Plant-feeding insects harbor double-stranded RNA viruses encoding a novel proline-alanine rich protein and a polymerase distantly related to that of fungal viruses.
Novel double-stranded RNAs (approximately 8 kbp) were isolated from threecornered alfalfa hopper (Spissistilus festinus) and beet leafhopper (Circulifer tenellus), two plant-feeding hemipteran insect pests. The two new viruses, designated Spissistilus festinus virus 1 (SpFV1) and Circulifer tenellus virus 1 (CiTV1), do not appear to be encapsidated in conventional virions and shared a genome organization similar to that of several unclassified fungal viruses. SpFV1 and CiTVl encode a proline-alanine rich protein (PArp) and an RNA-directed RNA polymerase (RdRp). Expression of the 3'-proximal RdRp ORF appears to result from -1 translational frameshifting of the PArp ORF. Phylogenetic analysis of the RdRp indicated that SpFV1 and CiTV1 were most closely related to each other and the unclassified plant virus Cucurbit yellows associated virus, and more distantly related to the unclassified fungal dsRNA viruses Phlebiopsis gigantea virus 2 and Fusarium graminearum virus 3.
Spear
Allyn
A
United States Department of Agriculture-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648, USA.
Sisterson
Mark S
MS
Yokomi
Raymond
R
Stenger
Drake C
DC
D000818:Animals; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D005658:Fungi / Q000821:virology; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016679:Genome, Viral; D006430:Hemiptera / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010942:Plant Viruses / Q000145:classification / Q000201:enzymology / Q000502:physiology; D012328:RNA Viruses / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000302:isolation & purification; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D012330:RNA, Double-Stranded; D012367:RNA, Viral; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases