Appearance of mycovirus-like double-stranded RNAs in the white root rot fungus,<i>Rosellinia necatrix</i>, in an apple orchard

Yaegashi, Hajime; Nakamura, Hitoshi; Sawahata, Takuo; Sasaki, Atsuko; Iwanami, Yasuhiko; Ito, Takumi; Kanematsu, Satoko

doi:10.1111/j.1574-6941.2012.01454.x

Cited by 73 publications

(49 citation statements)

References 45 publications

(76 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Milgroom and Cortesi concluded that the success of using hypoviruses to control chestnut blight at the population level depended on the natural spread of viruses, and they thought that the application of hypovirulenceassociated mycoviruses for biological control of other plant-pathogenic fungi was likely to meet the same constraints as those for chestnut blight (40). Our findings and previous studies on potential mycovirus transmission vectors (14)(15)(16)(17) suggest that vectors for mycoviruses are likely to exist in nature, and other mycophagous insects may function as mycovirus transmission vectors, as many fungi could release volatiles to attract insects (41). Thus, L. ingenua is not likely to be the only transmission vector for mycoviruses.…”

Section: Discussionsupporting

confidence: 70%

Fungal DNA virus infects a mycophagous insect and utilizes it as a transmission vector

Liu

Xiè

Chéng

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

147

View full text Add to dashboard Cite

Mycoviruses are usually transmitted horizontally via hyphal anastomosis and vertically via sexual/asexual spores. Previously, we reported that a gemycircularvirus, Sclerotinia sclerotiorum hypovirulenceassociated DNA virus 1 (SsHADV-1), could infect its fungal host extracellularly. Here, we discovered that SsHADV-1 could infect a mycophagous insect, Lycoriella ingenua, and use it as a transmission vector. Virus acquired by larvae feeding on colonies of a virus-infected strain of S. sclerotiorum was replicated and retained in larvae, pupae, adults, and eggs. Virus could be transmitted to insect offspring when larvae were injected with virus particles and allowed to feed on a nonhost fungus. Virus replication in insect cells was further confirmed by inoculating Spodoptera frugiperda cells with virus particles and analyzing with RT-PCR, Northern blot, immunofluorescence, and flow cytometry assays. Larvae could transmit virus once they acquired virus by feeding on virus-infected fungal colony. Offspring larvae hatched from viruliferous eggs were virus carriers and could also successfully transmit virus. Virus transmission between insect and fungus also occurred on rapeseed plants. Virus-infected isolates produced less repellent volatile substances to attract adults of L. ingenua. Furthermore, L. ingenua was easily observed on Sclerotinia lesions in rapeseed fields, and viruliferous adults were captured from fields either sprayed with a virus-infected fungal strain or nonsprayed. Our findings may facilitate the exploration of mycoviruses for control of fungal diseases and enhance our understanding of the ecology of SsHADV-1 and other newly emerging SsHADV-1-like viruses, which were recently found to be widespread in various niches including human HIV-infected blood, human and animal feces, insects, plants, and even sewage. mycovirus | biological control | mycophagous insect | mutualism | gemycircularvirus

show abstract

Section: Discussionsupporting

confidence: 70%

Fungal DNA virus infects a mycophagous insect and utilizes it as a transmission vector

Liu

Xiè

Chéng

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

147

View full text Add to dashboard Cite

show abstract

“…This distribution resembles the uneven distribution of viruses within clones of the pathogenic root rot fungi Helicobasidium mompa (Ikeda et al, 2005) and Rosellinia necatrix (Yaegashi et al, 2013) and the ascomycetous pathogen C. parasitica (Shain and Miller, 1992;Hoegger et al, 2003). We have shown that the partitivirus HetPV4 (formerly HetRV4) was transmitted via hyphal contact from an introduced strain of H. parviporum into native strains inhabiting Norway spruce stumps (Vainio et al, 2013a).…”

Section: Discussionmentioning

confidence: 95%

Viruses accumulate in aging infection centers of a fungal forest pathogen

Vainio¹,

Müller²,

Korhonen³

et al. 2014

The ISME Journal

View full text Add to dashboard Cite

Fungal viruses (mycoviruses) with RNA genomes are believed to lack extracellular infective particles. These viruses are transmitted laterally among fungal strains through mycelial anastomoses or vertically via their infected spores, but little is known regarding their prevalence and patterns of dispersal under natural conditions. Here, we examined, in detail, the spatial and temporal changes in a mycovirus community and its host fungus Heterobasidion parviporum, the most devastating fungal pathogen of conifers in the Boreal forest region. During the 7-year sampling period, viruses accumulated in clonal host individuals as a result of indigenous viruses spreading within and between clones as well as novel strains arriving via airborne spores. Viral community changes produced pockets of heterogeneity within large H. parviporum clones. The appearance of novel viral infections in aging clones indicated that transient cell-to-cell contacts between Heterobasidion strains are likely to occur more frequently than what was inferred from genotypic analyses. Intraspecific variation was low among the three partitivirus species at the study site, whereas the unassigned viral species HetRV6 was highly polymorphic. The accumulation of point mutations during persistent infections resulted in viral diversification, that is, the presence of nearly identical viral sequence variants within single clones. Our results also suggest that co-infections by distantly related viral species are more stable than those between conspecific strains, and mutual exclusion may play a role in determining mycoviral communities.

show abstract

“…W1029 is believed to be one of the subisolates that has naturally acquired dsRNA segments of RnVV1 and a partitivirus termed Rosellinia necatrix partitivirus 3-W1029 (RnPV3-W1029) in the soil. The genomic segments of these viruses were referred to as S1 and S2 by Yaegashi et al (36). The genotype and MCG (mycelial compatibility group) of W1029 were confirmed previously to be identical to the parental W563 (MCG139).…”

Section: Methodsmentioning

confidence: 82%

“…Rosellinia necatrix strain W1029 was reisolated in 2009 from an experimental orchard of apple trees (Nagano Fruit Tree Experiment Station) at Suzaka, Nagano Prefecture, Japan, where virusfree W563 had been buried in 2007 (36). W1029 is believed to be one of the subisolates that has naturally acquired dsRNA segments of RnVV1 and a partitivirus termed Rosellinia necatrix partitivirus 3-W1029 (RnPV3-W1029) in the soil.…”

Section: Methodsmentioning

confidence: 99%

“…Some of these viruses were shown to be able to confer hypovirulence under laboratory conditions. However, no victorivirus had been identified in this fungus until very recently (36), although victoriviruses are widely detectable in many filamentous fungi. In the present study, we carried out a molecular and biologic characterization of a novel victorivirus termed Rosellinia necatrix victorivirus 1-W1029 (RnVV1-W1029) that is infectious as particles to the natural host, R. necatrix, and a heterologous filamentous fungus, C. parasitica.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Novel Victorivirus from a Phytopathogenic Fungus, Rosellinia necatrix, Is Infectious as Particles and Targeted by RNA Silencing

Chiba

Lin

Kondō

et al. 2013

J Virol

Self Cite

View full text Add to dashboard Cite

Japan bA 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 ϳ40 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 (⌬dcl-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 ⌬dcl-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.

show abstract

Appearance of mycovirus-like double-stranded RNAs in the white root rot fungus,Rosellinia necatrix, in an apple orchard

Cited by 73 publications

References 45 publications

Fungal DNA virus infects a mycophagous insect and utilizes it as a transmission vector

Fungal DNA virus infects a mycophagous insect and utilizes it as a transmission vector

Viruses accumulate in aging infection centers of a fungal forest pathogen

A Novel Victorivirus from a Phytopathogenic Fungus, Rosellinia necatrix, Is Infectious as Particles and Targeted by RNA Silencing

Contact Info

Product

Resources

About