Plants respond to virus infections by activation of RNA-based silencing, which limits infection at both the single-cell and system levels. Viruses encode RNA silencing suppressor proteins that interfere with this response. Wild-type Arabidopsis thaliana is immune to silencing suppressor (HC-Pro)-deficient Turnip mosaic virus, but immunity was lost in the absence of DICER-LIKE proteins DCL4 and ...

RNA-dependent RNA polymerases (RDRs) act as key components of the small RNA biogenesis pathways and play significant roles in post-transcriptional gene silencing (PTGS) and antiviral defense. However, there is no information about the RDR gene family in Salvia miltiorrhiza, an emerging model medicinal plant with great economic value. Through genome-wide predication and subsequent molecular clon...

Antiviral immunity controlled by RNA interference (RNAi) in plants and animals is thought to specifically target only viral RNAs by the virus-derived small interfering RNAs (siRNAs). Here we show that activation of antiviral RNAi in Arabidopsis plants is accompanied by the production of an abundant class of endogenous siRNAs mapped to the exon regions of more than 1,000 host genes and rRNA. The...

Many eukaryotes initiate pathways of Argonaute-bound small RNA (sRNA) production with a step that specifically targets sets of aberrant and/or otherwise deleterious transcripts for recognition by an RNA-dependent RNA polymerase complex (RDRC). The biogenesis of 23- to 24-nt sRNAs in growing Tetrahymena occurs by physical and functional coupling of the growth-expressed Dicer, Dcr2, with one of t...

In plants, RNA silencing-based antiviral defense is mediated by Dicer-like (DCL) proteins producing short interfering (si)RNAs. In Arabidopsis infected with the bipartite circular DNA geminivirus Cabbage leaf curl virus (CaLCuV), four distinct DCLs produce 21, 22 and 24 nt viral siRNAs. Using deep sequencing and blot hybridization, we found that viral siRNAs of each size-class densely cover the...

The filamentous ascomycete Bipolaris maydis is a plant pathogen that causes corn leaf blight and has been used in cytological studies of sexual reproduction. In this fungus, when null mutants each septin are crossed with the wild-type strain, all ascospores derived from same asci show abnormal morphology. phenomenon was remarkably similar to event known as “ascus dominance” Neurospora crassa , ...