CP and infection: However, the infection of these YK CP-3'UTR transgenic papaya lines by a different potyvirus Papaya leaf-distortion mosaic virus (PLDMV) during field trials22 necessitated the development of double-virus-resistant transgenic papaya lines that carry a chimeric untranslatable transgene comprising parts of the PLDMV CP and PRSV YK CP-3'UTR sequences23.