Coat Protein-Mediated Protection Against White Clover Mosaic Virus and Potato Virus X in Tobacco

The coat protein genes of the potexviruses white clover mosaic virus (WClMY) or potato virus X (PVX) were introduced into Nicotiana benthamiana plants by gene transfer. Transgenic plants expressing the coal protein gene of WCIMY or PYX were highly resistant to infection when challenge-inoculated with the virus from which the coat protein gene was obtained (homologous challenge). Similar resistance was obtained when homologous viral RNA was used as inoculum, The transgenic plants were also protected against infection with the heterologous virus, but only at low inoculum concentrations. The level of protection in PYX transgenic plants was directly correlated with the level of expression of the PYX CP gene.