Tobacco Mosaic Virus Research Paper

The tobacco mosaic virus is a single-stranded RNA virus that belongs to the genus tobamovirus, the genus that specifically affects the family Solanaceae and belongs to the family Virgaviridae. The tobacco mosaic virus was the first virus to be discovered(1).

In 1982, Dmitri Ivanovsky suggested that there was a non-bacterial infectious agent that was still present in the infected sap after filtering(2,3). In 1898, Beijerinck repeated the Ivanovsky experiments and also found out that the infectious agent was able to reproduce in the tobacco plants(2,4). Beijerinck initially called it ‘contagium vivium fluidium’ and later on coined the term ‘virus’ to indicate that the infectious agent was of non-bacterial and non-capsular nature and thus was named ‘Tobacco Mosaic Virus’ because of its ability to reproduce in the tobacco plants. The tobacco mosaic virus was the first virus that was crystallized by W.M.Stanley.

STRUCTURE

It is constituting of 2130 coat protein molecules and a single-stranded RNA of 6400 bases. It’s rod like structure is assembled into a helix using the coat proteins and they form a hairpin structure(5,6). The protein monomer has 158 amino acids and assembled into four main alpha-helices that are joined to the central axis of the virus. The virion is 18 nm in width and 300 nm in length and a 4 nm core inside it(in the central part) (5,6,7). The TMV genome consists of 6.3-6.5 kb single stranded RNA and has a 3’ end which a t-RNA like structure and the 5’ end cap is methylated(8). It has 4 open-reading frames and its genes encode for RNA dependent RNA Polymerase, a replicase and a movement protein(8,9). The TMV is a thermostable virus and can withstand upto 50 degree