Title:Geminiviruses: Taxonomic Structure and Diversity in Genomic Organization
Volume: 14
Issue: 2
Author(s): Saurabh Kulshrestha*, Abhishek Bhardwaj and Vanshika
Affiliation:
- School of Biotechnology, Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan (H.P.),India
Keywords:
Geminiviridae, begomoviruses, aplhasatellites, betasatellites, deltasatellites, ssDNA.
Abstract:
Background: Geminiviridae is one of the best-characterized and hence, one of the largest
plant-virus families with the highest economic importance. Its members characteristically have
a circular ssDNA genome within the encapsidation of twinned quasi-icosaheadral virions (18-38 nm
size-range).
Objective: Construction of a narrative review on geminiviruses, to have a clearer picture of their
genomic structure and taxonomic status.
Methods: A thorough search was conducted for papers and patents regarding geminiviruses,
where relevant information was used to study their genomic organization, diversity and taxonomic
structure.
Results: Geminiviruses have been classified into nine genera (viz., genus Begomovirus, Mastrevirus,
Curtovirus, Topocuvirus, Becurtovirus, Turncurtovirus, Capulavirus, Eragrovirus and
Grablovirus) having distinct genomic organizations, host ranges and insect vectors. Genomic organization
of all genera generally shows the presence of 4-6 ORFs encoding for various proteins.
For now, Citrus chlorotic dwarf-associated virus (CCDaV), Camellia chlorotic dwarf-associated
virus (CaCDaV) and few other geminiviruses are still unassigned to any genera. The monopartite
begomoviruses (and few mastreviruses) have been found associated with aplhasatellites and betasatellites
(viz., ~1.3 kb circular ssDNA satellites). Recent reports suggest that deltasatellites potentially
reduce the accumulation of helper-Begomovirus species in host plants. Some patents have
revealed the methods to generate transgenic plants resistant to geminiviruses.
Conclusion: Geminiviruses rapidly evolve and are a highly diverse group of plant-viruses. However,
research has shown new horizons in tackling the acute begomoviral diseases in plants by
generating a novel bio-control methodology in which deltasatellites can be used as bio-control
agents and generate transgenic plants resistant to geminiviruses.