Geminiviruses, which are single-stranded DNA viruses
infecting a range of economically important crop species
(such as cassava, maize, cotton and tomato) in tropical
and subtropical regions, have become a major threat to
world agriculture in the past decade [8]. Based on genome
organization, insect vector and host range, the family
Geminiviridae can be classified into four genera: Begomovirus,
Mastrevirus, Curtovirus and Topocuvirus. So far, all
five Jatropha viral pathogens belong to one genera:Begomovirus. Most of these viruses contain two genomic
components termed DNA-A and DNA-B (approximately
2.7 to 3.0 kb) and they are all exclusively transmitted via
the whitefly, Bemisia tabaci. The virus DNA-A-positive
strand encodes the coat protein (CP/AV1) involved in the
encapsidation of viral DNA, virus movement and viral
transmission by B. tabaci). Among other encoded proteins,
the replication associated-protein (Rep) AC1 is absolutely
required for the replication of both genomic components.
The transcriptional activator protein (TrAP) AC2 is
needed for transcriptional activation of viral gene transcription
and plant host gene expression. The replication
enhancer protein (Ren) AC3 greatly enhances viral DNA
accumulation by interacting with Rep/AC1. Another viral
protein, AC4, acts as a gene-silencing suppressor to compromise
the host defense system. All these five genes are
essential for the virus life cycle and pathogenesis