scholarly journals Cell-wall polysaccharides and glycoproteins of parenchymatous tissues of runner bean (Phaseolus coccineus)

1990 ◽  
Vol 269 (2) ◽  
pp. 393-402 ◽  
Author(s):  
P Ryden ◽  
R R Selvendran
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Anion Exchange Chromatography ◽  
Structural Features ◽  
Good Evidence ◽  
Exchange Chromatography ◽  
Cell Wall Polysaccharides ◽  
Pectic Polysaccharides ◽  
Runner Bean ◽  
Cellulose Residue

1. Polymers were solubilized from the cell walls of parenchyma from mature runner-bean pods with minimum degradation by successive extractions with cyclohexane-trans-1,2-diamine-NNN′N′-tetra-acetate (CDTA), Na2CO3 and KOH to leave the alpha-cellulose residue, which contained cross-linked pectic polysaccharides and Hyp-rich glycoproteins. These were solubilized with chlorite/acetic acid and cellulase. The polymers were fractionated by anion-exchange chromatography, and fractions were subjected to methylation analysis. 2. The pectic polysaccharides differed in their ease of extraction, and a small proportion were highly cross-linked. The bulk of the pectic polysaccharides solubilized by CDTA and Na2CO3 were less branched than those solubilized by KOH. There was good evidence that most of the pectic polysaccharides were not degraded during extraction. 3. The protein-containing fractions included Hyp-rich and Hyp-poor glycoproteins associated with easily extractable pectic polysaccharides, Hyp-rich glycoproteins solubilized with 4M-KOH+borate, the bulk of which were not associated with pectic polysaccharides, and highly cross-linked Hyp-rich glycoproteins. 4. Isodityrosine was not detected, suggesting that it does not have a (major) cross-linking role in these walls. Instead, it is suggested that phenolics, presumably linked to C-5 of 3,5-linked Araf residues of Hyp-rich glycoproteins, serve to cross-link some of the polymers. 5. There were two main types of xyloglucan, with different degrees of branching. The bulk of the less branched xyloglucans were solubilized by more-concentrated alkali. The anomeric configurations of the sugars in one of the highly branched xyloglucans were determined by 13C-n.m.r. spectroscopy. 6. The structural features of the cell-wall polymers and complexes are discussed in relation to the structure of the cell walls of parenchyma tissues.

scholarly journals Coffee carbohydrates

2006 ◽  
Vol 18 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Robert Redgwell ◽  
Monica Fischer
Keyword(s):  
Cell Wall ◽  
Potential Role ◽  
Structural Features ◽  
Coffee Bean ◽  
Cell Wall Polysaccharides ◽  
Pectic Polysaccharides ◽  
Specific Polysaccharide ◽  
Chemical Studies ◽  
First Time ◽  
Detailed Chemical

This review summarises recent advances in the chemistry, physiology and molecular properties of coffee carbohydrates with a particular focus on the cell wall polysaccharides. The results of detailed chemical studies have demonstrated novel structural features of both the galactomannans and the arabinogalactan polysaccharides of the green and roasted coffee bean. For the first time immunological probes based on monoclonal antibodies for specific polysaccharide epitopes were used to reveal the patterns of distribution of the galactomannans, arabinogalactans and pectic polysaccharides in the coffee bean cell wall. Finally, the results of physiological and molecular studies are presented which emphasise the growing awareness of the potential role the metabolic status of the green bean may play in final coffee beverage quality.

scholarly journals Changes in pectins of the Xylopodium of Ocimum nudicaule from dormancy to sprouting

2006 ◽  
Vol 18 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Márcia Regina Braga ◽  
Nicholas C. Carpita ◽  
Sonia M. C. Dietrich ◽  
Rita de Cássia L. Figueiredo-Ribeiro
Keyword(s):  
Cell Wall ◽  
Molecular Mass ◽  
Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Pectic Polysaccharides ◽  
Pectic Polysaccharide ◽  
Rhamnogalacturonan I ◽  
Composition And Structure ◽  
Cell Wall Extension ◽  
Phenological Phases

The thickened underground organ of Ocimum nudicaule is a tuber-like structure (xylopodium) that is dormant in winter and sprouts at the beginning of the spring. Changes in content of cell wall polysaccharides were shown to occur from dormancy to sprouting. Pectic polysaccharides of O. nudicaule were analyzed in relation to composition, molecular mass, and linkage structure in these two phenological phases. The pectin content was 33 % lower during sprouting when compared to dormancy. Changes were also observed in the molecular mass of the pectin fraction from dormancy to sprouting. Galacturonic acid was the predominant sugar, suggesting the presence of a homogalacturonan as the main pectic polysaccharide. A decrease in the acidic polysaccharides, homogalacturonans and rhamnogalacturonan I, equally accounted for the decrease in the pectin composition upon sprouting. These acidic carbohydrates were predominantly detected in the cell walls of the phellogen region of the xylopodium, suggesting catabolism of the cell walls of this tissue during bud flushing. These results suggest that variations in the content and in the molecular mass of pectins, in addition to changes in their composition and structure could be related to storage function as well as cell wall extension growth, both required for the sprouting of new buds in the xylopodium of O. nudicaule.

scholarly journals Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1263
Author(s):  
David Stuart Thompson ◽  
Azharul Islam
Keyword(s):  
Cell Wall ◽  
Water Content ◽  
Bacterial Cellulose ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Plant Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Degree Of Hydration ◽  
Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

scholarly journals STRUCTURAL AND CHEMICAL CHARACTERISTIC OF PECTIN FROM PICEA ABIES GREENERY

2020 ◽  
pp. 59-71
Author(s):  
Evgeniy Gennad'yevich Shakhmatov ◽  
Elena Nikolayevna Makarova
Keyword(s):  
Cell Walls ◽  
New Technologies ◽  
Chemical Characteristic ◽  
Structural Features ◽  
Exchange Chromatography ◽  
Raw Material ◽  
Rhamnogalacturonan I ◽  
Wood Processing ◽  
Potential Source ◽  
Pectin Substances

The present work aimed to determine structural features of polysaccharides derived from the P. abies foliage by extraction with a (NH4)2C2O4 solution. The isolated polysaccharide was studied in detail by the methods of ion exchange chromatography, partial acidic hydrolys and NMR spectroscopy. It was shown that this polysaccharide contained polymers of various structures. The major constituents of PAO were low-methoxyl and low-acetylated 1,4-a-D-galacturonan and by minor parts of partly 2-O- and/or 3-O- acetylated rhamnogalacturonan-I (RG-I). The side carbohydrate chains of the branched region of RG-I were represented predominantly by highly branched 1,5-a-L-arabinan and minor portions of 1,4-β-D-galactan. In addition to the dominant pectins, polysaccharide PAO contained binding glycans of the glucomannans class, which indicated a close interaction of these polysaccharides in the cell walls. Thus, the structural features of pectin woody P. abies, extracted with a solution of (NH4)2C2O4, were first determined. It can be concluded that P. abies woody greens, a large tonnage waste from the wood processing industry, can be considered as a potential source of pectin substances. The results of studying the structure of components of woody green P. abies can be the basis for the development and improvement of new technologies for the integrated use of this raw material.

scholarly journals Modification of Cell Wall Polysaccharides during Drying Process Affects Texture Properties of Apple Chips

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Min Xiao ◽  
Jianyong Yi ◽  
Jinfeng Bi ◽  
Yuanyuan Zhao ◽  
Jian Peng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Structural Characteristics ◽  
Volume Ratio ◽  
Short Wave ◽  
Cell Wall Polysaccharide ◽  
Cell Wall Polysaccharides ◽  
Rehydration Ratio ◽  
Pectic Polysaccharides ◽  
Texture Properties ◽  
Instant Controlled Pressure Drop

The influences of hot air drying (AD), medium- and short-wave infrared drying (IR), instant controlled pressure drop drying (DIC), and vacuum freeze drying (FD) on cell wall polysaccharide modification were studied, and the relationship between the modifications and texture properties was analyzed. The results showed that the DIC treated apple chips exhibited the highest crispness (92) and excellent honeycomb-like structure among all the dried samples, whereas the FD dried apple chips had low crispness (10), the minimum hardness (17.4 N), and the highest volume ratio (0.76) and rehydration ratio (7.55). Remarkable decreases in the contents of total galacturonic acid and the amounts of water extractable pectin (WEP) were found in all the dried apple chips as compared with the fresh materials. The highest retention of WEP fraction (102.7 mg/g AIR) was observed in the FD dried apple chips, which may lead to a low structural rigidity and may be partially responsible for the lower hardness of the FD apple chips. In addition, the crispness of the apple chips obtained by DIC treatment, as well as AD and IR at 90°C, was higher than that of the samples obtained from the other drying processes, which might be due to the severe degradation of pectic polysaccharides, considering the results of the amounts of pectic fractions, the molar mass distribution, and concentrations of the WEP fractions. Overall, the data suggested that the modifications of pectic polysaccharides of apple chips, including the amount of the pectic fractions and their structural characteristics and the extent of degradation, significantly affect the texture of apple chips.

Composition and structural features of cell wall polysaccharides from tomato fruits

1990 ◽  
Vol 29 (3) ◽  
pp. 725-731 ◽  
Author(s):  
Graham B. Seymour ◽  
Ian J. Colquhoun ◽  
M.Susan Dupont ◽  
Keith R. Parsley ◽  
Robert R. Selvendran
Keyword(s):  
Cell Wall ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Tomato Fruits

Ultrastructural Changes in the Cell Walls of Cambial Derivatives During Wood Formation in Indian ELM (Holoptelea Integrifolia)

IAWA Journal ◽  
2012 ◽  
Vol 33 (4) ◽  
pp. 403-416 ◽  
Author(s):  
Karumanchi S. Rao ◽  
Yoon Soo Kim ◽  
Pramod Sivan
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Middle Lamella ◽  
Ultrastructural Changes ◽  
Cell Wall Polysaccharides ◽  
Lignin Distribution ◽  
Parenchyma Cells ◽  
Ray Cells ◽  
Xylem Elements ◽  
S2 Layer

Sequential changes occurring in cell walls during expansion, secondary wall (SW) deposition and lignification have been studied in the differentiating xylem elements of Holoptelea integrifolia using transmission electron microscopy. The PATAg staining revealed that loosening of the cell wall starts at the cell corner middle lamella (CCML) and spreads to radial and tangential walls in the zone of cell expansion (EZ). Lignification started at the CCML region between vessels and associated parenchyma during the final stages of S2 layer formation. The S2 layer in the vessel appeared as two sublayers,an inner one and outer one.The contact ray cells showed SW deposition soon after axial paratracheal parenchyma had completed it, whereas noncontact ray cells underwent SW deposition and lignification following apotracheal parenchyma cells. The paratracheal and apotracheal parenchyma cells differed noticeably in terms of proportion of SW layers and lignin distribution pattern. Fibres were found to be the last xylem elements to complete SW deposition and lignification with differential polymerization of cell wall polysaccharides. It appears that the SW deposition started much earlier in the middle region of the fibres while their tips were still undergoing elongation. In homogeneous lignin distribution was noticed in the CCML region of fibres.

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