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Updated: Jul 19, 2026
10:19
Screening and Identification of RNA Silencing Suppressors from Secreted Effectors of Plant Pathogens
Published on: February 3, 2020
A pathogen-inducible endogenous siRNA in plant immunity
Surekha Katiyar-Agarwal1, Rebekah Morgan, Douglas Dahlbeck
1Department of Plant Pathology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA.
Summary
Scientists discovered a novel endogenous small interfering RNA (siRNA) in plants that acts as a defense against bacterial pathogens. This nat-siRNAATGB2 is induced by Pseudomonas syringae and helps activate plant disease resistance.
Area of Science:
- Plant molecular biology
- RNA interference
- Plant-pathogen interactions
Background:
- RNA interference (RNAi) mediated by small interfering RNAs (siRNAs) is a known antiviral defense in plants and animals.
- The role of siRNAs in antibacterial defense in eukaryotic hosts remains largely unknown.
Purpose of the Study:
- To investigate the potential role of endogenous siRNAs in plant antibacterial defense.
- To identify and characterize novel siRNAs induced by bacterial pathogens.
Main Methods:
- Induction of siRNA by Pseudomonas syringae infection.
- Analysis of siRNA biogenesis pathway components (DCL1, HYL1, HEN1, RDR6, NRPD1A, SGS3).
- Dependence on host disease resistance genes (RPS2, NDR1).
Main Results:
- Discovery of a novel endogenous siRNA, nat-siRNAATGB2, specifically induced by Pseudomonas syringae carrying avrRpt2.
- siRNA biogenesis requires key components including DCL1, HYL1, HEN1, RDR6, NRPD1A, and SGS3.
- Induction of nat-siRNAATGB2 depends on RPS2 and NDR1, and it represses PPRL, a negative regulator of RPS2.
Conclusions:
- Endogenous siRNAs can function as a plant antibacterial defense mechanism.
- nat-siRNAATGB2 plays a crucial role in RPS2-mediated, race-specific disease resistance.
- This finding expands the known roles of RNA interference in host-pathogen interactions.
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