A novel victorivirus from a phytopathogenic fungus, rosellinia necatrix, is infectious as particles and targeted by RNA silencing

Sotaro Chiba, Yu Hsin Lin, Hideki Kondo, Satoko Kanematsu, Nobuhiro Suzuki

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

A novel victorivirus, termed Rosellinia necatrix victorivirus 1 (RnVV1), was isolated from a plant pathogenic ascomycete, white root rot fungus Rosellinia necatrix, coinfected with a partitivirus. The virus was molecularly and biologically characterized using the natural and experimental hosts (chestnut blight fungus, Cryphonectria parasitica). RnVV1 was shown to have typical molecular victorivirus attributes, including a monopartite double-stranded RNA genome with two open reading frames (ORFs) encoding capsid protein (CP) and RNA-dependent RNA polymerase (RdRp), a UAAUG pentamer presumed to facilitate the coupled termination/reinitiation for translation of the two ORFs, a spherical particle structure ̃40 nm in diameter, and moderate levels of CP and RdRp sequence identity (34 to 58%) to those of members of the genus Victorivirus within the family Totiviridae. A reproducible transfection system with purified RnVV1 virions was developed for the two distinct fungal hosts. Transfection assay with purified RnVV1 virions combined with virus elimination by hyphal tipping showed that the effects of RnVV1 on the phenotype of the natural host were negligible. Interestingly, comparison of the RNA silencing-competent (standard strain EP155) and -defective (Δdcl-2) strains of C. parasitica infected with RnVV1 showed that RNA silencing acted against the virus to repress its replication, which was restored by coinfection with hypovirus or transgenic expression of an RNA silencing suppressor, hypovirus p29. Phenotypic changes were observed in the Δdcl-2 strain but not in EP155. This is the first reported study on the host range expansion of a Totiviridae member that is targeted by RNA silencing.

Original languageEnglish
Pages (from-to)6727-6738
Number of pages12
JournalJournal of Virology
Volume87
Issue number12
DOIs
Publication statusPublished - Jun 2013

Fingerprint

Victorivirus
Rosellinia necatrix
plant pathogenic fungi
RNA Interference
RNA interference
Totiviridae
Fungi
RNA Replicase
Capsid Proteins
Viruses
Virion
Open Reading Frames
Transfection
Cryphonectria parasitica
RNA-directed RNA polymerase
Hypovirus
Ascomycota
Double-Stranded RNA
Host Specificity
Coinfection

ASJC Scopus subject areas

  • Immunology
  • Virology

Cite this

A novel victorivirus from a phytopathogenic fungus, rosellinia necatrix, is infectious as particles and targeted by RNA silencing. / Chiba, Sotaro; Lin, Yu Hsin; Kondo, Hideki; Kanematsu, Satoko; Suzuki, Nobuhiro.

In: Journal of Virology, Vol. 87, No. 12, 06.2013, p. 6727-6738.

Research output: Contribution to journalArticle

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