Tobacco mosaic virus
The tobacco mosaic virus (TMV) was the first virus to be discovered. That is to say, it was the first to be known as a virus.
| Tobacco mosaic virus | |
|---|---|
| File:TobaccoMosaicVirus.jpg | |
| Transmission electron micrograph of TMV particles negative stained to enhance visibility at 160,000× magnification | |
| Virus classification e | |
| Unrecognized taxon (fix): | Tobamovirus |
| Species: | Tobacco mosaic virus
|
It is a single stranded RNA virus which infects many plants, especially tobacco and other members of the family Solanaceae. The infection causes "mosaic"-like discolouration on the leaves. Although it was known from the late 19th century that an infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was known to be a virus.
History
In 1886, Adolf Mayer first described the tobacco mosaic disease that could be transferred between plants, similar to bacterial infections.[1][2]
In 1892, Dmitri Ivanovsky gave the first concrete evidence for the existence of a non-bacterial infectious agent. He claimed that infected sap remained infectious even after filtering through finest filters.[2][3]
In 1898, Martinus Beijerinck independently replicated Ivanovsky's filtration experiments and then showed that the infectious agent was able to reproduce and multiply in the host cells of the tobacco plant.[2][4] Beijerinck coined the term of "virus" to indicate that the causal agent of tobacco mosaic disease was of non-bacterial nature.
Tobacco mosaic virus was the first virus to be crystallized. It was achieved by Wendell Meredith Stanley in 1935 who also showed that TMV remains active even after crystallization.[2] For his work, he was awarded 1/3 of the Nobel Prize in Chemistry in 1946,[5] The first electron microscopical images of TMV were made in 1939.[6]
In 1955, Heinz Fraenkel-Conrat and Robley Williams showed that purified TMV RNA and its capsid (coat) protein assemble by themselves to functional viruses, indicating that this is the most stable structure (the one with the lowest free energy). The crystallographer Rosalind Franklin worked for Stanley for about a month at Berkeley, and later designed and built a model of TMV for the 1958 World's Fair at Brussels. In 1958, she speculated that the virus was hollow, not solid, and hypothesized that the RNA of TMV is single-stranded.[7] This conjecture was proved correct after her death.[8]
The investigations of tobacco mosaic disease and subsequent discovery of its viral nature were instrumental in the establishment of the general concepts of virology.[2]
Tobacco Mosaic Virus Media
- OPSR.Virga.Fig17.v4.png
Genome of tobacco mosaic virus
- Tobacco mosaic virus symptoms tobacco.jpg
Tobacco mosaic virus symptoms on tobacco
- TMV virus super resolution microscopy Christoph Cremer Christina Wege.jpg
TMV virus: super resolution light microscopy
References
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil). Translated into English in Johnson J. (ed) 1942. Phytopathological classics (St. Paul, Minnesota: American Phytopathological Society) #7, pp. 11–24.
- ↑ 2.0 2.1 2.2 2.3 2.4 Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil). Translated into English in Johnson J. (ed) 1942. Phytopathological classics (St. Paul, Minnesota: American Phytopathological Society) #7, pp. 27–30.
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil). Translated into English in Johnson J. (ed) 1942. Phytopathological classics. (St. Paul, Minnesota: American Phytopathological Society) #7, pp. 33–52 (St. Paul, Minnesota)
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).