PT  - JOURNAL ARTICLE
AU  - Carsten Poul Skou Nielsen
AU  - Lijuan Han
AU  - Laura Arribas-Hernández
AU  - Darya Karelina
AU  - Morten Petersen
AU  - Peter Brodersen
TI  - Sensing of viral RNA in plants via a DICER-LIKE Ribonuclease
AID  - 10.1101/2023.01.10.523395
DP  - 2023 Jan 01
TA  - bioRxiv
PG  - 2023.01.10.523395
4099  - http://biorxiv.org/content/early/2023/01/11/2023.01.10.523395.short
4100  - http://biorxiv.org/content/early/2023/01/11/2023.01.10.523395.full
AB  - Sensors of intracellular double-stranded RNA are central components of metazoan innate antiviral immunity, but such sensors have not been identified in plants. RNA interference (RNAi) constitutes a potent plant antiviral defense mechanism that relies on conversion of viral RNA into small interfering RNAs by two DICER-LIKE (DCL) ribonucleases, DCL4 and DCL2. Here, we show that while plant DCL4 is dedicated to RNAi, cytoplasmic dicing by DCL2 also triggers RNAi-independent defense gene expression via at least two intracellular nucleotide-binding domain/leucine-rich repeat (NLR) immune receptors. Combined DCL4/NLR inactivation abrogates basal resistance to a positive strand RNA virus. Our results redefine the basis of plant antiviral immunity, including autoimmunity as an explanation for DCL2-dependent growth arrest in dcl and RNA decay mutants in several plant species.One sentence summary The plant immune system uses Dicer-like ribonucleases for both antiviral RNA interference and double-stranded RNA sensing.Competing Interest StatementThe authors have declared no competing interest.