RNA silencing in fungi

Abstract

RNA silencing is an evolutionarily conserved mechanism in eukaryotic organisms induced by double-stranded RNA (dsRNA) and plays an essential role in regulating gene expression and maintaining genome stability. RNA silencing occurs at both posttranscriptional levels through sequence-specific RNA degradation or translational repression and at transcriptional levels through RNA-directed DNA methylation and/or heterochromatin formation. RNA silencing pathways have been relatively well characterized in plants and animals, and are now also being widely investigated in diverse fungi, some of which are important plant pathogens. This review focuses primarily on the current understanding of the dsRNA-mediated posttranscriptional gene silencing processes in fungi, but also discusses briefly the known gene silencing pathways that appear to be independent of the RNA silencing machineries. We review RNA silencing studies for a variety of fungi and highlight some of the mechanistic differences observed in different fungal organisms. As RNA silencing is being exploited as a technology in gene function studies in fungi as well as in engineering anti-fungal resistance in plants and animals, we also discuss the recent progress towards understanding dsRNA uptake in fungi.

Keywords

RNA silencing / gene silencing / heterochromatin formation / fungi / small interfering RNA / micro-RNA

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