Elucidation of the molecular nature of recessive resistance against potyviruses in a wide variety of crop plants has revealed that it corresponds either to eukaryotic translation initiation factor eIF4E or eIF(iso)4E gene. Plant susceptibility genes, which support potyvirus infection, as possible source of resistance were recently reviewed .
Several investigations on crop and model plants have confirmed that VPg-eIF4E/(iso)4E interaction is necessary for potyvirus infection. We investigated the functions of the VPg-eIF(iso)4E interaction in PVA infection by abolishing the eIF(iso)4E binding sequence within VPg . The results allow us to suggest that binding between VPg and eIF(iso)4E is an essential interaction for the assembly of a protective protein complex around PVA RNA, thus enabling silencing suppression and transfer of PVA RNA to polysomes for viral protein synthesis.