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Wine made from grapes subjected to accelerated ripening, an increasingly frequent phenomenon occurring in many wine regions due to peaks of heat and water stress, displays higher alcohol levels and lacks balance with color and flavor compounds. Herein, the rate of sugar accumulation of grapes was manipulated by varying the crop load and irrigation regime and the development of secondary metabolites was monitored by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). A 3-week delay in ripening correlated to an increase in the concentration of some monoterpenes and norisoprenoids and a greater decrease of green aroma compounds. Delayed ripening had a positive impact on the phenolic composition of grapes, displaying higher contents of total anthocyanins, total phenolics, quercetin glycosides, and polymeric pigments. A map of the chemical composition of grapes close to harvest allowed discrimination of compounds mainly responsive to delayed ripening from those driven by crop load or irrigation.

Phenolic compounds found in the berries of the grapevine Vitis vinifera L. are reported to reduce the incidence of some non-transmissible chronic pathologies such as cardiovascular diseases, cancer, obesity and diabetes. Elicitation of plant cell suspension cultures offers a way to experimentally determine how manipulating metabolic pathways can result in biosynthesis of higher levels of desired secondary metabolites. The goal of this work was, using cell suspension cultures of callus tissues obtained from berry slices of V. vinifera cv. Shahani grown on an optimized medium, to investigate the effects of elicitation on the synthesis of stilbene compounds including trans-resveratrol and its glucoside trans-piceid, and anthocyanin pigments. The effects of different concentrations of the phytohormone abscisic acid (ABA; 0, 50, 100 and 200 µM) applied to cell suspension cultures grown under either high-level light irradiation (135.1 μmol. s−1 m−2) or zero light conditions, were tested. The results showed that compared with dark conditions, cells treated with continuous light irradiation were capable of accumulating significantly higher levels of anthocyanin in all of the ABA concentrations. Cell cultures subjected to high-level light irradiation did not show statistically higher piceid amounts than cells grown in dark condition except for 200 µM ABA. A similar trend was found for resveratrol content of the cells exposed to the darkness. When cultures were grown in the presence of 200 µM ABA under dark conditions, the accumulation of trans-resveratrol was seen at 4.12 and 3.02-fold higher levels than in dark and light-grown control cultures respectively. Surprisingly, following light irradiation of 135.1 μmol. s−1 m−2 with 200 µM ABA, the cells accumulated the highest level of trans-piceid. This represented a remarkable increase of 19.97 and 12.71-fold in comparison with dark and light-grown control cultures respectively. In addition, the combined elicitation of light irradiation and 50 µM abscisic acid was found to be the most effective treatment for the production of anthocyanin. This value was 64.00 and 5.55-fold higher than those of the controls, respectively. These data suggest that the transduction pathway of abscisic acid is part of a complex signaling network that includes the visible light signaling pathway. Similarly, the results of the current study suggest that combinations of dark/light together with abscisic acid can be used as an efficient method for the future scale-up of V. vinifera cell cultures for the production of high value phenolic compounds in a bioreactor system. The influence of elicitation culture media with the phytohormone abscisic acid in combination or not with high-level light condition on stimulating valuable phenolic compounds production in cell suspension cultures of Vitis vinifera L. was proved.

Wine made from grapes subjected to accelerated ripening, an increasingly frequent phenomenon occurring in many wine regions due to peaks of heat and water stress, displays higher alcohol levels and lacks balance with color and flavor compounds. Herein, the rate of sugar accumulation of grapes was manipulated by varying the crop load and irrigation regime and the development of secondary metabolites was monitored by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). A 3-week delay in ripening correlated to an increase in the concentration of some monoterpenes and norisoprenoids and a greater decrease of green aroma compounds. Delayed ripening had a positive impact on the phenolic composition of grapes, displaying higher contents of total anthocyanins, total phenolics, quercetin glycosides, and polymeric pigments. A map of the chemical composition of grapes close to harvest allowed discrimination of compounds mainly responsive to delayed ripening from those driven by crop load or irrigation.

Tartaric acid has high economic value as an antioxidant and flavorant in food and wine industries. l-Tartaric acid biosynthesis in wine grape (Vitis vinifera) uses ascorbic acid (vitamin C) as precursor, representing an unusual metabolic fate for ascorbic acid degradation. Reduction of the ascorbate breakdown product 2-keto-l-gulonic acid to l-idonic acid constitutes a critical step in this l-tartaric acid biosynthetic pathway. However, the underlying enzymatic mechanisms remain obscure. Here, we identified a V. vinifera aldo-keto reductase, Vv2KGR, with 2-keto-l-gulonic acid reductase activity. Vv2KGR belongs to the d-isomer–specific 2-hydroxyacid dehydrogenase superfamily and displayed the highest similarity to the hydroxyl pyruvate reductase isoform 2 in Arabidopsis thaliana. Enzymatic analyses revealed that Vv2KGR efficiently reduces 2-keto-l-gulonic acid to l-idonic acid and uses NADPH as preferred coenzyme. Moreover, Vv2KGR exhibited broad substrate specificity toward glyoxylate, pyruvate, and hydroxypyruvate, having the highest catalytic efficiency for glyoxylate. We further determined the X-ray crystal structure of Vv2KGR at 1.58 Å resolution. Comparison of the Vv2KGR structure with those of d-isomer–specific 2-hydroxyacid dehydrogenases from animals and microorganisms revealed several unique structural features of this plant hydroxyl pyruvate reductase. Substrate structural analysis indicated that Vv2KGR uses two modes (A and B) to bind different substrates. 2-Keto-l-gulonic acid displayed the lowest predicted free-energy binding to Vv2KGR among all docked substrates. Hence, we propose that Vv2KGR functions in l-tartaric acid biosynthesis. To the best of our knowledge, this is the first report of a d-isomer–specific 2-hydroxyacid dehydrogenase that reduces 2-keto-l-gulonic acid to l-idonic acid in plants.

International audience; Tartaric acid (TA) is an obscure end point to the catabolism of ascorbic acid (Asc). Here, it is proposed as a « specialized primary metabolite », originating from carbohydrate metabolism but with restricted distribution within the plant kingdom and lack of known function in primary metabolic pathways. Grapes fall into the list of high TA-accumulators, with biosynthesis occurring in both leaf and berry. Very little is known of the TA biosynthetic pathway enzymes in any plant species, although recently some progress has been made in this space. New technologies in grapevine research such as the development of global co-expression network analysis tools and genome-wide association studies, should enable more rapid progress. There is also a lack of information regarding roles for this organic acid in plant metabolism. Therefore this review aims to briefly summarize current knowledge about the key intermediates and enzymes of TA biosynthesis in grapes and the regulation of its precursor, ascorbate, followed by speculative discussion around the potential roles of TA based on current knowledge of Asc metabolism, TA biosynthetic enzymes and other aspects of fruit metabolism.

Several vineyard techniques have been proposed to delay grape maturity in light of the advanced maturation driven by increasingly frequent water and heat stress events that are detrimental to grape quality. These studies differ in terms of their experimental conditions, and in the present work we have attempted to summarize previous observations in a quantitative, data-driven systematic review. A meta-analysis of quantitative data gathered across 43 relevant studies revealed the overall significance of the proposed treatments and evaluated the impact of different experimental conditions on the outcome of antitranspirants, delayed pruning and late source limitation. Antitranspirants were most effective when applied twice and closer to veraison, while di-1- p -menthene increased the ripening delay by about 1°Brix compared to kaolin. Larger ripening delays were achieved with delayed pruning of low-yielding vines or by pruning at later stages of apical bud development. Late defoliation or shoot trimming delayed ripening in high-yielding vines and represent suitable solutions for late-harvested varieties, but became ineffective where the treatment decreased yield. This quantitative meta-analysis of 242 primary observations uncovers factors affecting the efficacy of vineyard practices to delay ripening, which should be carefully considered by grape growers attempting to achieve this outcome.

Grape ripening accelerates under warmer and drier conditions, resulting in the accumulation of sugars (‘technological’ maturity) being decoupled from phenolic and aromatic composition. This study investigated the effect of different rates of ripening on the composition of Cabernet Sauvignon and Riesling wines. Manipulating crop load and irrigation led to distinct rates of berry ripening. In the resulting wines, reduced crop load affected the aroma composition, altering the profile and abundance of grape-derived compounds and fermentative esters. Phenolic composition was impacted by the irrigation regime, with color and tannin increased by late season irrigation. In Cabernet Sauvignon, the combination of treatments led to the largest ripening delay (3 weeks), resulting in less green and more fruity compounds, and improved phenolic composition. By mapping grape and wine metabolites and exploring their relationship, the outcomes of this study demonstrate the importance of ripening rates in determining wine quality.

Aims Transforming growth factor β1 (TGF-β1) is a prosclerotic cytokine involved in cardiac remodelling leading to heart failure (HF). Acetylation/de-acetylation of specific lysine residues in Smad2/3 has been shown to regulate TGF-β signalling by altering its transcriptional activity. Recently, the lysine de-acetylase sirtuin 1 (SIRT1) has been shown to have a cardioprotective effect; however, SIRT1 expression and activity are paradoxically reduced in HF. Herein, we investigate whether pharmacological activation of SIRT1 would induce cardioprotection in a pressure overload model and assess the impact of SIRT1 activation on TGF-β signalling and the fibrotic response. Methods and results Eight weeks old male C57BL/6 mice were randomized to undergo sham surgery or transverse aortic constriction (TAC) to induce pressure overload. Post-surgery, animals were further randomized to receive SRT1720 or vehicle treatment. Echocardiography, pressure-volume loops, and histological analysis revealed an impairment in cardiac function and deleterious left ventricular remodelling in TAC-operated animals that was improved with SRT1720 treatment. Genetic ablation and cell culture studies using a Smad-binding response element revealed SIRT1 to be a specific target of SRT1720 and identified Smad2/3 as a SIRT1 specific substrate. Conclusion Overall, our data demonstrate that Smad2/3 is a specific SIRT1 target and suggests that pharmacological activation of SIRT1 may be a novel therapeutic strategy to prevent/reverse HF via modifying Smad activity.

The majority of studies on grape secondary metabolism are focusing on the berry or stem and leaves phenolic composition. Although the composition of phytochemicals is known to be highly variable in different cultivars, the changes of this composition during vine growth in vegetative parts remain poorly understood. The present study was performed to profile and compare several non-colored polyphenol compounds and the antioxidant potential of Vitis vinifera leaves and stems during a part of growing season and early fall (July, August, September and October) from seventy Iranian native cultivars (white and red) using HPLC-DAD method. Leaves showed significantly higher amounts of analyzed phenolics. Considering the average amounts, the most predominant detected phenolics in the leaves were catechin and o-coumaric acid while the most abundant compound found in the stems was quercetin. Naringenin was found as the lowest detected phenolic. The phenolic potential of the samples varied in each time point. Antioxidant activity was detected higher in stems than leaves with the highest in white cultivar “Atabaki” in both leaves and stems. Leaves of the red cultivars “Angourab” and “Yaghouti shiraz” showed the highest concentrations considering the summation of analyzed phenolics. In addition to the cultivar and plant organ, the phenolic potential of the samples varied in each time point. All samples exhibited antioxidant activity using the DPPH radical and Folin-Ciocalteo Reagent, with mostly higher amounts in stems than leaves showing a strong correlation between two methods In view of both methods, white cultivars were more often higher than red ones with the highest amounts detected in stems and leaves of white cultivar “Atabaki”. PCA results confirmed the variability of phenolic composition in grapevines and during four-month development and showed no obvious discrimination among red and white cultivars. As far as we know, this is the first time that a relationship between the content of polyphenolic compounds is evaluated in leaves and stems, as well as the targeted phenolic profiling of several cultivars foliage. Targeted phenolics profiling indicated the high potential of such wastes to be used in the pharmaceutical, cosmetic and food industries.

Grape stilbenes are a well-known family of plant polyphenolics that have been confirmed to have many biological activities in relation to health benefits. In the present study, we investigated the effect of methyl jasmonate (MeJA) elicitor at four different concentrations (25, 50, 100 and 200 μM) in combination or not with high-level light irradiation (10,000 LUX) on a cell line obtained from the pulp of Vitis vinifera cv. Shahani. Our results showed that the stilbene synthesis pathway is inhibited by high-light conditions. A concentration of 50 μM MeJA was optimum for efficient production and high accumulation of total phenolics and total flavonoids as well as total stilbenoids. Furthermore, we showed that there is a significant negative correlation between the production of these metabolites and cell growth. These data provide valuable information for the future scale-up of cell cultures for the production of these very high value compounds in bioreactor system.

The U.S. military Standing Rules of Engagement (SROE) restrict the use of force in armed conflict to either self-defense or “mission-specific” rules of engagement, which refer to the use of force against members of enemy armed forces or organized armed groups that have been “declared hostile.” This bifurcation of authority works well in an international armed conflict, where the enemy force is uniformed and easily distinguished. In these circumstances, the overwhelming number of engagements are against identified hostile forces. In many non-international armed conflicts, however, combatants actively attempt to camouflage their status, and U.S. forces find themselves engaging enemy forces under a self-defense framework. This creates problems. Consider, for example, a situation where three individuals of unknown affiliation launch an attack against a U.S. military convoy in Afghanistan. After a short engagement, the attackers get in a van and speed away from the attack site. The U.S. convoy is disabled, but an unmanned aerial vehicle tracks the van as it retreats into the desert. Thirty minutes later an AH-64 Apache attack helicopter arrives on scene above the still-retreating van. Can the Apache attack the vehicle? The van is retreating and poses no threat, thus self-defense principles would not allow for the use of force, despite the fact that the occupants are clearly directly participating in hostilities. This chapter addresses three questions: Why are the SROE drafted in this manner? What is the basis in the law for the SROE’s approach to self-defense? What are the problems presented by this approach?

The chemical and sensory profiles of wines prepared from Cabernet Sauvignon grapes at different ripening stages vary greatly. Here, the soluble cell wall carbohydrate (SCWC) and phenolic profiles of wines were analyzed in parallel with the sensory evaluation of their mouthfeel and taste characteristics. Both SCWCs and phenolic compounds correlated with wine mouthfeel. When analyses were extended to specific classes of cell wall carbohydrates, it was shown that rhamnogalacturonan I/II, arabinan, arabinogalactan types I and II and xyloglucan from grapes were the key determinants of overall mouthfeel descriptors, particularly viscosity, astringency and roughness, whereas heteromannan from grapes was associated with mouth coating and chalkiness. A perceived sour taste was notably associated with higher homogalacturonan contents. This finding provides insights into the contributions of non-phenolic compounds to wine mouthfeel. The data provide opportunities for the development of simple monosaccharide marker assays to monitor major mouthfeel characteristics in red wines.

The accumulation of volatile phenol glycoconjugates in smoke-exposed grapes was monitored following grapevine exposure to smoke, with different glycoconjugate profiles observed for fruit sampled 1 and 7 days after smoke exposure, and at maturity. Foliar application of kaolin reduced the concentration of volatile phenol glycoconjugates in smoke-exposed fruit, but efficacy depended on the rate of application and extent of coverage. Smoke taint can be found in wines made from grapes exposed to smoke from bushfires or prescribed burns. It is characterized by objectionable smoky and ashy aromas and flavors, which have been attributed to the presence of smoke-derived volatile phenols, in free and glycoconjugate forms. This study investigated: (1) the accumulation of volatile phenol glycoconjugates in grapes following the application of smoke to Sauvignon Blanc, Chardonnay and Merlot grapevines at approximately 10 days post-veraison; and (2) the potential mitigation of smoke taint as a consequence of foliar applications of kaolin (a clay-based protective film) prior to grapevine smoke exposure. Varietal differences were observed in the glycoconjugate profiles of smoke-exposed grapes; the highest glycoconjugate levels were found in Merlot grapes, being pentose-glucosides of guaiacol, cresols, and phenol, and gentiobiosides of guaiacol and syringol. Changes in volatile phenol glycoconjugate profiles were also observed with time, i.e., between fruit sampled 1 day after smoke exposure and at maturity. The application of kaolin did not significantly affect the glycoconjugate profiles of Sauvignon Blanc and Chardonnay grapes, but significantly lower volatile phenol glycoconjugate levels were observed in Merlot fruit that was treated with kaolin prior to smoke exposure. The potential for control and smoke-exposed grapes to be differentiated by measurement of spectral reflectance was also demonstrated.

Wine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools to winemakers looking to differentiate their wines through the development of new wine styles. The addition of a non-Saccharomyces cerevisiae genome to a commercial wine yeast can generate novel phenotypes ranging from wine flavor and aroma diversity to improvements in targeted fermentation traits. In the current study we utilized a novel approach to screen isolates from an evolving population for increased fitness in a S. cerevisiae × S. uvarum interspecific hybrid previously generated to incorporate the targeted phenotype of lower volatile acidity production. Sequential grape-juice fermentations provided a selective environment from which to screen isolates. Chromosomal markers were used in a novel approach to identify isolates with potential increased fitness. A strain with increased fitness relative to its parents was isolated from an early timepoint in the evolving population, thereby minimizing the risk of introducing collateral mutations and potentially undesirable phenotypes. The evolved strain retained the desirable fermentation trait of reduced volatile acidity production, along with other winemaking traits of importance while exhibiting improved fermentation kinetics.

Highlight VvGuaS, a novel allele of the VvTPS24 gene, is responsible for the production of the rotundone precursor α-guaiene. Two specific polymorphisms distinguish VvGuaS from its non-guaiene-producing homologue VvPNSeInt., Rotundone was initially identified as a grape-derived compound responsible for the peppery aroma of Shiraz wine varieties. It has subsequently been found in black and white pepper and several other spices. Because of its potent aroma, the molecular basis for rotundone formation is of particular relevance to grape and wine scientists and industry. We have identified and functionally characterized in planta a sesquiterpene synthase, VvGuaS, from developing grape berries, and have demonstrated that it produces the precursor of rotundone, α-guaiene, as its main product. The VvGuaS enzyme is a novel allele of the sesquiterpene synthase gene, VvTPS24, which has previously been reported to encode VvPNSeInt, an enzyme that produces a variety of selinene-type sesquiterpenes. This newly discovered VvTPS24 allele encodes an enzyme 99.5% identical to VvPNSeInt, with the differences comprising just 6 out of the 561 amino acid residues. Molecular modelling of the enzymes revealed that two of these residues, T414 and V530, are located in the active site of VvGuaS within 4 Å of the binding-site of the substrate, farnesyl pyrophosphate. Mutation of these two residues of VvGuaS into the corresponding polymorphisms in VvPNSeInt results in a complete functional conversion of one enzyme into the other, while mutation of each residue individually produces an intermediate change in the product profile. We have therefore demonstrated that VvGuaS, an enzyme responsible for production of the rotundone precursor, α-guaiene, is encoded by a novel allele of the previously characterized grapevine gene VvTPS24 and that two specific polymorphisms are responsible for functional differences between VvTPS24 alleles.

Background and Aims The chemical composition of grape berries during development exhibits large variation within a single bunch. To monitor the change in the concentration of tartaric acid and malic acid between individual berries, a high-throughput method using UHPLC-MS/MS was developed to quantify these acids in berry extracts. Methods and Results The results from analysis of single-vine datasets indicated that there was a large variation in the concentration of tartaric acid and malic acid between individual berries and also between bunches of berries across a vine. From these data, an optimum sampling size of 30 berries per vine was determined, which has an estimated standard error under 10% of the expected average berry acid concentration. Conclusions A high-throughput UHPLC-MS/MS method using the stable isotope dilution analysis has been developed to quantify tartaric acid and malic acid in individual berry extracts and extracts prepared from samples of multiple berries. Significance of the Study This method enabled the study of variation in acid concentration and content between individual berries. This makes it possible to quantify the variation in the acids at several levels (berries, bunches and plants) and to recommend ideal sampling sizes for data collection in vineyards.

Summary Experiments conducted under controlled conditions in vineyards and growth chambers demonstrated day- and night-specific responses of grape berry organic acid levels through altered TCA cycle and amino acid metabolism., Berries of the cultivated grapevine Vitis vinifera are notably responsive to temperature, which can influence fruit quality and hence the future compatibility of varieties with their current growing regions. Organic acids represent a key component of fruit organoleptic quality and their content is significantly influenced by temperature. The objectives of this study were to (i) manipulate thermal regimes to realistically capture warming-driven reduction of malate content in Shiraz berries, and (ii) investigate the mechanisms behind temperature-sensitive malate loss and the potential downstream effects on berry metabolism. In the field we compared untreated controls at ambient temperature with longer and milder warming (2–4 °C differential for three weeks; Experiment 1) or shorter and more severe warming (4–6 °C differential for 11 days; Experiment 2). We complemented field trials with control (25/15 °C) and elevated (35/20 °C) day/night temperature controlled-environment trials using potted vines (Experiment 3). Elevating maximum temperatures (4–10 °C above controls) during pre-véraison stages led to higher malate content, particularly with warmer nights. Heating at véraison and ripening stages reduced malate content, consistent with effects typically seen in warm vintages. However, when minimum temperatures were also raised by 4–6 °C, malate content was not reduced, suggesting that the regulation of malate metabolism differs during the day and night. Increased NAD-dependent malic enzyme activity and decreased phosphoenolpyruvate carboxylase and pyruvate kinase activities, as well as the accumulation of various amino acids and γ-aminobutyric acid, suggest enhanced anaplerotic capacity of the TCA cycle and a need for coping with decreased cytosolic pH in heated fruit.

Retailing is continually evolving with different strategies used over time. In this era of customer relationships building, this study investigated an innovation gap; about Australian consumers' willingness to pay (WTP) a premium for the expert service of wine retailers. The study objectives were to evaluate factors that influence WTPs of wine retailers and to measure WTPs. A 2099 usable survey was obtained Australia-wide. The contingent valuation method was used to elicit the willingness of consumers. The data were analysed using the ordered probit model. On average, the premium respondents indicated WTP was $0.60 for the expert service of wine retailers. This study found that consumers are willing to pay for the expert service of wine retailers, and that consumers rely on the use of risk reduction strategy not only because of their perception of risk but they are also more desirous of wine knowledge and are willing to acquire it, even at a cost. This makes a strong case for the development and provision...

The essential oil, citral, has potential for non-conventional control of postharvest diseases of citrus caused by Penicillium digitatum, Penicillium italicum and Geotrichum citri-aurantii. Citral in volatile phase has been shown to inhibit the three pathogens in vitro. The effect of citral applied as a fumigant on the incidence of disease on navel oranges (Citrus sinensis) was therefore studied. Fumigation of oranges with citral (20, 60 or 150 mL L−1 in absorbent pads) in a closed system, following application of conidia (20 μL of 106 conidia mL−1) to puncture wounds, delayed the onset of sour rot at room temperature by 7–10 days and at 5 °C, by 13–30 days, but had limited effect on blue and green mould. Blue and green mould developed faster on oranges wounded by puncture than by abrasion and volatile citral delayed the development of blue mould in abraded, but not punctured, oranges stored at 5 °C. Phytotoxicity symptoms were observed on the upper surface of some fruit close to or in direct contact with citral-soaked pads at concentrations of 60 and 150 mL L−1. Citral residue was not detected in the rind of fumigated oranges. Volatile citral applied at 60 mL L−1 appeared to have potential for the control of sour rot, although phytotoxicity was associated with high concentrations of volatile citral.

Background and Aims Green aroma compounds are considered undesirable when present at a high concentration in red wines. This study aimed to understand the effect of two irrigation levels and a higher than standard nitrogen fertilisation on the concentration of both 3-isobutyl-2-methoxypyrazine (IBMP) and six C6 compounds during fruit development. Methods and Results Fruit samples were collected biweekly during the 2009 and 2010 seasons in a commercial Vitis vinifera L. Merlot vineyard in California, USA, where two irrigation levels (70 and 100% of crop evapotranspiration) and a higher than standard nitrogen fertilisation dose were implemented. The higher irrigation level and additional nitrogen promoted canopy growth and decreased fruit exposure, resulting in increased concentration of IBMP during fruit maturation. The concentration of the six measured C6 compounds, however, was not affected. Deficit irrigation increased fruit colour, quercetin glycosides and phenol-free glucose glycosides (i.e. aroma precursors), and decreased vine yield. The two irrigation levels did not differ on the sensory vegetal perception of the wines, but the additional application of nitrogen fertiliser at fruitset enhanced it. Significance of the Study These findings confirm previous work showing that vineyard management practices influence fruit and wine concentration of IBMP, and demonstrate for the first time that the same practices have no significant impact on the concentration of six C6 compounds in grapes or on the concentration of hexanol in wines. Grapegrowers aiming to minimise IBMP concentration in fruit at harvest would probably benefit from a reduced application of water and nitrogen to the vineyard.

The cultivated grapevine V. vinifera is a rich source of stilbene compounds such as resveratrol, which are widely believed to provide dietary protection against the development of cardiovascular disease and some forms of cancer. Elicitation is a well-known strategy to increase commercial production of natural products in plant cell suspension culture systems. Callus tissues obtained from berry slices of V. vinifera cv. Shahani grown on an optimized medium were used to develop cell suspension cultures used to study the effects of elicitation on stilbene synthesis. The effect of two light regimes (135.1 μmol. s−1 m−2 radiation, and dark), the concentration of phenylalanine (Phe; 0, 0.1, 0.5 and 1 mM) and of methyl jasmonate elicitor (MeJA; 0 and 25 μM), alone or in combination, were tested. The results showed that cultures grown in darkness resulted in significantly higher levels of the accumulation of total stilbenes (resveratrol + piceid) compared with the high light condition. The combined treatments of dark +1 mM Phe and dark +25 μM MeJA induced the synthesis of high levels of total phenolics, total flavonoids and total stilbenes. Finally, the combined elicitation of dark +1 mM Phe + 25 μM MeJA gave the highest synergistic coefficient (1.24) and proved to be the most effective treatment for the production of total phenolics, total flavonoids, and total stilbenes with mean contents of 384.80 mg GA/g DW, 527.62 mg catechin/g DW and 188.34 μg/g DW, respectively. The results of our study suggest that the combinations of dark together with MeJA and/or Phe can be used as an efficient method for the future scale-up of V. vinifera cell cultures for the production of high value stilbene compounds in a bioreactor system.

Background and Aims: A field trial during the 2009 and 2010 seasons evaluated the impact of winter rainfall on the main compounds responsible for green aromas in grapes and wines, 3-isobutyl-2-methoxypyrazine (IBMP) and C6 compounds. These compounds are considered undesirable in grapes and wines above the threshold concentration. Methods and Results: One treatment subjected vines to average rainfall, while the other excluded winter rainfall by covering the ground with a plastic tarpaulin during the entire dormant season (November to mid-March). Irrigation for both treatments was maintained at a weekly rate of 70% of crop evapotranspiration until commercial harvest. Canopy growth, berry size and vine yield were significantly reduced by rainfall exclusion, and a significant increase in the fruit to pruning mass ratio was recorded from one season to another. Synthesis of IBMP was significantly greater in vines under normal rainfall, whereas C6 compounds were significantly different between treatments only at the end of the second season. Fruit and wine composition, mainly colour and mouthfeel compounds, were positively affected by the absence of rainfall in both years. Wine descriptive analysis showed that the lack of rainfall produced wines perceived as less green and of more intense fruit attributes in the first season. As a consequence of the reduction in vine growth, however, the same treatment produced wines less intense in fruit aromas and of inferior tannin quality in the following season. Conclusions: These results show that the soil moisture level prior to budbreak affects both canopy growth and vine yield, even when irrigation is applied following budbreak. If the rainfall level is below normal, the positive effect on fruit and wine composition achieved through smaller berry size may be offset by a significant reduction in canopy growth, resulting in severely unbalanced vines, i.e. inadequate fruit to pruning mass ratio. Significance of the Study: Growers aiming to minimise the level of IBMP at harvest would benefit from applying moderate deficit irrigation and nitrogen fertilisation rates and also might achieve an earlier harvest date for those vineyards where the absence of undesirable vegetal characters is considered a key harvest metric.

A field study was conducted from 2007 to 2010 to examine regional and seasonal variability of the main compounds responsible for green aromas in grapes and wines, 3-isobutyl-2-methoxypyrazine and C6 compounds. Sixty-nine commercial Vitis vinifera L. Merlot vineyards located in three distinctly different winegrape growing regions within the Central Valley of California were sampled at commercial harvest, fruit samples were analyzed for green aroma compounds and standard chemometrics, and several weather parameters such as growing degree days and rainfall were recorded at the vineyard level. Seasonal variation was found to be more important than regional variation, and similar trends among regions were found within each season. Temperature during the spring, a period of active growth, was found to be a significant driver of fruit green aroma compounds at harvest, likely due to its interactions with vine vigor and fruit shading.

The intent of this article is thus two-fold. First to provide background on what a Mission Command Training Program (MCTP) run exercise is; how it works and what can be expected of Judge Advocates participating in the exercise. Second, this article seeks to share substantive insights gained from observing hundreds of Judge Advocates executing operational law in a multitude of scenarios and all levels of command.This article contains three sections. The first section provides a brief history of the Combined Training Center program, with particular focus on MCTP. The second section discusses Army doctrine and its relevance to the JAG Corps. These sections provide important context for the final section of the article, which discusses the major Judge Advocate related observations made over the last several years. Where possible, this article seeks to articulate broad themes that are applicable to legal sections at all echelons.

BACKGROUND: The accumulation of L-ascorbate (Asc) in fruits is influenced by environmental factors including light quantity. Fruit exposure to ambient light is often reduced by the surrounding leaf canopy, and can be altered by cultivation practices. The influence of reduced sunlight exposure on the accumulation of Asc and its catabolites was investigated in field-grown berries of the cultivated grapevine Vitis vinifera L. cv. Shiraz. RESULTS: Growth under sunlight-eliminated conditions resulted in reduced berry fresh weight, chlorosis and a reduced total L-ascorbate pool size. The concentration of the Asc catabolite L-tartaric acid (TA) was reduced in berries grown without light. Conversely, concentrations of oxalic acid (OA), an alternative catabolite of Asc, and malic acid (MA), were unaffected by shading the berries during development. Brief and significant reductions in transcription of the Asc metabolic genes were observed in shade-grown berries after 4 weeks of dark acclimatisation whilst a key TA biosynthetic gene was not regulated by light. CONCLUSIONS: The results demonstrate that light-regulation of Asc and TA occurs only at brief stages of development and that OA and MA accumulation is light independent. Additionally, the comparable ratios of TA product to Asc precursor under both light regimes suggest that the diversion of Asc to TA is driven by factors that are not responsive to light. These findings suggest that an altered light regime is not the key to manipulating TA or MA levels in the harvested berry. Copyright © 2011 Society of Chemical Industry

In previous work, we reported characterization of a phospho-β-glucosidase gene bglD in a β-glucoside metabolizing operon in the oenologically important lactic acid bacterium Oenococcus oeni . Here we report a second phospho-β-glucosidase gene celD which has been cloned and expressed in Escherichia coli . This gene is found in a putative operon 6043 bp long encoding six genes designated celA to celF . Comparative sequence analyses of lactic acid bacteria suggest that the open reading frames of celA , B and F from the sequenced O. oeni PSU-1 encode phosphoenolpyruvate dependent phosphotransferase system (PEP-PTS) components IIB, IIA and IIC, respectively, which regulate the uptake and phosphorylation of β-glucosides across the cytoplasmic membrane. celE is speculated to have a regulatory function. celD was cloned and expressed in E. coli followed by purification of the gene product. The purified protein His-tagged CelD (485 residues, Mw = 55.8 kDa) has high homology to known phospho-β-glucosidases and has high activity towards the phosphorylated β-glucoside para-nitrophenol-β- d -glucopyranoside-6-phophate (pNPβG6P). CelD has an optimum pH between 4.0 and 5.0 and is most active at 40 °C. The gene celC was cloned, heterologously expressed and purified (481 residues, Mw = 55.7 kDa) but showed no significant activity towards pNPβG6P despite high sequence homology to celD and characterized phospho-β-glucosidases. Neither CelC nor CelD are active against non-phosphorylated β-glucosides.

Background and Aims: The majority of the acidity of a grapevine (Vitis vinifera L.) berry is a result of the accumulation of l-tartaric (TA) and l-malic acids (MA). TA is synthesised from l-ascorbic acid (Asc, vitamin C), the metabolism of which is poorly characterised in grapevines. In a distinct pathway, oxalic acid (OA) is also formed from Asc degradation. The aim of this study was to develop a single method whereby the distribution of Asc and its catabolites from fruit and vegetative sources could be determined. Methods and Results: Effective recoveries of total Asc, TA, OA and MA were achieved with this extraction method, while chromatographic separation was accomplished with reversed-phase high-performance liquid chromatography (RP-HPLC). These results demonstrate that Asc and its catabolites TA and OA rapidly accumulate in immature berries, and that the Asc to dehydroascorbate ratio increases with berry maturity. Conclusions: A method for the simultaneous analysis of Asc, TA, OA and MA in fruits is provided; moreover, we have demonstrated its use to study their distribution in fruits, rachis, leaves and roots. Significance of the Study: This method enables accurate monitoring of the accumulation of Asc, permitting further research towards understanding acid metabolism during berry ripening.

Background and Aims: Grapevines (Vitis vinifera L.) are considered to have non-climacteric fruit, but the trigger initiating ripening (veraison) is poorly understood. This study aimed to further investigate the role of abscisic acid (ABA) during berry ripening. Methods and Results: In field-grown grapes over three seasons, free ABA levels increased at veraison then subsequently declined to low levels. Bound ABA increased as the free ABA level decreased after 10–11 weeks post-flowering (wpf), but ABA must also be degraded and/or exported. The absence of a large pool of bound ABA before veraison makes it unlikely that the increase in free ABA is due to the mobilization of conjugated ABA. The expression pattern of genes crucial for ABA synthesis, zeaxanthin epoxidase and two 9-cis-epoxycartenoid dioxygenases (NCEDs) indicates that berries may have the potential to synthesize ABA in situ. However, the expression profile of these genes did not correlate well with ABA levels indicating that ABA accumulation is under more complex control. The application of (+)-ABA advanced ripening as measured by colour formation, berry size increase and to a lesser extent sugar accumulation and altered the expression of one of the NCED genes. Conclusions: The changes in berry ABA levels around the time of veraison, which influence the timing of ripening, are under complex developmental control. Significance of the Study: The improved understanding of the control of berry ripening is vital to attempts to successfully manipulate this process.

Volatile phenols are produced by Dekkera yeasts and are of organoleptic importance in alcoholic beverages. The key compound in this respect is 4-ethylphenol, responsible for the medicinal and phenolic aromas in spoiled wines. The microbial synthesis of volatile phenols is thought to occur in two steps, beginning with naturally occurring hydroxycinnamic acids (HCAs). The enzyme phenolic acid decarboxylase (PAD) converts HCAs to vinyl derivatives, which are the substrates of a second enzyme, postulated to be a vinylphenol reductase (VPR), whose activity results in the formation of ethylphenols. Here, both steps of the pathway are investigated, using cell extracts from a number of Dekkera and Brettanomyces species. Dekkera species catabolise ferulic, caffeic and p-coumaric acids and possess inducible enzymes with similar pH and temperature optima. Brettanomyces does not decarboxylate HCAs but does metabolise vinylphenols. Dekkera species form ethylphenols but the VPR enzyme appears to be highly unstable in cell extracts. A partial protein sequence for PAD was determined from Dekkera anomala and may indicate the presence of a novel enzyme in this genus.

Cold stabilisation is a widely used industrial process to prevent tartrate instability in bottled wines. In this article, current knowledge regarding performance and cost of cold stabilisation and alternative technologies for tartrate stabilisation is reviewed. Whilst there have been occasional cost comparisons between cold stabilisation and alternative technologies published in the literature, existing data is not satisfactory to permit an accurate economic evaluation of the different process options. Therefore, alternative technologies to cold stabilisation, including the Westfalia process, nanofiltration and electrodialysis were compared for both technical and economic performance. The engineering calculations and conceptual cost estimates were based on real world data from an Australian winery. Product loss was a key cost driver in differentiating tartrate stabilisation processes. Cold stabilisation was found to be the most economic treatment process irrespective of scale or winery size. Westfalia process and nanofiltration were the next most cost effective options.

The response of grape berries at a cellular level to environmental change was explored with particular emphasis on physiological changes such as weight, sugar content, and the biosynthesis of organic acids. Three levels of light were used: highly exposed, moderately exposed, and light-excluding boxes (1% ambient with no change in temperature effect). Berry weight was significantly lower in light-excluding boxes than in exposed bunch treatments. Organic acid content and berry development were followed throughout the growing season. Light exclusion resulted in a significant reduction of both tartaric acid and oxalic acid compared with highly exposed fruit, suggesting that in this experiment, light irradiance influenced accumulation of these metabolites. In contrast, malic acid was broken down postveraison at a dramatically slower rate in light exclusion treatments. The sink properties of grape berries appear to change according to the light received by the bunch. These data imply that cluster shading significantly reduced berry size and suggest the role of organic acids as osmotica.

To determine the chemical basis of almond flavour phenotypes, non-bitter, semi-bitter, and bitter kernels from 101 almond trees, all derived from a common maternal parent, were evaluated for flavou...

Background Sorbitol dehydrogenase (SDH, EC 1.1.1.14) is the key enzyme involved in sorbitol metabolism in higher plants. SDH genes in some Rosaceae species could be divided into two groups. L-idonate-5-dehydrogenase (LIDH, EC 1.1.1.264) is involved in tartaric acid (TA) synthesis in Vitis vinifera and is highly homologous to plant SDHs. Despite efforts to understand the biological functions of plant SDH, the evolutionary history of plant SDH genes and their phylogenetic relationship with the V. vinifera LIDH gene have not been characterized. Results A total of 92 SDH genes were identified from 42 angiosperm species. SDH genes have been highly duplicated within the Rosaceae family while monocot, Brassicaceae and most Asterid species exhibit singleton SDH genes. Core Eudicot SDHs have diverged into two phylogenetic lineages, now classified as SDH Class I and SDH Class II. V. vinifera LIDH was identified as a Class II SDH. Tandem duplication played a dominant role in the expansion of plant SDH family and Class II SDH genes were positioned in tandem with Class I SDH genes in several plant genomes. Protein modelling analyses of V. vinifera SDHs revealed 19 putative active site residues, three of which exhibited amino acid substitutions between Class I and Class II SDHs and were influenced by positive natural selection in the SDH Class II lineage. Gene expression analyses also demonstrated a clear transcriptional divergence between Class I and Class II SDH genes in V. vinifera and Citrus sinensis (orange). Conclusions Phylogenetic, natural selection and synteny analyses provided strong support for the emergence of SDH Class II by positive natural selection after tandem duplication in the common ancestor of core Eudicot plants. The substitutions of three putative active site residues might be responsible for the unique enzyme activity of V. vinifera LIDH, which belongs to SDH Class II and represents a novel function of SDH in V. vinifera that may be true also of other Class II SDHs. Gene expression analyses also supported the divergence of SDH Class II at the expression level. This study will facilitate future research into understanding the biological functions of plant SDHs. Electronic supplementary material The online version of this article (doi:10.1186/s12870-015-0478-5) contains supplementary material, which is available to authorized users.

The biosynthetic pathway of l -tartaric acid, the form most commonly encountered in nature, and its catabolic ties to vitamin C, remain a challenge to plant scientists. Vitamin C and l -tartaric acid are plant-derived metabolites with intrinsic human value. In contrast to most fruits during development, grapes accumulate l -tartaric acid, which remains within the berry throughout ripening. Berry taste and the organoleptic properties and aging potential of wines are intimately linked to levels of l -tartaric acid present in the fruit, and those added during vinification. Elucidation of the reactions relating l -tartaric acid to vitamin C catabolism in the Vitaceae showed that they proceed via the oxidation of l -idonic acid, the proposed rate-limiting step in the pathway. Here we report the use of transcript and metabolite profiling to identify candidate cDNAs from genes expressed at developmental times and in tissues appropriate for l -tartaric acid biosynthesis in grape berries. Enzymological analyses of one candidate confirmed its activity in the proposed rate-limiting step of the direct pathway from vitamin C to tartaric acid in higher plants. Surveying organic acid content in Vitis and related genera, we have identified a non-tartrate-forming species in which this gene is deleted. This species accumulates in excess of three times the levels of vitamin C than comparably ripe berries of tartrate-accumulating species, suggesting that modulation of tartaric acid biosynthesis may provide a rational basis for the production of grapes rich in vitamin C.

A multigenic trait (biosynthesis of the secondary metabolite, dhurrin cyanogenic glucoside) was engineered de novo in grapevine (Vitis vinifera L.). This follows a recent report of transfer of the same trait to Arabidopsis (Arabidopsis thaliana) using three genetic sequences from sorghum (Sorghum bicolor): two cytochrome P450-encoding cDNAs (CYP79A1 and CYP71E1) and a UDPG-glucosyltransferase-encoding cDNA (sbHMNGT). Here we describe the two-step process involving whole plant transformation followed by hairy root transformation, which was used to transfer the same three sorghum sequences to grapevine. Transgenic grapevine hairy root lines that accumulated transcript from none, one (sbHMNGT), two (CYP79A1 and CYP71E1) or all three transgenes were recovered and characterisation of these lines provided information about the requirements for dhurrin biosynthesis in grapevine. Only lines that accumulated transcripts from all three transgenes had significantly elevated cyanide potential (up to the equivalent of about 100 mg HCN kg(-1) fresh weight), and levels were highly variable. One dhurrin-positive line was tested and found to release cyanide upon maceration and can therefore be considered 'cyanogenic'. In in vitro dual co-culture of this cyanogenic hairy root line or an acyanogenic line with the specialist root-sucking, gall-forming, aphid-like insect, grapevine phylloxera (Daktulosphaira vitifoliae, Fitch), there was no evidence for protection of the cyanogenic plant tissue from infestation by the insect. Consistently high levels of dhurrin accumulation may be required for this to occur. The possibility that endogenous grapevine gene expression is modulated in response to engineered dhurrin biosynthesis was investigated using microarray analysis of 1225 grapevine ESTs, but differences in patterns of gene expression associated with dhurrin-positive and dhurrin-negative phenotypes were not identified.

Biomineralisation in the fleshy pericarp of berries of Vitis vinifera L. gives rise to crystals of two distinct forms, viz. raphides and druses, which are found in exocarp and endocarp cells respectively. Druses have generally been considered as crystalline aggregates of calcium oxalate. However, the organic moiety of raphide crystals has been commonly accepted as tartrate, although we have found no analytical data to support that assumption. We now present TEM and X-ray powder diffraction analysis data showing that raphide crystals of V. vinifera berries are composed of calcium oxalate monohydrate. This work also established ascorbic acid as the biosynthetic precursor of both oxalic and tartaric acids. When ascorbic acid labelled with 14C at position 1 was introduced into berries via the rachis, 21% and 52% of the added radiolabel was recovered as oxalic and tartaric acids respectively. Purified crystals from the radiolabelled grape berries contained approximately 20% of the original radioactivity, further confirming the role of ascorbic acid in oxalic acid biosynthesis. To our knowledge, this is the first evidence to be published on the formation of oxalic and tartaric acids from ascorbic acid via two distinct pathways operating within the same physiological entity (organ).

The conjugation by glycosyltransferases of sugars to primary and secondary metabolites is widespread among plants and almost certainly a prerequisite for the accumulation of secondary metabolites at high levels. In the case of the grapevine, Vitis vinifera, modulating the levels of specific secondary berry metabolites is a desirable outcome for the development of wines with particular style characteristics. This can be achieved only by a thorough understanding of the processes underlying glucoside formation and accumulation during berry development. Using protein extracts prepared from leaves and berries of Vitis vinifera cvs, we show here that glucosyltransferase activities can be detected against a wide range of substrates. Among the substrates glucosylated were several classes of phenylpropanoids, including flavonols, anthocyanidins, flavanones, flavones, isoflavones, and a stilbene. Additionally, simple phenols and monoterpenes were glucosylated. Total soluble leaf proteins subjected to ion‐exchange chromatography separated into fractions with differing glucosyltransferase activities. This provided strong evidence for the existence both of multiple distinct enzyme activities, and multiple isozymes catalysing identical reactions. Polyclonal antiserum raised to a V. vinifera UDP‐glucose:anthocyanidin glucosyltransferase was used to demonstrate the existence of multiple glucosyltransferases in berries and leaves of the grapevine cvs Muscat of Alexandria and Shiraz, thereby confirming data obtained previously through biochemical analyses of recombinant glucosyltransferase.

We report here the cloning and optimized expression at 16 degrees C and the characterization of a Vitis vinifera UDP-glucose:flavonoid 3-O-glucosyltransferase, an enzyme responsible for a late step in grapevine anthocyanin biosynthesis. The properties of this and other UDP-glucose:flavonoid 3-O-glucosyltransferases, homologues of the product encoded by the maize Bronze-1 locus, are a matter of conjecture. The availability of a purified recombinant enzyme allowed for the unambiguous determination of the characteristics of a flavonoid 3-O-glucosyltransferase. Kinetic analyses showed that kcat for glucosylation of cyanidin, an anthocyanidin substrate, is 48 times higher than for glucosylation of the flavonol quercetin, whereas Km values are similar for both substrates. Activity toward other classes of substrates is absent. Cu2+ ions strongly inhibit the action of this and other glucosyltransferases; however, we suggest that this phenomenon in large part is due to Cu2+-mediated substrate degradation rather than inhibition of the enzyme. Additional lines of complementary biochemical data also indicated that in the case of V. vinifera, the principal, if not only, role of UDP-glucose:flavonoid 3-O-glucosyltransferases is to glucosylate anthocyanidins in red fruit during ripening. Other glucosyltransferases with a much higher relative activity toward quercetin are suggested to glucosylate flavonols in a distinct spatial and temporal pattern. It should be considered whether gene products homologous to Bronze-1 in some cases more accurately should be referred to as UDP-glucose:anthocyanidin 3-O-glucosyltransferases.

This paper describes the isolation of the cDNA encoding a protein previously shown to be indicative of the disease-resistance phenotype mediated by the Yd2 gene in barley (Hordeum vulgare L.). Amino acid sequences of four peptides obtained after isolation of the protein on two-dimensional polyacrylamide gels were completely homologous to sequences occurring within subunit E of barley vacuolar proton-translocating ATPase. Nucleotide sequence data of cloned cDNAs from both Yd2 and non-Yd2 barley varieties showed an amino acid change arising from a single-base-pair polymorphism. This was predicted to result in the shift in isoelectric point used previously to differentiate the protein in Yd2 and non-Yd2 barleys. Earlier work had indicated very close linkage between the gene from which this cDNA is derived, which we have named Ylp, and Yd2, the barley yellow dwarf virus resistance gene. We report here the development of PCR-based assays which discriminate between the two alleles of Ylp and thereby act as valuable predictors of Yd2 for barley breeders and others looking to study this important gene in cereal crops. The validity of each assay was tested with an extensive survey of over 100 barley varieties currently under cultivation in Australia or of importance to Australian barley breeding programmes. Complete agreement was observed between the allele of Ylp detected by the assay and the known Yd2 status of the barleys. A dominant PCR marker for the Yd2-associated allele of Ylp was subsequently developed using an allele-specific primer pair. This fast and economical assay will have broad application in the marker-assisted selection of Yd2-containing lines.

Barley yellow dwarf luteovirus (BYDV) causes serious yield losses in all cereals worldwide. The Yd2 gene from a number of Ethiopian barleys (Hordeum vulgare L.) has been the most effective means of providing resistance against BYDV in cultivated barley. Isolation of the Yd2 gene will enable characterisation of the molecular basis of the Yd2-BYDV interaction. This paper describes the first stage in a project to isolate the gene: the construction of a detailed linkage map of the Yd2 region. The map encompasses 27.6 centiMorgans (cM) of chromosome 3 and contains 19 RFLPs, 2 morphological marker loci, the centromere and Yd2. In the mapping population of 106 F2 individuals, Yd2 perfectly cosegregated with the RFLP loci Xwg889 and XYlp, which were located on the long arm, 0.5 cM from the centromere. The two morphological marker loci, uzu dwarfand white stripe j, both mapped distal to Yd2. The protein product of the gene at the XYlp locus will provide a convenient assay for the selection of Yd2 during the breeding of BYDV-resistant barley varieties.

International audience; Grapes (Vitis spp.) are economically significant fruit species. Many scientific advances have been achieved in understanding physiological, biochemical, and molecular aspects of grape berry maturation. Some of these advances have led to the improvement of wine quality through better grape growing practices; but this avenue of research is still wide open due to the complexity of the biochemical mechanisms involved in the development and ripening of grapes and their response to environment. The Biochemistry of the Grape Berry is a pioneer offering for readers - giving a focused and integrated coverage of the key biochemical and molecular aspects of grape berry development and ripening. Readers will benefit from a comprehensive and updated coverage on key steps, mechanisms and regulation in grapevine biochemistry and molecular biology, provided by an international team of leading scientists. It provides useful references on this research area and original data from laboratories worldwide. The comprehensive range of topics covered in this e-book is valuable to a multidisciplinary readership including plant physiologists, enologists, microbiologists, wine makers, biochemists and students. Thus The Biochemistry of the Grape Berry represents a step forward in the comprehension of grape berry biochemistry, wine quality and health benefits.

Background Despite a high genetic similarity to peach, almonds (Prunus dulcis) have a fleshless fruit and edible kernel, produced as a crop for human consumption. While the release of peach genome v1.0 provides an excellent opportunity for almond genetic and genomic studies, well-assessed segregating populations and the respective saturated genetic linkage maps lay the foundation for such studies to be completed in almond. Results Using an almond intraspecific cross between 'Nonpareil' and 'Lauranne' (N × L), we constructed a moderately saturated map with SSRs, SNPs, ISSRs and RAPDs. The N × L map covered 591.4 cM of the genome with 157 loci. The average marker distance of the map was 4.0 cM. The map displayed high synteny and colinearity with the Prunus T × E reference map in all eight linkage groups (G1-G8). The positions of 14 mapped gene-anchored SNPs corresponded approximately with the positions of homologous sequences in the peach genome v1.0. Analysis of Mendelian segregation ratios showed that 17.9% of markers had significantly skewed genotype ratios at the level of P < 0.05. Due to the large number of skewed markers in the linkage group 7, the potential existence of deleterious gene(s) was assessed in the group. Integrated maps produced by two different mapping methods using JoinMap® 3 were compared, and their high degree of similarity was evident despite the positional inconsistency of a few markers. Conclusions We presented a moderately saturated Australian almond map, which is highly syntenic and collinear with the Prunus reference map and peach genome V1.0. Therefore, the well-assessed almond population reported here can be used to investigate the traits of interest under Australian growing conditions, and provides more information on the almond genome for the international community.

Organic acids are present in all plants, supporting numerous and varied facets of cellular metabolism. The type of organic acid found, and the levels to which they accumulate are extremely variable between species, developmental stages and tissue types. Acidity plays important roles in the organoleptic properties of plant tissues, where examples of both enhanced and reduced palatability can be ascribed to the presence of specific organic acids. In fruits, sourness is generally attributed to proton release from acids such as citric, malic, oxalic, quinic, succinic and tartaric, while the anion forms each contribute a distinct taste. Acidity imposes a strong influence on crop quality, and is an important factor in deciding the harvest date, particularly for fruits where acidity is important for further processing, as in wine grapes. In the grape, as for many other fruits, malate is one of the most prevalent acids, and is an important participant in numerous cellular functions. The accumulation of malate is thought to be due in large part to de novo synthesis in fruits such as the grape, through metabolism of assimilates translocated from leaf tissues, as well as photosynthetic activity within the fruit itself. During ripening, the processes through which malate is catabolised are of interest for advancing metabolic understanding, as well as for potential crop enhancement through agricultural or molecular practices. A body of literature describes research that has begun to unravel the regulatory mechanisms of enzymes involved in malate metabolism during fruit development, through exploration of protein and gene transcript levels. Datasets derived from a series of recent microarray experiments comparing transcript levels at several stages of grape berry development have been revisited, and are presented here with a focus on transcripts associated with malate metabolism. Developmental transcript patterns for enzymes potentially involved in grape malate metabolism have shown that some flux may occur through pathways that are less commonly regarded in ripening fruit, such as aerobic ethanol production. The data also suggest pyruvate as an important intermediate during malate catabolism in fruit. This review will combine an analysis of microarray data with information available on protein and enzyme activity patterns in grapes and other fruits, to explore pathways through which malate is conditionally metabolised, and how these may be controlled in response to developmental and climatic changes. Currently, an insufficient understanding of the complex pathways through which malate is degraded, and how these are regulated, prevents targeted genetic manipulation aimed at modifying fruit malate metabolism in response to environmental conditions.

Simple phenolic components of wine, hydroxycinnamic acids (HCAs) are known to have antimicrobial properties. This study sought to determine the potential of ferulic acid as an antifungal agent for the control of Dekkera. Growth was inhibited by all HCAs examined in this study, with ferulic acid being the most potent at all concentrations. In the presence of ethanol, the inhibitory effects of ferulic acid were amplified. Scanning electron microscopy images reveal cellular damage upon exposure to ferulic acid. Thus, manipulation of ferulic acid concentrations could be of industrial significance for control of Dekkera and may be the basis for differences in susceptibility of wines to Dekkera spoilage.

Organic acids are present in all plants, supporting numerous and varied facets of cellular metabolism. The type of organic acid found, and the levels to which they accumulate are extremely variable between species, developmental stages and tissue types. Acidity plays important roles in the organoleptic properties of plant tissues, where examples of both enhanced and reduced palatability can be ascribed to the presence of specific organic acids. In fruits, sourness is generally attributed to proton release from acids such as citric, malic, oxalic, quinic, succinic and tartaric, while the anion forms each contribute a distinct taste. Acidity imposes a strong influence on crop quality, and is an important factor in deciding the harvest date, particularly for fruits where acidity is important for further processing, as in wine grapes. In the grape, as for many other fruits, malate is one of the most prevalent acids, and is an important participant in numerous cellular functions. The accumulation of malate is thought to be due in large part to de novo synthesis in fruits such as the grape, through metabolism of assimilates translocated from leaf tissues, as well as photosynthetic activity within the fruit itself. During ripening, the processes through which malate is catabolised are of interest for advancing metabolic understanding, as well as for potential crop enhancement through agricultural or molecular practices. A body of literature describes research that has begun to unravel the regulatory mechanisms of enzymes involved in malate metabolism during fruit development, through exploration of protein and gene transcript levels. Datasets derived from a series of recent microarray experiments comparing transcript levels at several stages of grape berry development have been revisited, and are presented here with a focus on transcripts associated with malate metabolism. Developmental transcript patterns for enzymes potentially involved in grape malate metabolism have shown that some flux may occur through pathways that are less commonly regarded in ripening fruit, such as aerobic ethanol production. The data also suggest pyruvate as an important intermediate during malate catabolism in fruit. This review will combine an analysis of microarray data with information available on protein and enzyme activity patterns in grapes and other fruits, to explore pathways through which malate is conditionally metabolised, and how these may be controlled in response to developmental and climatic changes. Currently, an insufficient understanding of the complex pathways through which malate is degraded, and how these are regulated, prevents targeted genetic manipulation aimed at modifying fruit malate metabolism in response to environmental conditions.