Effect of bearing position on phenolics profiles in the skins of four cultivars of grapevine (Vitis vinifera L.)

Summary

The fan-shaped trellis training system, resulting in grapevines (Vitis vinifera L.) with more than two trunks, has been widely used in northern China. The fruiting zone of grapevines trained to the fan-shaped trellis system is distributed from the top to the bottom of the canopy. The phenolics profiles of the skins of ‘Cabernet Sauvignon’, ‘Merlot’, ‘Chardonnay’, and ‘Italian Riesling’ grape berries were analysed to measure the effect of differences in bearing position on the phenolic compound and anthocyanin compositions of grape berries.The results showed that the upper bearing position significantly increased the concentrations of most phenolic compounds in grape berry skins. Among the non-anthocyanin and anthocyanin phenolic compounds identified in this study, the upper bearing position promoted the accumulation of delphinidin-, cyanidin-, and petunidin-glucosides in the skin of the two red grape cultivars. However, lowering the bearing position was associated with greater methylation of anthocyanins, and the flow of photosynthate towards the biosynthesis of kaempferol. These results were correlated with micrometeorological alterations in the canopy at the different bearing positions. The findings of this study suggest that higher bearing positions can increase the accumulation of phenolic compounds in grape berry skins in four different grapevine cultivars.     

‘Chambourcin’ grapevine (Vitis vinifera Vitis L.) berries display sustained post-veraison accumulation of oxalic acid

SUMMARY

A substantial accumulation of organic acids (OAs) occurs during pre-veraison grape berry development, which results in low pH conditions and contributes to the organoleptic properties of the fruit. The main OAs in most grape berries are tartaric acid (TA) and malic acid (MA). MA is accumulated via a primary metabolic shunt, whereas TA is accumulated via ascorbic acid (AA; vitamin C) metabolism. Oxalic acid (OX) is also derived from AA in competition with TA, and results from a cleavage between the second and third carbon atoms. Oxalic acid is subsequently biomineralised as calcium oxalate crystals in idioblast cells. We have examined the biosynthesis of TA, MA, and OX during grape berry development in four grapevine cultivars. We show that in the Vitis vinifera L. Vitis L. complex inter-specific hybrid, ‘Chambourcin’, there is a high capacity to accumulate OX during post-veraison fruit development. OX content increased from approx. 1 mg g^–1 to 3 mg g^–1 berry fresh weight between 14 and 16 weeks post-anthesis, resulting in OX levels that were similar to the MA levels in mature fruit. Whether OX accumulation occurs due to increased biomineralisation or biosynthesis, our results show that ‘Chambourcin’ grape berries represent the only documented case of post-veraison accumulation of OX.     

Decreased anthocyanin biosynthesis in grape berries grown under elevated night temperature condition

In grape cultivation, high night temperature generally reduces anthocyanin accumulation in berry skin. To clarify the regulatory mechanism of anthocyanin biosynthesis under the conditions of high night temperatures, we examined flavonoid accumulation, the activities of related enzymes and gene expression in the anthocyanin biosynthetic pathway in grape berries grown under cool and warm night conditions. Anthocyanin accumulation in the skin of berries grown at high night temperatures (30 °C continuous) was reduced as compared to that of berries grown at low night temperatures (30 °C in daytime/15 °C in night time). On the other hand, flavonol levels in the skin of berries were not significantly different between low and high night temperature conditions. High night temperatures also inhibited the gene expression of chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX) and UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) at veraison and an increase in UFGT activity after veraison. These results suggest that the inhibition of anthocyanin biosynthesis in grape berries grown under high night temperature condition could be caused by lower expression levels of anthocyanin biosynthetic genes at an early stage of ripening and lower activities of anthocyanin biosynthetic enzymes, particularly UFGT.     

Changes in sugar content and relative enzyme activity in grape berry in response to root restriction

Root restriction often depresses photosynthetic capacity and reduces shoot growth, but the photosynthate accumulation in fruit under restriction is higher than in control fruit. However, changes in metabolism responsible for these differences are unclear. To identify the metabolic mechanism by which root restriction affects sugar accumulation in fruit of ‘Kyoho’ grape (Vitis vinifera × V. labruscana), sugar metabolism and related enzyme activities in grape berries produced with and without root restriction were compared. Total sugar content of fruit produced under root restriction was higher than that of control fruit. Acid invertase (AI, EC 3.2.1.26) activity, which increases with berry development, was significantly higher in root-restricted berries than in control berries. Neutral invertase (NI, EC 3.2.1.26) activity showed a similar trend to AI, but the amount of NI activity was lower than AI in both treatments. Sucrose phosphate synthase (SPS, EC 2.4.1.14) and sucrose synthase (SS, EC 2.4.1.13) activity changed slightly with berry development, and there was no significant difference in SS and SPS activity between root restriction and control treatments. Therefore, AI appears to be the key enzyme induced by root restriction that explains the higher sugar content found in grape berry produced under root restriction.     

Scoring increases carbohydrate availability and berry size in seedless grape ‘Emperatriz’

In grapes, seedlessness is an important quality attribute for fresh consumption. There are seedless cultivars but their berries are often very small. A cane-scoring technique proved effective in increasing average berry size of ‘Emperatriz’ seedless grape by 16% in a 4-year experiment, and increased bunch weight by 8.2–28.6%, compared with unscored bunches, depending on the year, but had no effect in ‘Aledo’ seeded grape. This effect was due to: (1) a significantly higher daily berry growth rate in scored vines at 30–50 d after scoring; (2) an advance in time of accumulation of reducing sugars, particularly glucose; (3) a reduction of berry water potential of seedless ‘Emperatriz’ of similar values to those of seeded ‘Aledo’. Cane scoring showed no negative effect on the number of harvested bunches per vine the year following the scoring year, both in ‘Emperatriz’ and ‘Aledo’ cultivars.     

葡萄离体叶片和果实白藜芦醇及其糖苷合成对UV-C辐射诱导的响应

以‘北丰’和‘北全’葡萄离体叶片和果实为试材,研究了葡萄不同器官内白藜芦醇（Res）及其糖苷合成对紫外线C（UV-C）辐射诱导的响应,结果表明：不同器官反式白藜芦醇（trans-Res）合成积累对UV-C辐射诱导反应存在差异。叶片适宜的UV-C辐射剂量为1.8 kJ · m-2,而果皮为1.8 ~ 5.4 kJ · m-2,果实Res合成积累对UV-C辐射诱导的敏感性低于叶片。3.6 kJ · m-2 UV-C辐射果粒对种子中trans-Res含量没有显著影响,直接辐射完整种子或剖开种子切面也不能显著提高trans-Res含量。UV-C辐射处理的叶片和果皮中trans-Res含量随辐射后常温避光孵育时间的延迟表现出先升后降的趋势,而反式白藜芦醇苷（trans-PD）和顺式白藜芦醇苷（cis-PD）含量在12 ~ 48 h内迅速提高,之后维持在相对稳定状态。种子中trans-Res含量在整个孵育过程中与对照之间均不存在显著差异。     

Improving yield,quality, and shelf life of Thompson seedless grapevine by preharvest foliar applications

Ten-year-old Thompson seedless grape vines were sprayed during 2009 and 2010 growing seasons with putrescine (Put), gibberellic acid (GA₃), ascorbic acid (AA), ethephon (Eth), salicylic acid (SA), cytofex (CPPU) and calcium chloride (CaCl₂) at two stages of berry development; pea stage (4–5 mm fruitlet diameter, ∼30–35 days after fruit set) and veraison stage (when approximately 20% of the berries on 50% of the clusters had softened) in order to investigate their influence on yield and postharvest fruit quality characters at commercial harvest day as well as the berry keeping quality. Cluster and berry quality characters as well as vine yield were improved by all sprayed chemicals, especially Put, GA₃, SA, CPPU and CaCl₂. GA₃ increased cluster and berry width, and resulted in better clusters shape. A positive increase in berry firmness was obtained by Put, GA₃, CPPU, SA and CaCl₂ sprays. Berry adherence strength increased and the percentage of unmarketable berries decreased by all sprayed compounds except Eth. Shelf life (keeping quality) was increased by spraying Put, GA₃, SA, CPPU and CaCl₂, as they increased berries firmness and decreased the percentage of unmarketable berries after keeping at ambient temperature for seven days after harvest.     

The occurrence of phosphoenolpyruvate carboxykinase (PEPCK) in the pericarp of different grapevine genotypes and in grape leaves and developing seeds

The occurrence of phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate orthophosphate dikinase (PPDK) was determined in the ripe pericarps of several grape genotypes. Moreover, the abundance pattern of PEPCK during the development of grape berries was studied in a range of cultivars. In addition, the presence of PEPCK in grape leaves and the location/abundance of PEPCK in developing grape seeds were investigated. PEPCK was present in the pericarp of all the cultivars of Vitis vinifera studied and in that of the hybrid 420A (Vitis berlandieri × Vitis riparia). By contrast, PPDK was either not present or present at very low abundance. The results strongly indicated that the PEPCK and not the PPDK pathway is the predominant one utilised in gluconeogenesis in the berry pericarp of grape genotypes. Further, the results showed that the abundance of PEPCK increased greatly at the start of ripening in all the cultivars, showing a similar pattern in all of them. PEPCK was not present (or at very low abundance) in grape leaves throughout their development. In developing grape seeds, the results indicated a similar abundance of PEPCK in both the seed coat and the tissues enclosed by it.     

Fruit growth,cuticle deposition,water uptake,and fruit cracking in jostaberry,gooseberry, and black currant

Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10⁻⁸, 5.2 ± 0.1 × 10⁻⁸, and 3.3 ± 0.3 × 10⁻⁸ m s⁻¹. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry.     

葡萄果实β–葡萄糖苷酶基因克隆、原核表达及活性检测

 以‘玫瑰香’葡萄着色期的果肉为试材,通过反转录技术克隆了ABA合成相关酶β–葡萄糖苷酶基因VvBG1的1 518 bp编码区核苷酸序列,其编码1个含有505氨基酸的多肽。生物信息学分析表明,VvBG1含有1个跨膜区和糖基水解酶1超家族保守域。通过BamHⅠ和XhoⅠ限制性内切酶将除去信号的编码区克隆到原核表达载体pET28a（+）中,并转化大肠杆菌表达菌株BL21（DE3）,成功诱导并纯化了VvBG1融合蛋白。经过透析复性和超滤浓缩得到了0.8 mg · mL^-1可溶的融合蛋白。通过纯化蛋白葡萄果肉均浆液孵育试验和GC–MS ABA含量分析证实了葡萄果实中β–葡萄糖苷酶VvBG1具有较高的生理活性。     

Vegetative Growth,Productivity, Berry Quality Attributes and Leaf Macronutrients Content of Currants as Affected by Species and Cultivars

Bush vigor, berry physical traits and chemical composition, seasonal changes of leaf macronutrients content and leaf mineral status at mid-summer (120 DAFB, Days After Full Bloom) were evaluated in black, red and white currants and their cultivars which are grown on heavy soil, and with reduced cultural practices, except pruning, fertilization with cattle manure and weed control with herbicide, under western Serbian conditions. Results indicated that black currant had lower bush size, yield, bunch weight and number of berries per bunch, but had significantly higher berry weight as compared to red and white currants. Red and white currants had similar bush size, yield and bunch weight. Berries of black currant contained much higher levels of soluble solids content, acidity, vitamin C, total phenolics and flavonoids content than both red and white currants, whereas ripening index was similar. Leaf of black currants had lower macronutrients content, except leaf Mg, as compared with others. Very high excesses of all leaf macronutrients content, except in some cases for leaf N and Mg, were observed in currants in mid summer, i.?e. at 120 DAFB. Black currant showed the best balanced nutritional values, whereas red currant showed a wider imbalance in nutritional values. Beside currant species, strong effect of cultivar per se was found on the most of evaluated features. Generally, black currant cv. ‘Eva’, red currant cv. ‘Slovakia’, somewhat ‘Detvan’, and white currant cv. ‘Primus’ had higher bush size, better berry physico-chemical attributes and higher leaf macronutrients content than others. Finally, ‘Eva’, ‘Tatran’ and ‘Meridian’ showed the best balanced nutritional values at 120 DAFB.     

Biology of some Predatory Insects and Mites Associated with the Fruit Tree Red Spider Mite (Metatetranychus Ulmi (Koch)) in South-Eastern England II. Some Important Predators of the Mite

Two shading experiments on the sultana are described, a preliminary one in which shades of different intensities were used during October and November, and a main experiment in which shades reducing light intensity by about 70% were applied for different lengths of time between October and January.

In the season of shading, bunch weight was reduced because of smaller, and possibly fewer, berries by shades of greatest intensity in the first experiment. In the second, shades in position later than 8th December reduced berry size, and yield was depressed when shading lasted for at least six weeks.

In the season following shading, fruitfulness and consequently yields were severely depressed where light intensities had been reduced by about 70% for at least four weeks between early November and mid-December. The only other yield component affected was sugar concentration of the berries which was increased where fresh yield was depressed, but not enough to prevent depression of dried yield also.

It is concluded that light intensity is an important factor for fruit bud formation in the sultana; reduction of light is inhibitory, but only during the period of inflorescence initiation.     

Uneven ripening in ‘Bangalore blue’ grape (Vitis vinifera × Vitis labrusca) berries in India is linked to seed viability

Uneven ripening (UR) is a physiological disorder of unknown origin in ‘Bangalore blue’ grape (Vitis vinifera × Vitis labrusca) leading to wine of inferior quality. A preliminary study found wide variations in total dehydrogenase activity (TDH) of seeds from unevenly ripe berries. In our experiments, gibberellin (GA₃) applied to young grapes increased seed TDH activity and reduced the incidence of uneven ripening to 2% compared with 35% in the control. In contrast, paclobutrazol (PBZ) decreased TDH activity and increased the incidence of the disorder to 58%. GA₃-treated berries had higher concentrations of sucrose and TDH activity in seed representing mature seeds with high viability. In contrast, PBZ-treated and control berries had higher concentrations of glucose and lower TDH activity, indicating immature seeds with low viability. These results suggested that competition among developing berries can lead to differences in seed gibberellin content, seed viability and the rate of berry growth resulting in green, purple, and black berries at harvest. The study established the role of seed viability in uneven ripening and demonstrated that the incidence of the disorder is reduced by the application of GA₃ to immature berries.     

Dynamics of anthocyanin and flavonol profiles in the ‘Crimson Seedless’ grape berry skin during development and ripening

‘Crimson Seedless’ grapes (Vitis vinifera L.) do not develop adequate berry colour in different parts of the world including Australia and USA leading to serious economic losses to the growers. In the present study, various anthocyanins and flavonols were identified in the skin of the ‘Crimson Seedless’ grape berries using LC/PDA/ESI-MS and their changes in the berry skin during development and ripening of ‘Crimson Seedless’ grape berries were investigated during 2005–2006 and 2006–2007. Eleven anthocyanins and two flavonols were identified in the berry skin using LC/PDA/ESI-MS. Of the anthocyanins identified, four anthocyanins including cyanidin 3-O-(6″-O-acetyl)-glucoside, peonidin 3-O-(6″-O-acetyl)-glucoside, malvidin 3-O-(6″-O-acetyl)-glucoside and malvidin 3-O-(6″-O-coumaroyl)-glucoside were not reported earlier. During both the years, the concentration of the 3-O-glucosides of delphinidin, petunidin, peonidin, and malvidin as well as the acetyl and coumaroyl esters of the 3-O-glucosides of cyanidin, peonidin, and malvidin in the berry skin increased during berry development and ripening. During 2006–2007, the concentration of cyanidin 3-O-glucoside in the berry skin increased during the early stages of berry ripening and subsequently declined till harvest while in 2005–2006, the concentration increased during the initial phase of berry ripening and remained relatively stable thereafter till harvest. The concentration of total anthocyanins in the berry skin was higher during 2006–2007 as compared to 2005–2006. During both years, the concentration of quercetin 3-O-glucoside in the berry skin increased during berry development and ripening while the concentration of quercetin 3-O-glucuronide in the berry skin decreased during the same period. To the best of our knowledge, this is the first report on the evolution of different anthocyanins and flavonols in the ‘Crimson Seedless’ berry skin during berry development and ripening.     

Gibberellin and Auxin-Induced Berry Enlargement in Vitis Vinifera L.

Gibberellic acid (GA) and the auxin, 4 chlorophenoxyacetic acid (CPA), differ in their effects upon berry enlargement in two seedless varieties of Vitis vinifera L., cv. Black Corinth and Thompson Seedless. Although initially both substances cause nearly equal increases in berry growth rates, at maturity GA-treated berries far surpass those treated with CPA. The growth rate of CPA-treated berries declines, relative to that of the GA group, two to seven days after treatment. The results of experiments in which berries received treatment with both GA and CPA show that CPA may act as an inhibitor of GA-induced expansion, particularly during the later stages of enlargement. Also, GA-treated berries have a greater length-to- width ratio than CPA-treated berries. Thus, there are apparently qualitative differences in mode of action between the two substances. Increase in berry size, regardless of treatment, is the result of water uptake accompanied by solute storage and synthesis of cell components. Histological studies reveal that berry enlargement is the result of tissue growth in a region of the pericarp between the locule and peripheral vascular tissues. This tissue increases in size within 48 hours after treatment with GA or CPA. In GA- treated berries there is a 10-fold increase in parenchyma cell diameter in this tissue between anthesis and maturity. New cell formation in the pericarp of the GA-treated berries may also occur. GA has a more pronounced effect upon enlargement of distal than of proximal parenchyma tissues in the Black Corinth variety. Tissue expansion in CPA-treated berries, as well as those on girdled vines, was approximately equal at both poles. Such differential effects upon expansion at the proximal and distal poles may account for the difference in shape between GA- and CPA-treated berries.     

Gewurztraminer Grapevines Respond to Length of Water Stress Duration

Abstract

Gewurztraminer grapevines planted in 1989 were subjected to one of three durations of water stress (deficits imposed at postbloom, lag phase, veraison) in combination with three vineyard floor management strategies (clean cultivated, total herbicide, permanent sod). Data were gathered on vine performance, fruit composition, and water relations from 1991-96. Yield per vine, cluster weight, and berry weight were reduced linearly with duration of water deficit. Transpiration, stomatal conductance, and leaf water potential were likewise reduced with increased duration of water stress. Titratable acidity decreased and pH increased with duration of water stress, but °Brix was unaffected. Decreasing duration of water stress increased free volatile terpenes (FVT) at harvest, as well as increased potentially volatile terpenes (PVT) at both veraison and harvest. Maintaining a permanent sod tended to reduce all yield components, especially berry weight, but basic fruit composition was unaffected. FVT were highest at both veraison and harvest in berries from clean cultivated plots; however, PVT concentration was highest in berries from permanently sodded plots. Permanent sod treatments displayed lowest transpiration rate and stomatal conductance. Monitoring physiological response (particularly stomatal conductance) of the plant to reduced soil moisture provides a reliable indication of when to relieve irrigation deficits, as opposed to relying on soil moisture monitoring and/or visual assessment of water stress.     

Size factors in strawberry fruit

Analysis of data relating to berries of 9 cultivars grown under different conditions indicates that the weight of ripe berries can be accounted for by the general equation

$\text{Berry fresh weight (g)}\text{=}\text{(}\text{Total no. of achenes}\text{? C)F}\text{(}\text{No. of achenes/cm}{}^2\text{of surface}\text{)}$

where C is a numerical adjustment probably due to the non-spherical shape of berries, and F is the weight in g per unit area of tissue which forms the berry, and both may be characteristic of each cultivar under normal conditions.The number of achenes on perfect berries, equal to the number of ovules initiated on the flowers, is closely related to the position of the flower on the inflorescence. Expressing Rank value on the scale 1 : $\text{1}\text{2}$ : $\text{1}\text{4}$ : $\text{1}\text{8}$ for Rank 1 : Rank 2 : Rank 3 : Rank 4, a general equation

$\text{Achene no.}\text{= (K ×}\text{Rank value}\text{) + D}$

can be applied to all cultivars, although K and D may vary between cultivars and to a less extent within a cultivar. If these size factors are in fact basically genetic, a grower may have little scope for influencing berry size except during berry development in the fruiting-season.     

Abnormal auxin distribution and poor berry setting (coulure) in grapes

A constant low auxin level was observed in a normally setting trimmed cluster of the tetraploid grape ‘Kyoho’ (Vitis vinifera L. × Vitis labrusca L.). The basipetal auxin transport in the trimmed cluster was always 2–3 times higher than the acropetal transport during the flowering-period. In a non-treated cluster, showing a tendency towards excessive berry abscission, the auxin level in the apical parts of the cluster fluctuated within the range of 20–70 times that of the auxin content at full bloom. The ratio of basipetal to acropetal auxin transport was nearly unity or less than unity.The results support the hypothesis of apical dominance and auxin gradient in the formation of an abscission zone.     

Identification and structure of six members of the hexokinase gene family in Vitis vinifera: Cloning,expression, and functional analysis of a putative chloroplast stromal-type hexokinase

Summary

Hexokinase catalyses the first step in the metabolism of glucose, but has also been proposed to be involved in sugar sensing and signalling in both yeasts and plants. The substrates of hexokinase such as glucose (Glc) and fructose (Fruc) are also the most important sugars during grape berry ripening. The grapevine proteome database was analysed to investigate the roles of hexokinases in grape berry growth and development. Six hexokinase genes displaying high nucleotide sequence identity (72 – 87%) with hexokinase genes in other species were identified. Most of the Vitis vinifera hexokinase (VvHXK) genes had a highly conserved genomic structure consisting of nine exons and eight introns. A search for cis–regulatory elements in the promoter regions of all six hexokinase genes revealed that most were probably regulated by light, sugar, phytohormones, or abiotic stress. The isolation and expression of a hexokinase cDNA from V. vinifera ‘Sultanine’, named VvHXK3, was also reported. Analysis of the predicted amino acid sequence of VvHXK3 suggested that the protein could be a chloroplast-stromal hexokinase with a possible transit peptide cleavage site after amino acid residue 26. The VvHXK3 gene was differentially expressed in a variety of organs including berries, leaves, roots, and pollen, but its expression was highest in berries during their early development and at the start of ripening. To determine its function, VvHXK3 cDNA was expressed in a triple mutant yeast strain that lacked the ability to phosphorylate Glc and Fru and, therefore, was unable to grow on these sugars as sole carbon source. Mutant yeast cells that expressed VvHXK3 grew on both Glc and Fru, indicating that VvHXK3 could complement this mutant and had hexokinase activity.