Molecular characterization of a novel species of capillovirus from Japanese apricot (Prunus mume)

Abstract

With the increased use of high-throughput sequencing methods, new viruses infecting Prunus spp. are being discovered and characterized, especially in the family Betaflexiviridae. Double-stranded RNAs from symptomatic leaves of a Japanese apricot (Prunus mume) tree from Japan were purified and analyzed by Illumina sequencing. Blast comparisons of reconstructed contigs showed that the P. mume sample was infected by a putative novel virus with homologies to Cherry virus A (CVA) and to the newly described Currant virus A (CuVA), both members of genus Capillovirus. Completion of the genome showed the new agent to have a genomic organization typical of capilloviruses, with two overlapping open reading frames encoding a large replication-associated protein fused to the coat protein (CP), and a putative movement protein (MP). This virus shares only, respectively, 63.2% and 62.7% CP amino acid identity with the most closely related viruses, CVA and CuVA. Considering the species demarcation criteria in the family and phylogenetic analyses, this virus should be considered as representing a new viral species in the genus Capillovirus, for which the name of Mume virus A is proposed.