Molecular and biological characterization of begomoviruses infecting Andrographis paniculata and their genetic recombination lineage

Begomoviruses infect a wide range of plant species and are emerging as one of the most detrimental pathogens. Recombination has led to the evolution and emergence of new species of begomoviruses that are better adapted to new hosts. With the development of computational recombination detection programs, better detection methods and increased availability of complete genome sequences in the database, it has become easier to identify recombination events. Andrographis paniculata is an important medicinal plant and known for the synthesis of various metabolites of high pharmaceutical value. In a recent field survey, a new strain of begomovirus infecting A. paniculata was discovered and full genome analysis revealed it to be different from the two isolates of begomoviruses reported earlier on this plant. Recombination Detection Program and SimPlot analysis showed the inter-species recombination in these begomoviruses infecting A. paniculata, while no recombination was detected in the previous isolates of these viruses. This study highlights the diversity of begomoviruses infecting A. paniculata in nature and also analyzes the role of recombination events responsible for the emergence of new begomovirus isolates/strains.