In this article we will discuss about the structure and replication of togaviruses. Structure of Togaviruses: The virus is enveloped and forms spherical particle of 65-70 nm diameter. It includes icosahedral capsid, which is made up of 240 monomers (Fig. 17.26). It has a triangulation number of (74). Envelope consists of 80 trimer spikes; dimension of each spike is 3xE1/E2 [...]
In this article we will discuss about the structure of reoviruses (explained with diagram). Non-enveloped, icosahedral virion with a double capsid structure (e.g. rotavirus and orthoreovirus) where iuter capsid has an icosahedral T=13 symmetry, and inner capsid an icosahedral 7=2 symmetry. The outer capsid is positioned upon the virion in such a way that the capsomeres of each capsid layer [...]
The following points highlight the eight modes of transmission of plant viruses. The modes are: 1. Mechanical Transmission 2. Vegetative and Graft Transmission 3. Pollen Transmission 4. Seed Transmission 5. Nematode Transmission 6. Fungal Transmission 7. Insect Vector Transmission 8. Dodder Transmission. Mode # 1. Mechanical Transmission: In nature plant viruses are mechanically transmitted from diseased to healthy plants by [...]