C3-P-15Spatio-temporal differences between RanGAP and microtubule bands during the development of preprophase bands in onion root tip cells

Microscopy ◽  
2015 ◽  
Vol 64 (suppl 1) ◽  
pp. i133.2-i133
Author(s):  
Takatoshi Yabuuchi ◽  
Tomonori Nakai ◽  
Daisuke Yamauchi ◽  
Seiji Sonobe ◽  
Yoshinobu Mineyuki
Keyword(s):  
Root Tip ◽  
Onion Root ◽  
Temporal Differences ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Preprophase Bands

INATE AND PHOTO-CONTROLLED MITOTIC RHYTHMS IN ONION ROOT-TIP CELLS

1973 ◽  
Vol 15 (4) ◽  
pp. 667-670 ◽  
Author(s):  
Richard C. Bishop ◽  
Richard M. Klein
Keyword(s):  
Mitotic Activity ◽  
Diurnal Rhythm ◽  
Low Temperatures ◽  
Root Tip ◽  
Fluorescent Light ◽  
Onion Root ◽  
Seed Imbibition ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Red Radiation

A four-peaked diurnal rhythm in mitotic activity of dark-grown onion root-tip cells is initiated upon seed imbibition, damps rapidly and is lost within 5 days. It is abolished by continuous white fluorescent light, by continuous blue, green or red radiation, by low temperatures, high osmotica or anoxia. Photoperiodic light controls the well-known two-peaked persistent rhythm. The nature of the zeitgeber for either the inate or the photoperiodically-controlled rhythms is unknown.

Depolymerization of microtubule arrays in root tip cells by oryzalin and their recovery with modified nucleation patterns

1988 ◽  
Vol 66 (12) ◽  
pp. 2353-2366 ◽  
Author(s):  
A. L. Cleary ◽  
A. R. Hardham
Keyword(s):  
Immunofluorescence Microscopy ◽  
Root Tip ◽  
Cell Cortex ◽  
Microtubule Depolymerization ◽  
Higher Plant ◽  
Resistant Plant ◽  
Normal Functional ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Preprophase Bands

Immunofluorescence microscopy with anti-tubulin has been used to study the effects of the dinitroaniline herbicide, oryzalin, on microtubule arrays in root tip cells of a number of species of plants. All species of grasses that were examined showed rapid microtubule depolymerization, as did the nongrass Potamogeton. All other nongrass monocotyledons and dicotyledons tested required much longer treatment times to achieve microtubule depolymerization in the majority of root tip cells. Correlated immunofluorescence and electron microscopy have been used to obtain details of depolymerization and repolymerization of microtubules during treatment and recovery in a resistant plant, Zinnia elegans, and in a sensitive plant, Lolium rigidum. Although rates of disruption differ, both plants displayed similar patterns of microtubule depolymerization and repolymerization. The microtubules that comprise the different categories of array in the root tip cells were differentially sensitive to oryzalin. In order of increasing stability they were as follows: polar microtubules in mitotic cells < interphase arrays < preprophase bands ≤ phragmoplasts [Formula: see text] kinetochore microtubules. During recovery, microtubules are nucleated in the cell cortex in interphase and at the kinetochores during mitosis. The cells are able to reinstate cortical interphase arrays, preprophase bands, and phragmoplasts of apparently normal organization, but not normal, functional spindles. Our results provide basic information on the use of oryzalin in studying the organization and dynamics of microtubule arrays in higher plant cells.

Cytological investigations on onion root-tip cells treated with some cigarette smoke constituents

1974 ◽  
Vol 65 (5) ◽  
pp. 311-313 ◽  
Author(s):  
P. R. BHALLA ◽  
R. C. ARNOLD ◽  
P. S. SABHARWAL
Keyword(s):  
Cigarette Smoke ◽  
Root Tip ◽  
Onion Root ◽  
Tip Cells ◽  
Root Tip Cells

Effect of Reserpine Phosphate on Dividing Onion Root-tip Cells

1958 ◽  
Vol 98 (2) ◽  
pp. 252-254 ◽  
Author(s):  
M. R. Grimm ◽  
F. C. Rull ◽  
R. L. Mayer
Keyword(s):  
Root Tip ◽  
Onion Root ◽  
Tip Cells ◽  
Root Tip Cells

scholarly journals Chromosomes and Mitotic Cell Division Phase In Onion Roots After 24 Hours Acetoorcein Soaking Time

2012 ◽  
Vol 14 (2) ◽  
pp. 46
Author(s):  
Hermin Pancasakti Kusumaningrum ◽  
Arina Tri Lunggani ◽  
Muhammad Amal Nurhakim
Keyword(s):  
Mitotic Index ◽  
Chromosomal Aberration ◽  
Control Treatment ◽  
Root Tip ◽  
Root Growth Inhibition ◽  
Root Cells ◽  
Soaking Time ◽  
Onion Root ◽  
Tip Cells ◽  
Root Tip Cells

Onions (Allium cepa) are usually used in vitro to assess effect of chemical subtances by allowing developing roots to come into contact with substances to be tested. Acetic orcein staining of onion chromosomes has remained a standard method of preparation. However, aceto-orcein stain is corrosive and poisonous chemical substances since it containing oxidising agents such as organic peroxides, the toxic substances which are are cyanides, acid corrosives agents, and  also radioactive substances.  This research study mitotic activity in the roots of onion plants to determine the effects of soaking time of aceto orcein dye on actively dividing root cells. A series of several root tip from each bulb was harvested were soaked in 1, 3 and 24 hours on aceto-orcein stain and processed further for cytological studies by the aceto-orcein squash technique. The research  was carried out to study the effect of to mitotic index and chromosomal aberration  on  onion root. It will determine the percentage of cells that are undergoing mitosis. The squash techniques were used to observe mitosis in the tip of onion root cells during actively mitotic division cells time. Mitotic divisions occur in several phases, consist of prophase, metaphase, anaphase, telophase and interphase. Experiment were repeated six times for every soaking time. The data was analyzed by using T-Test. The result showed that various duration of soaking time significantly influenced the  reduction of mitotic index value. The lowest mitotic index  on glyphosate concentration 100 ppm i.e. 10. 73% and 7.19% for the duration  of soaking time 3 and 6 hours. The highest mitotic index on  glyphosate concentration 0 ppm i.e.  37.71% and 32.76% for the duration  of soaking time 3 and 6 hours. The result also showed that the chromosomal aberration were increased significantly. The lowest  chromosomal aberration  obtained i.e. 2.55% and 2.96% for the duration of aceto orcein soaking time 1, 3 and 24 hours. The highest chromosomal aberration obtained i.e. 21.71% and 36.26% for the duration of soaking time 1,3 and 24 hours. The type of chromosomal aberration were abnormal prophase, stickiness, bridge, abnormal anaphase, clumping chromosome, c- metaphase,  change of nucleous  shape and size. At 72h, their cytotoxic effects on the root tips showed strong growth retardation in high concentrations of all the wastewaters. Compared to the control, treatment with the wastewaters resulted in root growth inhibition with EC50 values of 35, 50 and 62% for bottling, rubber and brewery effluents respectively, and decrease in mitotic index with increasing concentration for all samples and these were statistically significant (p<0.05). Chromosomal aberrations induced in the onion root tip cells were mostly sticky chromosomes and bridges. Chromosomes with disturbed spindles and fragments were also present in appreciable amounts. Based on the EC50 values, the bottling wastewater was most toxic, followed by rubber effluent while effluents from the brewery were least toxic. The findings in this study indicate that there are toxic chemicals present in the wastewaters which are responsible for the observed genotoxic effects on the onion root tip cells. The study also reveals that the Allium test is a useful and reliable tool for the genotoxicity screening of industrial effluents which could be employed by environmental managers before these effluents are finally discharged into the environment.     Key words: chromosomes, onion roots, acetoorcein

The electron microscopy of onion root tip cells

1951 ◽  
Vol 2 (4) ◽  
pp. 630-641 ◽  
Author(s):  
George Rozsa ◽  
Ralph W.G. Wyckoff
Keyword(s):  
Electron Microscopy ◽  
Root Tip ◽  
Onion Root ◽  
Tip Cells ◽  
Root Tip Cells
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