Changes of dictyosome ultrastructure during the cell cycle in onion root meristematic cells. A morphometric and stereological study

PROTOPLASMA ◽  
1988 ◽  
Vol 146 (1) ◽  
pp. 35-40 ◽  
Author(s):  
J. A. Gonzalez-Reyes ◽  
F. Grac�a-Navarro ◽  
G. Garcia-Herdugo ◽  
P. Navas
Keyword(s):  
Cell Cycle ◽  
Onion Root ◽  
Meristematic Cells ◽  
Root Meristematic Cells

scholarly journals Incorporation of thymidine into onion root meristematic cell nuclei in presence of hydroxyurea and its role in recovery of mitotic activity

2015 ◽  
Vol 46 (4) ◽  
pp. 701-711
Author(s):  
H. Habdas
Keyword(s):  
S Phase ◽  
The Other ◽  
Cell Nuclei ◽  
Onion Root ◽  
Meristematic Cells ◽  
Hydroxyurea Treatment ◽  
Mitotic Block ◽  
Root Meristematic Cells ◽  
Mitotic Figures ◽  
Root Meristematic Cell

Hydroxyurea treatment of onion roots induced mitotic block which was released by transfer of bulbs to water, and also to some extent by addition of cold or <sup>3</sup>H-thymidine to hydroxyurea solutions. In presence of hydroxyurea there was noted very intense incorporation of <sup>3</sup>H-thymidine into cell nuclei, giving labelling index of 40-70%. However, all the mitotic figures appearing in presence of hydroxyurea and <sup>3</sup>H-thymidine were unlabelled. On the other hand, labelled mitotic figures were obtained when roots incubated with <sup>3</sup>H-thymidine in presence of hydroxyurea had been transferred to water. Incorporation of <sup>3</sup>H-uridine was unaffected by hydroxyurea. The results show that hydroxyurea arrests onion root meristematic cells, either in the S phase and the G<sub>2</sub> phase. Enhanced incorporation of <sup>3</sup>H-thymidine in the presence of hydroxyurea, and release by added thymidine of the mitotic block indicate that hydroxyurea induces in onion root meristematic cells a particular shortage of thymidylate.

État nucléaire des méristèmes du pois dans la graine sèche; imbibition et reprise du cycle cellulaire

1985 ◽  
Vol 63 (12) ◽  
pp. 2200-2208 ◽  
Author(s):  
E. Schatt ◽  
P. Landré ◽  
A. Nougarède
Keyword(s):  
Cell Cycle ◽  
Shoot Apex ◽  
Root Apex ◽  
Organ Specificity ◽  
Light Conditions ◽  
Fresh Weight ◽  
Meristematic Cells ◽  
Root Meristematic Cells ◽  
Dark Conditions ◽  
S Period

In the dry seed of pea (Pisum sativum cv. Nain Hâtif d'Annonay), the shoot and root meristematic cells are arrested at specific phases of the cell cycle, showing organ specificity. The root apex contains resting nuclei both at the 2C- and 4C-DNA levels in approximately the same proportions; the shoot apex possesses nuclei arrested only at the 2C-DNA level. The emergence of the radicle (20th–24th hour) follows a 100% increase in fresh weight (16th hour) and is due to cell elongation only. Under dark conditions, this emergence occurs at the same time than the beginning of the S period (24th hour) from the 2C nuclei of root meristematic cells. The first mitoses of 4C nuclei occur only at the 26th hour of imbibition. In the shoot apex, the cell cycle does not start with the 2C nuclei entering the S period before the 36th hour under dark conditions, and later, in light conditions. The first mitoses begin around the 48th hour, suggesting a S + G2 period of about 12 h. These data are discussed in relation to the mechanisms responsible for the various types of blockage or control of the cell cycle.

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
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