CONFIRMATION THAT THE SUGARCANE MOSAIC-VIRUS SUBGROUP CONSISTS OF 4 DISTINCT POTYVIRUSES BY USING PEPTIDE PROFILES OF COAT PROTEINS

The taxonomic status of sugarcane mosaic virus (SCMV) strains reported from various parts of the world has been uncertain. Previous analyses of 17 SCMV strains with virus-specific polyclonal antibodies demonstrated that they represent four distinct potyviruses, namely Johnsongrass mosaic virus (JGMV), maize dwarf mosaic virus (MDMV), sorghum mosaic virus (SrMV), and SCMV. To confirm this classification, we have now compared six strains of SCMV, three strains of JGMV, and two strains each of MDMV and SrMV using high-performance liquid chromatographic (HPLC) peptide profiling of tryptic digests of their coat proteins. The results showed that peptide profiles could be divided into four distinct groups, which are as different from each other as are peptide profiles of other distinct potyviruses. These findings confirm our previous classification of SCMV strains based on N-terminal serology.