<p style="text-align: justify;">Papaya line X17-2 was developed via <i>Agrobacterium</i>-mediated transformation using vector pBI121fs, which contained two gene expression cassettes located within the T-DNA region. The <i>prsv-cp</i> expression cassette consisted of the 35S promoter from cauliflower mosaic virus (CaMV), a frame-shift mutant of the coat protein encoding gene from PRSV isolate H1K, and the nopaline synthase (NOS) 3&rsquo; untranslated region from <i>Agrobacterium tumefaciens</i>. In order to enhance transcription of the <i>prsv-cp</i> gene, the uidA sequence with an initiation codon was placed at the 5&rsquo; terminus of the <i>prsv-cp</i> gene. The second cassette contained the NOS promoter region from <i>A. tumefaciens</i>, the neomycin phosphotransferase II (NPTII) encoding gene from the Tn5 transposon of <i>Escherichia coli</i>, and the NOS 3&rsquo; untranslated region from <i>A. tumefaciens</i>.</p>
