RT Journal Article SR Electronic T1 Sensing of viral RNA in plants via a DICER-LIKE Ribonuclease JF bioRxiv FD Cold Spring Harbor Laboratory SP 2023.01.10.523395 DO 10.1101/2023.01.10.523395 A1 Carsten Poul Skou Nielsen A1 Lijuan Han A1 Laura Arribas-Hernández A1 Darya Karelina A1 Morten Petersen A1 Peter Brodersen YR 2023 UL http://biorxiv.org/content/early/2023/01/11/2023.01.10.523395.abstract 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.