Bidirectional cross-kingdom RNAi and fungal uptake of external RNAs confer plant protection

Some plant pathogenic fungi use RNA molecules to interfere with the plants they colonise via a mechanism that silences the systems plants have to protect them against disease. It’s also possible to artificially use a similar silencing mechanism against the fungi themselves to protect plants against the pathogenic fungi. It’s like spy versus spy.

Scientific Summary. Aggressive fungal pathogens such as Botrytis andVerticillium spp. cause severe crop losses worldwide. We recently discovered that Botrytis cinerea delivers small RNAs (Bc–sRNAs) into plant cells to silence host immunity genes. Such sRNA effectors are mostly produced byBotrytis cinerea Dicer-like protein 1 (Bc-DCL1) and Bc-DCL2. Here we show that expressing sRNAs that targetBc-DCL1 and Bc-DCL2 in Arabidopsis and tomato silencesBc-DCL genes and attenuates fungal pathogenicity and growth, exemplifying bidirectional cross-kingdom RNAi and sRNA trafficking between plants and fungi. This strategy can be adapted to simultaneously control multiple fungal diseases. We also show that Botrytis can take up external sRNAs and double-stranded RNAs (dsRNAs). Applying sRNAs or dsRNAs that target Botrytis DCL1 and DCL2 genes on the surface of fruits, vegetables and flowers significantly inhibits grey mould disease.Such pathogen gene-targeting RNAs represent a new generation of environmentally friendly fungicides.

See @ Bidirectional cross-kingdom RNAi and fungal uptake of external RNAs confer plant protection : Nature Plants: