Evidence that RNA silencing functions as an antiviral defense mechanism in fungi

• Gert C. Segers

  Center for Biosystems Research, University of Maryland Biotechnology Institute, Shady Grove Campus, Rockville, MD 20850

• Xuemin Zhang

  Center for Biosystems Research, University of Maryland Biotechnology Institute, Shady Grove Campus, Rockville, MD 20850

• Fuyou Deng

  Center for Biosystems Research, University of Maryland Biotechnology Institute, Shady Grove Campus, Rockville, MD 20850

• Qihong Sun

  Center for Biosystems Research, University of Maryland Biotechnology Institute, Shady Grove Campus, Rockville, MD 20850

• Donald L. Nuss

  Center for Biosystems Research, University of Maryland Biotechnology Institute, Shady Grove Campus, Rockville, MD 20850

抄録

The role of RNA silencing as an antiviral defense mechanism in fungi was examined by testing the effect of dicer gene disruptions on mycovirus infection of the chestnut blight fungus Cryphonectria parasitica. C. parasitica dicer-like genes dcl-1 and dcl-2 were cloned and shown to share a high level of predicted amino acid sequence identity with the corresponding dicer-like genes from Neurospora crassa [Nc dcl-1 (50.5%); Nc dcl-2 (38.0%)] and Magnaporthe oryzae [ MDL-1 (45.6%); MDL-2 (38.0%)], respectively. Disruption of dcl-1 and dcl-2 resulted in no observable phenotypic changes relative to wild-type C. parasitica . Infection of Δ dcl-1 strains with hypovirus CHV1-EP713 or reovirus MyRV1-Cp9B21 resulted in phenotypic changes that were indistinguishable from that exhibited by wild-type strain C. parasitica EP155 infected with these same viruses. In stark contrast, the Δ dcl-2 and Δ dcl-1 /Δ dcl-2 mutant strains were highly susceptible to mycovirus infection, with CHV1-EP713-infected mutant strains becoming severely debilitated. Increased viral RNA levels were observed in the Δ dcl-2 mutant strains for a hypovirus CHV1-EP713 mutant lacking the suppressor of RNA silencing p29 and for wild-type reovirus MyRV1-Cp9B21. Complementation of the Δ dcl-2 strain with the wild-type dcl-2 gene resulted in reversion to the wild-type response to virus infection. These results provide direct evidence that a fungal dicer-like gene functions to regulate virus infection.

収録刊行物

• Proceedings of the National Academy of Sciences

  Proceedings of the National Academy of Sciences 104 (31), 12902-12906, 2007-07-31

  Proceedings of the National Academy of Sciences

キーワード

• Multidisciplinary

詳細情報

• CRID: 1362544419551859328
• NII論文ID: 80018422140
• DOI: 10.1073/pnas.0702500104
• ISSN: 10916490
• ISSN: 00278424
• Web Site: https://pnas.org/doi/pdf/10.1073/pnas.0702500104
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