Electron microscope observations of periodicities in the surface structure of tobacco mosaic virus

Vacuum ◽  
1956 ◽  
Vol 6 ◽  
pp. 247
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Surface Structure ◽  
Mosaic Virus

Electron Microscope Observations of Periodicities in the Surface Structure of Tobacco Mosaic Virus

Nature ◽  
1956 ◽  
Vol 178 (4534) ◽  
pp. 635-636 ◽  
Author(s):  
R. E. F. MATTHEWS ◽  
R. W. HORNE ◽  
E. M. GREEN
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Surface Structure ◽  
Mosaic Virus

Quantitative Measurements on the Ion Etching of TMV

1973 ◽  
Vol 31 ◽  
pp. 336-337
Author(s):  
Irwin Bendet ◽  
Nabil Rizk
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Ion Current ◽  
Beam Diameter ◽  
Ion Etching ◽  
Preliminary Results ◽  
Quantitative Measurements ◽  
Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

Three-dimensional reconstruction of the stacked-disk aggregate of tobacco mosaic virus protein from electron micrographs

1971 ◽  
Vol 261 (837) ◽  
pp. 211-219 ◽  
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Virus Protein ◽  
Protein Subunits ◽  
Microscope Images ◽  
Dimensional Reconstruction ◽  
Inner Parts

The three-dimensional structure of the stacked-disk rod of tobacco mosaic virus protein has been reconstructed to a resolution of about 2 nm from electron microscope images. Closed rings of seventeen protein subunits (compared with 16 ⅓ in one turn of the virus helix) are stacked in polar fashion, the stacking being accompanied by an axial perturbation of periodicity 5.3 nm connecting successive pairs of rings into disks. The axial perturbation consists of a movement towards each other of the outer parts of the subunits in the two rings comprising a disk, together with a movement of the inner parts in the opposite direction. This could be explained either by a bending of parts of the subunits in the appropriate directions or by a bodily tilting of the subunits in the two rings in opposite directions.

Ultrastructure of tobacco mosaic virus lesions and surrounding tissue in Phaseolus vulgaris var. Pinto

1971 ◽  
Vol 49 (3) ◽  
pp. 417-421 ◽  
Author(s):  
D. F. Spencer ◽  
W. C. Kimmins
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Phaseolus Vulgaris ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Healthy Tissue ◽  
Surrounding Tissue ◽  
Infected Area ◽  
Membrane Bound

Leaves of Phaseolus vulgaris var. Pinto were inoculated with the U1 strain of tobacco mosaic virus TMV (U1) and fully expanded lesions and adjacent healthy tissue were examined in the electron microscope. Emphasis was placed on the band of healthy cells (resistant zone) surrounding the lesion, with the object of detecting the first changes in ultrastructure as healthy tissue graded into the infected area. Cells in the resistant zone were characterized by the appearance of membrane-bound vesicular bodies (paramural bodies) between the plasmalemma and cell wall. Where paramural bodies accumulated, the plasmalemma was withdrawn and intercellular cytoplasmic connections through the plasmodesmata were severed. These changes were found most frequently for a distance of about three cell diameters beyond cells visibly infected at the lesion periphery. It is suggested that these changes in ultrastructure are related to the events of localization. Spread of the virus may be inhibited because of a lack of cytoplasmic connections between cells surrounding the virus-induced lesion.

scholarly journals RELATION OF TOBACCO MOSAIC VIRUS TO THE HOST CELLS

1967 ◽  
Vol 33 (3) ◽  
pp. 665-678 ◽  
Author(s):  
Katherine Esau ◽  
James Cronshaw
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Host Cells ◽  
Vascular Bundles ◽  
Mesophyll Cells ◽  
Virus Particles ◽  
Nicotiana Tabacum L ◽  
Parenchyma Cells ◽  
Particle Aggregates

The relation of tobacco mosaic virus (TMV) to host cells was studied in leaves of Nicotiana tabacum L. systemically infected with the virus. The typical TMV inclusions, striate or crystalline material and ameboid or X-bodies, which are discernible with the light microscope, and/or particles of virus, which are identifiable with the electron microscope, were observed in epidermal cells, mesophyll cells, parenchyma cells of the vascular bundles, differentiating and mature tracheary elements, and immature and mature sieve elements. Virus particles were observed in the nuclei and the chloroplasts of parenchyma cells as well as in the ground cytoplasm, the vacuole, and between the plasma membrane and the cell wall. The nature of the conformations of the particle aggregates in the chloroplasts was compatible with the concept that some virus particles may be assembled in these organelles. The virus particles in the nuclei appeared to be complete particles. Under the electron microscope the X-body constitutes a membraneless assemblage of endoplasmic reticulum, ribosomes, virus particles, and of virus-related material in the form of wide filaments indistinctly resolvable as bundles of tubules. Some parenchyma cells contained aggregates of discrete tubules in parallel arrangement. These groups of tubules were relatively free from components of host protoplasts.

scholarly journals A STUDY OF CHROMOSOMES WITH THE ELECTRON MICROSCOPE

1956 ◽  
Vol 2 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Hans Ris
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Meiotic Prophase ◽  
Inner Core ◽  
Outer Part ◽  
Lampbrush Chromosomes ◽  
Interphase Nuclei ◽  
Chemical Difference ◽  
Ultrathin Sections

Amphibian lampbrush chromosomes and meiotic prophase chromosomes of various insects and plants consist of a bundle of microfibrils about 500 A thick. These fibrils are double, being made of two closely associated fibrils 200 A thick. Fragments of interphase nuclei contain a mass of fibrils 200 A thick. Ultrathin sections through nuclei in prophase or interphase show sections of these double or single fibrils cut at various angles. A comparison of sections with the methacrylate left in and sections that were shadowed after removing the methacrylate suggests that the OsO4 reacts only with the outer part of the fibrils either because it does not penetrate, or as a result of a chemical difference of the inner core and the outside of the fibril. It is suggested that in analogy to the structure of the tobacco mosaic virus the chromosomal microfibril may have an inner core of DNA surrounded by a shell of protein.

Electron Microscope Studies on Isolated Plant Protoplasts

1966 ◽  
Vol 21 (6) ◽  
pp. 581-585b ◽  
Author(s):  
E. C. Cocking
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Close Association ◽  
Physiological Activity ◽  
Tomato Fruit ◽  
Plant Protoplasts ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Microscopic Studies

Isolated tomato fruit protoplasts have been observed to take up both tobacco mosaic virus and ferritin by the process of pinocytosis. These studies have involved electron microscopic observations on thin sections of suitably fixed and embedded material. These electron microscopic studies have also shown that very close association exists between the nucleus and chloroplasts in these protoplasts and that occasionally there are present channels extending from the plasmalemma into the cytoplasm. The implication of these results is discussed in relation to the general physiological activity of protoplasts.

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