Ion behaviour in plant cell walls. IV. Selective cation binding by Sphagnum russowii cell walls

1990 ◽  
Vol 68 (4) ◽  
pp. 773-781 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Divalent Cations ◽  
Selectivity Coefficient ◽  
Weak Acid ◽  
Small Population ◽  
Cation Binding ◽  
Trivalent Cations ◽  
Using Data ◽  
A Site

Selective cation binding by Sphagnum russowii cell walls was investigated using data from bicationic potentiometric titrations of isolated cell walls. Selectivity measurements were interpreted in the context of Manning condensation. In titrations with cations of different valency, selectivity favoured the higher valency cation, as expected in Manning condensation. This selectivity generally increased with bathing pH until the wall-bound polyuronic acids became fully ionized (pH > 5). The selectivity coefficient order at full ionization was Na+–Ca2+ > Na+–La3+ > Ca2+–La3+, as predicted by the weak acid Donnan–Manning (WADM) model. Other phenomena also appear to influence binding selectivity. A small population of isolated binding sites are more effectively neutralized by univalent (or divalent) than divalent (or trivalent) cations. High selectivity for cations of lower valency at low pH also suggests a site isolation effect. In bicationic titrations involving divalent cations only, Sr24+ and Ca2+ were bound by the cell wall with approximately equal effectiveness, as predicted by the WADM model. However, cation or binding site specificities probably account for the favoured binding of Ca2+ over Mg2+ by the cell wall. Key words: ion exchange, cell wall, selectivity.

Ion behaviour in plant cell walls. III. Measurement of the mean charge separation distance and the linear charge density parameter in delignified Sphagnum russowii cell walls

1990 ◽  
Vol 68 (4) ◽  
pp. 768-772 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty
Keyword(s):  
Cell Wall ◽  
Charge Density ◽  
Charge Separation ◽  
Cell Walls ◽  
Separation Distance ◽  
Cation Binding ◽  
Density Parameter ◽  
Linear Charge Density ◽  
The Mean ◽  
Mean Charge

According to the Manning condensation theory, the structure of cation-binding uronates in the cell wall can influence ionic behaviour. Assuming the theory is valid, we measured, in cation-binding experiments, the dimensionless linear charge density parameter and the mean charge separation distance in the fully ionized delignified Sphagnum russowii cell wall. Our charge separation estimate, 1.00 ± 0.02 nm, indicates that approximately 1.3 neutral sugars are interpolated between the uronic acids in the polyuronate chains of the cation exchanger. This compares well with chemical data of isolated wall fractions from another Sphagnum species reported by other workers. The charge density parameter estimate, 0.71 ± 0.02, implies that univalent cations never condense, whereas cations with two or more positive charges condense when the degree of ionization of the fixed (wall) charges is high enough. Key words: ion exchange, cell wall, charge density.

Microdistribution of copper in copper-ethanolamine (Cu-EA) treated southern yellow pine (Pinus spp.) related to density distribution

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Jinzhen Cao ◽  
D. Pascal Kamdem
Keyword(s):  
Cell Wall ◽  
Density Distribution ◽  
Cell Walls ◽  
Middle Lamella ◽  
Treated Wood ◽  
Yellow Pine ◽  
Using Data ◽  
Pinus Spp ◽  
Southern Yellow Pine ◽  
The Relationship

Abstract The relationship between copper absorption and density distribution in wood cell walls was investigated in this study. The density distribution on layer level was obtained from two approaches: (1) calculation by using data obtained from literature; (2) microdistribution of carbon and oxygen atoms in the wood cell. The microdistribution of carbon and oxygen in untreated southern yellow pine (Pinus spp.) sapwood, as well as copper in cell walls of copper-ethanolamine (Cu-EA) treated wood was determined by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDXA). Both approaches for density distribution led to the same result: the density was higher in the compound middle lamella and cell corners than in the secondary wall. The concentration/intensity of Cu, C and O in the cell wall follow the same trend as the density distribution; suggesting that density may play a major role in SEM-EDXA study of the distribution of metal-containing wood preservatives within the wood cell wall.

The interaction of divalent cations with pectic substances and their influence on acid-induced cell wall loosening

1981 ◽  
Vol 59 (8) ◽  
pp. 1522-1525 ◽  
Author(s):  
Mark Tepfer ◽  
Iain E. P. Taylor
Keyword(s):  
Cell Wall ◽  
Growth Inhibition ◽  
Binding Affinity ◽  
Higher Plants ◽  
Divalent Cations ◽  
Cation Binding ◽  
Cell Wall Loosening ◽  
Good Correspondence ◽  
Cation Binding Site ◽  
Wall Loosening

Certain divalent cations are potent inhibitors of acid-induced cell wall loosening in both higher plants and green algae. It has been proposed that this inhibition involves the formation of pectic gels in the cell wall. To test this hypothesis, we have looked for a relationship between the ability of various ions to inhibit growth and (i) their ability to cause gelation of isolated pectins, (ii) their binding affinity for isolated cell walls, and (iii) their binding affinity for purified pectin. There is good correspondence between the effectiveness of an ion as a growth inhibitor and its binding affinity for the cell wall. There is very poor correspondence between growth inhibition and the ability to induce the gelation of pectin. Our results indicate that pectic gel formation is not involved in cation-induced growth inhibition, but that the major cation binding site in the cell wall may be involved in a nongel-forming capacity.

scholarly journals IONIC EFFECTS ON LIGNIFICATION AND PEROXIDASE IN TISSUE CULTURES

1965 ◽  
Vol 25 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Jacques Lipetz ◽  
Anthony J. Garro
Keyword(s):  
Cell Wall ◽  
Crown Gall ◽  
Cell Walls ◽  
Tumor Tissue ◽  
Divalent Cations ◽  
Tissue Cultures ◽  
Crown Gall Tumor ◽  
Washed Cell ◽  
Calcium Magnesium ◽  
Ionic Effects

Crown-gall tumor tissue cultures release peroxidase into the medium in response to the concentration of specific ions in the medium. This release is not due to diffusion from cut surfaces or injured cells. Calcium, magnesium, and ammonium were, in that order, most effective in increasing peroxidase release. The enzyme was demonstrated cytochemically on the cell walls and in the cytoplasm. Cell wall fractions, exhaustively washed in buffer, still contained bound peroxidase. This bound peroxidase could be released by treating the wall fractions with certain divalent cations or ammonium. The order of effectiveness for removing the enzyme from the washed cell walls is: Ca++ ≈ Sr++ > Ba++ > Mg++ > NH4+. These data support the thesis presented that specific ions can control the deposition of lignin on cell walls by affecting the peroxidase levels on these walls.

Action of ethylenediaminetetraacetic acid, tris(hydroxymethyl)aminomethane, and lysozyme on cell walls of Pseudomonas aeruginosa

1968 ◽  
Vol 14 (8) ◽  
pp. 913-922 ◽  
Author(s):  
S. T. Cox Jr. ◽  
R. G. Eagon
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Cell Walls ◽  
Ethylenediaminetetraacetic Acid ◽  
Individual Cell ◽  
Intact Cell ◽  
Divalent Cations ◽  
Total Cell ◽  
The Individual ◽  
Phosphate Groups

Incubation of isolated cell walls of Pseudomonas aeruginosa with tris(hydroxymethyl)aminomethane (Tris), ethylenediaminetetraacetic acid (EDTA), and lysozyme, either singly or in combinations, results in partial solubilization of the cell walls.When cell walls were incubated with a combination of Tris and EDTA, approximately 30% of the total cell wall and 32% of the lipopolysaccharide fraction were solubilized. The following percentages of the individual cell wall constituents were solubilized: protein, 19%; carbohydrate, 35%; lipid, 5%; ash, 54%; and, phosphorus 23%. When lysozyme was included with Tris and EDTA, approximately 36% of the total cell wall and 86% of the lipopolysaccharide fraction were solubilized. Solubilization of the individual cell wall constituents was similarly increased.Phospholipids, which make up 7–8% of the intact cell wall of P. aeruginosa, were not released by incubation of the cell walls with these agents. Fatty acids in addition to those found in the lipopolysaccharide, however, were detected in the solubilized cell wall materials.Incubation systems composed of Tris, of EDTA, and of Tris and lysozyme solubilized cell walls to a lesser extent than incubation systems of Tris and EDTA, and of Tris, EDTA, and lysozyme. Incubation of cell walls in water, furthermore, was effective in solubilizing approximately 8% of the cell walls. Muramic acid containing materials were solubilized only in the presence of lysozyme.Materials liberated from cell walls which were incubated in systems containing EDTA exhibited single symmetrical Schlieren peaks characterized by uncorrected sedimentation constants of approximately 7 S, suggesting the release of homogenous subunits from the cell walls.Intra- and inter-molecular cross-linking by divalent cations via phosphate groups contained in lipoprotein and lipopolysaccharide components of the cell wall of P. aeruginosa is proposed.

Ion behavior in plant cell walls. I. Characterization of the Sphagnum russowii cell wall ion exchanger

1989 ◽  
Vol 67 (2) ◽  
pp. 451-459 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty
Keyword(s):  
Cell Wall ◽  
Cation Exchange ◽  
Binding Sites ◽  
Cell Walls ◽  
Weak Acid ◽  
Wall Material ◽  
Plant Cell Walls ◽  
Donnan Free Space ◽  
Donnan Model

The ion-exchange properties of Sphagnum russowii cell wall material were studied in the context of the Donnan weak acid model. Titrations in the presence of Na+, Ca2+, or La3+ revealed two classes of weak acid binding sites, one with a low pK between 2 and 4 and the other with a high pK > 5. The total cation-exchange capacities of the low and high pK species were 1071 and 545 μequiv./g dry wt. wall material, respectively, and were related to the uronic, amino, and phenolic acid contents of the walls. Differences in pK estimates obtained in the presence of the different cations (pKNa > pKCa > pKLa) could not be explained by our semiarbitrary choice (1 mL/dry wt. wall material), for the effective volume (Donnan free space) bathing the exchange sites. It was concluded that valence-dependent reductions in cation activities in the wall phase are an important contributor to the differences in the pK estimates. Key words: cation exchange, cell wall, titration, Donnan model, weak acid.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

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