic potentials near maximum weight. Backflow could account for a weight loss of 43 mg per day in Shiraz berries for a relatively small gradient of 0.1 MPa.

The effects of homogenisation method and freezing on the determination of quality parameters in red grape berries of Vitis vinifera

The effect of sample processing with three different blenders, sample freezing and storage time on the determination of berry quality parameters – total anthocyanins, total soluble solids (TSS), total phenolics (TP) and pH – in homogenates of red grape berries has been examined. Samples of Cabernet Sauvignon, Merlot and Shiraz from four regions of South Australia were homogenised using Ultra-Turrax, Waring or Retsch commercial blenders applied to fresh samples, and to samples held in frozen storage overnight or for 1, 3, 6 and 12 months. All samples were analysed immediately after homogenisation. The results showed that neither homogeniser type nor freezing had any significant effect on total anthocyanins or TSS. However, freezing had an effect on total anthocyanins concentrations in samples with higher colour. The homogeniser type had a significant effect on TP and pH for all varieties analysed together. Freezing had no significant effect on TP, but significant effect on pH, the value being greater in samples at the lower end of the pH range. Frozen storage time of up to 3 months had no significant effect on total anthocyanins, TSS or T P. Statistically significant differences were observed in the concentration of total anthocyanins in samples after 3 months of frozen storage.

Effect of Lime-Induced Leaf Chlorosis on Ochratoxin A,trans-Resveratrol, and ε-Viniferin Production in Grapevine (Vitis vinifera L.) Berries Infected by Aspergillus carbonarius

Berries of Vitis vinifera L. cv. Merlot, grown on a neutral or calcareous soil, were infected, at phenological phases of veraison and ripening, by a conidial suspension of Aspergillus carbonarius to control ochratoxin A production and trans-resveratrol- and epsilon-viniferin-induced synthesis as affected by the soil lime content. Chlorosis occurrence was evaluated by a visual rating scale at veraison, and the leaves from vines growing on the calcareous soil showed the typical yellowing, whereas those grown on the neutral soil were dark green. Berry mineral element yield was recorded at veraison and ripening. Infection symptoms on berries were more severe at ripening in bunches collected from vines grown in calcareous soil. Ochratoxin A concentration increased at phenological phase of veraison in berries harvested from vines cultivated in calcareous soil. A. carbonarius enhanced trans-resveratrol and epsilon-viniferin production in infected berries more than in the control samples. Moreover, at veraison their concentration in the berries collected from vines grown in calcareous soil was greater than that recorded from berries collected from vines grown in the neutral soil. The lowest symptom severity was observed on berries containing the highest copper concentration.

Analysis of grape berry cell wall proteome: A comparative evaluation of extraction methods

Different methods were tested for the extraction of proteins from the cell wall-enriched fraction (CWEf) obtained from a sample formed by skin and seeds of ripe berries of Vitis vinifera L. cv. Cabernet Sauvignon. The CWEf was isolated using a disruptive approach that involves tissue homogenization and precipitation by centrifugation. To extract proteins, the CWEf was treated with CaCl(2) and LiCl in two successive steps or, alternatively, with phenol. The efficiency of the protocols was evaluated by measuring protein yield and by analyzing two-dimensional gel electrophoresis (2-DE) gels for the highest detectable spot number and the greatest spot resolution. The phenol method was also adopted for the extraction of proteins from the cytosolic fraction (CYf). The comparison of 2-DE reference maps of protein extracts from CWEf and CYf indicated the presence of both common traits and unique characteristics. To survey this aspect some spots detected in both fractions or present in only one fraction were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Of the 47 spots identified, some were found to be cell wall proteins, while others were proteins not traditionally considered as localized in the apoplastic space. The data presented here provide initial information regarding the apoplastic proteome of grape berry tissues, but also raise the issue of the technical problems that characterize the isolation of cell wall proteins from these very hardy tissues.

Effect of Shading on Proanthocyanidin Biosynthesis in the Grape Berry

Proanthocyanidins, which are oligomers and polymers of flavan-3-ol units (e.g., (+)-catechin and (−)-epicatechin), are important components of grapes for red winemaking. Flavan-3-ols are biosynthesized by the catalysis of anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR). In this study, we investigated the effect of shading on proanthocyanidin biosynthesis in berries of Vitis vinifera ‘Cabernet Sauvignon’. Shading of the berries reduced the accumulation of proanthocyanidins and the transcription of ANR and LAR genes in the skins during berry development, while no significant effect was observed in the seeds. Because the proanthocyanidins significantly decreased in the skins and seeds of the control berries during ripening, the levels of proanthocyanidins were similar in the shaded and control berries at the harvest stage.

Effect of vine nitrogen status on grape aromatic potential: flavor precursors (S-cysteine conjugates), glutathione and phenolic content in <em>Vitis vinifera</em> L. Cv Sauvignon blanc grape juice

<p style="text-align: justify;">Vine nitrogen status influence on S-cysteine conjugate precursors of volatile thiols, glutathione and phenolic content of the berries of Vitis vinifera L. cv. Sauvignon blanc have been assessed. Despite an increase in berry weight, the increase in nitrogen supply in the vine leads to higher cysteine precursor levels in grape juice. We also show that a late addition of nitrogen at berry set leads to a lower level of phenolic compounds in white grapes and to higher glutathione levels. Therefore, in white varieties, and particularly Sauvignon blanc, improving the nitrogen supply of the vine clearly increases its aromatic potential. However, an excess of nitrogen supply would increase the grape sensitivity to Botrytis cinerea and therefore decrease its quality.</p>

Headspace-SPME applied to varietal volatile components evolution during Vitis vinifera L. cv. ‘Baga’ ripening

Grape berries of Vitis vinifera L. cv. Baga were collected during 7 weeks since half- véraison to a post-maturation stage. Two vineyards in different locations in Bairrada Appellation, Pedralvites (Ped) and Colégio (Col) were used. The free varietal and pre-fermentative related volatile compounds that arise in the first 2 h after crushing the grapes were followed by Headspace-Solid Phase Microextraction (HS-SPME). Twenty-three sesquiterpenoids, 13 monoterpenoids, 6 norisoprenoids, 2 aromatic alcohols, and 1 diterpenoid were detected in both vineyards. However, 40 sesquiterpenoids and 10 norisoprenoids were detected in Ped. The maximum gas chromatographic peak area was reached at the maturity, and remained constant until post-maturation. At maturity sesquiterpenoids represented 56% and 80% of the total varietal GC peak area in Col and Ped, respectively, which was the group with higher number of constituent varietal compounds. The results obtained indicated a high number of sesquiterpenoid compounds, namely (+)-cycloisosativene, γ-elemene, α-ylangene, β-bourbonene, β-cubenene, β-caryophyllene, 3,7-guaiadiene, (−)-isoledene, (+)-aromadendrene, α-amorphene, (−)-δ-selinene, germacrene D, epizonarene, β-cadinene, γ-cadinene, δ-cadinene, α-muurolene, α-calacorene in ‘Baga’ ripe grapes, which allows to suggest that this variety is a potential source of sesquiterpenoids.