DIURNAL RHYTHMS IN MITOSIS OF CELLS OF THE ONION ROOT TIP MERISTEM

1971 ◽  
Vol 13 (3) ◽  
pp. 597-599 ◽  
Author(s):  
Richard C. Bishop ◽  
Richard M. Klein
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Constant Temperature ◽  
Time Of Day ◽  
Diurnal Rhythms ◽  
Root Tip ◽  
Root Tips ◽  
Complete Darkness ◽  
Onion Root

Seeds of Allium cepa were grown in complete darkness at constant temperature. The root tips, collected from hours 72 to 96 after the start of imbibition, exhibited four maxima and four minima in mitotic activity. The timing of this rhythm was dependent upon the time of imbibition and not upon the time of day.

In Vitro Evaluation of Anti-Mitotic Activity of Green Synthesized Silver Nanoparticles from Ethanolic Extract of Chromolaena odorata, Caesalpinia coriaria (Bark and Leaves) using Allium cepa Roots

2021 ◽  
pp. 4107-4110
Author(s):  
Nishita Gogia ◽  
Anandhi D ◽  
Kanaga G ◽  
Revathi K
Keyword(s):  
Silver Nanoparticles ◽  
Mitotic Activity ◽  
Mitotic Index ◽  
Allium Cepa ◽  
Chromolaena Odorata ◽  
Root Tips ◽  
Antimitotic Activity ◽  
Biological Potential ◽  
Green Synthesized Silver Nanoparticles

The scope of the present study was to evaluate the In-vitro biological potential of Green synthesized silver nanoparticles from Chromolaena odorata, Caesalpinia coriaria (Bark) and Caesalpinia coriaria (Leaf). We investigated the effect of green synthesized silver nanoparticles from Chromolaena odorata, Caesalpinia coriaria (Bark) and Caesalpinia coriaria (Leaf) by studying anti-mitotic activity An attempt has been made to evaluate the anti-mitotic activity of silver nanoparticles using Allium cepa roots. The mitotic index of the root tips meristem was calculated and compared with the standard methotrexate. Antimitotic activity results shows the mitotic index was ranged from 30-40%. Green synthesized silver nanoparticles from Chromolaena odorato, Caesalpinia coriaria (Bark) and Caesalpinia coriaria (Leaf) possess significant anti-mitotic activity.

scholarly journals Genotoxic Effect of Heavy Metals Cr, Cu, Pb and Zn using Allium cepa L.

2017 ◽  
Vol 14 (3) ◽  
pp. 1181-1186 ◽  
Author(s):  
M.N. Abubacker ◽  
C. Sathya
Keyword(s):  
Heavy Metals ◽  
Allium Cepa ◽  
Chromosomal Abnormalities ◽  
Root Tip ◽  
Chromosome Loss ◽  
Chromosome Break ◽  
Root Tips ◽  
Lead And Zinc ◽  
Chromosome Bridge ◽  
Copper Lead

ABSTRACT: Angiosperms are recognized as appropriate genetic models to detect heavy metal based environmental mutagens and are used in monitoring studies. Allium cepa (onion) has been used to evaluate DNA damages like chromosome aberrations and abnormalities in the mitotic cycle. The aim of the present study is to analyze the cytotoxic effects of chromium, copper, lead and zinc in A. cepa root tip squash mitotic cell divisions. The root tips were treated with three concentrations, viz. 5, 10 and 20 mg/100 ml of chromium, copper, lead and zinc at room temperature for 24 h. Mitotic indices and chromosomal abnormalities were calculated. It was observed that these heavy metals induced different types of chromosomal abnormalities comprising of Chromosome break, Chromosome bridge, C-mitosis, Vagrant, Delayed Anaphase and Vagrant, Chromosome Loss, Polyploidy and Chromosome Bridge, Chromosome Loss and Loculated Nucles, Stickiness, Multipolarity and Polyploid prophase along with the increasing doses. The effect of chromium and lead at 20 mg/100 ml concentration was found to be more toxic rather than copper and zinc to the root meristem of A. cepa. The ranking of cytotoxic potentials was in the descending order: lead > chromium > copper > zinc.

scholarly journals Effect of Ferrous Gluconate on Chromosomal Abnormality Index of Allium Cepa Root Tip

2021 ◽  
Vol 9 (4) ◽  
pp. 755-758
Author(s):  
Nergis Kaya
Keyword(s):  
Allium Cepa ◽  
Chromosomal Aberration ◽  
Chromosomal Abnormality ◽  
Genotoxic Effect ◽  
Root Tip ◽  
Control Group ◽  
Root Tips ◽  
Ferrous Gluconate ◽  
Allium Cepa L ◽  
Abnormality Index

In completed research, ferrous gluconate -a food additive- used to preserve black color to prevent discoloration during storage in ripe black olives, and Allium cepa L. species. A. cepa L. roots were treated with different doses of ferrous gluconate. The effective concentration EC50 (0.068 g/l) was determined. A. cepa root tips were treated with EC50/2 (0.034 g/l), EC50 (0.068 g/l), 2XEC50 (0.136 g/l) dose for 24, 48, 72 hours, and afterward, the root tips were prepared for observation under the light microscope according to the method of preparing mitotic preparation. Chromosomal abnormality index (CAI) and genotoxic effect of ferrous gluconate in A. cepa root tip cells were determined. Repeated measurement ANOVA and TUKEY multiple comparison tests were used to investigate the effect of time and dose together on genotoxicity. C-mitosis, polyploidy, polar shifting in anaphase, polar shifting in telophase, equatorial plate shifting, laggard chromosome was observed by microscope. The highest CAI (70.16±4.85) was observed at 72h for 2XEC50 dose. Chromosomal aberration is also observed in control group. While the most common chromosomal aberration is determined as C-mitosis; The least observed chromosomal aberration is determined as polyploidy. Research results revealed that ferrous gluconate has a genotoxic effect on the root tip of A. cepa.

scholarly journals Effect of triazophos on mitotic activity and chromosomal behavior in root meristems of Allium cepa L.

2010 ◽  
Vol 6 ◽  
pp. 4-7 ◽  
Author(s):  
Archana Pandey ◽  
Shyam R Sakya
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Root Meristem ◽  
Plant Science ◽  
Root Tip ◽  
Allium Cepa L ◽  
Meristematic Region ◽  
Cellular Abnormalities ◽  
Tip Cells ◽  
Root Tip Cells

Effect of triazophos (an organophosphorous insecticide) on mitotic activity and chromosomal behavior in the meristematic region of root tip cells of Allium cepa L. was assessed. The insecticide showed mitotic depression and positive chromo-toxic effects. Abnormalities, such as stickiness, plasmolysed cells, equatorial plate shifting, polar shifting, irregular chromosome arrangement, precocious arms formation, bridge formation, C-metaphase, fragmentation of chromosomes, unequal cytokinesis, diagonal cytokinesis, delayed cytokinesis and formation of binucleated cells, were recorded in the chemically pretreated root meristem. Key-words: chromosomal and cellular abnormalities; cytotoxic effect; mitotic index; phase indices.DOI: 10.3126/botor.v6i0.2903 Botanica Orientalis - Journal of Plant Science (2009) 6: 4-7

scholarly journals Binding of 1-nitro-9- (3-dimethylaminopropylamino)-acridine to the DNA of the apical meristem cells of adventitious onion (Allium cepa L.) roots

2014 ◽  
Vol 53 (2) ◽  
pp. 217-222
Author(s):  
Danuta Antosiewicz
Keyword(s):  
Allium Cepa ◽  
Apical Meristem ◽  
Root Tips ◽  
Onion Root ◽  
Allium Cepa L ◽  
Covalently Bound

It was established that one half of the ledakrin (I-nitro-9-(3-dimethylaminopropylamino)-acridine) bound to the DNA in the cells of the studied onion root tips (<em>Allium cepa</em> L.), forms labile complexes with it, the remaining half is covalently attached to only one strand of the DNA. One molecule of covalently bound ledakrin falls on average to 10<sup>4</sup>-2X10<sup>4</sup> pairs of bases.

scholarly journals Effects of sodium hypochlorite on some physiological and cytogenetical parameters in Allium cepa L. exposed to salt stress

2019 ◽  
Vol 48 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Kürşat Çavuşoğlu ◽  
Fadime Doğu ◽  
Dilek Çavuşoğlu
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Mitotic Activity ◽  
Allium Cepa ◽  
Sodium Hypochlorite ◽  
Seedling Growth ◽  
Chromosomal Aberrations ◽  
Root Tip ◽  
Fresh Weight ◽  
Allium Cepa L

The effects of sodium hypochlorite (NaClO) on the seed germination, seedling growth (radicle length, radicle number and fresh weight), mitotic activity and chromosomal aberrations of Allium cepa L. germinated under salt stress were studied. Salt stress considerably inhibited the seed germination and seedling growth of A. cepa. Furthermore, it markedly reduced the mitotic index in root tip meristems of the seeds and increased the number of chromosomal aberrations. Whereas, the detrimental effects of salt on the seed germination, seedling growth, mitotic activitiy and chromosomal aberrations were dramatically alleviated in varying degrees by NaClO application.

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.

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.

scholarly journals Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells ofAllium cepa

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jigna G. Tank ◽  
Vrinda S. Thaker
Keyword(s):  
Cell Division ◽  
Allium Cepa ◽  
Vegetative Growth ◽  
Research Work ◽  
Colchicine Treatment ◽  
Root Tip ◽  
Root Tips ◽  
Ofallium Cepa ◽  
Elongation Process ◽  
Growth Formation

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by usingAllium cepa rootsas a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips ofAllium cepaby giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

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