scholarly journals PRELIMINARY ATTEMPTS AT ULTRASTRUCTURAL POLYSACCHARIDE LOCALIZATION IN ROOT TIP CELLS

1967 ◽  
Vol 15 (8) ◽  
pp. 442-455 ◽  
Author(s):  
J. D. PICKETT-HEAPS
Keyword(s):  
Cell Walls ◽  
Periodate Oxidation ◽  
Ultrastructural Localization ◽  
Epidermal Cells ◽  
Root Tip ◽  
Staining Reaction ◽  
Thin Sections ◽  
Golgi Bodies ◽  
Aldehyde Groups ◽  
Tip Cells

A basic method and many variations are described which initially appear to give good ultrastructural localization of polysaccharide material and also sulfhydryl groups in sections of plant tissues. Using permanganate fixation, alkaline silver hexamine solutions very strongly stained cell walls and starch grains (if they survived the treatment) in thin sections; in root cap and epidermal cells, Golgi bodies and associated vesicles also strongly reacted. The reaction was markedly reduced if sections were pretreated with aldehyde-complexing reagents (dimedone, etc.) and reintroduced after such blocking reactions by further periodate oxidation. Apart from a variable unspecific argentophilic reaction of manganese in the sections (which does not appear if the manganese is leeched out), other components of the cells showed very little staining in permanganate-fixed cells. Differences were noted between the reactivity of various polysaccharides. A strong generalized staining reaction was observed over sections of glutaraldehyde-fixed tissues, and this could be almost entirely blocked by pretreatment of the sections with iodoacetate; such treatment also indicated that there were comparatively few aldehyde groups present, either native and/or introduced by the fixative. Periodate oxidation then introduced staining groups in some Golgi bodies and cell walls, particularly in epidermal cells.

Further Ultrastructural Observations on Polysaccharide Localization in Plant Cells

1968 ◽  
Vol 3 (1) ◽  
pp. 55-64
Author(s):  
J. D. PICKETT-HEAPS
Keyword(s):  
Cell Wall ◽  
Periodic Acid ◽  
Periodate Oxidation ◽  
Plant Cells ◽  
Primary Cell Wall ◽  
Root Tip ◽  
Root Tips ◽  
Golgi Bodies ◽  
Golgi Vesicles ◽  
Aldehyde Groups

Standard periodic acid/Schiff (PAS) techniques have not shown the existence of aldehyde groups in sections of glutaraldehyde-fixed, Araldite-embedded root-tip tissue; peroxidation of such sections resulted in a typical PAS staining pattern. Permanganate-fixed root tips also gave a weak PAS reaction which was intensified by prior peroxidation of the sections. At the ultrastructural level, silver hexamine was used to detect aldehyde groups produced in polysaccharide by permanganate and/or periodate oxidation. Golgi vesicles and slime material in root-cap cells always reacted strongly; the cell wall proper was less reactive. A marked increase in the stainability of the vesicles was evident, the further removed they were from Golgi bodies. This also occurred in root epidermal cells. In both these types of cells, smallersized vesicles and/or the contents of reticulate Golgi cisternae showed evidence of histochemical staining. In meristematic root tip cells, vesicles closely apposed to Golgi bodies did not stain convincingly, though cell walls stained readily. During cell-plate formation, however, both smaller (possibly Golgi) and larger vesicles (phragmoplasts) stained strongly. The walls of permanganate-fixed sieve-tube cells also stained quite strongly, but callose did not unless the tissue block had been treated with periodate before being embedded. In glutaraldehyde-fixed xylem cells, older wall thickenings reacted very strongly even when the sections had been blocked with iodoacetate and bisulphite (which rendered the rest of the section unreactive). If similar sections of younger xylem cells were peroxidized after such blocking reactions, the primary cell wall and the wall thickenings stained, as did many of the Golgi vesicles. The results are related to other experimental observations, both ultrastructural and histochemical, on plant cells.

EFFECTS OF NICKEL SULFATE ON ROOT GROWTH AND NUCLEOLI IN ROOT TIP CELLS OF ALLIUM CEPA

1994 ◽  
Vol 42 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Lin Guo ◽  
Yuqing Hao ◽  
Cheng Lu ◽  
...  
Keyword(s):  
Root Growth ◽  
Allium Cepa ◽  
Silver Staining ◽  
Nickel Sulfate ◽  
Inhibitory Effect ◽  
Root Tip ◽  
Staining Reaction ◽  
Nucleolar Material ◽  
Tip Cells ◽  
Root Tip Cells

The effects of different concentrations of nickel sulfate on root growth and nucleoli in root tip cells of Allium cepa were studied. The concentrations of nickel sulfate (NiSO4 · 7H2O) used were in the range of 10−7-10−1M. The results showed that nickel sulfate has a stimulatory effect on root growth at lower concentrations, and an inhibitory effect at higher concentrations. Nickel has toxic effects on nucleoli at higher concentrations. Phenomena we observed were irregularly shaped nucleoli, weaker silver staining reaction at the periphery of the nucleolus, and extrusion of nucleolar material from nuclei into the cytoplasm after treatment with higher concentrations of Ni.

Memoirs: Ultra-Centrifuging the Spermatocytes of Helix Aspersa

1936 ◽  
Vol s2-78 (311) ◽  
pp. 387-396
Author(s):  
H. W. BEAMS ◽  
J. BRONTË GATENBY ◽  
J. A. MULIYIL
Keyword(s):  
Guinea Pig ◽  
Helix Aspersa ◽  
Root Tip ◽  
Golgi Bodies ◽  
Gland Cells ◽  
Uterine Gland ◽  
Tip Cells ◽  
Root Tip Cells

In the spermatocyte of Helix, as in the guinea-pig uterine gland cells and in the root-tip cells of the bean, the Golgi bodies pass centripetally whereas the mitochondria pass centrifugally when ‘ultra-centrifuged’.

scholarly journals ALKALINE BISMUTH REAGENT FOR HIGH RESOLUTION ULTRASTRUCTURAL DEMONSTRATION OF PERIODATE-REACTIVE SITES

1972 ◽  
Vol 20 (12) ◽  
pp. 995-1005 ◽  
Author(s):  
STERLING K. AINSWORTH ◽  
MORRIS J. KARNOVSKY ◽  
SUSUMU ITO
Keyword(s):  
High Resolution ◽  
Periodic Acid ◽  
Periodate Oxidation ◽  
Ultrastructural Localization ◽  
Blocking Agent ◽  
Hydroxyl Groups ◽  
Electron Microscopic ◽  
Periodic Acid Schiff ◽  
Thin Sections ◽  
Bismuth Subnitrate

A simple technique is described for the ultrastructural localization of periodate-reactive mucosubstances and polysaccharides containing 1,2-glycols in thin sections of routinely fixed tissues. In this method the sugar residues are oxidized by periodic acid and the resulting aldehydes presumably reduce chelated bismuth subnitrate to metallic bismuth which then appears as a fine electron-opaque precipitate at the sites of the reducing sugars. The periodic acid-alkaline bismuth procedure provides a high resolution electron microscopic technique for demonstrating tissue sites of periodate-engendered groups very similar to the light microscopic periodic acid-Schiff reaction. The reaction can be prevented by the omission of periodate oxidation or alkaline bismuth subnitrate and by aldehyde blockage with the blocking agent, m-aminophenol. However, glycogen stains markedly without prior periodate oxidation, presumably through chelation of bismuth by hydroxyl groups. Other structures which stain without prior periodate oxidation are liver lysosomal dense bodies and, occasionally, ribosomes.

Structural, chemical, and permeability changes following wounding in onion roots

1984 ◽  
Vol 62 (11) ◽  
pp. 2253-2259 ◽  
Author(s):  
G. J. Moon ◽  
Carol A. Peterson ◽  
R. L. Peterson
Keyword(s):  
Cell Walls ◽  
Cortical Cell ◽  
Root Tip ◽  
Cortical Cells ◽  
Calcofluor White ◽  
Suberin Lamellae ◽  
Histochemical Tests ◽  
Apoplastic Barrier ◽  
Tip Cells ◽  
Root Tip Cells

Onion roots were wounded by scoring them with a needle 80 to 120 mm proximal to the root tip. Cells in the region of the wound were studied immediately after wounding and daily for the next 6 days. By the 2nd day, cortical cells near the wound had produced pit callose and deposited suberin in their walls and air spaces. The amount of suberin deposited increased until 4 days after wounding. No suberin lamellae were observed in cortical cell walls, but histochemical tests and acid digestion confirmed the presence of suberin within the existing wall. Intercellular air spaces adjacent to the wound were totally occluded with an electron-dense material which had characteristics of suberin. Penetration studies using Calcofluor white M2R, a fluorescent apoplastic dye, showed that the wound was completely sealed 4 days after wounding. Thus, in response to wounding, nonlamellar suberin was deposited in the cortical cell walls and air spaces surrounding the wound and was continuous with the suberin present in the normal hypodermis, forming a complete apoplastic barrier.

scholarly journals Structural Evidence of Programmed Cell Death Induction by Tungsten in Root Tip Cells of Pisum sativum

Plants ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 62 ◽  
Author(s):  
Ioannis-Dimosthenis Adamakis ◽  
Eleftherios Eleftheriou
Keyword(s):  
Cell Death ◽  
Pisum Sativum ◽  
Programmed Cell Death ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Root Tip ◽  
Confocal Laser ◽  
Golgi Bodies ◽  
Tip Cells ◽  
Root Tip Cells

Previous studies have shown that excess tungsten (W), a rare heavy metal, is toxic to plant cells and may induce a kind of programmed cell death (PCD). In the present study we used transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) to investigate the subcellular malformations caused by W, supplied as 200 mg/L sodium tungstate (Na2WO4) for 12 or 24 h, in root tip cells of Pisum sativum (pea), The objective was to provide additional evidence in support of the notion of PCD induction and the presumed involvement of reactive oxygen species (ROS). It is shown ultrastructurally that W inhibited seedling growth, deranged root tip morphology, induced the collapse and deformation of vacuoles, degraded Golgi bodies, increased the incidence of multivesicular and multilamellar bodies, and caused the detachment of the plasma membrane from the cell walls. Plastids and mitochondria were also affected. By TEM, the endoplasmic reticulum appeared in aggregations of straight, curved or concentric cisternae, frequently enclosing cytoplasmic organelles, while by CLSM it appeared in bright ring-like aggregations and was severely disrupted in mitotic cells. However, no evidence of ROS increase was obtained. Overall, these findings support the view of a W-induced vacuolar destructive PCD without ROS enhancement.

EVALUATION OF METAL ION TOXICITY ON ROOT TIP CELLS BY THE ALLIUM TEST

1995 ◽  
Vol 43 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Wei Wang ◽  
Lin Zhai
Keyword(s):  
Metal Ion ◽  
Potassium Dichromate ◽  
Lead Nitrate ◽  
Nickel Sulfate ◽  
Rapid Screening ◽  
Root Tip ◽  
Staining Reaction ◽  
Nucleolar Material ◽  
Tip Cells ◽  
Root Tip Cells

The effects of different concentrations of eleven different metals (aluminum chloride, chromium nitrate and potassium dichromate, lead nitrate, copper sulfate, manganous sulfate, cobaltous nitrate, zinc sulfate, magnesium sulfate, nickel sulfate, cadmium chloride, and mercuric chloride) on cell division and nucleoli in root tip cells of Allium cepa were studied. The results showed that the metal ions could, in varying degrees, cause chromosome, nucleus, and nucleolus irregularities, including c-mitosis, chromosome bridges, chromosome stickiness, irregularly shaped nuclei, micronuclei, irregularly shaped nucleoli, some silver-stained material scattered in the nucleus, the weakening of silver-staining reaction at the periphery of the nucleolus, and the release of nucleolar material from the nucleus into the cytoplasm. The Allium test may be useful for the rapid screening of chemicals involved in environmental problems.

scholarly journals The Preservation and Investigation of Plant Mitochondria

1953 ◽  
Vol s3-94 (25) ◽  
pp. 29-36
Author(s):  
J. CHAYEN ◽  
URSULA J. MILES
Keyword(s):  
Polyvinyl Alcohol ◽  
Simple Technique ◽  
Plant Root ◽  
Plant Mitochondria ◽  
Root Tip ◽  
Cytoplasmic Bodies ◽  
Free Aldehyde ◽  
Aldehyde Groups ◽  
Tip Cells ◽  
Root Tip Cells

A method for making squash preparations of plant root tip cells is described. This entails the use of an inert preserving substance, polyvinyl alcohol. The advantages of the method are the preservation of the cytoplasmic bodies, including the mitochondria ; the retention of fat droplets inside the cells; the fact that the nucleus remains optically homogeneous; and the fixing of free aldehyde groups and of diffusible substances in the cytoplasm. It is a relatively rapid and simple technique, and the cells produced by it resemble closely those produced by the method for making living squash preparations of such cells.

scholarly journals The positions of centromeres on the somatic metaphase plate of grasses

1983 ◽  
Vol 64 (1) ◽  
pp. 163-177
Author(s):  
J.S. Heslop-Harrison ◽  
M.D. Bennett
Keyword(s):  
Metaphase Plate ◽  
Grass Species ◽  
Root Tip ◽  
Thin Sections ◽  
Centromere Position ◽  
Random Expectation ◽  
The Mean ◽  
Ice Water ◽  
Tip Cells ◽  
Root Tip Cells

Centromere positions on the metaphase plate of 48 root-tip cells of four grass species were analysed using metaphases reconstructed from electron micrographs of serial thin sections. Centromere alignment was almost perfect on a plane in 15 untreated metaphases of cereals where 2n = 14; only 2% of the total variance in centromere position was out of the plane of the metaphase plate. In 23 similar cells pretreated with ice-water, the mean out-of-plate variance was 9%, compared to an expectation of 18% if centromeres were positioned randomly in space. In cold-treated cells of Zea mays (2n = 20), the out-of-plate variance (14%) was significantly less than a random expectation of 20%. The distances of centromeres from the mean centromere position (MCP) were also analysed. They showed that the centromeres tended to be normally distributed about a circle around the MCP in all the species. Thus centromeres tend towards a ring arrangement in metaphase cells. Analysis of separation distances of all pairs of centromeres in each reconstructed cell showed that the distribution of distances between centromeres is not random: there are significantly fewer centromeres that are close together and more that are at medium separation distances than is expected on a random basis. This is different from previously published assumptions about centromere disposition in squashed metaphases.

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