A chimeric Potato virus X encoding a heterologous peptide affects Nicotiana benthamiana chloroplast structure

The cytopathology of a Potato virus X (PVX) recombinant variant (encoding as fusion of an epitope of immunological interest with the N-terminus of the coat protein, PVX Sma P18DD) has been compared with that induced by the wild-type virus (PVX wt) in Nicotiana benthamiana plants. Both PVX wt and PVX Sma P18DD caused similar ultrastructural alterations, characterized by the presence of laminated inclusion components and bulk virus accumulations in mesophyll cells. However, some striking differences were observed not only in the morphology of these accumulations (typically ordered in PVX wt infection and disordered in PVX Sma P18DD infection) but also because the chimeric virus caused peculiar alterations in chloroplasts structure.