Changes In Carbohydrate Content Research Articles

Sources of variation between apple fruits within a season, and between seasons

In 1987,1988 and 1989, we studied the main differences between apple fruits (Malus dom- estica Borkh., cv. Golden Delicious) produced by the same type of inflorescence (central flowers or peripherial ones) and collected from one or two year old wood. This apples produced by the younger wood were lighter than the others; this was due to their significantly lower cell numbers and smaller cell diameters. Percentage dry matter content of the fruits from the same inflorescence were very similar, but higher for apples obtained from the younger wood. The concentrations of main sugars (sucrose, fructose, glucose and sorbitol) were significantly greater in peripherial fruits than in the central ones, but there was no difference between the two ages of wood. Year to year cytological factors were mainly found within the younger wood, and therefore on the lightest fruits. In addition, dry weight and sugar concentrations differed between the two carrying woods. Dry weight varitions were mainly due to changes in carbohydrate content.

Super Absorbent Materials from Lignocellulosic Materials by Phosphorylation. (Part 3). Chlorite Treatment and Phosphorylation of Woodmeal for Water Absorbency.

The effects of delignification with acidified sodium chlorite and phosphorylation with phosphoric acidurea on swelling behavior of woodmeal were investigated. Chlorite treatment of todomatsu was quite selective in removing lignin, and this treatment caused no significant change in carbohydrate content. Chlorite treatment of woodmeal followed by phosphorylation rapidly increased its water absorbency with increasing degree of delignification up to 30%. After phosphorylation, the woodmeal with 65% of degree of delignification had maximum water absorbency (141g H2O/g absorbent). The removal of lignin was a dominant factor for the hydrogelation of phosphorylated products. The water absorbencies increased with increasing content of phosphate groups in the products, and reached a maximum at the phosphorus content of 6.6% (0.43 ester group/glucose anhydride unit). These results indicated that the water absorbency of phosphorylated products depended on the degree of substitution of phosphate groups. Sufficient hydrogelation required the phosphorylation with 60g of urea and 1.5g of phosphoric acid on 2g of chlorite-treated woodmeal at 150°C for 60min.

Ecological Study on the Barnyard Grass Stem Borer, Enosima leucotaeniella(RAGONOT)(Lepidoptera:Pyralidae) : VIII. Seasonal Changes of Carbohydrate Contents in Overwintering Larvae

The seasonal changes of carbohydrate contents in overwintering larvae of Enosima leucotaeniella were investigated to understand the relationship between carbohydrate contens and diapause. More than eight kinds of sugars and polyols were detected in the haemolymph and body by gas-liquid chromatography. Trehalose was a dominant substance and trace levels of other sugars and polyols appeared during hibernation. From September to January, trehalose content increased with decreasing glycogen in spite of diapause termination in late November, but total carbohydrate (trehalose plus glycogen) content stayed at an approximately constant level. In February, however, both trehalose and glycogen contents decreased.

Chemical changes and carbon isotope variations in a cross-section of a large Miocene gymnospermous log

The cross-sectional radius of a 3-m (diam.) brown coal gymnospermous log of Miocene age, previously analyzed for carbohydrate and lignin methoxyl content by solid-state 13C nuclear magnetic resonance spectroscopy, was examined using stable carbon isotopic ratios in order to determine if the isotopic composition could be related to chemical changes or to radial position. This study found a possible relationship between δ 13C-values and radial position; however, these changes cannot be linked to carbohydrate content and are probably attributable to changing growth conditions during the lifetime of the tree. An apparent linear relationship between the changes in carbohydrate content after sodium para-periodate treatment and corresponding changes in the δ 13C-values indicates constant isotopic fractionation between lignin and carbohydrates along the cross-sectional radius. This result indicates that diagenesis has not produced any significant change in the lignin-carbohydrate carbon isotopic fractionation or, alternatively, that diagenesis has erased any fractionation pattern that once existed. A sample of fresh wood from another gymnospermous species was analyzed by the same methods and found to have lignin-carbohydrate carbon isotopic fractionation significantly different from that of the Miocene log section samples, suggesting that differences may be species-related or that the complex mixture of carbohydrates in the fresh wood was isotopically different from that of the degraded wood, and the whole Miocene log was uniformly altered.

Developmental changes in carbohydrate concentration and activaties of sucrose metabolizing enzymes in fruits of two Capsicum annuum L. genotypes

Recently it was reported that hexose sugars accumulate in pepper ( Capsicum annuum) fruit during ripening as a result of increased acid invertase (EC 3.2.1.26) activity. In this study, fruit of two pepper genotypes which differ in size, shape and carbohydrate concentration were evaluated during growth and development. Carbohydrate concentrations and sucrose metabolizing enzyme activities were measured. Starch and sucrose concentration increased midway through development and declined during fruit ripening. The increase in sucrose concentration was seemingly unrelated to activity of sucrose-phosphate synthase (SPS) (EC 2.4.1.14). As sucrose and starch concentrations declined during ripening, hexose sugar concentration increased. This change in carbohydrate composition was associated with increased acid and neutral invertase activity. Overall trends in carbohydrate pools and enzyme activities were similar between the two genotypes. However, the smaller jalapeno-shaped pepper had much higher carbohydrate concentrations and enzyme activities than the bell pepper. The most striking differences between the two genotypes were a very high concentration of hexose sugars (> 90 mg/g fresh wt.) and the extent to which activity of acid and neutral invertases increased during the final stages of ripening in the jalapeno-shaped pepper compared to the bell-shaped pepper. Thus, there may be an association between increased invertase activity and the accumulation of hexose sugars in pepper fruit during ripening.

Effects of carbohydrate content on the seasonal rooting of vegetative and reproductive cuttings of olive

SummaryExperiments on the rooting of vegetative and reproductive cuttings of olive showed that the availability and mobilization of carbohydrates towards the base of the cuttings were essential for rooting. Seasonal variation in the rooting of vegetative and reproductive cuttings was associated with concomitant changes in carbohydrate concentrations in the bases of the cuttings. Rooting of cuttings with the reproductive organs attached was prevented by fruit growth or fruit ripening, as carbohydrates were diverted towards the reproductive organs rather than to the IBA-treated bases of the cuttings. However, the failure of rooting in winter for most types of cuttings could not be explained in terms of carbohydrate availability. Similarly, the role of the inflorescence in reducing rooting could not be explained by redirection of assimilates to this reproductive organ.

Role of Sucrose Phosphate Synthase in Sucrose Biosynthesis in Ripening Bananas and Its Relationship to the Respiratory Climacteric

During ripening of bananas (Musa spp. [AAA group, Cavendish subgroup]), there is a massive conversion of starch to sucrose. Also during ripening there is a rise in respiration known as the respiratory climacteric. In this study changes in carbohydrate content, activities of starch and sucrose metabolizing enzymes, and respiration were measured to assess their potential interrelationships. Sucrose phosphate synthase activity increased dramatically during the first 4 days after initiation of ripening by ethylene treatment. Starch concentration decreased and sucrose concentration increased during this time period. Developmental changes in sucrose phosphate synthase activity were measured with limiting substrate (plus Pi) and saturating substrate concentrations. Activities were not parallel under the two assay conditions, providing tentative evidence that kinetically different forms of the enzyme may exist at different stages of ripening. Sucrose accumulation rate was most highly correlated with sucrose phosphate synthase activity assayed with limiting substrate concentrations (plus Pi). The cumulative amount of CO(2) respired during ripening was positively correlated with sugar accumulation (R(2) = 0.97). From this linear regression it was calculated that a constant 0.605 millimoles of CO(2) was evolved per mole of sucrose formed throughout ripening. Using this quantity, the percentage of the total respiratory ATP produced which was required for the conversion of starch to sucrose was calculated assuming different models for carbon export from the amyloplast. The results suggest that sucrose biosynthesis during ripening constitutes a significant sink for respiratory ATP.

Ertragsstruktur alter und neuer Winterweizensorten unter dem Aspekt der Einlagerung und Remobilisation von Fruktanen im Weizenhalm

Abstract Yield components in old and new german winter wheat varieties with respect to the storage and remobilization of fructan in the wheat stem Yield components and changes in carbohydrate content of four old german winter wheat varieties, bred before 1950, were compared with six new varieties over two years in field trials. In both years the old varieties built up more biomass than the new varieties. In the latter a better harvest‐index (0,56) as compared to the old varieties (0,43) was obtained, resulting in higher grain yields for the new varieties. Changes in water‐soluble carbohydrate (WSC) content were mainly due to variations in fructan content. Maximum of fructan content was mostly reached at the stage of early milk ripeness. In the new varieties a faster and more complete remobilization of fructan occurred; especially in the year with the short grainfilling period.

Fructan and cryoprotection in ryegrass (Lolium perenne L.).

Changes in carbohydrate content and composition of ryegrass (Lolium perenne L.) cv. Reveille field-grown in Normandy were investigated from May 1987 to May 1988. During the winter period, the concentrations of high DP (degree of polymerization) fructan were the lowest whilst those of ethanol-soluble carbohydrates were the highest. Ethanol-soluble carbohydrates also accounted for most of the non-structural carbohydrates of four cultivars of Lolium perenne field-grown in central France in January 1989. The accumulation of osmotically active carbohydrates during winter leads only to a small depression of freezing point and consequently, these sugars cannot be considered as efficient cryoprotectants in ryegrass.

Seasonal changes in carbohydrate content and frost resistance of leaves of Nothofagus species

The annual course of frost hardiness and soluble carbohydrate content in leaves of woody Nothofagus species, located at different attitudes in Southern Chile, were studied. Frost resistance reached a maximum in the coldest period and a minimum in spring or summer. Leaves from individuals subjected to lower temperatures (higher altitudes) were more frost-resistant than those from warmer conditions (lower altitudes). Frost resistance was positively correlated with total sugar accumulation. In N. dombeyi sucrose was the only sugar whose content correlated with frost resistance. At higher altitudes a slight increase of fructose with respect to sucrose was found. However, the accumulation of the individual sugars measured accounted for only a small fraction of the increase in soluble total carbohydrates. Therefore the observed resistance is associated most likely with other factors. Artificial hardening at 0° for different periods of time caused changes in the carbohydrate levels of leaves. A rapid but small increase in the sugar concentration and frost hardiness after two hr of hardening were found. The nature of cold-induced metabolic adjustments and their ecophysiological significance are discussed.

BIOLOGICAL EFFECTS OF CHRONIC ETHANOL CONSUMPTION: A REAPPRAISAL OF THE LIEBER-DE CARLI LIQUID-DIET MODEL WITH REFERENCE TO SKELETAL MUSCLE

This paper responds to the recent article by Rao et al. (Alcohol and Alcoholism 21, 369-373, 1986) which suggested that the Lieber-De Carli liquid diet for chronic ethanol-feeding studies may not be suitable for the rat because of the changes in carbohydrate content. The viability of the Lieber-De Carli model was, therefore, re-examined. The content of the liquid diet was shown to be nutritionally adequate, when compared to a solid laboratory chow. However, rats on an alcohol feeding regime had sub-optimal growth rates, because of a reduction in the amount of liquid diet consumed. When compared to pair fed controls, rats fed the ethanol-containing diet showed marked changes in skeletal muscle. These observations are similar to those in man and we conclude that the use of the Lieber-De Carli feeding regime in experimental animals is a suitable means of investigating the mechanism of skeletal myopathy.

Growth synchrony and cellular parameters of the unicellular nitrogen‐fixing marine cyanobacterium, Synechococcus sp. strain Miami BG 043511 under continuous illumination

A marine unicellular aerobic nitrogen‐fixing cyanobacterium Synechococcus sp. strain Miarni BG 043511 was pretreated with different light and dark regimes in order to induce higher growth synchrony. A pretreatment of two dark and light cycles of 16 h each yielded good synchrony for 3 cell division cycles. Longer dark treatments decreased the degree of synchrony and shorter dark treatments caused irregular cell division. Once synchronous culture was established, distinct phases of cellular carbohydrate accumulation and cellular carbohydrate degradation were observed even under continuous illumination. Changes in carbohydrate content were repeated in a cyclic manner with approximately 20 h intervals, the same as the cell division cycle. This change in carbohydrate metabolism provided a good index of growth synchrony under nitrogen‐fixing conditions.Photosynthetic oxygen evolution and nitrogen fixation capabilities and their activities in near, in situ, culture conditions were measured in well synchronized cultures of this strain under continuous illumination. Distinct oscillations of both photosynthetic oxygen evolution and nitrogen fixation capabilities with ca 20‐h intervals, similar to the interval of the cell division cycle, were observed for three cycles. However, the activities of photosynthetic oxygen evolution were inversely correlated with those of nitrogen fixation. During the nitrogen fixation period, net oxygen consumption was observed even in the light under conditions approximating in situ culture conditions. The phase of temporal appearance of nitrogenase activity during the cell division cycle coincided with the phase of carbohydrate net degradation. These data indicate that this unicellular cyanobacterium can grow diazotrophically under conditions of continuous illumination by the segregation of photosynthesis and nitrogen fixation within a cell division cycle.

Carbohydrate dynamics and growth rate of natural phytoplankton populations

Diurnal changes in carbohydrate content of natural phytoplankton populations differed from those found for cyanobacteria grown in continuous cultures. The carbohydrate accumulation rate was not constant during the light period. Also in contrast to results obtained using continuous cultures the photosynthetic characteristics changed during the light period. A close correlation was observed between changes in carbohydrate accumulation rate and the efficiency of photosynthesis over 24 hours. Seasonal changes in carbohydrate consumption rate over the dark period were proportional to changes in growth rate.

Studies on glomerular basement membrane in experimental diabetes using lectin histochemistry in Wistar rats

This study was designed to establish whether specific early changes in carbohydrate content of proteins in the glomerulus of the diabetic rat could be detected. Lectin staining of kidney sections from streptozotocin-induced diabetic rats were compared with similar sections from healthy and diabetic rats that were treated with insulin. Animal groups were killed 1 month, 3 months and 6 months after induction of diabetes. There were no differences in the staining of the glomerular basement membrane between control, insulin-treated and diabetic rats for the lectins concanavalin A, lotus tetragonolobus, soybean and kidney bean, with and without trypsinisation. Staining of the glomerular basement membrane with wheat germ agglutinin after trypsinisation was significantly increased in the diabetic group when compared to both healthy and insulin-treated groups (p less than 0.01). It was concluded that, in experimental diabetes mellitus in the rat, there is an accumulation of substances in the glomerular basement membrane and mesangium with an affinity for wheat germ agglutinin, most probably N-acetyl glucosamine, and this is partially prevented by insulin treatment.

Changes in carbohydrate contents of germinating cowpea seeds

A decrease in the concentration of total carbohydrates was observed during 144 hours' germination of three cowpea varieties. However, whilst starch, raffinose, stachyose and verbascose levels decreased, the reducing sugars, including glucose and fructose, increased. Starch was the major carbohydrate and about 50% of it was hydrolysed after 144 hours' germination. Changes also occurred in the concentration of the unavailable carbohydrates. Lignin contents increased slightly while hemicelluloses and celluloses decreased. The above-mentioned changes, occurring during germination, appear to have a favourable effect on the nutritional value of cowpea varieties.

Changes in Carbohydrate Concentration during Watermelon Juice Storage

Abstract Watermelon [Citrullus lanatus (Thunberg) Matsumura and Nakai] juice samples of ‘Allsweet’ and ‘Crimson Sweet’ were stored at 0° and −30°C. Concentrations of fructose, glucose, and sucrose were determined by using HPLC over a period of 44 days at 2- to 7-day intervals. Changes in sugar concentrations suggest that sucrose is hydrolyzed to fructose and glucose within a period of 10 days for samples stored at 0°. A 19.6% decrease in total sugar concentration was observed after 37 days storage. A 17.8% sugar loss also was observed in samples stored at −30° for 37 days.

DIEL PATTERNS OF CARBOHYDRATE METABOLISM IN LEAF BLADES AND LEAF SHEATHS OFPOA ANNUAL. ANDPOA×JEMTLANDICA(ALMQ.) RICHT.

SummaryA study was made of diel changes in carbohydrate content, net gas exchange and export from leaf blades and leaf sheaths inPoa annuaL. (a ruderal) andPoa×jemtlandica(Almq.) Richt. (a sub‐arctic grass). Sucrose was the most abundant form of carbohydrate in the leaf blades with lesser amounts of starch and fructans also present. The proportions of fixed carbon allocated to export, storage and respiration in leaf blades were similar, and carbohydrates showed broadly similar patterns of diel fluctuation, in both species. However, the relative rates of sucrose and starch accumulation and depletion and the diel patterns of export in the leaf blades were different in the two species. Starch was the predominant form of carbohydrate in the sheath, with soluble sugars and fructans also present. Starch and soluble sugars showed diel accumulation and depletion in the sheathsof Poa annuabut not inPoa×jemtlandica.The effects of extended darkness suggest that factors controlling carbohydrate metabolism in the sheath may be different to those operating in the leaf blade. The large fluxes of carbohydrate through the sheath suggest that it serves mainly as a thoroughfare for carbohydrates.

Correlative Changes in Carbohydrate Content and Starch Hydrolysing Enzymes in Corms of Saffron Crocus (Crocus sativus L.) during Dormancy and Sprouting

Summary Changes have been studied in the tissue level of starch and sugars, and the activity of amylase and starch phosphorylase in corms of saffron crocus (Crocus sativus L.) during their development. As sprouting progresses, starch content decreases and total sugars increase steadily. During dormancy, tissue concentration of soluble protein does not change appreciably but increases steadily as growth and development proceed in the buds. Protein related specific activity of amylase increases steadily as sprouting progresses. However, the electrophoretic pattern of amylases changes only after leaf and floral primordia have been initiated. The specific activity of soluble starch phosphorylase does not change markedly during the period of development between May and October, but that of granule-bound enzyme decreases progressively during the same period.

Carbohydrate reserves and root growth potential in Douglas-fir seedlings before and after cold storage

Carbohydrate reserves and root growth potential (RGP) of 2 + 0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were monitored through a lifting season and during dark, cold storage. Concentrations of total nonstructural carbohydrate and extractable sugars in root and stem tissues remained relatively constant through winter, while foliar sugars showed a sharp midwinter peak at about 195 mg•g−1 dry weight. RGP was lowest in November and March and peaked in January. During storage at +2 and −1 °C, carbohydrates were depleted in all tissues through respiratory consumption. In contrast, RGP increased during the first 6 months in storage and then fell rapidly. The results do not support the view that changes in RGP are driven by changes in carbohydrate concentrations. Storage may affect frost hardiness and drought resistance through its effect on sugar concentrations.

Growth and Nonstructural Carbohydrate Content of Southern Browse Species as Influenced by Light Intensity

Growth and Nonstructural Carbohydrate Content of Southern Browse Species as Influenced by Light Intensity