![]() followed by de novo assembly of the complete genome. In recent years, increasingly novel viruses were identified by deep sequencing virus-derived small-interfering RNAs (siRNA). SMV is the most devastating and widely distributed virus in China. The soybean crops are constantly threatened by diverse viruses, such as soybean mosaic virus (SMV), cucumber mosaic virus (CMV) and bean common mosaic virus (BCMV), resulting in global yield reduction. Soybean ( Glycine max L.) is an economically important oilseed crop and vegetable-protein resource. A short non-AUG-initiated ORF, termed ORF3a, is located in the upstream of ORF3 and is involved in the viral long-distance movement and systemic infection of plants. ORF5 is expressed via translational readthrough of the leaky stop codon of ORF3 to produce the putative P3–P5 fusion protein, which is necessary for vector transmission of the viral component. ORF3 and ORF4 are expressed by translation from subgenomic RNAs to encode coat protein (CP) and movement protein (MP), respectively. In addition, ORF1 could be expressed with ORF2 in a −1 ribosomal frameshift manner as a viral RNA-dependent RNA polymerase (RdRp). ORF1 encodes P1, which contains the VPg and serine proteinase domain. ORF0 encodes the viral silencing suppressor (VSR). The typical polerovirus genome is organized by seven ORFs, with a viral protein genome linked (VPg) covalently linked to the 5′-end. Polerovirus contains the most species among the four genera. The family members are characterized by a single-stranded positive-sense RNA genome of 4–4.6 kb in length and an icosahedral (t = 3) virion with a diameter of 26–34 nm. Solemoviridae is a recently recognized plant-infecting virus family divided into four genera, named Enamovirus, Polemovirus, Polerovirus and Sobemovirus. Subsequently, we demonstrated the infectivity of SbCLRV in Nicotiana benthamiana via infectious cDNA clone generation and agroinoculation. Phylogenetic analyses of the genome and encoded protein sequences revealed that the new virus is closely related to phasey bean mild yellows virus, CPPV2 and siratro latent polerovirus. Recombination analysis identified a recombination event in the ORF5 of the 3’ portion in the genome. Amino acid sequence identities of the protein products between the virus and its relatives are below the threshold determined by the International Committee of Taxonomy of Viruses (ICTV) for species demarcation, and this strongly supports this virus’ status as a novel species, for which the name soybean chlorotic leafroll virus (SbCLRV) is proposed. The full genome is composed of single-stranded RNA of 5822 nucleotides in length, with the highest nucleotide sequence identity (79.07% with 63% coverage) for cowpea polerovirus 2 (CPPV2). Its genome organization is typical of the members of genus Polerovirus, containing seven putative open reading frames (ORFs). ![]() The complete viral genome sequence was identified using high-throughput sequencing and confirmed using rapid amplification of cDNA ends (RACE), RT-PCR and Sanger sequencing. In this study, we describe the identification of a novel polerovirus isolated from soybean displaying curled leaves. Poleroviruses are positive-sense, single-stranded viruses.
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