Tobacco Mosaic Virus
Tobacco mosaic virus (TMV) is a positive-sense single stranded RNA virus that infects plants, namely tobacco and other members of the family Solanaceae. It causes characteristic patterns on the leaves. In 1930 it was determined that an infectious agent was determined to be a virus.
Adolf Mayer first described the disease in 1883. The disease can be transferred between plants similar to bacterial infections. Dimitri Ivanovski was the first to show that infected sap remained infectious even after filtering. Wendell Meredith Stanley crystallized the virus in 1935 and showed that the virus remained active even after crystallization.
It has a rod-like appearance and a capsid made from 2130 molecules of coat protein. It is a thermostable virus and on a dried leaf it can withstand up to 120 degrees Fahrenheit for 30 minutes. It will over-winter in infected tobacco stalks and leaves in the soil. It can be transmitted from one plant to another through direct contact. It is one of the most stable viruses and has a very wide survival range.
Consumption of tobacco products infected with the tobacco mosaic virus has not been found to have any effect on humans. Sanitation is one of the most common control methods for TMV. Crop rotation should also be used in order to avoid infected soil/seed beds for at least 2 years. Some genetic engineering has been done in order to prevent TMV replication within the plant. In some rare cases spraying milk on the host plant is known to inhibit the TMV infection.