Near-complete genomic characterisation and experimental host infection observations of pepper veinal mottle virus isolates from Taiwan

Pepper veinal mottle virus (PVMV; genus Potyvirus, family Potyviridae) primarily infects pepper but it also occurs in tomato and eggplant. Although several complete genome sequences of PVMV isolates have been found around the world, genomic information concerning the isolates preserved in Taiwan is still scarce. In this study, two isolates – Tom1 (derived from tomato) and EP1 (derived from eggplant), isolated in Taiwan, were examined using near-complete genome sequencing and infection assays. The near-complete genomic sequences of Tom1 and EP1, consisting of 9796 nucleotides, contained a 3073-amino-acid polyprotein, which is cleaved into the 10 general proteins found in potyviruses. A comparison of the genomic sequences of Tom1 and EP1 showed that the two have 94.3 % nucleotide sequence similarity. Phylogenetic analysis, using close to near-complete genomic sequences, placed the isolates of Tom1 and EP1, along with isolates from Taiwan, Japan and Korea, within a relatively conserved group. Gene-wise comparison showed high sequence conservation in the coat protein (CP), while moderate variation was observed in the P1, HC-Pro, CI and VPg regions. The two isolates exhibited isolate-dependent symptom expressions in selected experimental hosts, as observed qualitatively without quantitative assessment. No recombination signals were detected between Tom1 and EP1. This study provides updated genomic reference data for PVMV isolates from Taiwan and documents qualitative host infection outcomes, offering baseline information for future molecular, epidemiological and functional studies of PVMV.