Overview of TMV essays

Overview of TMV essays The tobacco mosaic virus, or as it is usually referred to, TMV, is a common pathogen of many crops including bean, tobacco, and tomato. The virus is known to produce systematic infections in its hosts by spreading throughout the organism from the initial site of entry (usually an injury) via the vascular tissues. In the case of the tomato plant, it does its damage by causing numerous small lesions to form on the surface of an infected plant leaves, thereby interfering with the organisms photosynthetic mechanisms. All multi-cellular organisms will attempt to resist a pathogen with some form of immune response. When exposed, organisms can quickly produce natural resistance compounds and antibiotic-like compounds. Depending on the degree of exposure, the age, and general health of the organism, it will either produce a weak response and fail to prevent the disease from spreading, or it will produce a strong response and develop what is known as Systematic Acquired Resistance, or SAR. Researchers believe that SAR creates a generalized barrier against the invading disease that essentially immunizes the plant against it. There are two methods used to develop SAR in plants. The first is by deliberate weak exposure of a pathogen, which works in the same fashion as the animal immune system. Inducing a small amount of a virus such as TMV to the lower leaves of tomato plants can cause the remainder of the plant to become immune to further infection. This is referred to as the traditional vaccination method. An excellent example that you can all relate to that demonstrates this property is the chicken pox vaccine, which exposes a person to a small amount of the virus. The body can fight off this weakened form and become resistant to it. If this person were to then be exposed to a full strain of the virus, the body would be able to instantly recognize it, and destroy the virus. ...