scholarly journals Effect of short- and long-lasting chilling on pre-rRNA synthesis and transport in root meristematic cells of three soybean cultivars

2011 ◽  
Vol 72 (4) ◽  
pp. 319-324 ◽  
Author(s):  
Dariusz Stępiński
Keyword(s):  
Cold Stress ◽  
Rrna Synthesis ◽  
Morphometric Measurements ◽  
Radioactive Precursor ◽  
Uridine Incorporation ◽  
Meristematic Cells ◽  
Soybean Cultivars ◽  
Root Meristematic Cells ◽  
And Control ◽  
Rna Precursor

<p>Autoradiographic studies of <sup>3</sup>H-uridine incorporation (20-min incubation) and dynamics of radioactive particle translocation from nucleolus into cytoplasm (following 80-min postincubation in non-radioactive medium) in root meristematic cells of soybean have been carried out. The experiment was performed with plants subjected to 4-day acclimation in chilling or subjected to 2-hour cold stress and control plants. Three cultivars of soybean: Mazowia, Polan and Progres (cultivated in Poland) were used in the experiment.</p><p>It has been shown that in control conditions the greatest number of RNA precursor is incorporated into nucleoli after 20-min incubation. Following 80-min postincubation cytoplasm is the most radioactive area of the cell - this mainly testifies to dynamic translocation of radioactive ribosome subunits from nucleolus into cytoplasm.</p><p>In chilling conditions the reduction of <sup>3</sup>H-uridine incorporation into cells occurs, as compared to control conditions. Plants subjected to a 4-day acclimation incorporate the radioactive precursor more intensively than plants subjected to cold stress.</p><p>Following 80-min postincubation - in the case of acclimated plants - the nucleolus is the most radioactive area of the cell, which testifies to accumulation of pre-rRNA in it. After the cold stress cytoplasm is more radioactive than the nucleolus. In all three cultivars the processes of synthesis and transport of pre-rRNA particles are similar, only their intensity is different.</p><p>Morphometric measurements of nucleoli in all cultivars subjected to 4-day chilling have shown that root cell nucleoli are larger than those in control. This phenomenon can be connected with stronger inhibition of rRNA transport than its synthesis.</p>

scholarly journals Action of Ponceau 4R (E-124) food dye on root meristematic cells of Allium cepa L.

2015 ◽  
Vol 37 (1) ◽  
pp. 101 ◽  
Author(s):  
Gleuvânia Santana Marques ◽  
Josefa Janaína do Anjos Sousa ◽  
Ana Paula Peron
Keyword(s):  
Allium Cepa ◽  
Meristematic Cells ◽  
Food Dye ◽  
Root Meristematic Cells ◽  
Ponceau 4R

scholarly journals Sodium cacodylate as antimitotic agent

2014 ◽  
Vol 57 (3) ◽  
pp. 329-340
Author(s):  
Jadwiga A. Tarkowska
Keyword(s):  
Allium Cepa ◽  
Mitotic Spindle ◽  
Sodium Cacodylate ◽  
Antimitotic Agent ◽  
Ultrastructural Studies ◽  
Meristematic Cells ◽  
Cacodylate Buffer ◽  
Root Meristematic Cells ◽  
Dividing Cells

The effect of pure sodium cacodylate on dividing cells was studied. The root meristematic cells of <em>Allium cepa</em> L. (the roots were squashed in acetoorcein) and endosperm cells of <em>Haemanthus katherinae</em> Bak. (<em>in vitro</em> observations) were used. Serious disturbances in karyokinesis and cytokinesis were found that led most often to the formation of polyploid or multinucleate (<em>A. cepa</em>) cells. These results point to damage of the mitotic spindle and phragmoplast. Careful use of cacodylate buffer in ultrastructural studies of microtubules is advised.

scholarly journals Functional alterations of root meristematic cells of Arabidopsis thaliana induced by a simulated microgravity environment

2016 ◽  
Vol 207 ◽  
pp. 30-41 ◽  
Author(s):  
Elodie Boucheron-Dubuisson ◽  
Ana I. Manzano ◽  
Isabel Le Disquet ◽  
Isabel Matía ◽  
Julio Sáez-Vasquez ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Simulated Microgravity ◽  
Microgravity Environment ◽  
Meristematic Cells ◽  
Root Meristematic Cells

The subcellular concentration of ions and elements in thin cryosections of onion root meristem cells. An electron-probe EDS study

1984 ◽  
Vol 72 (1) ◽  
pp. 295-306
Author(s):  
I.L. Cameron ◽  
K.E. Hunter ◽  
N.K. Smith
Keyword(s):  
Electron Probe ◽  
Dry Weight ◽  
Cell Types ◽  
Meristematic Cells ◽  
Freeze Dried ◽  
Concentration Of Ions ◽  
Intracellular Compartments ◽  
Root Meristematic Cells ◽  
Storage Granules ◽  
First Time

Quantitative electron-probe energy dispersive X-ray microanalysis has, for the first time, been accomplished at a subcellular level in plant tissue using cryofixed and thin freeze-dried cryosections. The subcellular concentrations of Na+, Cl-, K+, P, S, Mg2+ and Ca2+ were measured in mol/kg dry weight in two types of root meristematic cells of the onion, Allium cepa. The cell wall of the meristematic cells had much higher concentrations of K+ and Ca2+ than was found in the intracellular compartments. Storage granules in the protoderm cells were about 6–12 times lower in P and were about four times higher in S as compared to other intracellular compartments. Comparison between the concentrations of ions and other elements in meristematic plant cells and in mouse cardiac myocytes confirms that major differences in cytoplasmic Na+ and Cl- concentrations do indeed exist between these cell types.

Normal incorporation rates for precursors of collagen and mucopolysaccharide during expression of micromelia induced by 6-aminonicotinamide

Development ◽  
1974 ◽  
Vol 31 (2) ◽  
pp. 305-312
Author(s):  
Robert E. Seegmiller ◽  
Meredith N. Runner
Keyword(s):  
Core Protein ◽  
Limb Bud ◽  
Matrix Proteins ◽  
Synthesis Rate ◽  
Control Groups ◽  
In Ovo ◽  
Limb Buds ◽  
Radioactive Precursor ◽  
Hind Limbs ◽  
And Control

Further delineation of mechanisms by which 6-aminonicotinamide (6-AN) induces micromelia in the chick embryo was investigated by studies on rates of incorporation of thymidine, proline, glucosamine and sulfate as precursors to DNA, collagen and mucopolysaccharide, respectively. Twenty-four hours after in ovo administration of the vitamin antagonist, 6-AN, to day-4 chick embryos, hind limbs from experimental and control groups were excised and incubated for 1 h in medium containing 3 × 10−6m radioactive precursor. Molar incorporation of precursors into the TCA-precipitable fraction showed, in isolated limb buds, (a) that 6-AN enhanced incorporation of thymidine, (b) that 6-AN inhibited utilization of sulfate, and (c) that 6-AN did not significantly alter utilization of glucosamine and proline. Rates of incorporation of thymidine, glucosamine and proline indicate that 6-AN is not cytotoxic to the isolated limb bud. Enhanced incorporation of thymidine suggests expression of compensatory change 24 h after initial effects of 6-AN on DNA synthesis. Rate of incorporation of proline suggests that, under the influence of 6-AN, tropocollagen was synthesized in normal quantities by limb cells. Similarly, rate of incorporation of glucosamine suggests that under the influence of 6-AN normal amounts of hexosamine sugars were being attached to the nascent core-protein of chondroitin. Inhibition of sulfation and failure to complete the chondroitin sulfate molecule seem to account for 6-AN-induced micromelia. This suggests that sulfation depends upon specific NAD-dependent dehydrogenase reactions. As far as can be established by rates of incorporation of labeled precursors, 5-day limb buds, at 24 h after exposure to teratogenic levels of 6-AN, synthesize matrix proteins and hexosamine polysaccharides at normal rates.

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