Potato plants were modified with the insertion of a consitiutively
expressed pr17 gene of the potato leafroll virus, which is presumed
to be a transport protein which spreads the viral genome as a
ribonucleoprotein complex by the passage through plasmodesmata in
the phloem of infected plants.
As a result of the genetic modification, in the event of a PLRV
infection, the modified protein could inhibit the formation of the
viral transport structures in the genetically modified plants by
forming hetero-oligomers with the wild-type transport protein
encoded by the viral genome.
This could prevent the long-distance transport of viral RNA in the
phloem and consequently the spread and further multiplication of
the virus in the plant. Greenhouse experiments revealed that the
genetically modified plants were resistant to the potato viruses
PLRV, PVX and PVY.