Table of Contents
Introduction of Tobacco Mosaic Virus
Tobacco mosaic virus is rod shape helical virus consists of single standard RNA (5-6%) envelope protein coat(92-94%).
The rod is consider to be 3000A°in length and about 180A°in diameter.
The protein coat is technical called capsid are franklin stemating 2936 subunit namely capsomere in a complete rod and 49 Capsomere one every throter of the helix.
Thus there would be about 130 turns per rod of TMV. The diameter of Rna helix is about 80A°and Rna molecule lie about 50A°in width from outermost surface of the cod.
Life Cycle of Tobacco Mosaic Virus (TMV)
The virus gets inside the plant host cells via vectors such as aphids, flies and other insects. After entering the host cell the virus starts to multiply and spreads to the nearby cells via Plasmodesmata.
The virus can be transmitted to other healthy plants by coming in direct contact with the infected plants. For replication and multiplication inside the host cell, the viral particle releases its genomic material.
The SSRNA then translates multiple mRNAs that can replicate the viral genome and the capsid proteins. All these proteins assemble to form a newly synthesised cell of tobacco mosaic virus that is ready to infect another cell.
The viral RNA first induced the formation of specific enzyme called RNA polymerase.
The single standard viral RNA synthesized and additional RNA strand called replication RNA.
Tobacco Mosaic Virus Symptoms
The first symptoms appear about 10 days after infection. Plants usually do not die, but their growth can be severely stunted. In tomatoes, certain her TMV strains can cause fruit deformation, uneven fruit color, and delayed ripening.
The specific symptoms depend on the host plant, the age of the affected plant, environmental conditions, virus strain, and the genetic background of the host plant.
However, common signs include mosaic mottling (mottling) on leaves, curling of leaves, and yellowing of plant tissue.
Treatment of Tobacco Mosaic Virus
- Maintain good hygiene throughout the growing season. Remove rotten leaves from the plant and surrounding soil.
- Burn all parts of infected plants, never place them in a compost pile, and never bury them in the ground. Wash your hands thoroughly and disinfect all garden tools after handling infected plants.
- Check plants regularly for signs of TMV infection.