Abstract:
Begomoviruses (family Geminiviridae) are circular, single-stranded DNA (ssDNA)
viruses having monopartite or bipartite genome. The genome is very small and
comprises four to six ORFs. These viruses are economically important as they cause a
number of diseases in plants, the most significant being Cotton leaf curl disease
(CLCuD).. In plants more than one virus can exist at a particular time resulting in mixed
infections. Mixed infections are common in nature and often result in causing disease
severity in infected plants. Such infections are frequently observed in viruses of the
genus Begomovirus, as they are transmitted by the ubiquitous whitefly Bemisia tabaci,
a polyphagous insect that can infest multiple hundred plant species. In the present study,
the coinfection of two Begomoviruses, Tomato leaf curl New Delhi virus (ToLCNDV)
and Cotton leaf curl Kokhran Virus-Burewala strain (CLCuKoV-Bur) in relation to
CLCuD by taking in account the interactions taking place between the proteins of the
two viruses . By Adopting an in-silico approach, viral sequences were retrieved from
GenBank viral proteins were modelled using homology modelling, threading and ab
initio approaches. Structure assessment of the predicted structures was done using
ERRTA, PROCHECK, and RAMPAGE and the most suitable models were docked
using HADDOCK2.2 webserver. 56 interactions were performed by docking all the
proteins of CLCuKoV-Bur with the proteins of TOLCNDV. All interactions exhibited
a significant HADDOCK2.2 score, proving a strong interaction existed between the
viruses. The most significant interaction of the proteins of CLCuKoV-Bur was seen
between MP and NSP proteins of DNA-B of ToLCNDV. The interacting residues
between the viruses were determined by PRODIGY webserver and important domains
taking part in the interaction were determined, and interacting domains were identified.
IX
Based on the strong interaction existing between the proteins, and the domains taking
part in the interaction control strategies maybe devised to limit the spread of the two
viruses.
