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bioRxiv · 10.1101/2023.01.10.523395

Sensing of viral RNA in plants via a DICER-LIKE Ribonuclease

Nielsen, C. P. S.·Han, L.·Arribas-Hernandez, L.·Karelina, D.·Petersen, M.·Brodersen, P.
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Abstract

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 summaryThe plant immune system uses Dicer-like ribonucleases for both antiviral RNA interference and double-stranded RNA sensing.

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Nielsen, C. P. S., Han, L., Arribas-Hernandez, L., Karelina, D., Petersen, M., Brodersen, P.. 2023-01-11. Sensing of viral RNA in plants via a DICER-LIKE Ribonuclease. https://doi.org/10.1101/2023.01.10.523395

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