title: A novel flavivirus in the soybean cyst nematode.
abstract: Heterodera glycines, the soybean cyst nematode (SCN), is a subterranean root pathogen that causes the most damaging disease of soybean in the USA. A novel nematode virus genome, soybean cyst nematode virus 5 (SbCNV-5), was identified in RNA sequencing data from SCN eggs and second-stage juveniles. The SbCNV-5 RNA-dependent RNA polymerase and RNA helicase domains had homology to pestiviruses in the family Flaviviridae, suggesting that SbCNV-5 is a positive-polarity ssRNA virus. SbCNV-5 RNA was present in all nematode developmental stages, indicating a transovarial mode of transmission, but is also potentially sexually transmitted via the male. SbCNV-5 was common in SCN laboratory cultures and in nematode populations isolated from the field. Transmission electron microscopy of sections from a female SCN showed virus particles budding from the endoplasmic reticulum and in endosomes. The size of the viral genome was 19 191 nt, which makes it much larger than other known pestiviruses. Additionally, the presence of a methyltransferase in the SbCNV-5 genome is atypical for a pestivirus. When cDNA sequences were mapped to the genome of SbCNV-5, a disproportionate number aligned to the 3' NTR, suggesting that SbCNV-5 produces a subgenomic RNA, which was confirmed by RNA blot analysis. As subgenomic RNAs and methyltransferases do not occur in pestiviruses, we conclude that SbCNV-5 is a new flavivirus infecting SCNs.
authors.affiliation: Department of Agricultural and Biological Engineering, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Sadia
authors.initials: S
authors.lastname: Bekal
authors.affiliation: US Department of Agriculture, Agricultural Research Service, University of Illinois, Urbana, IL 61801, USA.|Department of Crop Sciences, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Domier
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Biruk
authors.initials: B
authors.lastname: Gonfa
authors.affiliation: US Department of Agriculture, Agricultural Research Service, University of Illinois, Urbana, IL 61801, USA.|Department of Crop Sciences, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Nancy K
authors.initials: NK
authors.lastname: McCoppin
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Kris N
authors.initials: KN
authors.lastname: Lambert
authors.affiliation: Department of Agricultural and Biological Engineering, University of Illinois, Urbana, IL 61810, USA.
authors.forename: Kaustubh
authors.initials: K
authors.lastname: Bhalerao
mesh_terms: D000818:Animals; D001483:Base Sequence; D005260:Female; D005416:Flavivirus / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D049751:Genome, Helminth; D016679:Genome, Viral; D008297:Male; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000469:parasitology / Q000821:virology; D018517:Plant Roots / Q000469:parasitology / Q000821:virology; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D013025:Glycine max / Q000469:parasitology* / Q000821:virology*; D059467:Transcriptome; D014431:Tylenchoidea / Q000254:growth & development / Q000472:pathogenicity* / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins