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A Simple and Rapid Extraction Method of Carbohydrates from Petals or Sepals of Four Floricultural Plants for Determination of Their Content
Abstract
We developed a simple and rapid extraction method of soluble carbohydrates from petals for analysis by high performance liquid chromatography (HPLC), using a centrifugal filter device in a test tube without homogenization. Rose 'Sonia' petals were immersed in 99.5% ethanol solution in a test tube and kept at 75 degrees C for 20 min. Sorbitol was then added to the solution as an internal standard, and the petals were transferred to the centrifugal filter device and centrifuged at 12000 x g for 10 min. Following removal of the filtrate, 99.5% ethanol was added to the filter device and a second round of centrifugation performed. Filtrated solution obtained from both centrifugations was combined with the ethanol solution remaining in the test tube, heated to dryness at 80 degrees C, and used for HPLC analysis. Few differences in soluble carbohydrate content were observed between the new method and a conventional method in which soluble carbohydrates are extracted by homogenization. We confirmed that most carbohydrate was extracted by the new method. Moreover, the soluble carbohydrate content of samples extracted from 'Sonia' petals using the new method did not change during one week of storage at -30 degrees C, indicating the stability of the samples. Marked differences in soluble carbohydrate content were not observed among 'Chanel', 'New Bridal', 'Rote Rose', or 'Saturn' rose petals, carnations or Tweedia caerulea petals or Delphinium sepals, using either the new or conventional method. Marked differences in soluble carbohydrate content were also not observed among leaves and stems in carnations, Delphinium or rose 'Sonia' using either the new or conventional method. These results suggest that the new method, which does not require homogenization, appears to be a more simple and rapid method of extraction of soluble carbohydrates from various organs of floricultural plants.
... 16 out of 18 amino acids were quantified to similar levels regardless of the hydrolysis approach ( Table 4). Absence of Trp indicated interference from carbohydrates during hydrolysis [42,52] which can be removed through prior processing [56][57][58]. When H 2 O 2 was added to oxidize methionine and cysteine, subsequent hydrolysis with 6 M HCl resulted in halogenation and loss of tyrosine [54]. ...
... Additional file 2: Figure S1. Amino acid quantitation from BSA hydrolyzed using seven different approaches from the literature [21,[56][57][58]61]. Peak areas were log 10 transformed for relative comparison. ...
Background
Methods used to quantify protein from biological samples are often inaccurate with significant variability that requires care to minimize. The errors result from losses during protein preparation and purification and false detection of interfering compounds or elements. Amino acid analysis (AAA) involves a series of chromatographic techniques that can be used to measure protein levels, avoiding some difficulties and providing specific compositional information. However, unstable derivatives, that are toxic and can be costly, incomplete reactions, inadequate chromatographic separations, and the lack of a single hydrolysis method with sufficient recovery of all amino acids hinder precise protein quantitation using AAA.
Results
In this study, a hydrophilic interaction chromatography based method was used to separate all proteinogenic amino acids, including isobaric compounds leucine and isoleucine, prior to detection by multiple reaction monitoring with LC–MS/MS. Through inclusion of commercially available isotopically labeled (¹³C, ¹⁵N) amino acids as internal standards we adapted an isotopic dilution strategy for amino acid-based quantification of proteins. Three hydrolysis methods were tested with ubiquitin, bovine serum albumin, (BSA), and a soy protein biological reference material (SRM 3234; NIST) resulting in protein estimates that were 86–103%, 82–94%, and 90–99% accurate for the three protein samples respectively. The methane sulfonic acid hydrolysis approach provided the best recovery of labile amino acids including: cysteine, methionine and tryptophan that are challenging to accurately quantify.
Conclusions
Accurate determination of protein quantity and amino acid composition in heterogeneous biological samples is non-trivial. Recent advances in chromatographic phases and LC–MS/MS based methods, along with the availability of isotopic standards can minimize difficulties in analysis and improve protein quantitation. A robust method is described for high-throughput protein quantification and amino acid compositional analysis. Since accurate measurement of protein quality and quantity are a requirement for many biological studies that relate to crop improvement or more generally, our understanding of metabolism in living systems, we envision this method will have broad applicability.
Electronic supplementary material
The online version of this article (10.1186/s13007-019-0430-z) contains supplementary material, which is available to authorized users.
... The phenol-sulfuric acid method is directly applied on collected microalgal cells [9]. For macroalgae, several methods of carbohydrate extractions exist such as the use of hot ethanol or water [19], pressurized liquid extraction (PLE; [20]), or enzymes such ...
... 18. Use a fume cupboard, cover water bath, and cuvettes with stoppers when using this acid. 19. The working reagent is slightly yellow when mixed, but becomes purple (λ max = 565 nm) upon standing, so it must be prepared fresh each day [46]. ...
This chapter describes spectrophotometric assays of major compounds extracted from microalgae and macroalgae, i.e., proteins, carbohydrates, pigments (chlorophylls, carotenoids, and phycobiliproteins) and phenolic compounds. In contrast to other specific analytical techniques, such as high pressure liquid chromatography (HPLC) or mass spectrometry (MS), commonly applied to purified extracts to reveal more detailed composition and structure of algal compound families, these assays serve as a first assessment of the global contents of extracts.
... Boron plays a role in improving the quality of ornamental plants and in particular the vase life of cut flower (Malakouti, 2003). This element improves carbohydrate metabolism and translocation, whose function is to provide a substrate for cell respiration and cell wall synthesis (Norikoshi et al., 2008). It also acts in the processes of capture and transport (Brown and Hu, 1996), cell wall formation (O'Neill et al., 2004), cell membrane functions (Goldbach et al., 2001) and anti-oxidant defense system (Cakmak and Romheld, 1997). ...
Gerbera is a very popular ornamental plant and used in ornamental gardens or as a cut flower. However, as a cut flower, postharvest quality is minimal, which requires solutions to ensure its longevity, especially with acidic solutions. The study was conducted understand if the action of maintenance solutions with acids influence the postharvest physiology of gerbera cv. ‘Piang’. The experimental design was factorial completely randomized consisting of two factors: four postharvest treatments and seven evaluation times. The flowers were kept in 200 mg L-1 of citric acid solution (ACS reagent, ? 99.5 % - Sigma-Aldrich), 200 mg L-1 of boric acid solution (ACS reagent, ? 99.5 %) and 200 mg L-1 of salicylic acid solution (ACS reagent, ? 99.0 %) and potable water as a control. During the postharvest period, fresh mass loss, water absorption, petal luminosity, total longevity, peroxidase (POD) enzyme activity, superoxide dismutase (SOD) activity, total protein and total carbohydrate content were studied. Treatments with boric and salicylic acids recorded higher percentage of fresh weight loss. Citric acid showed higher water absorption rate and better appearance in the luminosity of the petals. The total protein and carbohydrate content decreased during the evaluation period but in the citric acid treatment, the reduction was not so significant. On the other hand, citric acid induced higher peroxidase and superoxide dismutase activity in the second day of evaluation and lower activity until the tenth day.
... This makes this enzyme useful as a biochemical marker of oxidative physiological events. Other substances may also be related to senescence in plants, such as carbohydrates, whose function is to provide substrates for respiration and cell wall synthesis (Norikoshi et al. 2008) and proteins (Azeez et al. 2007). Increased shelf-life of vegetables and horticultural commodities is extremely important, and much research has been undertaken to determine the factors that influence the ® A B Fig. 1 (A) Greenhouses used for the cultivation of chrysanthemum (Dendranthema grandiflora Tzvelev) cv. ...
The aim of the present work was to evaluate the changes in polyamine (PA) content, peroxidase (POX) activity and levels of total protein and total soluble carbohydrates throughout the lifetime of leaves and inflorescences of chrysanthemum 'Faroe' treated with gibberellic acid (GA 3) (used in production practices) and kept at room temperature and cold storage. The treatments were composed of four doses of GA 3 (0, 15, 30 and 45 mg L-1) applied at the beginning of flower bud formation (28 days after transplanting of seedlings). After harvesting, the stems (95% of the expanded ligule) were stored at 10°C and 95% relative humidity for 48 hrs, or kept at room temperature. For biochemical analysis samples of leaves and inflorescences were collected at the 4 th , 8 th , 12 th and 16 th day after harvest. The application of GA 3 in the field and cold storage increased the content of PAs. There was an increase in POX activity in leaves and inflorescences during postharvest and this increase was related to oxidation of the PAs studied. The amount of proteins and carbohydrates in chrysanthemum 'Faroe' decreased during storage at 25°C and under cold conditions.
... Various polyols are found in ornamental plants of many species; for example, carnation and redbud contain pinitol (Griffin et al., 2004;Norikoshi et al., 2008). Redbud accumulates pinitol under environmental stress and pinitol is the methyl ester of chiro-inositol, a cyclitol (cyclic polyol). ...
Sucrose is generally considered the primary photosynthate in plants; however, many horticultural crops, including rosaceous fruit trees, synthesize and use polyols (sugar alcohols). This review describes recent progress in physiological research on the metabolism and transport of sorbitol in rosaceous fruit trees, and of mannitol, another common polyol, in horticultural crops. Studies on various polyols other than sorbitol (in rosaceous fruit trees) and mannitol are then described. Polyols play a role not only in the translocation and storage of photosynthates but also in biotic and abiotic responses in many horticultural crops; therefore, this review also provides insights into the effects of polyol metabolism on the biochemical mechanisms of pathogenicity and environmental stress tolerance, including a novel strategy for engineering stress tolerance.
В обзоре обсуждаются достоинства и ограничения хроматографических и электрофоретических подходов при определении нейтральных углеводов в различных объектах со сложной матрицей, возможность реализации многообразия режимов жидкостной хроматографии и капиллярного электрофореза (в зонном и мицеллярном вариантах), особенности их сочетания с различными вариантами дериватизации, детектирования и пробоподготовки. Обсуждаются условия косвенного детектирования сахаров при введении в подвижную фазу или фоновый электролит различных поглощающих добавок, лигандообменного капиллярного электрофореза и внутрикапиллярного комплексообразования, определение углеводов методами анионообменной и гидрофильной хроматографии.
Qualitative and quantitative profiling of sugars in vegetal materials from Olea europaea cultivars is here reported. Vegetal tissues from olive fruits, leaves, and stems have been characterized by determination of 22 compounds belonging to monosaccharides, disaccharides, trisaccharides, sugar carboxylic acids and alcohols, cyclic polyols, and derived compounds. Sugar isolation was carried out by leaching into a 2:1 dichloromethane/methanol extraction solution under ultrasonic assistance. Multivariate optimization made possible complete isolation of the target fraction in 10 min with an efficiency similar to that provided by a conventional protocol based on 24 h maceration of the vegetal samples. An aliquot of the extract was dried and reconstituted for silylation prior to GC-MS/MS analysis for selective and sensitive identification/quantitation of sugars. Monitoring the target product ions generated after isolation of the precursor ions for each analyte increases the selectivity of the method. The proposed approach is of particular interest for characterization of the sugar fraction in O. europaea, which is of great relevance because of the role of sugars in the metabolism of lipids, proteins, and antioxidants.
Pigeonpea is a tropical grain-legume, which is highly dehydration tolerant. The effect of drought stress on the carbohydrate
metabolism in mature pigeonpea leaves was investigated by withholding water from plants grown in very large pots (50 kg of
soil). The most striking feature of drought-stressed plants was the pronounced accumulation of D-pinitol (1D-3-methyl-chiro-inositol), which increased from 14 to 85 mg g−1 dry weight during a 27 d stress period. Concomitantly, the levels of starch, sucrose and the pinitol precursors myo-inositol and ononitol all decreased rapidly to zero or near-zero in response to drought. The levels of glucose and fructose
increased moderately. Drought stress induced a pronounced increase of the activities of enzymes hydrolysing soluble starch
(amylases) and sucrose (invertase and sucrose synthase). The two anabolic enzymes sucrose phosphate synthase (sucrose synthetic
pathway) and myo-inositol methyl transferase (pinitol synthetic pathway) also showed an increase of activity during stress. These results
indicate that pinitol accumulated in pigeonpea leaves, because the carbon flux was diverted from starch and sucrose into polyols.
Post-harvest characteristics of Rosa hybrida L. cv. 'Delilah', a long-lived cultivar, were compared with those of cv. 'Sonia', a short-lived cultivar. The vase-life of 'Delilah' was 10.6 d whereas that of 'Sonia' was 5.6 d. Petals of 'Sonia' flowers kept in water did not reflect fully and showed blueing. However, treatment with sucrose plus 8-hydroxyquinoline sulphate (HQS) markedly promoted petal reflection and inhibited blueing. In contrast, 'Delilah' flowers kept in water reflected fully and did not show blueing. In both cultivars, hydraulic conductance of stem segments in the control treatment decreased rapidly after harvest. Treatment with HQS suppressed this decrease. Concentrations of glucose, fructose and sucrose in petals of 'Delilah' were much higher throughout the experimental period than those of 'Sonia'. There was no difference between 'Sonia' and 'Delilah' in soluble carbohydrate concentrations in stems and leaves. Starch concentration in petals of 'Sonia' was higher than in 'Delilah'. However, the starch concentration in both cultivars was much lower than the total soluble carbohydrate concentration in 'Delilah'. Sensitivity to ethylene in 'Delilah' was greater than in 'Sonia'. There was little difference in ethylene production trends between 'Sonia' and 'Delilah' flowers. The results suggest that complete petal reflection and the longer vase-life of 'Delilah' versus 'Sonia' flowers may be attributed to higher soluble carbohydrate concentrations in petals of the former.
Sugars play important roles in keeping the quality of cut flowers because the amount of sugar contained in cut flowers is limited. Effects of sucrose treatment on the vase life of several cut flowers were investigated. Continuous treatment with sucrose markedly promoted floret opening and extended the vase life of cut sweet pea flowers. Pulse treatment with sucrose was also fairly effective in improving the vase life of these flowers. Continuous treatment with sucrose increased anthocyanin concentrations in petals as well as extended the vase life of several cultivars of cut Eustoma flowers. This treatment was also effective in improving the vase life of cut snapdragon flowers. Although pulse treatment with sucrose was fairly effective in improving the vase life of cut hybrid Limonium, pulse treatment with sucrose in combination with alpha-aminoisobutyric acid (AIB), an ethylene biosynthesis inhibitor, was markedly effective in improving the vase life. Role of the application of sucrose to cut flowers was reviewed and discussed.
The dry matter and carbohydrate contents of intact growing ‘Sonia’ rose corollas were measured from an immature bud to full expansion of the petals. Reducing sugars and starch, but not sucrose, accumulated throughout most of the corolla development. These findings were compared with the carbohydrate changes in the corollas of flowers cut at different stages and allowed to age with their stems either in water or in a sucrose-containing solution. For a few days after cutting the carbohydrate metabolism of the cut flower roughly paralleled that of the intact flower until starch hydrolysed to maintain the soluble carbohydrate pool. Feeding with the sucrose solution maintained the soluble carbohydrate levels and retarded the hydrolysis of starch.
The cut flowers were fed with ¹⁴C-sucrose and the labelled metabolites in the leaves and flowers were analysed. Active incorporation of ¹⁴C into ethanol-soluble carbohydrates, starch and ethanol-insoluble material was found indicating that an active anabolic phase precedes the catabolic phase during the senescence of the cut flower. The findings are discussed in relation to the source-sink hypothesis of flower development, with regard to the senescence and growth of the corollas of cut and intact flowers respectively.
A study was conducted to determine the distribution of sugars in vacuoles, cytoplasm, and free space in apples (Malus domestica Bork) picked at the immature and mature stage of maturity. The volumes of free space and air space were 13.4% and 14.5%, respectively, in immature fruit, and 14.6% and 25.6%, respectively, in mature fruit. The inner cellular volume (vacuole + cytoplasm) was 72% and 60% for immature and mature fruit, respectively. About 90% of each sugar (glucose, fructose, sucrose, and sorbitol) was found in the vacuole. The concentration of total sugar in the inner cell or free space was 326 or 128 m m each in immature fruit and 937 or 406 m m each in mature fruit. Permeability to sugars across the plasma membrane and tonoplast also increased with fruit maturation, 7- to 30-fold for the tonoplast and 4- to 5-fold for the plasma membrane in mature compared to immature fruit. Cells in immature fruit apparently enlarge through higher turgor pressure from sequestering of sugars into vacuoles, and cease to enlarge in mature fruit as the amount of sugar unloading into the fruit is reduced due to the accumulation of sugar in the free space or cytoplasm.
The role of sugars in the prolongation of the vase life of cut flowers was reviewed. Beneficial effect of sugars on the supply of substrates for respiration and, therefore, on longer life of cut flowers is generally recognized. This widely accepted role of sugars as providers of additional substrates for respiration has perhaps largely over-shadowed other important roles. In this review, attempts were made to study the role of sugars in the prolongation of the vase life of cut flowers in general, and in the delay in ethylene biosynthesis or decrease in sensitivity to ethylene in particular.
An unknown sugar-like compound other than glucose, fructose, sucrose and myo-inositol was detected in the ethanol extract of carnation (Dianthus caryophyllus L.) leaves and isolated using high performance liquid chromatography. The isolated compound was identified as D-(+)-chiro-inositol monomethylether (pinitol) by 1H-NMR and 1C-NMR spectra. Pinitol was the most abundant sugar in the leaf and also was present in stem, petal and the remaining part of flower in large amounts in 4 cultivars tested. In petals, the pinitol content remained constant during flower bud development on a fresh weight basis, but the organ pinitol content increased markedly. The pinitol content was also high in the other parts of the flower. These findings suggest that pinitol, a major sugar constituent, contributes to the bud growth and subsequent petal opening in the carnation together with other metabolic sugars, such as glucose and sucrose.
Cut sweet pea flowers were put in vase water containing 200 mg l-1 8-hydroxyquinoline sulfate (HQS), and 100 g l-1 sucrose was added to the solution during the first 24 h (initial treatment), from the 24th h on (late treatment) or throughout the experimental period (continuous treatment). The vase life of the florets in the control (with no sucrose added), initial-, late-, and continuous-treatment groups were 2.8, 6.0, 5.0 and 8.0 days, respectively. Climacteric ethylene production of the florets was the earliest in the control group followed by the late-, initial- and continuous-treatment groups, in this order. The concentrations of glucose, fructose and s ucrose at the 2nd day and later were the highest in the continuous-treatment group followed by the initial-treatment, late-treatment and control group, in this order. Thus, the correlation between sugar concentrations in petals and vase life was positive, whereas that between the sugar concentrations and ethylene production was negative. These results suggest that sugar concentration in petals affects the vase life of cut sweet pea flowers through ethylene production.
To clarify to what extent vascular occlusion or shortage of soluble carbohydrate shortens vase life of cut 'Sonia' roses (Rosa hybrida L.), cut flowers were continuously treated with 200 mg·liter-1 8-hydroxyquinoline sulphate (HQS group), 20 g·liter-1 sucrose (Suc group) or 20 g·liter-1 sucrose plus 200 mg·liter-1 HQS (Suc + HQS group), whereas control flowers were kept in water. All cut flowers were kept at 23°C, 70% RH and 12 hr photoperiod, with 10 μmol·m-2·s-1 irradiance. Although all treatments extended the vase life, sucrose was more effective than HQS. Treatment with sucrose promoted unfolding of petals, suppressed the decrease in fresh weight of cut flowers, and inhibited the occurrence of blueing more than did HQS. Water conductivity of stem segments in the control and Suc groups decreased rapidly after harvest, but that in the HQS and Suc + HQS groups was maintained near the initial level for seven days. The number of bacteria in the stem segments increased in the control and Suc groups, but this increase was suppressed by HQS. Glucose, fructose and sucrose concentrations in petals in the Suc and Suc + HQS groups were much higher than those in the control or HQS groups. These results show that decrease in the soluble carbohydrate concentration in petals was more important than vascular occlusion in determining the vase life of cut 'Sonia' roses under our experimental conditions.
Freshly harvested 'Bridal Pink' roses (Rosa hybrida L.), with their stem bases in test tubes containing deionized water, were placed in a glass tank and held in a controlled environment room at 14, 20, or 30 °C. The vapor pressure deficit (VPD) in the tank was maintained at nearly 0 kPa (no VPD: NVPD) or 0.9 kPa (intermediate VPD: IVPD). At all temperatures and VPDs, the fresh weight of cut roses increased initially and then decreased; the decrease occurred earlier in IVPD than in NVPD and at higher temperatures. Necks of all flowers placed in IVPD became bent within 48, 144, and 312 hr of postharvest at 30, 20, and 14 °C, respectively; whereas, bent neck did not develop in NVPD. Irrespective of temperature, transpiration and water uptake rates of the roses placed in IVPD were markedly higher than those in NVPD. In IVPD, these rates increased initially, but decreased after 48, 72, and 96 hr at 30, 20, and 14 °C, respectively. Petal water potential gradually decreased during the first 36 hr at 30 °C in IVPD, but did not change at 14 °C. The osmotic potential increased with time and was higher at 30 °C than at 14 °C. Fructose, glucose, and sucrose were the major sugars in petals. Concentrations of these sugars decreased during the first 36 hr, the decrease being greater at 30 °C than at 14 °C. The contribution of these sugars to the petal osmotic potentials was only 10%. These data indicate that the water relations of cut roses, immediately after harvest, was greatly influenced by high VPD by hastening the transpiration rate, and subsequently by increasing temperature through rise in the osmotic potential which was partly attributable to the consumption of respiratory substrate.
Effects of continuous treatment with sucrose on floret opening, vase life, carbohydrate concentrations, and ethylene production in cut snapdragon (Antirrhinum majus L. cv. Yellow Butterfly) flowers were investigated. Continuous treatment with sucrose at 25, 50, 75, or 100 g · liter-1 in combination with 200 mg · liter-1 8-hydroxyquinoline sulfate markedly promoted floret opening and extended the vase life of flower spikes. The most effective sucrose concentration was 50 g - liter-1 so that this concentration was used for the following experiments. This treatment suppressed the decrease in fresh weight of florets. Glucose, fructose, sucrose, and mannitol were detected in petals. Glucose, fructose, and sucrose concentrations of petals in control spikes decreased one day after the harvest and remained at low levels but the sucrose treatment suppressed the decrease in these sugars. Regardless of the sucrose treatment, mannitol concentration gradually decreased. The onset of climacteric ethylene production was delayed by the sucrose treatment which suggests that the effects of sucrose for promoting bud opening and inhibiting flower senescence is attributed to an increase in sugar concentrations and the inhibition of ethylene synthesis.
To supply high quality cut carnation flowers in summer, budded shoots harvested on replanting time (from mid-May to early June) were pre-conditioned with silver thiosulphate (STS) and/or sucrose and stored at 1 °C for 12 weeks. The effects of pre-conditioning on the opening, vase life, and sugar contents were investigated.1. The vase life of 'Nora' and 'Coral' carnation flowers pre-conditioned with STS was extended after the 12 weeks of cold storage, but vase life of 'Coral' treated with STS +sucrose was slightly shortened because less preservative solution was absorbed.2. The sugar concentration in petals of 'Nora' was maintained at a certain level by sugars translocated from leaves during 12-week storage. After cold storage, petals of shoots pre-conditioned with 0.3 mM STS + 10% sucrose had the highest sugar concentration but no promotive effect on vase life was observed.The results confirm that high grade cut carnation flowers can be obtained in mid-summer by pre-treating budded shoots with STS and cold storing them at 1 °C for 12 weeks.
The relationship between freezing tolerance and sugar content in cabbage seedlings was investigated. Seedlings exposed to non-freezing low temperature (5 °C) acquired freezing tolerance down to -6 °C. The degree of freezing tolerance increased with duration of exposure to low temperature (up to 10 d). Sucrose, glucose, fructose and myo -inositol were detected as soluble sugars in cabbage leaves, and all soluble sugars, except for myo -inositol, and starch increased gradually during cold acclimation such that their levels were positively correlated with the degree of freezing tolerance. The induced freezing tolerance was attributed not to ontogenetic changes but to cold acclimation. However, the induced freezing tolerance was lost after only 1 d of deacclimation at control temperatures, and this change was associated with a large reduction in sugar content.
These results reveal that the sugar content of cabbage leaves is positively correlated with freezing tolerance.
Two unidentified sugars were isolated from rose petals using HPLC. The isolated compounds were identified as methyl β-glucopyranoside and xylose using (1)H-NMR, (13)C-NMR, and GC-MS. Methyl β-glucopyranoside and xylose were distributed in three cultivars tested relatively in large amounts. These results indicate that methyl β-glucopyranoside and xylose occur universally as soluble sugar constituents in roses.
The sugar contents of strawberry fruits extracted by the conventional ethanol method were compared with those extracted with water followed by microwave heating. Sucrose, glucose, fructose and total sugar contents did not differ significantly between the two methods. The time for the water extraction method required approximately half that needed for the conventional ethanol method. Sugar metabolizing enzymes are inactivated by boiling in a microwave oven. In this method, frozen fruits should be chopped, quickly weighed at a low temperature, and the pieces immediately heated in a microwave oven. After strawberry fruits are heated in a microwave oven, they could be processed at a room temperature. Thus, the water extraction method followed by microwave heating is less time consuming but equally accurate for measuring the concentration and composition of soluble sugars in strawberry fruits.
A carbohydrate other than sucrose, glucose, fructose and myo-inositol was detected in sepal extracts of Delphinium. This compound was identified as mannitol by 1H-NMR. Mannitol was the major carbohydrate in all examined organs: the sepal, the other parts of the flower, the stem and leaves. Mannitol as well as glucose (both at 0.55 M), fed to cut Delphinium flowers, similarly delayed the abscission of sepals. 3-O-methyl glucose (3-OMG) and polyethylene glycol 200 at the same molar concentrations had no such effect. The treatment with glucose markedly increased the concentrations of glucose and fructose in the sepals without changing the concentrations of sucrose and mannitol. On the other hand, the treatment with mannitol increased the concentrations of glucose and fructose in addition to mannitol in the sepals, suggesting that mannitol is metabolized in Delphinium flowers. The treatment with 3-OMG increased the concentration of 3-OMG but not other carbohydrates. Mannitol and glucose similarly delayed the increase in ethylene production in flowers, but 3-OMG did not. The sensitivity to ethylene was similarly reduced by the treatment with glucose and mannitol, but not by 3-OMG. These results suggest that the treatment with mannitol, a major carbohydrate in Delphinium, delayed the abscission of sepals by reducing the sensitivity to ethylene. Mannitol further acted, not merely as an osmolyte, but as an apparent source for carbohydrate metabolism in the flower.
Dry weight, water content, soluble carbohydrate content, and carbohydrate composition of daylily (Hemerocallis hybrid cv Cradle Song) flower petals were monitored in the 3 d leading up to full opening and in the first day of senescence. Timing of events was related to the time (hour 0) when flower expansion was 60% complete. Petal dry weight increased linearly from hour -62 (tight bud) to hour 10 (fully developed flower), then fell rapidly to hour 34 as senescence advanced. Increase in water content was proportional to dry weight increase from hour -62 to hour -14, but was more rapid as the bud cracked and the flower opened, giving an increase in fresh weight/dry weight ratio. Soluble carbohydrate was 50% of petal dry weight up to hour 10, then decreased during senescence to reach 4% by hour 34. Up until hour -14, fructan accounted for 80% of the soluble carbohydrate in the petals, whereas hexose accounted for only 2%. Fructan hydrolysis started just prior to bud crack at hour -14, reaching completion by hour 10 when no detectable fructan remained, and fructose plus glucose accounted for more than 80% of the total soluble carbohydrate. The proportion of sucrose remained constant throughout development. Osmolality of petal cell sap increased significantly during fructan hydrolysis, from 0.300 to 0.340 osmolal. Cycloheximide applied to excised buds between hour -38 and hour -14 halted both fructan hydrolysis and flower expansion. The findings suggest that onset of fructan hydrolysis, with the concomitant large increase in osmoticum, is an important event driving flower expansion in daylily.
2-C-methyl-D-erythritol, a soluble carbohydrate that is not ubiquitously found in higher plants, was detected in the ethanol extract from Phlox subulata petals and isolated using HPLC. The isolated compound was identified by 1H-NMR, 13C-NMR and Cl-MS spectra. 2-C-methyl-D-erythritol was a major soluble carbohydrate in petals, leaves and stems. In petals, the concentration of 2-C-methyl-D-erythritol markedly increased during flower development and opening and was similar in concentration to glucose, a ubiquitous metabolic sugar. This suggests that 2-C-methyl-D-erythritol may contribute to flower opening in association with glucose in the P. subulata.
Tomato (Lycopersicon esculentum Mill. cv New Yorker) plants subjected to 100 millimolar NaCl plus Hoagland nutrients exhibited a pattern of wilting, recovery of turgor, and finally recovery of growth at a reduced level, which required 3 days. During the nongrowing, adaptation phase there were immediate increases in free hexoses and sucrose which declined to near control levels as growth resumed. There was a steady increase in myo-inositol content which reached its maximal level at the time of growth resumption. The myo-inositol level then remained elevated for the remainder of the experiment. Myo-inositol constituted two-thirds of the soluble carbohydrate in leaves and three-fourths of the soluble carbohydrate in roots of salt-adapted plants. Plants which were alternated daily between salt and control solutions accumulated less myo-inositol and exhibited less growth than the continuously salt-treated plants. In L. pennellii and in salt-tolerant and salt-sensitive breeding lines selected from L. esculentum x L. pennellii BC(1) and F(8), myo-inositol content was highest in the most tolerant genotypes, intermediate in the normal cultivar, and lowest in the sensitive genotype after treatment with salt.