{Reference Type}: Journal Article
{Title}: A fungal RNA-dependent RNA polymerase is a novel player in plant infection and cross-kingdom RNA interference.
{Author}: Cheng AP;Lederer B;Oberkofler L;Huang L;Johnson NR;Platten F;Dunker F;Tisserant C;Weiberg A;
{Journal}: PLoS Pathog
{Volume}: 19
{Issue}: 12
{Year}: 2023 Dec 20
{Factor}: 7.464
{DOI}: 10.1371/journal.ppat.1011885
{Abstract}: Small RNAs act as fungal pathogen effectors that silence host target genes to promote infection, a virulence mechanism termed cross-kingdom RNA interference (RNAi). The essential pathogen factors of cross-kingdom small RNA production are largely unknown. We here characterized the RNA-dependent RNA polymerase (RDR)1 in the fungal plant pathogen Botrytis cinerea that is required for pathogenicity and cross-kingdom RNAi. B. cinerea bcrdr1 knockout (ko) mutants exhibited reduced pathogenicity and loss of cross-kingdom small RNAs. We developed a "switch-on" GFP reporter to study cross-kingdom RNAi in real-time within the living plant tissue which highlighted that bcrdr1 ko mutants were compromised in cross-kingdom RNAi. Moreover, blocking seven pathogen cross-kingdom small RNAs by expressing a short-tandem target mimic RNA in transgenic Arabidopsis thaliana led to reduced infection levels of the fungal pathogen B. cinerea and the oomycete pathogen Hyaloperonospora arabidopsidis. These results demonstrate that cross-kingdom RNAi is significant to promote host infection and making pathogen small RNAs an effective target for crop protection.