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.

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 An Electron Microscope Study of Snow Crystal Nuclei

1953 ◽  
Vol 2 (13) ◽  
pp. 176-180
Author(s):  
Ukichiro Nakaya
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Condensation Nuclei ◽  
Electron Microscopic ◽  
Carbon Particles ◽  
Snow Crystal ◽  
Microscopic Studies ◽  
Snow Crystals ◽  
Micro Organisms ◽  
Collodion Film

AbstractSnow crystals were received on the collodion film of the holder of an electron microscope, and made to sublimate without melting. These specimens were investigated under an electron microscope. One solid nucleus was always observed in the central portion of a snow crystal. These centre nuclei were of sizes between 0.5 and 8μ. Most of them were presumed to be kaolin, clay or carbon particles; some were considered to be micro-organisms. In the other parts of snow crystals numerous smaller nuclei were observed, whose dimensions were of the order of those of condensation nuclei. These condensation nuclei were found to be of two kinds, the larger ones most frequently having a diameter of about 0.15μ, the smaller ones of about 0.05μ. A new theory was proposed from the data of the electron microscopic studies and those of the conditions of formation of snow crystals. In this theory it is proposed that minute water droplets of 1μor so play an important rôls in the process of snow crystal growth.

Electron microscopic observations of the envelopes of isolated algal packets of Azolla

1991 ◽  
Vol 69 (7) ◽  
pp. 1418-1419 ◽  
Author(s):  
Eiji Uheda ◽  
Shunji Kitoh
Keyword(s):  
Electron Microscope ◽  
Nitric Acid ◽  
Sodium Hydroxide ◽  
Key Words ◽  
Layer Structure ◽  
Sodium Dodecylsulfate ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
20 Nm

The envelopes of isolated algal packets from cyanobiont-containing and cyanobiont-free Azolla were examined with the electron microscope. Both types of envelope were 10–20 nm thick and composed of three layers. The three-layer structure was also observed when algal packets were treated with cellulase, pectinase, lipase, protease, sodium hydroxide, nitric acid, or sodium dodecylsulfate. Thus, the envelopes do not appear to be membrane-like in nature and the presence and ultrastructure of the envelopes are not affected by cyanobiont filaments. Key words: algal packet, cyanobiont-free Azolla, Azolla, electron microscopic studies, envelope.

FRUIT DISORDER OF GLASSHOUSE TOMATOES CAUSED BY A TOBACCO FORM OF TOBACCO MOSAIC VIRUS

1975 ◽  
Vol 55 (2) ◽  
pp. 597-604
Author(s):  
W. R. ALLEN ◽  
K. C. CHADHA
Keyword(s):  
Lycopersicon Esculentum ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Tomato Fruit ◽  
Cross Protection ◽  
Mature Fruit ◽  
Leaf Stage ◽  
Lycopersicon Esculentum Mill ◽  
Dark Green

A severe fruit disorder of tomato (Lycopersicon esculentum Mill.) was induced with a tobacco form of tobacco mosaic virus isolated from blemished tomato fruit (cv. Ohio WR25) from a glasshouse crop in southwestern Ontario. Symptoms on green tomatoes consisted of slightly sunken, pale or yellowish-brown lesions with a thin, dark green margin. Lesions frequently expanded and coalesced along the flutes. The shoulders of the fruit were the most extensively affected areas. On mature fruit, the lesions appeared either silvery or silvery-brown and generally had a scabby appearance due to cracking and lifting of the surface tissues. Lesions were superficial and internal symptoms were not detected. First-truss inoculations prevented or delayed the fruit disorder. Inoculations at truss stages two, three, and four, however, resulted in development of affected fruit on inoculated as well as lower and subsequent trusses with the exception of the first truss. Similar susceptibilities to the fruit disorder occurred among the glasshouse cultivars Michigan Ohio (Burghart strain), Ohio WR25, Vantage, Veegan, and Vendor. No cross protection against the fruit disorder was provided by a mild tomato form of TMV introduced at the second-leaf stage.

Electron Microscopic Studies of Fillers in Rubber. III. Effect of Milling on the Dispersion of Fillers

1956 ◽  
Vol 29 (3) ◽  
pp. 1003-1010 ◽  
Author(s):  
Eiji Suito ◽  
Masafumi Arakawa ◽  
Hiroshi Hasegawa ◽  
Yonemasa Furusawa
Keyword(s):  
Electron Microscope ◽  
Marked Effect ◽  
The State ◽  
Replica Method ◽  
Interesting Problem ◽  
Electron Microscopic ◽  
Vulcanized Rubber ◽  
Microscopic Studies ◽  
Filler Particles ◽  
The Relationship

Abstract In the study of types of fillers which have a marked effect on the properties of rubber, information as to how the filler particles are dispersed in rubber is a prerequisite. The authors have already reported on the state of dispersion of various fillers in vulcanized rubber, observed under an electron microscope by the replica method. How the dispersion of these fillers affects the properties of rubber is an interesting problem. Since, in the earlier work, filler particles were observed to orient themselves in certain directions, in this report the relationship between the state of dispersion observed under an electron microscope of filler particles in rubber milled in different ways and the resulting characteristics of the mixtures were examined.

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