HETEROLOGOUS ENCAPSIDATION OF POTATO VIRUS-Y STRAIN-O (PVYO) WITH THE TRANSGENIC COAT PROTEIN OF PVY STRAIN-N (PVYN) IN SOLANUM-TUBEROSUM CV BINTJE

Potato plants transgenic for the coat protein (CP) gene of Potato virus Y strain N (PVY(N)) were examined for the accumulation of the transgenic PVY(N) CP. The protein remained undetectable in healthy plants of lines Bt6 and Bt10 that are completely or partially resistant to this virus, but accumulated when the plants were infected by a related strain, PVY(O). One possible explanation was that the transgenic CP is stabilized by integration into the capsid of the infecting virus. To investigate this, virus particles originating from these plants were examined by immuno-electron microscopy. Heterologous encapsidation was observed between the infecting PVY(O) virus and the transgenic PVY(N) CP. These results have implications for the understanding of the mechanism of CP-mediated protection and assessing its impact on agricultural ecosystems.