Double-stranded RNAs induce a pattern-triggered immune signaling pathway in plants.
Fiche publication
Date publication
août 2016
Journal
The New phytologist
Auteurs
Membres identifiés du Cancéropôle Est :
Dr HEINLEIN Manfred
Tous les auteurs :
Niehl A, Wyrsch I, Boller T, Heinlein M
Lien Pubmed
Résumé
Pattern-triggered immunity (PTI) is a plant defense response that relies on the perception of conserved microbe- or pathogen-associated molecular patterns (MAMPs or PAMPs, respectively). Recently, it has been recognized that PTI restricts virus infection in plants; however, the nature of the viral or infection-induced PTI elicitors and the underlying signaling pathways are still unknown. As double-stranded RNAs (dsRNAs) are conserved molecular patterns associated with virus replication, we applied dsRNAs or synthetic dsRNA analogs to Arabidopsis thaliana and investigated PTI responses. We show that in vitro-generated dsRNAs, dsRNAs purified from virus-infected plants and the dsRNA analog polyinosinic-polycytidylic acid (poly(I:C)) induce typical PTI responses dependent on the co-receptor SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (SERK1), but independent of dicer-like (DCL) proteins in Arabidopsis. Moreover, dsRNA treatment of Arabidopsis induces SERK1-dependent antiviral resistance. Screening of Arabidopsis wild accessions demonstrates natural variability in dsRNA sensitivity. Our findings suggest that dsRNAs represent genuine PAMPs in plants, which induce a signaling cascade involving SERK1 and a specific dsRNA receptor. The dependence of dsRNA-mediated PTI on SERK1, but not on DCLs, implies that dsRNA-mediated PTI involves membrane-associated processes and operates independently of RNA silencing. dsRNA sensitivity may represent a useful trait to increase antiviral resistance in cultivated plants.
Mots clés
Arabidopsis, RNA silencing, double-stranded RNA (dsRNA), natural variation, pathogen-associated molecular pattern (PAMP), pattern-triggered immunity (PTI), somatic embryogenesis receptor-like kinase, virus
Référence
New Phytol.. 2016 08;211(3):1008-19