Effects of humic substances on carbohydrate metabolism of maize leaves

1991 ◽  
Vol 71 (2) ◽  
pp. 419-425 ◽  
Author(s):  
L. Merlo ◽  
R. Ghisi ◽  
C. Passera ◽  
N. Rascio
Keyword(s):  
Carbohydrate Metabolism ◽  
Humic Substances ◽  
Starch Content ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Sucrose Phosphate Synthase ◽  
Fructose 1,6 Bisphosphatase ◽  
Maize Leaves ◽  
Udpglucose Pyrophosphorylase ◽  
Sucrose Biosynthesis

Maize plants were grown in nutrient solution with or without 100 mg organic carbon L−1 of humic substances (HS) (MW > 12 000) extracted from a cambisol. To evaluate the effect of HS on leaf carbohydrate metabolism, after 14 d of growth apical and basal segments from the third leaf were collected and analyzed for sugar content and for the activities of enzymes involved in the synthesis and breakdown of starch and sucrose. Leaf starch content decreased in treated plants, whereas the level of soluble sugars increased. The decrease of starch was accompanied by an enhanced activity of amylase, whereas the activity of ADPglucose pyrophosphorylase was not affected. Activities of invertases and sucrose synthase were stimulated by HS treatment in apical tissue, and inhibited in basal one. Activities of enzymes involved in sucrose biosynthesis (sucrose phosphate synthase, cytoplasmic fructose-1,6- bisphosphatase, UDPglucose pyrophosphorylase) were stimulated or inhibited depending on the enzyme and on the tissue examined. Our results show that HS may affect both the level and percent distribution of sugars of maize leaves; these effects seem to be mediated by changes in the activities of enzymes involved in carbohydrate metabolism. Key words: Humic substances, enzymes, carbohydrate metabolism, maize

Sucrose Metabolism of Perennial Ryegrass in Relation to Cold Acclimation

2006 ◽  
Vol 61 (1-2) ◽  
pp. 99-104 ◽  
Author(s):  
Pankaj K. Bhowmik ◽  
Ken-ichi Tamura ◽  
Yasuhara Sanada ◽  
Kazuhiro Tase ◽  
Toshihiko Yamada
Keyword(s):  
Cold Acclimation ◽  
Perennial Ryegrass ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Sugar Metabolism ◽  
Sucrose Phosphate Synthase ◽  
Sugar Accumulation ◽  
Sucrose Metabolizing Enzymes ◽  
Acclimation Period ◽  
Sucrose Biosynthesis

Abstract Sugar metabolism is one of the important factors involved in winter hardiness and since the discovery of sucrose biosynthesis, considerable advances have been made in understanding its regulation and crucial role. This investigation examined the changes in activities of sucrose metabolizing enzymes and sugar content during cold hardening of perennial ryegrass (Lolium perenne L.). Changes in acid invertase (AI), sucrose synthase (SS) and sucrose phosphate synthase (SPS) along with all the three soluble sugars glucose, fructose and sucrose were measured in leaves and stem base tissue during cold acclimation. Although fructans were the predominant carbohydrate the changes in glucose, fructose and sucrose were significant. All the three soluble sugars in both leaf and stem tissues started to decrease from the first day and continued up to day 7 and thereafter started to increase until day 28. AI in the soluble fraction showed a higher activity than that in the cell wall bound fraction. In both the leaf and stem bases soluble AI activity increased during the first week and after that it started to decrease gradually. On the other hand both the SS and SPS increased gradually throughout the acclimation period. Sucrose content was negatively correlated with AI and positively correlated with SS and SPS accounting well for the relation between the substrate and enzyme activity. These results suggest that AI, SS and SPS in ryegrass are regulated by cold acclimation and play an important role in sugar accumulation and acquisition of freezing tolerance

Nutritional composition of fruit of four date palm (Phoenix dactylifera L.)cultivars grown in Haryana, India

2016 ◽  
Vol 35 (4) ◽  
Author(s):  
Vinita Vinita ◽  
Darshan Punia
Keyword(s):  
Dietary Fiber ◽  
Starch Content ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Reducing Sugar ◽  
Fiber Content ◽  
Crude Fibre ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Date Fruit

The present investigation was conducted to evaluate the nutrient composition of four varieties of date fruit. The results of the study indicated that the variety Shamran had highest protein (2.77%) content and the variety Medjool the lowest (1.88%). Fat and crude fibre contents of date fruit varieties ranged from 0.17 to 0.50% and 1.71 to 2.22%, respectively. The variety Medjool had lowest amount of total soluble sugars (67.49g/100g) and reducing sugar (61.31g/100g). All the varieties of date fruit differed non-significantly among themselves for their non- reducing sugar content. The variety Khadrawi had the highest amount of starch content. Total dietary fiber (11.70g/100g) and soluble dietary fiber (3.34g/100g) were highest in variety Hillawi. All the four varieties of date fruit differed significantly from each other for their total dietary fiber content and soluble dietary fiber content. The varieties Khadrawi (8.46%), Hillawi (8.35%) and Shamran (7.94%) had significantly (p£ 0.05) higher insoluble dietary fiber as compared to variety Medjool (4.25%). The variety Shamran had highest amount of calcium (195.33mg/100g) and zinc (1.81mg/100g). The variety Medjool contained lowest amount of calcium (70.33mg/100g), iron (1.91mg/100g) and potassium (713mg/100g) while the highest amount of phosphorus (52.66mg/100g). A non-significant (p£0.05) difference was observed in magnesium content of all the varieties. Polyphenol content of date fruits from different varieties ranged from 228.79 to 253.21 mg/100g.

scholarly journals Changes in Soluble Sugars, Sugar Profile, Starch and Proline in Developing Coconut (Cocos nucifera L.) Inflorescences

CORD ◽  
2008 ◽  
Vol 24 (1) ◽  
pp. 7
Author(s):  
Bandupriya H.D.D.
Keyword(s):  
Starch Content ◽  
Cocos Nucifera ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Total Sugar ◽  
Mature Stage ◽  
Inflorescence Development ◽  
Total Sugars ◽  
Total Sugar Content ◽  
Maturity Stages

Changes in soluble sugars, sugars profile, starch and proline levels in inflorescence rachillae from individual coconut palms were investigated during inflorescence development with the aim of determining a possible correlation between these characters and morphogenic potential of inflorescence tissues. Rachillae for analysis were collected from unopened inflorescences of -1 to -13 stages (considering the youngest open inflorescence as 0 stage) in decreasing order of maturity (–1 stage is the most mature stage whereas –13 is the most immature stage). Important differences among the maturity stages were observed for total sugars. In very tender inflorescences (-13 and -12), the total sugar content was very low whereas a gradual increase was observed from -11 to -7 stages, with  -7 stage having the highest level. The total sugar content in more mature inflorescences was relatively low, with the exception of -2 stage, which had a high total sugar content. In regard to sugar profiles, sucrose, fructose and glucose were the main soluble sugars present in coconut inflorescence and sucrose was the most abundant sugar in -5 to -9 maturity stages. Total soluble sugars and sucrose in maturity stages from -5 to -9 showed a very similar variation and significantly higher levels of sucrose were observed in -6 to -8 stages. The proline content in the mature stages, -1 to –3, was significantly lower than in the other stages with no significant variation in the stages –4 to –11. The pattern of variation in starch content was similar to that of proline which decreased with increasing maturity of inflorescence. In view of the results obtained, the higher accumulation of sucrose and total sugars in -6, -7 and -8 stages may have some significance in morphogenesis, especially as an energy source. The 10 cm length inflorescence that responds better for callusing falls within this range. Thus total sugar and sucrose content may be possible biochemical markers for assessing the morphogenic potential of inflorescence explants.

scholarly journals Effect of Short-Term Cold Treatment on Carbohydrate Metabolism in Potato Leaves

2021 ◽  
Vol 22 (13) ◽  
pp. 7203
Author(s):  
Sławomir Orzechowski ◽  
Dorota Sitnicka ◽  
Agnieszka Grabowska ◽  
Julia Compart ◽  
Joerg Fettke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carbohydrate Metabolism ◽  
Cold Exposure ◽  
Starch Content ◽  
Soluble Sugars ◽  
Plant Stress ◽  
Cold Treatment ◽  
Early Response ◽  
Starch Degradation ◽  
Short Term

Plants are often challenged by an array of unfavorable environmental conditions. During cold exposure, many changes occur that include, for example, the stabilization of cell membranes, alterations in gene expression and enzyme activities, as well as the accumulation of metabolites. In the presented study, the carbohydrate metabolism was analyzed in the very early response of plants to a low temperature (2 °C) in the leaves of 5-week-old potato plants of the Russet Burbank cultivar during the first 12 h of cold treatment (2 h dark and 10 h light). First, some plant stress indicators were examined and it was shown that short-term cold exposure did not significantly affect the relative water content and chlorophyll content (only after 12 h), but caused an increase in malondialdehyde concentration and a decrease in the expression of NDA1, a homolog of the NADH dehydrogenase gene. In addition, it was shown that the content of transitory starch increased transiently in the very early phase of the plant response (3–6 h) to cold treatment, and then its decrease was observed after 12 h. In contrast, soluble sugars such as glucose and fructose were significantly increased only at the end of the light period, where a decrease in sucrose content was observed. The availability of the monosaccharides at constitutively high levels, regardless of the temperature, may delay the response to cold, involving amylolytic starch degradation in chloroplasts. The decrease in starch content, observed in leaves after 12 h of cold exposure, was preceded by a dramatic increase in the transcript levels of the key enzymes of starch degradation initiation, the α-glucan, water dikinase (GWD-EC 2.7.9.4) and the phosphoglucan, water dikinase (PWD-EC 2.7.9.5). The gene expression of both dikinases peaked at 9 h of cold exposure, as analyzed by real-time PCR. Moreover, enhanced activities of the acid invertase as well as of both glucan phosphorylases during exposure to a chilling temperature were observed. However, it was also noticed that during the light phase, there was a general increase in glucan phosphorylase activities for both control and cold-stressed plants irrespective of the temperature. In conclusion, a short-term cold treatment alters the carbohydrate metabolism in the leaves of potato, which leads to an increase in the content of soluble sugars.

scholarly journals Carbohydrate metabolism in floral structures of Lilium pumilum in different development stages

2016 ◽  
Vol 46 (7) ◽  
pp. 1142-1144 ◽  
Author(s):  
Mirelle Nayana de Sousa Santos ◽  
Ana Maria Mapeli ◽  
Márcia Martins Tolentino
Keyword(s):  
Carbohydrate Metabolism ◽  
Reducing Sugars ◽  
Sugar Content ◽  
Soluble Sugars ◽  
High Energy ◽  
Reducing Sugar ◽  
Energy Potential ◽  
Open Flower ◽  
Total Soluble Sugars ◽  
Development Stages

ABSTRACT: Lilium pumilum is a species that stands out in floriculture for presenting orange inflorescences that attract the consumer. This study thus aimed at characterizing the carbohydrate metabolism of floral structures of L. pumilum in different development stages. For this purpose, carbohydrate levels (total soluble sugars, reducing sugars, non-reducing sugars, and starch), at different floral stages (E0 - bud with no color; E1 - bud at early coloring; E2 - orange bud; E3 - open flower; E4 - senescent flower) were quantified after extraction with ethanol. Lilium pumilum flowers showed high energy potential during floral opening and senescence; total soluble sugars were the main carbohydrates present in the species, reducing with the floral development, and the same occurred with the non-reducing sugar and starch contents. The reducing-sugar content increased with the floral stages. Therefore, this species presents great mobilization of compounds, which are utilized in the production of energy that is employed in floral opening.

scholarly journals (75) Sugars and Flower Induction in Poinsettia

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1065C-1065
Author(s):  
Emilia Orozco-Gaeta ◽  
Maria-Teresa Colinas-Leon ◽  
Luis-Alonso Valdez-Aguilar ◽  
Edilberto Avitia-Garcia ◽  
Ismael Leon-Rivera
Keyword(s):  
Starch Content ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Plant Part ◽  
Flower Induction ◽  
Starch Hydrolysis ◽  
Soluble Carbohydrates ◽  
Fresh Weight ◽  
Young Leaves ◽  
The Relationship

During Fall 2004, poinsettia plants were grown in a greenhouse (Texcoco, Edo. Mexico, 19°29'N). The objectives were to: 1) evaluate which soluble carbohydrates (mono- and disaccharides) are present in the cultivars Supjibi and Peter Star and their concentrations; 2) study the relationship between sugar content and flower induction; and 3) analyze the relationship between starch content and phenology of the plant. Apical meristems were prepared for microscopy, soluble sugars, and sugars from starch hydrolysis were studied by HPLC. Flower induction in `Supjibi' took place about 99 days after transplant (DAT), with no artificial short photoperiod. In `Peter Star', flower induction took place about 137 DAT, 19 days after initiation of short-day photoperiod. Soluble sugars found were: sucrose, maltose, glucose, and fructose (in order of the highest to lowest concentration). Concentration varied from 0.5% to 2.1% for `Supjibi' and from 1.1% to 2.9% for `Peter Star', based on fresh weight. Sucrose content is reduced in root and mature leaf during flower induction, probably sent to young leaves. During flower induction, there is also an increase in glucose in young leaves. Sugars from starch hydrolysis were: fucose, (6-desoxi-L-galactose), fructose, and galactose. Soluble sugars content generated from starch varies in each organ from 2.0% to 32% for `Supjibi', and from 2.0% to 39% in `Peter Star'. During induction, starch content is reduced (between 6% and 9%). After flower induction, there is an increase in leaf area and in starch content (from 32% to 39%), during bract development starch seems to be utilized in this plant part.

scholarly journals Dynamic Changes in Starch Metabolism and Endogenous Hormones during Stolon Formation in Tulipa edulis

2016 ◽  
Vol 141 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Yuanyuan Miao ◽  
Qiaosheng Guo ◽  
Zaibiao Zhu ◽  
Xiaohua Yang ◽  
Changlin Wang ◽  
...  
Keyword(s):  
Starch Content ◽  
Initial Period ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Sucrose Phosphate Synthase ◽  
Starch Synthase ◽  
Endogenous Hormones ◽  
Dynamic Changes ◽  
Total Soluble Sugar ◽  
Middle Period

The stolon is the main asexual reproductive organ of the medicinal plant Tulipa edulis and has special morphology. In the greenhouse experiment presented herein, the dynamic changes in carbohydrates and related enzymes, proteins, and endogenous hormones of stolons during T. edulis stolon formation were investigated. The results showed that the content of total soluble sugar, sucrose, reducing sugar, fructose, and starch were all significantly enhanced in the middle period when stolon emerged and maintained at relatively high levels until the later period of stolon formation, while protein content decreased during stolon formation. The activities of amylase (AMY), sucrose phosphate synthase (SPS), and sucrose synthase (SS) peaked in the initial period and were negatively correlated with soluble sugars. However, adenosine diphosphoglucose pyrophosphorylase (AGPase) activity increased as stolon formation progressed, and the changes in soluble starch synthase (SSS), granule-bound starch synthase (GBSS) activities presented a single peak, reaching their maximums in the middle period. AGPase, SSS, and GBSS activities were all positively related to starch content. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) verified the changes in SS and SSS activities via the expression levels of the SS, SSSI, and SSSII genes. The gibberellin (GA) and zeatin riboside (ZR) content attained their maximum in the initial period of stolon formation. Indole-3-acetic acid (IAA) and abscisic acid (ABA) remained at high levels during the initial and middle period and decreased significantly during the later period of stolon formation, inversely to the ratio of ABA:IAA. Analysis of the physiological changes in T. edulis stolon indicated that the accumulation of soluble sugars and starch via various enzymes, a high level of IAA and a low ABA to IAA ratio mainly contributed to stolon development of T. edulis. This paper explored carbohydrate levels and endogenous hormones profiles during stolon formation, which provided the theory basis for further regulating stolon growth of T. edulis.

scholarly journals Changes in Carbohydrate Metabolism in Two Kentucky Bluegrass Cultivars during Drought Stress and Recovery

2013 ◽  
Vol 138 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Zhimin Yang ◽  
Lixin Xu ◽  
Jingjin Yu ◽  
Michelle DaCosta ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Carbohydrate Metabolism ◽  
Poa Pratensis ◽  
Soluble Sugars ◽  
Sucrose Phosphate Synthase ◽  
Kentucky Bluegrass ◽  
Water Soluble ◽  
Drought Recovery ◽  
Physiological Analysis

Carbohydrate metabolism is important for plant adaptation to drought stress. The objective of this study was to examine major forms of carbohydrates associated with superior drought tolerance and post-drought recovery in kentucky bluegrass (Poa pratensis) by comparing responses of different forms of carbohydrates with drought stress and re-watering in two cultivars contrasting in drought tolerance. Plants of drought-tolerant ‘Midnight’ and drought-sensitive ‘Brilliant’ were maintained well watered or subjected to drought stress for 10 days by withholding irrigation, and drought-stressed plants were re-watered for 3 days. Physiological analysis (turf quality, relative water content, and electrolyte leakage) confirmed the genetic variability of the two cultivars in drought tolerance. The two cultivars exhibited differential responses to drought stress and re-watering for the content of water-soluble sugars (sucrose, fructose, and glucose) and storage carbohydrates (starch and fructan), and ‘Midnight’ maintained higher sucrose content at 10 days of drought stress and more fructan at 3 days of re-watering. The greater accumulation of sucrose in ‘Midnight’ under drought stress corresponded with higher activities of two sucrose-synthesizing enzymes (sucrose phosphate synthase and sucrose synthase) but was not related to the sucrose-degrading enzyme activity (acid invertase). These results suggested that increased sucrose accumulation resulting from the maintenance of active sucrose synthesis could be associated with superior turf performance during drought stress, whereas increased fructan accumulation could contribute to rapid re-growth and post-drought recovery on re-watering in kentucky bluegrass.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.). X.* Isoflavone formation and carbohydrate metabolism

1972 ◽  
Vol 23 (3) ◽  
pp. 419 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Carbohydrate Metabolism ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Leaf Expansion ◽  
Curvilinear Relationship ◽  
Controlled Environment ◽  
Low Light ◽  
Trifoliate Leaf ◽  
Carbon Substrates

The relationships between isoflavone formation and carbohydrate metabolism were studied in a controlled-environment experiment at low (4700 lux) and high (31,200 lux) light intensities. During expansion of the first trifoliate leaf, isoflavone contents per cell were much lower at low light supply than at high. These low isoflavone contents were associated with low contents of sugars and starch. Protein and cell walls were less affected by low light than were sugars and starch and, presumably, competed strongly with isoflavones for carbon substrates. From the results of this and earlier controlled-environment experiments a close curvilinear relationship was obtained between isoflavones and soluble sugars per cell at the stage of full leaf expansion (when isoflavone synthesis normally ceases). Thus soluble sugar content provided a good index of the level of carbon substrates used for isoflavone synthesis. Some instances where isoflavones increase after full leaf expansion are also discussed. _________________ *Part IX, Aust. J. Agric. Res., 23: 411 (1972).

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