Tobacco Mosaic Virus, A Danger for Plants

Discovered by Martinus Beijerinck in 1898 the Tobacco Mosaic Virus affects tobacco, tomatoes and other varieties of Solanaceous plants. It is a plant pathogen and is a member of a large group of viruses that belong to the genus Tobamovirus. The virus resembles rigid rods that are 300 nanometers long and 18 nanometers wide. It is a single strand of RNA coated with protein molecules that are stacked helically.

This virus enters the plants through wounds. The Virus hijacks the host plants protein synthesis machinery to produce viral proteins and makes copies of its RNA that spreads in the neighboring cells and slowly infects the whole plant. This virus spreads very fast and is difficult to contain. An infected leaf brushing against another healthy plant leaf is enough to transmit this virus into the healthy plants. Not just this, if a person handles an affected plant and touches any other things around like a door handle the virus sticks to the door handle and can easily be transmitted to other plants unknowingly.  Luckily this is not spread majorly by insects except for occasional transmission by caterpillars or grasshoppers. The symptoms of TMV affected plants are stunted growth. Mosaic patterns of yellow and green leaves, malformation of leaves at the point of growth, yellow leaf veins and distinct yellow spotting. Treatment for TMV is removal of affected leaves and plants and should be burned. The infected plants should not be buried. Although the virus can multiply only within a living cell, but burying will not kill it, as can survive in dormant state in a dead tissue for years.

Madhuchanda Saxena

https://extension.psu.edu/tobacco-mosaic-virus-tmv