scholarly journals AN ELECTRON MICROSCOPE STUDY OF TOBACCO MOSAIC VIRUS LESIONS IN NICOTIANA GLUTINOSA L

1964 ◽  
Vol 23 (3) ◽  
pp. 499-509 ◽  
Author(s):  
M. Weintraub ◽  
H. W. J. Ragetli

Ultra-thin sections of Nicotiana glutinosa L. leaves inoculated with a concentrated solution of tobacco mosaic virus were made at short intervals from 0 to 78 hours after inoculation. Eight hours after inoculation, the size of starch grains increased. This was followed by rupture of cytoplasmic and chloroplast membranes. At about 24 hours there was a great increase in number of mitochondria, which persisted until about 60 hours, when some became electron opaque while others appeared to disintegrate. Finally, the cell contents were compressed into one area of the cell, where they became electron opaque. This was accompanied by collapse of the rest of the cell and tearing away of the cell walls from adjacent cells. The nucleus remained stable and intact for as long as observations could be made. No identifiable virus particles were seen.

1967 ◽  
Vol 35 (1) ◽  
pp. 183-192 ◽  
Author(s):  
M. Weintraub ◽  
H. W. Ragetli ◽  
V. T. John

Tobacco mosaic virus particles were found in small packets and in small numbers, with the electron microscope, in necrotic leaf cells of Nicotiana glutinosa when the samples were fixed in glutaraldehyde and postfixed in OsO4, and the sections were stained with heavy metals. The numbers and size of the virus packets were increased greatly when the leaves were detached from the plant after inoculation Assay of concentration showed that detachment resulted in a 30-fold increase of virus. A similar increase in the number of virus particles detected by electron microscopy was produced by keeping inoculated plants at an air temperature of 26°C. A still greater increase in concentration was effected by incubating detached inoculated leaves at 26°C. Moreover the arrangement of virus particles in these cells resembled that of a systemic virus infection. Cells in local lesions of Chenopodium amaranticolor contained large numbers of virus particles both as packets and in the loose arrangement characteristic of systemic infection. Neither the number of particles nor their arrangement was affected in this host by detaching the leaf or by changing the air temperature. It is suggested that there may be two types of localized virus infections, one of which produces virus in low concentration and is amenable to changes in virus concentration and arrangement as a result of environmental manipulation.


1965 ◽  
Vol 25 (3) ◽  
pp. 77-97 ◽  
Author(s):  
L. Kolehmainen ◽  
H. Zech ◽  
D. von Wettstein

The submicroscopic organization of mesophyll cells from tobacco leaves systemically infected with tobacco mosaic virus (TMV) is described. After fixation with glutaraldehyde and osmium tetroxide the arrangement of the TMV particles within the crystalline inclusions is well preserved. Only the ribonucleic acid-containing core of the virus particles is visible in the micrographs. Besides the hexagonal virus crystals, several characteristic types of "inclusion bodies" are definable in the cytoplasm: The so-called fluid crystals seem to correspond to single layers of oriented TMV particles between a network of the endoplasmic reticulum and ribosomes. Unordered groups or well oriented masses of tubes with the diameter of the TMV capsid are found in certain areas of the cytoplasm. A complicated inclusion body is characterized by an extensively branched and folded part of the endoplasmic reticulum, containing in its folds long aggregates of flexible rods. Certain parts of the cytoplasm are filled with large, strongly electron-scattering globules, probably of lipid composition. These various cytoplasmic differentiations and the different forms of presumed virus material are discussed in relation to late stages of TMV reproduction and virus crystal formation.


Virology ◽  
2001 ◽  
Vol 284 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Yurii G. Kuznetsov ◽  
Steven B. Larson ◽  
John Day ◽  
Aaron Greenwood ◽  
Alexander McPherson

1955 ◽  
Vol 1 (7) ◽  
pp. 549-559 ◽  
Author(s):  
M. Weintraub ◽  
W. G. Kemp

A number of heterocyclic and miscellaneous organic compounds have been tested for their effectiveness as virus inhibitors by a half-leaf technique using Nicotiana glutinosa and tobacco mosaic virus. Several of these compounds were found to be effective in varying degrees, the main effects being a reduction in the total number of lesions produced, a delay in symptom expression, and a decrease in virus multiplication as indicated by small lesions, on the treated half-leaves. Although nothing is known about the mechanism of inhibition, it can be concluded that to effect inhibition compounds act through the physiology of the host, rather than directly on the virus. The virus content of treated half-leaves has been estimated by measuring their rate of oxygen consumption. These data indicate that the inhibiting compounds affect the metabolism of the host, as reflected in a change in respiration when compared to control half-leaves, and that the symptomless areas on the treated half-leaves do not contain significant concentrations of virus.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 65 ◽  
Author(s):  
Ya-Han Chen ◽  
Dong-Sheng Guo ◽  
Mei-Huan Lu ◽  
Jian-Ying Yue ◽  
Yan Liu ◽  
...  

The coumarin compound of osthole was extracted from Cnidium monnieri and identified by LC-MS and 1H- and 13C-NMR. Osthole was tested for anti-virus activity against tobacco mosaic virus (TMV) using the half-leaf method. The results showed that stronger antiviral activity on TMV infection appeared in Nicotiana glutinosa than that of eugenol and ningnanmycin, with inhibitory, protective, and curative effects of 72.57%, 70.26%, and 61.97%, respectively. Through observation of the TMV particles, we found that osthole could directly affect the viral particles. Correspondingly, the level of coat protein detected by Western blot was significantly reduced when the concentrations of osthole increased in tested plants compared to that of the control. These results suggest that osthole has anti-TMV activity and may be used as a biological reagent to control the plant virus in the half-leaf method.


2005 ◽  
Vol 79 (22) ◽  
pp. 14421-14428 ◽  
Author(s):  
Alexey I. Prokhnevsky ◽  
Valera V. Peremyslov ◽  
Valerian V. Dolja

ABSTRACT The cell-to-cell movement of plant viruses involves translocation of virus particles or nucleoproteins to and through the plasmodesmata (PDs). As we have shown previously, the movement of the Beet yellows virus requires the concerted action of five viral proteins including a homolog of cellular ∼70-kDa heat shock proteins (Hsp70h). Hsp70h is an integral component of the virus particles and is also found in PDs of the infected cells. Here we investigate subcellular distribution of Hsp70h using transient expression of Hsp70h fused to three spectrally distinct fluorescent proteins. We found that fluorophore-tagged Hsp70h forms motile granules that are associated with actin microfilaments, but not with microtubules. In addition, immobile granules were observed at the cell periphery. A pairwise appearance of these granules at the opposite sides of cell walls and their colocalization with the movement protein of Tobacco mosaic virus indicated an association of Hsp70h with PDs. Treatment with various cytoskeleton-specific drugs revealed that the intact actomyosin motility system is required for trafficking of Hsp70h in cytosol and its targeting to PDs. In contrast, none of the drugs interfered with the PD localization of Tobacco mosaic virus movement protein. Collectively, these findings suggest that Hsp70h is translocated and anchored to PDs in association with the actin cytoskeleton.


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