Studies on purification of ΒC1 protein of geminivirus satellite and geminivirus pathogenesis

Abstract

Begomoviruses constitute the largest genus of the family Geminiviridae which causes huge loss of the crops worldwide. Monopartite begomoviruses are usually associated with betasatellite which highly increases disease development process and therefore possess a great threat for the economically important crops. βC1, the only protein encoded by the betasatellite plays multitasking roles and aid helper virus to promote infection by increasing symptom severity, by suppressing the transcriptional and post transcriptional gene silencing etc. In this study PatnaβC1 protein encoded by Tomato leaf curl Patna betasatellite and its ATPase deficient mutant has been purified by affinity chromatography to examine the structural changes of the protein after the mutation. Furthermore to study the begomovirus mediated pathogenesis, Nicotiana benthamiana plants infected with Tomato leaf curl New Delhi virus DNA-A (ToLCNDV-A) and its mutants along with Radish leaf curl betasatellite (RaLCB). The plants infected with ToLCND-A along with RaLCB shows severe symptoms like veinal chlorosis, leaf curling, stunted growth etc. However plants infected with ToLCNDV-AC2 and ToLCNDV-AC4 along with RaLCB did not shows any symptoms. RaLCB specific PCR analysis did not support the result observed for ToLCNDV-AC4 – RaLCB inoculated plants, however the PCR analysis of ToLCNDV-AC2 – RaLCB inoculated plants suggests the influence of RaLCB for symptom development.