Cation-exchange capacity of plant cell walls at neutral pH

1985 ◽  
Vol 36 (11) ◽  
pp. 1065-1072 ◽  
Author(s):  
Michael S. Allen ◽  
Michael I. McBurney ◽  
Peter J. Van Soest
Keyword(s):  
Cation Exchange ◽  
Plant Cell ◽  
Cell Walls ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Plant Cell Walls ◽  
Neutral Ph

Measurement of Cation Exchange Capacity (CEC) of Plant Cell Walls by X-Ray Microanalysis (EDX) in the Transmission Electron Microscope

2007 ◽  
Vol 13 (4) ◽  
pp. 233-244 ◽  
Author(s):  
Eberhard Fritz
Keyword(s):  
Electron Microscope ◽  
Cation Exchange ◽  
Plant Cell ◽  
Transmission Electron Microscope ◽  
Cell Walls ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Root Tissue ◽  
Plant Cell Walls ◽  
Transmission Electron

Cation exchange capacity (CEC) characterizes the number of fixed negative charges of plant cell walls and is an important parameter in studies dealing with the uptake of ions into plant tissues, especially in roots. Conventional methods of CEC determination use bulk tissue, the results are the mean of many cells, and differences in the CEC of different tissue types are masked. Energy-dispersive microanalysis (EDX) in the transmission electron microscope allows CEC determinations on much finer scales. Shoot and fine root tissue ofPicea abieswas acid washed to remove exchangeable cations. Tissue blocks or semithin tissue sections were loaded with 0.2 mM CaCl2, AlCl3, or Pb(NO3)2at pH 4.0. The amount of Ca, Al, or Pb adsorbed to the exchange sites of cell walls was determined by EDX. The CEC of cell walls of different tissue types was highly different, ranging in shoot tissues from 0 to 856 mM Ca and 5.8 to 1463 mM Al (block loading) or 4.3 to 1116 mM Ca and 0 to 2830 mM Al (section loading). In root tissue, Pb adsorption to semithin sections yielded CEC values between 29.1 and 954 mM Pb. In mostP. abiesshoot tissues, the binding capacity was clearly higher for Al than for Ca.

Ion behavior in plant cell walls. II. Measurement of the Donnan free space, anion-exclusion space, anion-exchange capacity, and cation-exchange capacity in delignified Sphagnum russowii cell walls

1989 ◽  
Vol 67 (2) ◽  
pp. 460-465 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Free Space ◽  
Cell Walls ◽  
Cation Exchange Capacity ◽  
Dry Weight ◽  
Exchange Capacity ◽  
Anion Exchange Capacity ◽  
Anion Exclusion ◽  
Donnan Free Space

Isolated delignified cell walls from Sphagnum russowii Warnsdorf were incubated in various chloride salt solutions at neutral pH (pH 7 – 8), and ion sorption was measured directly by neutron activation analysis. The anion-exchange capacity was estimated to be 63 – 66 μequiv./g dry weight of wall material in the protonated form. The volume of the anion-exclusion space was 2.63 ± 0.21 (± SD, n = 3) and 1.65 ± 0.35 (± SD, n = 2) mL/g dry weight in NaCl and CaCl2, respectively. A novel approach to measure the Donnan free space is proposed: for walls equilibrated in a salt mixture containing 10 mequiv./L NaCl and 10 mequiv./L CaCl2, the Na+ ions can be considered "uncondensed" in the Manning sense. From the Donnan relationship for Na+ and Cl− ions in the internal and external phases, the Donnan free space was calculated to be 1.77 mL/g dry weight. Titrating walls from pH 2.1 to 9.1 in the presence of 10 mequiv./L NaCl and 10 mequiv./L CaCl2 revealed a maximum cation-exchange capacity above pH 6 of ca. 1900 μequiv./g dry weight. This corresponds to a fixed anionic charge concentration in the Donnan free space of 1.1 M. Key words: ion exchange, cell wall, Donnan free space.

Biosynthèse des pectines et différenciation des fibres cellulosiques au cours de la croissance du lin

1989 ◽  
Vol 67 (1) ◽  
pp. 135-139 ◽  
Author(s):  
O. Morvan ◽  
A. Jauneau ◽  
C. Morvan ◽  
H. Voreux ◽  
M. Demarty
Keyword(s):  
Cell Wall ◽  
Cation Exchange ◽  
Cell Walls ◽  
Cation Exchange Capacity ◽  
Stem Elongation ◽  
Exchange Capacity ◽  
Pectin Content ◽  
Cellulose Deposition ◽  
Cellulosic Fibres ◽  
Elongation Phase

During the first stage of flax growth, stem elongation reaches 2.4 cm per day and the percentage of cell wall remains quite constant (4–15%). Cellulosic fibres develop principally during capsule formation and seed maturation. During the latter stage, the proportion of walls increases from 15 to 60% and the elongation is diminished to 0.5 cm per day. The lowering of the cation exchange capacity and of the pectin content of the cell walls during growth results principally from increased cellulose deposition in the fibre cells. The changes in the cation exchange capacity and in the percentage of cell wall show that when cellulose biosynthesis predominates, there is a continuous synthesis of pectins (10–15%) during the development of the plant. Methylated pectins are synthesized during the elongation phase. During maturation, the relative amounts of highly and less methylated pectins remain the same and thus it is not possible to determine what type of pectin is preferentially synthesized.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

EVALUASI PERUBAHAN KUALITAS TANAH PADA LAHAN BEKAS PENAMBANGAN NIKEL DI PULAU GEBE

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo
Keyword(s):  
Organic Carbon ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Mining Activity ◽  
Evaluation Activity ◽  
Land Quality ◽  
Environment Quality

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan

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