Geminiviruses and their interaction with host proteins

Geminivirida e is one of the most important families in plant viruses with a single-stranded DNA genome comprises one or two genomes (DNA-A and DNA-B) of 2.5–5.2Kb. These viruses infect economically important food and fiber crops worldwide. Till to date nine genera ( Mastrevirus , Curtovirus , Becurtovirus , Turncurtovirus , Begomovirus , Capulavirus , Topocuvirus , Eragrovirus , and Grablovirus ) have been reported which are transmitted by four insect vectors (whiteflies, leafhoppers, aphids, and treehoppers). DNA-A encodes replication-associated protein, coat protein, replication enhancer protein, transcriptional activator protein, AV2, AC4, and AC5 while DNA-B encodes nuclear shuttle protein and movement protein. Satellite molecules have also been reported to be associated with the family Geminiviridae that includes alphasatellite, betasatellite which encode alpha rep and βC1 gene respectively. A non-coding deltasatellite has also been reported to be associated with geminivirus infections. Geminivirus encoded proteins interact with host proteins to perform a variety of functions which include reprogramming of cell cycle, inhibition of cell death pathways, transcriptional control of multiple genes, interference with cell signaling pathways and overcoming host defense response. Our current knowledge regarding interactions of geminivirus encoded proteins with the host has been described in the following chapter.