Mastrevirus
Curtovirus
Begomovirus
Topocuvirus

Geminiviruses are plant viruses which have ambisense single-stranded circular DNA and are members of class II of the Baltimore classification of viruses. The genome can either be segmented (2500-3000 nucleotides) or non-segmented (4800-5600 nucleotides).They have an elongated, geminate capsid with incomplete icosahedral symmetry of T=1 joined at the missing vertex. The capsid ranges from 18-20 nm in diameter with a length of 30nm. These viruses can be bipartite, therefore individual segments can be separated into two different particles, therefore more than one virus particle is required to infect a cell.

Transmission of these viruses can be via the leafhopper or whitefly.

Purified Maize streak virus (MSV) particles stained with uranyl acetate. Size bar indicates 50 nm.

The Geminiviridae include the following genera:

• Genus Mastrevirus; type species: Maize streak virus
• Genus Curtovirus; type species: Beet curly top virus
• Genus Begomovirus; type species: Bean golden mosaic virus
• Genus Topocuvirus; type species: Tomato pseudo-curly top virus

References

• Description of Plant Viruses
• University of Leicester Microbiology
• International Committee on Taxonomy of Viruses

Viruses