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.     

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.     

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.     

一种连续测定葡萄果实糖分积累的新方法

介绍了一种测定葡萄二次生长高峰期葡萄果实糖分卸载和积累的非离体试验体系-新浆果杯法。新浆果杯是由1粒剥皮后的葡萄果实侵入盛有缓冲溶液、由注射器制成的小杯组成。利用该试验体系,水分胁迫和2．5 mmol/L对氯汞苯甲酸(pCMB)可明显抑制葡萄果实糖分卸载,而1．5 mmol／L二硫基苏糖醇(DTT)则可促进葡萄果实糖分卸载。结果表明新浆果杯法可连续测定葡萄第二生长期果实糖分积累,是研究葡萄韧皮部糖分卸载机理和内外因子对葡萄果实糖分积累影响的理想方法。     

根域限制对‘巨玫瑰’葡萄果实可溶性糖含量及相关代谢酶活性的影响

 以‘巨玫瑰’葡萄（Vitis vinifera L. × V. labrusca L.）为试材,从始熟期开始研究了根域限制栽培对果实可溶性糖积累及相关代谢酶活性的影响。结果表明：‘巨玫瑰’葡萄果实中主要以葡萄糖和果糖积累为主。从始熟期开始果实中的葡萄糖和果糖含量持续增加,与此同时,酸性转化酶（AI）的活性也随果实发育进程而逐步增强。AI活性与果实中含量最多的葡萄糖和果糖含量显著相关。中性转化酶（NI）和蔗糖合成酶（SS）的分解方向的活性只是在始熟期3周后开始增加,且活性低于AI。蔗糖合成酶（SS）的合成方向和蔗糖磷酸合成酶（SPS）的活性在始熟期开始后稍有增加,此后保持平稳,且活性远远低于蔗糖分解相关酶AI、NI和SS的分解方向活性。根域限制栽培可以显著提高‘巨玫瑰’果实中可溶性糖的含量、糖积累期间的AI活性和成熟时的NI活性,但对其他酶活性影响不显著。由此推断AI是葡萄果实糖积累的最重要的调节因子,也是根域限制提高果实糖含量的关键代谢酶。     

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.     

酿酒葡萄成熟特性的研究

葡萄浆果成熟过程中,存在着多方面的变化。只有含糖量、含酸量的变化最有规律,最能代表葡萄品种的成熟特性。含糖量的变化与logistic曲线、含酸量的变化与对数曲线拟合性最好。不同品种成熟特性的差异,主要表现为含糖量上升速率与含酸量下降速率的不同。气象因素能明显影响葡萄的成熟特性,最终造成同一品种在不同地区成熟度的差异。     

Das Platzen von Weinbeeren (Vitis vinifera) bei Befall mit Grauschimmel (Botrytis cinerea)

Rain-cracking of post-veraison grape berries (Vitis vinifera L.) reduces yield and quality of must and wine. Under vineyard conditions, cracking is often associated with bunch rots. The objective of the present study was to identify the role of Botrytis cinerea Pers.: Fr. as the dominant bunch rot fungus in cracking of Riesling berries. For these experiments grape berries with characteristic symptoms of Botrytis infections were selected in the vineyard. Berries infected by Botrytis always cracked in those regions of the berry where symptoms of the infections (brownish purple colour of the fruit skin) were present. In 55 % of these berries, cracks were orientated perpendicularly to the pedicel/stylar scar axis. Microscopic cracks referred to as microcracks were often present in the stylar scar region and occasionally in the vicinity of lenticels. These cracks allowed penetration of the fluorescent tracer acridine orange. The area infiltrated by the dye was positively related to crack length (r²?=#x003D;?0.43*). Water uptake of detached berries increased with time. Rates of uptake were highly variable and higher for infected berries as compared to berries without infections. Rates of water uptake into infected berries were positively related to cumulative crack length (number of cracks multiplied with average crack length) per berry (r²?=#x003D;?0.45*). Exposing the outer surface of the strained grape berry exocarp to water increased the frequency of microcracks. The increase was larger in infected berries than in those without symptoms. Our data demonstrate that Botrytis infections increase the cracking susceptibility of Riesling grape berries by weakening the grape berry exocarp, increasing crack length per berry which in turn resulted in increased water uptake.     

葡萄延迟采收期间糖含量及其代谢酶活性的变化

对‘京秀’、‘亚历山大’以及‘京秀’ ב亚历山大’和‘京秀’ ב香妃’葡萄杂交后代群体的共20个单株成熟时及延迟采收期间浆果可溶性糖含量进行研究。结果表明, 延迟采收, 浆果内可溶性糖变化可分为积累型和相对稳定型两种。延迟采收3周, 糖积累型的‘京秀’和8个单株浆果可溶性糖显著积累, 蔗糖分解酶(酸性转化酶、中性转化酶、蔗糖合成酶分解方向) 活性持续升高, 而相对稳定型的‘亚历山大’和12个单株的糖与成熟时没有显著差异, 但酶活性急剧降低。果实成熟和延迟采收期间的呼吸速率也存在差异。成熟后延迟采收由蔗糖分解酶活性反映的浆果库力的大小和呼吸速率存在的差异可能是两种类型延迟采收期间糖含量存在差异的重要原因。     

‘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.     

根域限制对‘峰后’葡萄果实韧皮部糖卸载的影响

 为了探明根域限制提高葡萄果实糖度的机制,用5 年生‘峰后’葡萄为材料,在果实成熟 期用“浆果杯”技术比较了根域限制处理与对照的果实韧皮部糖卸载的日变化。结果表明,葡萄果实韧 皮部糖卸载在一天中有3 次高峰,分别出现在上午、下午和晚上（9：00、17：00 和21：00 左右）。上午 卸载量大,其峰值分别为下午和晚上的2.1 和1.4 倍左右;根域限制处理果实的糖卸载量始终高于对照, 约为对照的1.5 倍,并且上午糖的快速卸载提前了3 h,峰值为对照的2.0 倍。给“浆果杯”中的糖卸载 缓冲液添加ABA、EGTA,促进了糖卸载,但添加EB 却抑制糖卸载。表明葡萄果实韧皮部糖卸载需要消 耗能量,根域限制促进了葡萄果实韧皮部的糖卸载,并可能与其诱导ABA 含量的升高有关。     

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.     

葡萄果实始熟前后ABA积累关键酶基因VvNCED1和VvBG1转录水平的研究

以始熟期花后7 ~ 11周的‘玫瑰香’葡萄果肉为试材,利用荧光定量PCR分析了VvNCED1和VvBG1基因在5个时期的表达量。结果表明,VvNCED1基因在花后7 ~ 8周表达量很高,随后快速降低至最低值;随着果实着色,表达量略有升高。VvBG1基因在果实始熟前表达量较低,随着果实始熟启动和果实着色,表达量基本呈持续升高的趋势。结合果实ABA含量在始熟期前后一直升高的结果分析,认为果实始熟前ABA积累归因于VvNCED1基因的高水平表达,始熟后ABA积累主要归因于VvBG１基因的高水平表达。     

Impact of Leaf Removal on Yield Components and Monoterpene Composition during Maturation of Vitis vinifera L. CV ‘Italia’ Cultivated in Tunisia

ABSTRACT

The effect of leaf removal on the yield components, the fruit composition and the free and bound monoterpenol concentrations during maturation of Vitis vinifera L. ‘Italia’ berries were studied over two years (2002 and 2003). Results suggest that leaf removal treatments had no impact on berry and cluster weights, whereas it induced a significant modification in chemical composition of the fruit expressed by Brix degree, titratable acidity, and monoterpenol concentrations.     

油菜素内酯和脱落酸调控葡萄果实花色苷合成的研究

【目的】为研究2,4-表油菜素内酯(2,4-epibrassinolide,EBR)和脱落酸(abscisic acid,ABA)处理对葡萄花色苷合成与可溶性固形物含量、果皮苯丙氨酸解氨酶(PAL)和类黄酮糖基转移酶(UFGT)活性以及果实内源ABA含量的影响,探索油菜素内酯调控葡萄果实成熟及花色苷合成的机理。【方法】以酿酒葡萄‘赤霞珠’(Cabernet Sauvignon)和‘烟73’(Yan 73)为试材,在葡萄转色前分别用0.1、0.4、0.8 mg.L-1EBR,1mg.L-1Brz(brassinazole,BR生物合成抑制剂)和200 mg.L-1ABA,均匀喷施于葡萄果实,在葡萄成熟过程中测定葡萄果皮花色苷含量及PAL和UFGT酶活性,同时测定果实ABA和可溶性固形物含量。【结果】在果实着色初期,‘赤霞珠’和‘烟73’葡萄果皮PAL和UFGT活性及果实内源ABA含量均逐渐升高,当果实接近成熟花色苷含量基本稳定时ABA含量开始降低。与对照相比,0.4mg.L-1EBR和200 mg.L-1ABA处理显著增加了果实内源ABA含量,提高了果皮PAL和UFGT活性,促进了果皮花色苷的合成和果实可溶性固形物的积累。0.1 mg.L-1和0.8 mg.L-1EBR处理总体增加了果实内源ABA含量,促进了花色苷的合成和可溶性固形物的积累,并提高了UFGT和PAL酶活性,但比0.4 mg.L-1EBR处理提高的幅度小,且差异显著。1 mg.L-1Brz处理使果实ABA的合成推迟,果实可溶性固形物含量、果皮PAL和UFGT活性以及花色苷含量均低于对照,但差异不显著。【结论】外源EBR和ABA处理促进了葡萄成熟和花色苷合成,在不同浓度EBR处理中,以0.4 mg.L-1处理效果较好;内源ABA可能参与了EBR对葡萄成熟和花色苷合成的调控。     

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.     

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.     

Factors Governing Fruit Bud Formation.: VIII. The Seasonal Elongation Growth of Apple Varieties on Some Vegetative Rootstocks; and its Possible Relation to Fruit Bud Formation.

Summary

The moisture, dry matter and soluble sugar composition of Vitis vinifera L. advanced selections of dry-on-the-vine raisins were determined over several seasons. Moisture loss from post-veraison berries occurred in a graduated stepwise manner, with a rapid decline from an initial 86±2% to 60±5% 108 d from first bloom, a slower loss and a final accelerated loss to 25±4% after 151 days from first flowering. The pattern of dry-matter accumulation was similar in large, medium, or small berries but dry matter was higher in large (0.65±0.04 g dry wt. per berry) than medium (0.52±0.03 g dry wt. per berry) or small (0.36±0.03 g dry wt. per berry raisin). Incipient browning was seen with raisin formation at the distal berry region with a higher sugar concentration than in the proximal (pedicel) region. Sucrose in the raisins exhibited two maxima, one (1.4±0.2 mg g^–1 fresh wt.) 96 d from first bloom, and a second (2.4±0.4 mg g^–1 fresh wt) 123 d after first bloom, with each maximum occurring before the rise in glucose, fructose, and sorbitol, and decreasing as these sugars increased. Sorbitol was not detected initially in mature berries, but increased in raisins. It was proposed that sorbitol or its biosynthetic enzyme might be useful for determining raisin harvest. Raffinose and sucrose contents of the peduncle were higher than raisins and may indicate a role of these sugars in the physiology of the peduncle.     

Jasmonic acid effects on gibberellic acid-induced seedlessness in ‘Neo Muscat’ table grapes

Summary

The effect of jasmonic acid (JA), applied alone or in combination with gibberellin A3 (GA₃), on the induction of seedlessness in ‘Neo Muscat’ (Vitis vinifera) was investigated. Endogenous JA levels in the florets of ‘Neo Muscat’ and ‘Delaware’ (Vitis vinifera x Vitis labrusca) were also studied. The proportion of seedless berries induced by application of GA₃ alone 12 d before full bloom (DBB) was 17.0%, and at 6 DBB it was 62.7%. The proportion of seedless berries induced by GA₃ + JA applied 6 DBB increased significantly with increasing JA concentration, while pollen germination decreased quadratically with increasing JA concentration. JA did not affect seed number per berry or the seed’s fresh weight. Treatment with JA alone also induced seedlessness effectively. Although the fresh weight of the seedless berries induced by the application of GA₃ + JA 12 DBB decreased quadratically with increasing JA concentration, there were no significant differences between the treatments at 6 DBB. Fruit soluble solids and titratable acidity were not affected by JA. There were no obvious differences in the amounts of JA in the florets of ‘Delaware’ and ‘Neo Muscat’.