Comparison of the Nuclear Inclusion b Protein and Coat Protein Genes of Five Papaya Ringspot Virus Strains Distinct in Geographic Origin and Pathogenicity

Abstract

A complementary DNA library was constructed to the genomic RNA of an isolate of papaya ringspot virus (PRSV), PRSV YK (YK), that represents the most prevalent mosaic strain of Taiwan. A 2.96-kb clone, pYKB9, corresponding to the 3'-region of YK RNA was selected by immunoscreening with the antiserum to the coat protein (CP). The clone had 2,960 nucleotide residues and represented part of the nuclear inclusion a (NIa) gene, the complete nuclear inclusion b (NIb) gene, the entire CP gene, and the 3'-noncoding region of YK RNA. The nucleotide sequence was compared to those of the 3' regions of the published Hawaii severe strain, PRSV HA (HA), the Hawaii mild strain PRSV HA 5-1 (HA 5-1), the nonpapaya-infecting Florida strain, PRSV W(fl) (W(fl)), and the nonpapaya-infecting Australia strain PRSV W(aust) (W(aust))