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Here, we report the complete genome sequence of a novel polerovirus, "Plantago asiatica virus A" (PlaVA), detected in Plantago asiatica using high-throughput RNA sequencing and validated by Sanger sequencing. The complete PlaVA genome contains 5,881 nucleotides and has seven open reading frames (ORF0-5 and ORF3a) encoding putative proteins (P0-5 and P3a, respectively) in an arrangement that is similar to that of typical Polerovirus members. Pairwise sequence comparisons revealed that P0 to P5 encoded by PlaVA had the highest sequence identity (25.48%-79.21%) to the corresponding proteins of previously reported poleroviruses. A phylogenetic analysis using the PlaVA P1-2 and P3 amino acid sequences and those of members of the family Solemoviridae (formerly Luteoviridae) indicated that although PlaVA belongs to the genus Polerovirus, it does not represent a known species. Consequently, PlaVA should be considered a member of a new species within the genus Polerovirus.

The complete genomic sequence of scorzonera virus A (SCoVA) from a Scorzonera austriaca Willd. plant in South Korea was determined by high-throughput sequencing and confirmed by Sanger sequencing. The SCoVA genome contains 9867 nucleotides, excluding the 3'-terminal poly(A) tail. The SCoVA genome structure is typical of potyviruses and contains a single open reading frame encoding a large putative polyprotein of 3168 amino acids. Pairwise comparison analysis of the complete genome and polyprotein sequences of SCoVA with those of other potyviruses showed that they shared the highest nucleotide and amino acid sequences identity (54.47% and 49.57%, respectively) with those of lettuce mosaic virus (GenBank accession number KJ161185). Phylogenetic analysis of the amino acid sequence of the polyprotein confirmed that SCoVA belongs to the genus Potyvirus. These findings suggest that SCoVA should be considered a novel member of the genus Potyvirus, family Potyviridae.

A new member of the genus Closterovirus was detected in Platycodon grandiflorus using high-throughput RNA sequencing analysis. The complete genome sequence of this new virus isolate, tentatively named “platycodon closterovirus 1” (PlaCV1), comprises 16,771 nucleotides with nine predicted open reading frames (ORFs) having the typical closterovirus genome organization. PlaCV1 shares 37%–50% nucleotide sequence identity with other known closterovirus genome sequences. The putative RNA-dependent RNA polymerase (RdRp), heat shock protein 70-like protein (HSP70h), viral heat shock protein 90-like protein (HSP90h), minor coat protein (CPm), and coat protein (CP) show 47–68%, 39–66%, 24–52%, 21–57%, and 16–35% amino acid sequence identity, respectively, to homologous proteins in previously identified closteroviruses, suggesting that it represents a distinct, new species in the genus. Phylogenetic analysis of HSP70h sequences places PlaCV1 alongside other members of the genus Closterovirus in the family Closteroviridae. To our knowledge, this study is the first report of the complete genome sequence of PlaCV1 infecting P. grandiflorus in the Republic of Korea.

The complete genome sequence of a new polerovirus found naturally infecting Artemisia princeps, artemisia virus B (ArtVB), was determined using high-throughput sequencing. The ArtVB genome comprises 6,141 nucleotides and contains six putative open reading frames (ORF0 to ORF5) with a genome structure typical of poleroviruses. A multiple sequence alignment showed that the complete ArtVB genome shares 50.98% nucleotide sequence identity with ixeridium yellow mottle virus 1 (IxYMaV-1, GenBank accession no. KT868949). ArtVB shares the highest amino acid sequence identity in P0 and P3–P5 (21.54%–51.69%) with other known poleroviruses. Phylogenetic analysis indicated that ArtVB should be considered a member of a new species within the genus Polerovirus, family Luteoviridae.

The genome of a new potyvirus from a Lamprocapnos spectabilis plant in South Korea was sequenced by high-throughput sequencing and confirmed by Sanger sequencing. The new potyvirus was tentatively named "lamprocapnos virus A" (LaVA); its complete genome contains 9,745 nucleotides, excluding the 3'-terminal poly(A) tail. The LaVA genome structure is similar to that of members of the genus Potyvirus and contains an open reading frame encoding a large putative polyprotein of 3,120 amino acids (aa) with conserved motifs. The complete genome shared 48%-56% nucleotide sequence identity and the polyprotein shared 41%-52% aa sequence identity with those of other potyviruses. These values are below the standard thresholds for potyvirus species demarcation. Phylogenetic analysis based on polyprotein sequences showed that LaVA belongs to the genus Potyvirus. To our knowledge, this is the first report of the complete genome sequence and genome characterization of a potyvirus infecting Lamprocapnos spectabilis.

The complete genomic nucleotide sequence of hemisteptia virus A (HemVA) from a Hemisteptia lyrata Bunge plant in South Korea was identified by high-throughput sequencing. The HemVA genome consists of 6,122 nucleotides and contains seven putative open reading frames, ORF0-5 and ORF3a, encoding the putative proteins P0-P5 and P3a, respectively. Pairwise amino acid sequence analysis shows that the HemVA P1-P5 proteins have the highest sequence identity (23.68%-54.15%) to the corresponding proteins of members of the families Solemoviridae and Tombusviridae. Phylogenetic analysis of the P1-P2 and P3 amino acid sequences indicated that HemVA should be classified as a member of a distinct species in the genus Polerovirus.

The complete genomic sequence of achyranthes virus A (AcVA), from an Achyranthes bidentata Blume plant in South Korea, was determined. The genomic RNA has 9491 nucleotides (nt), excluding the 3'-terminal poly(A) tail and contains an open reading frame typical of members of the genus Potyvirus, family Potyviridae, encoding a large putative polyprotein of 3103 amino acids (aa). Pairwise comparisons showed that the AcVA sequence shares 47.81-57.78% nt sequence identity at the complete genome level, 41.89-56.41% aa sequence identity at the polyprotein level, and 50-63.8% aa sequence identity at the coat protein level with other members of genus Potyvirus. These pairwise comparison values are below the species demarcation cutoff for the family Potyviridae. Our results therefore suggest that this virus should be regarded as a novel member of the genus Potyvirus, tentatively named "achyranthes virus A".

A new virus, tentatively named "kudzu virus D" (KuVD) was discovered in kudzu (Pueraria montana var. lobata) in South Korea. Its complete genome comprises 7,922 nucleotides, excluding the poly(A) tail, and contains five open reading frames (ORFs) encoding, from 5' to 3', a replicase (ORF1), three triple gene block proteins TGB1-3 (ORF2-ORF4), and a coat protein (ORF5). This genome organization is typical of members of the subfamily Quinvirinae of the family Betaflexiviridae. Pairwise alignment analysis revealed that the nucleotide sequences of the replicase and coat protein of KuVD were 12.13-54.46% and 24.03-50.67% identical, respectively, to those of other members of the family Betaflexiviridae. These values are far below the current species ICTV demarcation threshold. Consequently, KuVD should be considered a member of a new species in the subfamily Quinvirinae.

The complete genome sequence of a putative new virus isolate, provisionally named "Fagopyrum esculentum endornavirus 2" (FeEV2), is 15,706 nucleotides long with a single, large open reading frame and a typical endornavirus genome organization. FeEV2 shares 19.4%-22.1% nucleotide sequence identity with other known endornavirus genome sequences. The putative polyprotein, RNA-dependent RNA polymerase (RdRp), helicase, and glycosyltransferase (GT) share 10.6%-24.3%, 30.4%-66.1%, 16.3%-45.7%, and 10.1%-21.6% amino acid sequence identity, respectively, with the homologous sequenced proteins from known endornaviruses. This suggests that it is a member of a new, distinct species. Phylogenetic analysis of RdRp sequences places FeEV2 with other Alphaendornavirus genus members (family Endornaviridae). This is the first report of the complete genome sequence of FeEV2, which was isolated from Fagopyrum esculentum in South Korea.

The complete genomic sequence of scorzonera virus A (SCoVA) from a Scorzonera austriaca Willd. plant in South Korea was determined by high-throughput sequencing and confirmed by Sanger sequencing. The SCoVA genome contains 9867 nucleotides, excluding the 3'-terminal poly(A) tail. The SCoVA genome structure is typical of potyviruses and contains a single open reading frame encoding a large putative polyprotein of 3168 amino acids. Pairwise comparison analysis of the complete genome and polyprotein sequences of SCoVA with those of other potyviruses showed that they shared the highest nucleotide and amino acid sequences identity (54.47% and 49.57%, respectively) with those of lettuce mosaic virus (GenBank accession number KJ161185). Phylogenetic analysis of the amino acid sequence of the polyprotein confirmed that SCoVA belongs to the genus Potyvirus. These findings suggest that SCoVA should be considered a novel member of the genus Potyvirus, family Potyviridae.

A new member of the genus Closterovirus was detected in Platycodon grandiflorus using high-throughput RNA sequencing analysis. The complete genome sequence of this new virus isolate, tentatively named "platycodon closterovirus 1" (PlaCV1), comprises 16,771 nucleotides with nine predicted open reading frames (ORFs) having the typical closterovirus genome organization. PlaCV1 shares 37%-50% nucleotide sequence identity with other known closterovirus genome sequences. The putative RNA-dependent RNA polymerase (RdRp), heat shock protein 70-like protein (HSP70h), viral heat shock protein 90-like protein (HSP90h), minor coat protein (CPm), and coat protein (CP) show 47-68%, 39-66%, 24-52%, 21-57%, and 16-35% amino acid sequence identity, respectively, to homologous proteins in previously identified closteroviruses, suggesting that it represents a distinct, new species in the genus. Phylogenetic analysis of HSP70h sequences places PlaCV1 alongside other members of the genus Closterovirus in the family Closteroviridae. To our knowledge, this study is the first report of the complete genome sequence of PlaCV1 infecting P. grandiflorus in the Republic of Korea.

The complete genome sequence of a new polerovirus found naturally infecting Artemisia princeps, artemisia virus B (ArtVB), was determined using high-throughput sequencing. The ArtVB genome comprises 6,141 nucleotides and contains six putative open reading frames (ORF0 to ORF5) with a genome structure typical of poleroviruses. A multiple sequence alignment showed that the complete ArtVB genome shares 50.98% nucleotide sequence identity with ixeridium yellow mottle virus 1 (IxYMaV-1, GenBank accession no. KT868949). ArtVB shares the highest amino acid sequence identity in P0 and P3-P5 (21.54%-51.69%) with other known poleroviruses. Phylogenetic analysis indicated that ArtVB should be considered a member of a new species within the genus Polerovirus, family Luteoviridae.

The complete genomic sequence of achyranthes virus A (AcVA), from an Achyranthes bidentata Blume plant in South Korea, was determined. The genomic RNA has 9491 nucleotides (nt), excluding the 3'-terminal poly(A) tail and contains an open reading frame typical of members of the genus Potyvirus, family Potyviridae, encoding a large putative polyprotein of 3103 amino acids (aa). Pairwise comparisons showed that the AcVA sequence shares 47.81-57.78% nt sequence identity at the complete genome level, 41.89-56.41% aa sequence identity at the polyprotein level, and 50-63.8% aa sequence identity at the coat protein level with other members of genus Potyvirus. These pairwise comparison values are below the species demarcation cutoff for the family Potyviridae. Our results therefore suggest that this virus should be regarded as a novel member of the genus Potyvirus, tentatively named "achyranthes virus A".

High-throughput sequencing revealed a tentative new badnavirus infecting Codonopsis lanceolata, provisionally named Codonopsis vein clearing virus (CoVCV). The complete 8,112-nt CoVCV genomic DNA sequence (GenBank accession: MK044821) comprises three open reading frames (ORFs) encoding conserved domains, with typical features of badnaviruses. Additionally, BLASTn searches indicated the CoVCV genome sequence is most similar to the grapevine vein clearing virus (GVCV) genome (72% identity and 46% query coverage). Moreover, the polyprotein encoded in CoVCV ORF3 is most similar to the corresponding protein of GVCV, with 60% amino acid sequence identity (89% query coverage). These results suggest that CoVCV is a new member of the genus Badnavirus in the family Caulimoviridae.

We determined the complete genome sequence of a South Korean (SK) isolate of Brugmansia mosaic virus (BruMV), which has recently been proposed to be a member of a new species in the genus Potyvirus. The genomic RNA of BruMV isolate SK is 9781 nucleotides in length (excluding the 3'-terminal poly (A)) and shares complete nucleotide and polyprotein amino acid sequence identities of 85.6 % and 93.1 %, respectively, with the type isolate (D-437) of BruMV described in the USA. To our knowledge, this is the first report providing evidence of considerable sequence variation in BruMV.

The complete genome sequence of ligustrum virus A (LVA) from a Ligustrum obtusifolium Sieb. & Zucc. plant was determined. The genomic RNA has 8,525 nucleotides, excluding the poly(A) tail, and consists of six open reading frames typical of members of the genus Carlavirus, family Betaflexiviridae. Phylogenetic analysis of the viral replicase and coat protein (CP) indicated that LVA is closely related to daphne virus S and helenium virus. The replicase and CP of LVA shared 44.73–52.35 % and 25.39–62.46 % amino acid identity, respectively, with those of other carlaviruses. These results suggest that LVA is a member of a distinct carlavirus species.

From Daphne odora Thunb., an ornamental shrub in the Republic of Korea, a potyvirus was identified that has an RNA genome of 9,448 nucleotides (excluding the 3′-terminal poly(A) tail) encoding a polyprotein of 3,065 amino acids, with nine putative protease cleavage sites producing ten proteins. Since this potyvirus shared the highest nucleotide sequence identity (91 %; query coverage 5 %) with the available partial sequence of daphne virus Y (DVY) from New Zealand (EU179854), it was considered a Korean isolate of DVY. This is the first molecular characterization of the complete genome sequence of a DVY isolate.