Dataset Information

Comparative analysis of RNA interference and pattern-triggered immunity induced by dsRNA in response to virus infection

ABSTRACT: The main goal of this study was to compare the differential efficiency of the antiviral activity triggered by externally delivered virus-specific and nonspecific dsRNAs in plants. RNAi mediated by virus-specific dsRNA is the main antiviral defense mechanism in plants, but nonspecific dsRNA-triggered responses have been documented to play a role in antiviral defense. Using PVX as a model, we have determined that co-inoculation with either virus-specific or nonspecific dsRNA reduced virus accumulation in both inoculated and systemic leaves although at different extent. While the administration of dsRNA specific for the targeted virus induced a potent RNAi-based antiviral response that resulted in highly effective control of viral disease, the degree of interference with PVX-GFP infection afforded by nonspecific dsRNA (PTI) was limited. To identify early biological processes and pathways associated with dsRNA-based immunity, we conducted a global transcriptome RNAseq assay from N. benthamiana leaves inoculated with four different treatments, i.e., dsGFP alone (dsG), PVX-GFP combined with dsGFP (dsG_VG), wild-type (Wt) PVX combined with dsGFP (dsG_V) and bacterial nucleic acid extracts not expressing dsRNA as a control (Ctr). KEGG analysis of differentially expressed genes showed a significant enrichment of terms related to plant-pathogen signaling pathways (KEGG terms Plant-pathogen interaction and MAPK signaling) in all the three treatments with dsRNA. Our results further indicate that the transcriptomic response triggered by dsRNA alone includes canonical immune pathways or genes known to be involved in defense responses, i.e., Ca+2 signaling, ethylene signaling, MAPK signaling, WRKY transcription factors, PR transcriptional factors, NBS-LRR resistance genes, EDS1, and LRR receptor-like kinases, many of which are typical of antimicrobial PTI . Moreover, the transcriptomic response to the homologous combination (dsGFP plus PVX-GFP) had a greater overrepresentation of genes involved in plant-pathogen signaling pathways than the heterologous combination (dsGFP plus Wt PVX), highlighting a quantitative difference between RNAi and PTI immune responses.

ORGANISM(S): Nicotiana benthamiana

PROVIDER: GSE253964 | GEO | 2024/02/12

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:In Drosophila, the siRNA pathway is initiated when exogenous or endogenous double stranded RNA (dsRNA) is processed into siRNAs by Dicer-2 (Dcr-2) and a dsRNA-binding protein (dsRBP) cofactor called Loquacious (Loqs). The siRNAs are then loaded onto Argonaute-2 (Ago2) protein by the action of Dcr-2 with another dsRBP cofactor called R2D2. Loaded Ago2 executes the destruction of target RNAs that have sequence complementarity to the siRNA. Dcr-2, R2D2, and Ago2 have also been shown to be required for innate antiviral defense in Drosophila. However, the biogenesis of virus-derived siRNAs (vsiRNAs) and their targets in virus-infected cells remain unclear. Here, we analyzed the antiviral response in Drosophila by monitoring the replication of different RNA viruses and deep sequencing of small RNAs in infected animals. We show that vsiRNAs are generated by Dcr-2 processing of dsRNA formed during viral genome replication and transcription. These vsiRNAs then directly target viral transcripts but not genomes, to inhibit viral replication. The biogenesis of vsiRNAs was virtually independent of Loqs and R2D2. R2D2, however, was essential for sorting and loading of vsiRNAs onto Ago2 and effective silencing of viral RNA expression. Loqs was completely dispensable for silencing of viruses in contrast to its role in silencing of endogenous targets. Our results suggest the existence of a specific siRNA pathway triggered by viral infection independent of conserved dsRBP cofactors and separate from the endogenous pathway. Inhibition of virus replication resulting from direct injection of viral RNA into Drosophila embryos was also not dependent on Loqs, suggesting the distinction of the two pathways is not related to the mode of entry but recognition of intrinsic features of viral RNA or its mode of replication. We speculate that this unique framework might be necessary for a prompt and efficient antiviral response We analyzed the small RNA reponse to viral infection by deep sequencing of small RNA libraries from wild type and RNAi mutant adult flies infected with Sindbis birus and Vesicular Stomatatis virus.

Dataset Information

Comparative analysis of RNA interference and pattern-triggered immunity induced by dsRNA in response to virus infection

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure