Isolation and characterization of translation initiation factor 4E in Carica papaya and Vasconcellea species

Papaya ringspot virus (PRSV) causes a devastating disease of papaya and significantly limits papaya production worldwide. Several approaches have been employed in attempts to control PRSV, including the use of tolerant lines, induced virus resistance caused by cross-protection, and transgene-induced post-transcriptional gene silencing. Among these approaches, transgenic resistance has been most successful. However, because of its high cost, the long duration of the deregulation process and the lack of public acceptance, the transgenic approach is currently limited to a few countries. Moreover, transgenic resistance might break down when new PRSV strains emerge. Although resistance to PRSV has not been identified in papaya to date, several Vasconcellea species have been confirmed to contain genetic resistance against PRSV. PRSV belongs to the genus Potyvirus in the family Potyviridae. Translation initiation factor 4E (eIF4E) and its isoforms play a key role in virus multiplication and movement and are a required component for susceptibility to potyviruses. In this study, we isolated and characterized eIF4E genes in papaya and Vasconcellea species to provide essential information for understanding host-pathogen interactions as a key to develop sustainable and effective strategies to control and manage PRSV.