scholarly journals Influence of extract from shoots of Taxus baccata var. 'Elegantissima' on mitotic activity of meristematic cells of Allium cepa L. roots

2014 ◽  
Vol 69 (3) ◽  
pp. 185-192 ◽  
Author(s):  
Agnieszka Majewska ◽  
Mirosława Furmanowa ◽  
Elwira Śliwińska ◽  
Kazimierz Głowniak ◽  
Joanna Guzewska ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mitotic Activity ◽  
Genetic Material ◽  
Taxus Baccata ◽  
Alcoholic Extract ◽  
Root Tips ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
G2 Phase ◽  
Number Of Cells

We investigated the influence of different concentrations of alcoholic extract from young shoots of <em>Taxus baccata</em> var. 'Elegantissima' (TbE), containing paclitaxel (81.6 µg/g fresh mass), on mitotic activity and DNA content in meristematic ` cells of <em>Allium cepn</em> adventitious root tips. During 24 hours of incubation we obtained different level of inhibition of mitotic activity: ranging from slight changes (dilution 1:32), through complete inhibition reversible in postincubation (dilution 1:8), to whole inhibition irreversible in postincubation (dilution 1:4). Inhibition of mitotic activity was connected with an increase of prophases and metaphases and changes in morphology of chromosomes (thick chromosomes of prophases with diluted karyolymph and c-metaphases). During the experiment, the number of aberrations and micronuclei didn't increase but the number of cells with replicated DNA (4C) blocked in G2 phase was higher. This study was done by a flow cytometry method. The optimal concentration of the TbE extract, which inhibited mitotic activity, did not damage the genetic material (chromosomes) visibly.

scholarly journals Influence of extract from shoots of Taxus baccata var. elegantissima on ultrastructure and tubulin cytoskeleton of meristematic cells of Allium cepa L. roots

2014 ◽  
Vol 71 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Agnieszka Majewska ◽  
Mirosława Furmanowa ◽  
Kazimierz Głowniak ◽  
Joanna Guzewska ◽  
Alicja Zobel ◽  
...  
Keyword(s):  
Allium Cepa ◽  
Chromatin Condensation ◽  
Preprophase Band ◽  
Taxus Baccata ◽  
Cell Nuclei ◽  
Root Tips ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Interphase Cells ◽  
Average Size

We investigated the influence of extract from <em>Taxus baccata</em> var. Elegantissima (TbE) shoots in 1:8 dilution, containing paclitaxel in concentration of 81,6 µg/g fresh mass on ultrastructure and tubulin cytoskeleton of meristematic cells of <em>Allium cepa</em> L. root tips. Incubation time 3, 6, 12 and 24 h was followed with postincubation in water for 12 and 24 h. During shorter incubation (till 12 h) the surface of the cell nuclei decreased and chromatin became condensed (in comparison to control) but after 24 h the average surface increased and chromatin condensation decreased. In the course of incubation the average size of plastids and vacuoles increased. Moreover, after treatment mitochondria and plastids showed degradation of ultrastructure, which was reversed after 12 h of postincubation. Immunocytochemical assays demonstrated that in the course of incubation in the ThE extract, the tubulin cytoskeleton became partially disorganised. In most interphase cells, cortical microtubules (MTs) lost their oval transverse orientation. The preprophase band (PPB) position in the cell was often asymmetrical. The MTs array of the karyokinetic spindle and phragmoplast was also disturbed. These alterations were completely reversed during postincubation.

scholarly journals Mitotic activity, submicroscopic organization and respiration of meristematic cells of root tips of Allium cepa L. treated with dacarbazine (DTIC)

2014 ◽  
Vol 51 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Maria Podbielkowska ◽  
Anna Śluborska ◽  
Maria Wałęza
Keyword(s):  
Dna Synthesis ◽  
Mitotic Activity ◽  
Cell Respiration ◽  
Root Tips ◽  
Experimental Conditions ◽  
Respiratory Inhibitors ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Inhibition Of Dna Synthesis ◽  
Tissue Ultrastructure

Studies were carried out on the effect of dacarbazine (DTIC) on meristematic cells of root tips of <em>Allium</em> cepa L. Noticeable mitodepression was observed. It depended upon time of exposure and DTIC concentration. Mitodepression was caused by an inhibition of DNA synthesis and blocking of the G<sub>2</sub> phase. DTIC caused also disturbances of the karyokinesis and cytokinesis, similar as in case of colchicine effect. In the experimental conditions inhibition of cell respiration was noted, as also changes in the tissue ultrastructure. These changes were typical of the effect of respiratory inhibitors.

Comparison of the Effects of He:Neon and Nd:YAG Laser Radiation on Mitotic Activity of Meristematic Cells of Allium cepa L. Bulbs

1990 ◽  
Vol 8 (6) ◽  
pp. 35-38 ◽  
Author(s):  
M. Fiol de Cuneo ◽  
S. Rubiales de Barioglio ◽  
G. Stutz ◽  
H. Juri ◽  
J. L. Lacuara
Keyword(s):  
Laser Radiation ◽  
Mitotic Activity ◽  
Allium Cepa ◽  
Nd:Yag Laser ◽  
Meristematic Cells ◽  
Allium Cepa L

scholarly journals Effects of 5-fluorouracil on the mitotic activity of onion root tips apical meristem

2015 ◽  
Vol 45 (3) ◽  
pp. 225-237
Author(s):  
Waldemar Lechowicz
Keyword(s):  
Cell Division ◽  
Mitotic Activity ◽  
Mitotic Index ◽  
Apical Meristem ◽  
Root Tips ◽  
Onion Root ◽  
Control Value ◽  
Meristematic Cells ◽  
Cytological Changes ◽  
Chromatid Aberrations

The effects of various concentrations of 5-FU on the mitotic activity of onion root tips apical meristem were investigated during 24-hour incubation in 5-FU and postincubation in water. The incubation in 5-FU caused a reversible inhibition of mitotic activity, and waves of the partially synchronised mitoses were observed during the period of postincubation. The most pronounced synchronisation of mitoses was obtained after incubation in 100 mg/l. 5-FU but the mitotic index of the resumed mitotic activity amounted to only one half of the control value. 5-FU was found to cause some cytological changes in meristematic cells such as enlargement of the nucleoli, change in the interphasic nuclei structure, appearance of subchromatid and chromatid aberrations and micronuclei. The effects of 5-FU on nucleic acids and the cell division cycle ace discussed and compared with the effects of 5-FUdR.

scholarly journals Antimitotic effect, G2/M accumulation, chromosomal and ultrastructure changes in meristematic cells of Allium cepa L. root tips treated with the extract from Rhodiola rosea roots

Caryologia ◽  
2003 ◽  
Vol 56 (3) ◽  
pp. 337-351 ◽  
Author(s):  
Agnieszka Majewska ◽  
Ewa Wolska ◽  
Elwira Śliwińska ◽  
Mirosława Furmanowa ◽  
Natalia Urbańska ◽  
...  
Keyword(s):  
Allium Cepa ◽  
Rhodiola Rosea ◽  
Root Tips ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Antimitotic Effect

Effects of long exposure to spent potliner on seeds, root tips, and meristematic cells of Allium cepa L.

2017 ◽  
Vol 189 (10) ◽  
Author(s):  
Larissa Fonseca Andrade-Vieira ◽  
Marcel José Palmieri ◽  
Lisete Chamma Davide
Keyword(s):  
Allium Cepa ◽  
Root Tips ◽  
Meristematic Cells ◽  
Allium Cepa L

Cytogenetic Responses of Plant Root Meristematic Cells to the Arsenic (III) Contaminated Groundwater in Eastern Parts of Burdwan District, W.B., India

2015 ◽  
Vol 1 (01) ◽  
pp. 79-84
Author(s):  
Abhijit Bandyopadhyay
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Arsenic Concentration ◽  
In Situ Monitoring ◽  
Contaminated Groundwater ◽  
Eastern Region ◽  
Root Cells ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Root Meristematic Cells

Both geogenic and anthropogenic activities have resulted in arsenic pollution of groundwater especially in the Eastern region of Burdwan district in West Bengal. Response of Allium cepa L. genetic material to the presence of potential cytotoxic and genotoxic substances in aquatic environment was used to evaluate the arsenic contaminated groundwater-induced genotoxicity and hormesis. For in situ monitoring of the cytotoxicity level, the inhibition of mitosis in root meristematic cells was assayed. To study genotoxicity, micronucleus assay and DNA purity assay (by A260/280 ratio) were used. Treatment for 4 days of newly developed roots of Allium cepa L. with water samples with arsenic content 50 μg L-1 exhibited stimulation in mitotic activity whereas samples with arsenic 1000 μg L-1 showed inhibition of mitotic activity apparently indicating hormesis. Inhibition of mitosis was compared with the concentration dependent increase in generation of reactive oxygen species (ROS), cell death, decrease in activity of antioxidative enzymes (catalase, superoxide dismutase), the absorbance ratio (A260/280) of DNA, or micronuclei in root cells. These findings indicated that contaminated groundwater depending on the magnitude of the arsenic concentration, might either be mitogenic or mitostatic/toxic, which in turn has obvious implications in agriculture and human health.

Influence of methyl derivatives of coumarin on mitotic activity and ultrastructure of meristematic cells of Allium cepa root tips

Phytomedicine ◽  
1996 ◽  
Vol 2 (3) ◽  
pp. 275-281 ◽  
Author(s):  
E. Kupidlowska ◽  
B. Bieniak ◽  
A. Ruchirawat ◽  
A.M. Zobel
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Root Tips ◽  
Meristematic Cells ◽  
Methyl Derivatives ◽  
Derivatives Of

The preprophase band: possible involvement in the formation of the cell wall

1976 ◽  
Vol 22 (2) ◽  
pp. 403-411 ◽  
Author(s):  
M.J. Packard ◽  
S.M. Stack
Keyword(s):  
Cell Wall ◽  
Allium Cepa ◽  
Cell Walls ◽  
Preprophase Band ◽  
Adjacent Cell ◽  
Root Tips ◽  
Meristematic Cells ◽  
Narrow Region ◽  
The Matrix

Numerous vesicles were observed among the microtubules of the “preprophase” band in prophase cells from root tips of Allium cepa. The content of these vesicles looks similar to the matrix of adjacent cell walls, and these vesicles often appear to be involved in exocytosis. In addition, the cell walls perpendicular to the plane of (beneath) the preprophase band are often differentially thickened compared to the walls lying parallel to the plane of the band. Our interpretation of these observations is that the preprophase band may direct or channel vesicles containing precursors of the cell wall to localized regions of wall synthesis. The incorporation of constituents of the cell wall into a narrow region defined by the position of the preprophase band may be a mechanism that ensures unidirecitonal growth of meristematic cells.

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