Carmovirus

Carmoviridae are a genus of the Tombusvirus family. It is classified under the Baltimore classification system as a group IV virus; that is, it has an RNA, positive-sense genome. Replication occurs in the cytoplasm. The genome is 3800-4300 base pairs long, although the viron contains a longer copy. The viral cycle is complete when assembled viron particles are released during cell lysis.

The virus capsid is non-envoloped with icosahedral symmetry, made up of 32 capsomers. Each subunit consists of 180 proteins. The capsid diameter is around 30nm. By weight, the viron is 80% protein and 20% nucleic acids.

The virus’ natural host is species of Caryophyllaceae, responsible for carnation mottle, but it can infect a far larger range of plants. Symptoms are localised lesions where cell death has occurred. The virus spreads via arthropod vectors carrying infected sap. Although the disease is widespread in carnations, the symptoms are relatively mild and do not pose a major problem. In other plants however, such as the Calla lily, the disease is of more concern, as the plant is of significant economic importance to Taiwan.