Nickel effect on root-meristem cell division in Plantago lanceolata (Plantaginaceae) seedlings

2017 ◽  
Vol 65 (5) ◽  
pp. 446 ◽  
Author(s):  
Dolja Pavlova
Keyword(s):  
Cell Division ◽  
Mitotic Index ◽  
Root Meristem ◽  
Plantago Lanceolata ◽  
Nuclear Material ◽  
Root Tip ◽  
Dependent Manner ◽  
Meristem Cell ◽  
Anaphase Bridges ◽  
Tip Cells

The toxic effect of nickel (Ni) on cell division on root-meristem cells in seedlings of Plantago lanceolata L. was studied and compared. Seed material was collected from serpentine and non-serpentine populations of the species distributed in the Rhodope Mountains, Bulgaria. The root-tip meristem cells of germinated seeds were treated with different solutions of 0.01, 0.025, 0.05, 0.1 mM Ni as NiSO4 6H2O with distilled water for 24 h and 48 h respectively. The mitotic index decreased when Ni concentrations and exposure time increased in both type of samples. Significant differences in the mitotic indexes were found between the controls and the roots treated with Ni. The mitotic index was higher in root-meristem cells of serpentine seedlings. C-mitosis, anaphase bridges, chromosome stickiness, laggards and extrusion of nuclear material into the cytoplasm were observed in the root-tip cells treated with Ni. The percentage of aberrations generally increased in a concentration- and time-dependent manner. The percentage of the extruded nuclei was higher in cells treated with 0.05 and 0.1 mM Ni. It can be concluded that P. lanceolata seedlings on serpentine can tolerate higher Ni concentrations than can non-serpentine seedlings.

EFFECTS OF PB2+ ON ROOT GROWTH, CELL DIVISION, AND NUCLEOLUS OF BRASSICA JUNCEA L.

1999 ◽  
Vol 47 (3) ◽  
pp. 153-156 ◽  
Author(s):  
Wusheng Jiang ◽  
Donghua Liu
Keyword(s):  
Cell Division ◽  
Root Growth ◽  
Brassica Juncea ◽  
Lead Nitrate ◽  
Inhibitory Effect ◽  
Toxic Effects ◽  
Root Tip ◽  
Anaphase Bridges ◽  
Tip Cells ◽  
Root Tip Cells

The effects of different concentrations (10−5-10−2M) of lead nitrate on root growth and nucleoli in root tip cells of Brassica juncea L. were investigated. The results showed that lead nitrate has a stimulatory effect on root growth at lower concentrations, and an inhibitory effect at higher concentrations. Pb has toxic effects on chromosomal morphology, including c-mitosis and anaphase bridges, and on nucleoli, causing some particulate silver-stained material scattered in the nuclei and inducing irregularly shaped nucleoli. Once the nucleolus was affected, the root growth almost or completely stopped.

EFFECTS OF Mg2+ AND Co2+ ON CELL DIVISION AND NUCLEOLAR CYCLE DURING MITOSIS IN ROOT TIP CELLS OF ALLIUM CEPA

1994 ◽  
Vol 42 (3) ◽  
pp. 235-243 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Shuming Tong ◽  
Lin Zhai
Keyword(s):  
Cell Division ◽  
Allium Cepa ◽  
Magnesium Sulphate ◽  
Root Tip ◽  
Anaphase Bridges ◽  
Chromosome Stickiness ◽  
Nucleolar Cycle ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Cobaltous Nitrate

Effects of Mg2+ and Co2+ on cell division and the nucleolar cycle during mitosis in root tip cells of Allium cepa were studied. The concentrations used of magnesium sulphate and cobaltous nitrate were in the range of 10−7–10−1M. The results showed that both Mg and Co can, at higher concentration, have a toxic effect on cell division comprising c-mitosis and lagging chromosomes, anaphase bridges, and chromosome stickiness. Excessive Mg and Co can also induce some silver-stained particles similar to nucleoli, which are scattered around the chromosome or in the cytoplasm during metaphase and anaphase. The possible mechanism behind this phenomenon is briefly discussed.

scholarly journals Spatial differences in stoichiometry of EGR phosphatase and Microtubule-Associated Stress Protein 1 control root meristem activity during drought stress.

2021 ◽  
Author(s):  
Toshisagba Longkumer ◽  
Chih-Yun Chen ◽  
Marco Biancucci ◽  
Bhaskara Govinal Badiger ◽  
Paul E. Verslues
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Cell Expansion ◽  
Growth Regulation ◽  
Root Meristem ◽  
Stress Protein ◽  
Root Cell ◽  
Root Cortex ◽  
Meristem Cell ◽  
Meristem Size

During moderate severity drought and low water potential (Ψw) stress, poorly understood signaling mechanisms restrict both meristem cell division and subsequent cell expansion. We found that the Clade E Growth-Regulating 2 (EGR2) protein phosphatase and Microtubule Associated Stress Protein 1 (MASP1) differed in their stoichiometry of expression across the root meristem and had opposing effects on root meristem activity at low Ψw. Ectopic MASP1 or EGR expression increased or decreased, respectively, root meristem size and root elongation during low Ψw stress. This, along with the ability of phosphomimic MASP1 to overcome EGR suppression of root meristem size and observation that ectopic EGR expression had no effect on unstressed plants, indicated that during low Ψw EGR activation and attenuation of MASP1 phosphorylation in their overlapping zone of expression determines root meristem size and activity. Ectopic EGR expression also decreased root cell size at low Ψw. Conversely, both the egr1-1egr2-1 and egr1-1egr2-1masp1-1 mutants had similarly increased root cell size; but, only egr1-1egr2-1 had increased cell division. These observations demonstrated that EGRs affect meristem activity via MASP1 but affect cell expansion via other mechanisms. Interestingly, EGR2 was highly expressed in the root cortex, a cell type important for growth regulation and environmental response.

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 Characterization of pharmaceuticals industrial effluent using GC–MS and FT-IR analyses and defining its toxicity

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Vineeta Kumari ◽  
A. K. Tripathi
Keyword(s):  
Root Growth ◽  
Mitotic Index ◽  
Industrial Effluent ◽  
Root Tip ◽  
Chromosome Loss ◽  
Chromosome Break ◽  
Effluent Sample ◽  
Effluent Concentration ◽  
Tip Cells ◽  
Root Tip Cells

Abstract The physicochemical analysis of collected effluent sample for different parameters shown results as pH (pH 5.6 ± 0.11) slightly acidic, high conductivity (1563.34 ± 176 μs cm−1), total dissolved solids (920.34 ± 137 mg L−1), high BOD (7253.34 ± 1022 mg L−1), and COD (756.67 ± 1124 mg L−1) in the effluent sample. The results of heavy metals concentration are viz. as [Cu (1.98–2.56), Co (0.26–0.53), Cd (0.10–0.50), Ni (0.04–0.07), Pb (0.58–1.2), Mn (0.58–1.05), Cr (1.47–1.51), Zn (2.61–3.5), Fe (1.72–2.13), As (0.05–0.09), and Hg (0.003–0.006)]. Results revealed the higher concentration of BOD, COD, TDS, and conductivity and also the concentration of lead. Results of GC–MS also confirmed the high levels of organic pollutants in effluent. Further the effluent toxicity was evaluated by employing genotoxocity assays with the use of Allium cepa L. (onion) root tip cells. Genotoxicity measured mitotic index (MI) and chromosomal aberrations (CAs) in root tip cells obtained after treatment with effluent of 6.25, 12.5, and 25% concentration (v/v). The results of root growth test showed that inhibition of root growth occurred at effluent concentration ≥ 50% (v/v). The lowest MI was recorded (MI = 9.6%) in 25% of effluent concentration, showing a significant reduction in mitotic index compared with control which MI = 64.1%. Further, the chromosomal aberration was investigated in root tip cell after treating with different concentration ranges of effluent exhibiting various CA, viz. c-mitosis, chromosome loss, chromosome break, micronucleated cells, etc. The result suggests that the effluent contained toxic constituents, which imposed cytotoxic and genotoxic hazard.

MITOTIC INSTABILITIES IN TETRAPLOID, HEXAPLOID, AND OCTOPLOID BROMUS INERMIS

1977 ◽  
Vol 19 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Geok-Yong Tan ◽  
G. M. Dunn
Keyword(s):  
Somatic Cells ◽  
Morphological Characters ◽  
Bromus Inermis ◽  
Root Tip ◽  
Smooth Bromegrass ◽  
High Frequencies ◽  
Anaphase Bridges ◽  
Tip Cells ◽  
Chromosomal Instabilities ◽  
Root Tip Cells

Mitotic irregularities were observed in the root tip cells at three ploidies, tetraploid (4x), hexaploid (6x), and octoploid (8x), of smooth bromegrass (Bromus inermis Leyss.). These included endomitosis, fragments, chromosomes excluded from the spindle, anaphase bridges, laggards and micronuclei, at different stages of mitosis. High frequencies of anaphase irregularities were detected at the 4x and 6x levels. The commercial octoploid was more stable. Intraplant variations of some morphological characters in smooth bromegrass may be attributed to chromosomal instabilities in somatic cells.

Persistence of Nucleolar Material During Mitosis in Root Meristematic Cells of Allium sativum

1974 ◽  
Vol 32 ◽  
pp. 272-273
Author(s):  
L. Hanzely
Keyword(s):  
Cell Division ◽  
Allium Sativum ◽  
Animal Species ◽  
Root Tip ◽  
Late Prophase ◽  
Meristematic Cells ◽  
Nucleolar Material ◽  
Root Meristematic Cells ◽  
Tip Cells ◽  
Root Tip Cells

Nucleoli are generally thought to be organelles lacking a continuity during cell division, i.e., they disperse during late prophase and reform within the daughter nuclei at telophase. Recently, however, nucleoli have been shown to persist during mitosis in several plant and animal species (e.g., references 1-4). In this report, evidence is presented indicating the persistence of nucleolar material throughout mitosis in root tip cells of Allium sativum.

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