scholarly journals Changes in the ultrastructure of meristematic root cells of Allium sativum L. treated with selenium

2014 ◽  
Vol 69 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Sława Glińska ◽  
Barbara Gabara
Keyword(s):  
Cell Wall ◽  
Allium Sativum ◽  
Stress Factors ◽  
Ultrastructural Changes ◽  
Wall Material ◽  
Sodium Selenate ◽  
Cell Wall Material ◽  
Root Cells ◽  
Selenium Compounds ◽  
Material Deposition

Ultrastructure of meristematic cells of garlic (<em>Allium sativum</em> L.) roots treated with sodium selenate and sodium selenite was assessed using transmission electron microscopy. Both selenium compounds applied at the concentrations: 80, 160 and 320 µM caused many malformations in the ultrastructure of mitochondria, plastids, endoplasmic reticulum and Golgi apparatus such as deformation in shape and size, disturbances in inner membranes organization, appearance of concentric or parallel arrangement of ER cisternae. Moreover, in the presence of selenium, beside uneven thickening of cell wall, many vacuoles of different dimensions filled with wall-like material even in the vicinity of nucleus were visible. The latter results suggest that selenium not only intensified the synthesis of cell wall material but also inhibited the process of cell wall material deposition. The similarity of all observed ultrastructural changes in garlic root cells after selenium treatment with those appearing after action of other stress factors are discussed.

scholarly journals The amounts and rates of export of polysaccharides found within the membrane system of maize root cells

1974 ◽  
Vol 142 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Dianna J. Bowles ◽  
D. H. Northcote
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Golgi Apparatus ◽  
Cell Surface ◽  
Rough Endoplasmic Reticulum ◽  
Membrane System ◽  
Maize Root ◽  
Wall Material ◽  
Cell Wall Material ◽  
Root Cells

1. Maize seedling roots were incubated in vivo with d-[U-14C]glucose for 2, 5, 10, 15, 30 and 45min. The total incorporation of radioactivity into polysaccharide components in isolated fractions was investigated, and the pattern of incorporation into different polysaccharide components within the rough endoplasmic reticulum, Golgi apparatus and exported material was analysed. 2. The membrane compartments reached a saturation value of radioactivity in polysaccharide components by 30min incubation. Radioactivity in exported polysaccharide continued to increase after that time. The latter was formed and maintained by a steady-state turnover of polysaccharide synthesis and transport from the membrane system. 3. If the only access of the slime polysaccharide to the cell surface is via dictyosome-derived vesicles, the amount of slime components in the Golgi apparatus would have to be displaced every 0.3min in order to maintain the observed rates of increase in slime. This is in contrast with a displacement time of about 2.5min that is necessary for polysaccharide components in the Golgi apparatus to produce the observed increase in cell-wall material. The activity of the membrane system in the production of maize root slime is 8 times as great as that of the membrane system involved in cell-wall synthesis. 4. If the amount of polysaccharide material in the Golgi apparatus is maintained only by inflow of polymeric material from the rough endoplasmic reticulum the total amount of slime components in the rough endoplasmic reticulum would have to be displaced every 7min to maintain a constant amount in the Golgi apparatus. If the endoplasmic reticulum contributed directly to the cell surface in the synthesis of cell-wall material, displacement times necessary to maintain the observed rate of polymer production would be very slow.

Ultrastructural changes in the myxamoebae of Physarum polycephalum in response to a microcyst-inducing concentration of mannitol

1984 ◽  
Vol 62 (2) ◽  
pp. 272-280 ◽  
Author(s):  
Lynda M. Williams ◽  
Jean-G. Lafontaine
Keyword(s):  
Cell Wall ◽  
Osmotic Potential ◽  
Physarum Polycephalum ◽  
Morphological Changes ◽  
Ruthenium Red ◽  
Ultrastructural Changes ◽  
Wall Material ◽  
Cell Wall Material ◽  
Cell Coat ◽  
Ruthenium Red Staining

The response of axenically cultured Physarum polycephalum myxamoebae to a microcyst-inducing concentration of mannitol (0.5 M) has been studied for both log-phase and maximum-concentration cultures. Results indicate that mannitol alone is not sufficient to induce encystment; a population effect is also necessary. Myxamoebae may continue to divide in the presence of mannitol if this effect is absent. Early ultrastructural changes have been noted indicating that the primary mode of action of mannitol is via the change in osmotic potential of the medium. Nuclear and cytoplasmic ultrastructural changes during the encystment process are documented. Recovery of log-phase cells to undergo mitosis involves definite morphological changes, which are also described. Ruthenium red staining was utilised to emphasize changes in the cell coat and indicate possible sites of accumulation of cell wall material.

Synchrotron infrared microspectroscopy reveals the response of Sphagnum cell wall material to its aqueous chemical environment

2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Chemical Environment ◽  
Wall Material ◽  
Organic Soils ◽  
Cell Wall Material ◽  
Acid Base ◽  
Widespread Species ◽  
Flowing Liquid ◽  
Infrared Microspectroscopy

Environmental contextSphagnum moss is a widespread species in peatlands globally and responsible for a large fraction of carbon storage in these systems. We used synchrotron infrared microspectroscopy to characterise the acid-base properties of Sphagnum moss and the conditions under which calcium uptake can occur (essential for plant tissue integrity). The work allows a chemical model for Sphagnum distribution in the landscape to be proposed. AbstractSphagnum is one the major moss types responsible for the deposition of organic soils in peatland systems. The cell walls of this moss have a high proportion of carboxylated polysaccharides (polygalacturonic acids), which act as ion exchangers and are likely to be important for the structural integrity of the cell walls. We used synchrotron light source infrared microspectroscopy to characterise the acid-base and calcium complexation properties of the cell walls of Sphagnum cristatum stems, using freshly sectioned tissue confined in a flowing liquid cell with both normal water and D2O media. The Fourier transform infrared spectra of acid and base forms are consistent with those expected for protonated and deprotonated aliphatic carboxylic acids (such as uronic acids). Spectral deconvolution shows that the dominant aliphatic carboxylic groups in this material behave as a monoprotic acid (pKa=4.97–6.04). The cell wall material shows a high affinity for calcium, with a binding constant (K) in the range 103.9–104.7 (1:1 complex). The chemical complexation model developed here allows for the prediction of the chemical environment (e.g. pH, ionic content) under which Ca2+ uptake can occur, and provides an improved understanding for the observed distribution of Sphagnum in the landscape.

scholarly journals Influence of Lignin on Digestibility of Forage Cell Wall Material

1986 ◽  
Vol 62 (6) ◽  
pp. 1703-1712 ◽  
Author(s):  
H. G. Jung ◽  
K. P. Vogel
Keyword(s):  
Cell Wall ◽  
Wall Material ◽  
Cell Wall Material

The Effect of Siduron Upon Barley Root Metabolism

Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 344-347 ◽  
Author(s):  
Walter E. Splittstoesser
Keyword(s):  
Cell Wall ◽  
Nucleic Acid ◽  
Hordeum Vulgare ◽  
Shoot Growth ◽  
Acid Metabolism ◽  
Wall Material ◽  
Nucleic Acid Metabolism ◽  
Cell Wall Material ◽  
Cell Wall Synthesis ◽  
Root Metabolism

Barley (Hordeum vulgareL. var. Trail) root growth was inhibited at lower concentrations of 1-(2-methylcyclohexyl)-3-phenylurea (siduron) than was shoot growth. The influence of siduron upon root metabolism was assessed with excised roots grown in 0 or 5 ppm siduron. More glucose-U-14C and leucine-U-14C were degraded to CO2and less were incorporated into cell wall material and protein by roots grown in siduron. However, roots grown in siduron incorporated more adenine-8-14C into nucleic acids and degraded less adenine to CO2than roots grown in water. It was suggested that siduron disrupted the normal nucleic acid metabolism of barley roots which was necessary for protein and cell wall synthesis.

The impact of chemical structure on polyphenol bioaccessibility, as a function of processing, cell wall material and pH: A model system

2021 ◽  
Vol 289 ◽  
pp. 110304 ◽  
Author(s):  
Eden Eran Nagar ◽  
Liora Berenshtein ◽  
Inbal Hanuka Katz ◽  
Uri Lesmes ◽  
Zoya Okun ◽  
...  
Keyword(s):  
Cell Wall ◽  
Chemical Structure ◽  
Model System ◽  
Wall Material ◽  
Cell Wall Material ◽  
The Impact
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