Molecular Characterization and Pathogenicity of a Novel Soybean-Infecting Monopartite Geminivirus in China

Abstract

Soybean is a major legume crop that plays an important role in food production, industrial production, and animal husbandry. Here, we characterize a novel soybean-infecting monopartite geminivirus identified in China. Analysis of the contigs de novo assembled from sequenced small interfering RNAs, followed by PCR, cloning, and sequencing, the complete viral genome was determined to be 2782 nucleotides. The genome contains the conserved nonanucleotide sequence, TAATATTAC and other sequence features typical of the family Geminiviridae, and encodes two and four open reading frames in the virion-sense and the complementary-sense strands, respectively. Genome-wide pairwise identity analysis revealed that the novel virus shares less than 65.6% identity with previously characterized geminiviruses. Phylogenetic and recombination analysis indicated that this virus was placed in a unique taxon within the family Geminiviridae and potentially arose from recombination. An infectious clone of this virus was further constructed and its infectivity was tested in different species of plants. Successful infection and characteristic symptoms were observed in Glycine max, Nicotiana benthamiana, N. tabacum, N. glutinosa, and N. tabacum cv. Samsun plants. Taken together, this virus represents a member of an unclassified genus of the family Geminiviridae, for which the name soybean yellow leaf curl virus is proposed.

Whole‐plant microbiome profiling reveals a novel geminivirus associated with soybean stay‐green disease

“…Geminiviruses are among the most devastating plant pathogens worldwide (Roumagnac et al ., 2021). The documented geminiviruses that attack soybean include mung bean yellow mosaic virus (MYMV) (Malathi and John, 2008), soybean crinkle leaf virus (SCLV) (Iwaki et al ., 1983), soybean mild mottle virus (SbMMV) and soybean chlorotic blotch virus (SbCBV) (Alabi et al ., 2010), soybean blistering mosaic virus (SbBMV) (unpublished), and soybean yellow leaf curl virus (SbYLCV) (Du et al ., 2022); all of these viruses belong to the genus Begomovirus of the family Geminiviridae. However, phylogenetic analysis of the full‐length genome showed that SbSGSV is distinct from these documented geminiviruses as well as the 14 established genera of the Geminiviridae family.…”

Leafhopper transmits soybean stay-green associated virus to legume plants

“…to beans [34] and tobacco [35][36][37][38]. Since the SoSGV coat protein shares high homology with mastreviruses [29], and the coat protein determines the insect vector specificity…”

“…The common brown leafhopper can also transmit tobacco yellow dwarf virus ( Mastrevirus, Geminiviridae ) to beans [34] and tobacco [35–38]. Since the SoSGV coat protein shares high homology with mastreviruses [29], and the coat protein determines the insect vector specificity [39], the phylogenetic relations of SoSGV coat protein may explain why leafhopper, other than whitefly [13], transmits SoSGV. Leafhoppers are shown to transmit plant geminiviruses in a persistent circulative manner [40], and the common brown leafhopper has a comparatively broad host plant range [41].…”

“…Six viral genomic sequences (MT221447.1, OM914609.1, OL404964.1, OL855975.1, OM145986.1, and MZ505080.1) were obtained from NCBI. Although they were named differently [27–29], they all belong to the species termed SoSGV in this and the former study [13]. The 6 sequences were aligned with the 22 genomic sequences obtained in this study using MAFFT (version 7.475).…”

“…Recently, a novel geminivirus, soybean stay-green associated virus (SoSGV) [13], has been identified and found to be strongly associated with the SGS incidences in the Huang-Huai-Hai region of China [13, 27–29]. Inoculation of this virus to soybean plants based on an infectious viral clone recapitulates the SGS symptoms, like increased flat pod number and reduced yield, while the total pod number keeps unchanged [13].…”