1
|
Hoffmann G, Incarbone M. A resilient bunch: stem cell antiviral immunity in plants. THE NEW PHYTOLOGIST 2024; 241:1415-1420. [PMID: 38058221 DOI: 10.1111/nph.19456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/15/2023] [Indexed: 12/08/2023]
Abstract
Stem cells are vital for plant development and reproduction. The stem cells within shoot apical meristems are known to possess exceptionally effective antiviral defenses against pathogenic viruses which preclude their infection, yet how this is achieved remains poorly understood and scarcely investigated. In this Tansley Insight, we connect very recent experimental results with previous work to summarize the known molecular mechanisms determining stem cell antiviral immunity. More broadly, we attempt to define the viral features triggering immunity and the global consequences of virus infection in these essential cells. This brief article will highlight how these phenomena are fascinating, complex and often crucial for virus-host interactions, while emphasizing the potential for discovery in their investigation.
Collapse
Affiliation(s)
- Gesa Hoffmann
- Max Planck Institute of Molecular Plant Physiology (MPIMP), 1 Am Mühlenberg Strasse, 14476, Potsdam, Germany
| | - Marco Incarbone
- Max Planck Institute of Molecular Plant Physiology (MPIMP), 1 Am Mühlenberg Strasse, 14476, Potsdam, Germany
| |
Collapse
|
2
|
Jia Z, Chen J, Yan F, Wu G. Co-immunoprecipitation-Based Isolation of Double-Stranded RNA-Associated Protein Complexes in Nicotiana benthamiana. Methods Mol Biol 2024; 2771:91-98. [PMID: 38285395 DOI: 10.1007/978-1-0716-3702-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Double-stranded RNA (dsRNA) is associated with most viral infections, and is generated in host cells during viral replication. Viral RNA replication occurs within the viral factories called the viral replication complexes (VRCs). In addition to viral genome, viral-derived dsRNA and replicase, the VRCs composition remains largely unexplored. The dsRNA binding domain of the B2 protein from Flock house virus has been reported to be used for detecting viral-derived long dsRNA in plants efficiently. Nicotiana benthamiana is widely used as a model plant for plant-microbe interactions owing to its susceptibility to diverse plant diseases, especially viral diseases. Here, we describe the use of Nicotiana benthamiana stably expressing GFP-tagged dsRNA binding protein (B2: GFP) to pull down dsRNA and associated host and viral proteins from turnip mosaic virus-infected plants. The obtained protein complexes are compatible with functional assays, Western blotting, and mass spectrometry. This system provides a valuable and robust tool to study VRC proteome in N. benthamiana upon plant viral infections.
Collapse
Affiliation(s)
- Zhaoxing Jia
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Jianping Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Fei Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, China.
| | - Guanwei Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, China.
| |
Collapse
|
3
|
Incarbone M, Bradamante G, Pruckner F, Wegscheider T, Rozhon W, Nguyen V, Gutzat R, Mérai Z, Lendl T, MacFarlane S, Nodine M, Scheid OM. Salicylic acid and RNA interference mediate antiviral immunity of plant stem cells. Proc Natl Acad Sci U S A 2023; 120:e2302069120. [PMID: 37824524 PMCID: PMC10589665 DOI: 10.1073/pnas.2302069120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/30/2023] [Indexed: 10/14/2023] Open
Abstract
Stem cells are essential for the development and organ regeneration of multicellular organisms, so their infection by pathogenic viruses must be prevented. Accordingly, mammalian stem cells are highly resistant to viral infection due to dedicated antiviral pathways including RNA interference (RNAi). In plants, a small group of stem cells harbored within the shoot apical meristem generate all postembryonic above-ground tissues, including the germline cells. Many viruses do not proliferate in these cells, yet the molecular bases of this exclusion remain only partially understood. Here, we show that a plant-encoded RNA-dependent RNA polymerase, after activation by the plant hormone salicylic acid, amplifies antiviral RNAi in infected tissues. This provides stem cells with RNA-based virus sequence information, which prevents virus proliferation. Furthermore, we find RNAi to be necessary for stem cell exclusion of several unrelated RNA viruses, despite their ability to efficiently suppress RNAi in the rest of the plant. This work elucidates a molecular pathway of great biological and economic relevance and lays the foundations for our future understanding of the unique systems underlying stem cell immunity.
Collapse
Affiliation(s)
- Marco Incarbone
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
- Max Planck Institute of Molecular Plant Physiology, Potsdam Science Park, Potsdam14476, Germany
| | - Gabriele Bradamante
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Florian Pruckner
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Tobias Wegscheider
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Wilfried Rozhon
- Department of Agriculture, Ecotrophology, and Landscape Development, Anhalt University of Applied Sciences, Bernburg06406, Germany
| | - Vu Nguyen
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Ruben Gutzat
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Zsuzsanna Mérai
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| | - Thomas Lendl
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna1030, Austria
| | - Stuart MacFarlane
- The James Hutton Institute, Invergowrie, ScotlandDD25DA, United Kingdom
| | - Michael Nodine
- Department of Plant Sciences, Laboratory of Molecular Biology, Wageningen University and Research, Wageningen6700 AP, The Netherlands
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter, Vienna1030, Austria
| |
Collapse
|
4
|
Huang C, Sede AR, Elvira-González L, Yan Y, Rodriguez ME, Mutterer J, Boutant E, Shan L, Heinlein M. dsRNA-induced immunity targets plasmodesmata and is suppressed by viral movement proteins. THE PLANT CELL 2023; 35:3845-3869. [PMID: 37378592 PMCID: PMC10533371 DOI: 10.1093/plcell/koad176] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/24/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023]
Abstract
Emerging evidence indicates that in addition to its well-recognized functions in antiviral RNA silencing, dsRNA elicits pattern-triggered immunity (PTI), likely contributing to plant resistance against virus infections. However, compared to bacterial and fungal elicitor-mediated PTI, the mode-of-action and signaling pathway of dsRNA-induced defense remain poorly characterized. Here, using multicolor in vivo imaging, analysis of GFP mobility, callose staining, and plasmodesmal marker lines in Arabidopsis thaliana and Nicotiana benthamiana, we show that dsRNA-induced PTI restricts the progression of virus infection by triggering callose deposition at plasmodesmata, thereby likely limiting the macromolecular transport through these cell-to-cell communication channels. The plasma membrane-resident SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1, the BOTRYTIS INDUCED KINASE1/AVRPPHB SUSCEPTIBLE1-LIKE KINASE1 kinase module, PLASMODESMATA-LOCATED PROTEINs 1/2/3, as well as CALMODULIN-LIKE 41 and Ca2+ signals are involved in the dsRNA-induced signaling leading to callose deposition at plasmodesmata and antiviral defense. Unlike the classical bacterial elicitor flagellin, dsRNA does not trigger a detectable reactive oxygen species (ROS) burst, substantiating the idea that different microbial patterns trigger partially shared immune signaling frameworks with distinct features. Likely as a counter strategy, viral movement proteins from different viruses suppress the dsRNA-induced host response leading to callose deposition to achieve infection. Thus, our data support a model in which plant immune signaling constrains virus movement by inducing callose deposition at plasmodesmata and reveals how viruses counteract this layer of immunity.
Collapse
Affiliation(s)
- Caiping Huang
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Ana Rocío Sede
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Laura Elvira-González
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Yan Yan
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Miguel Eduardo Rodriguez
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Jérôme Mutterer
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Emmanuel Boutant
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| | - Libo Shan
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Manfred Heinlein
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67000 Strasbourg, France
| |
Collapse
|
5
|
Chergintsev DA, Solovieva AD, Atabekova AK, Lezzhov AA, Golyshev SA, Morozov SY, Solovyev AG. Properties of Plant Virus Protein Encoded by the 5'-Proximal Gene of Tetra-Cistron Movement Block. Int J Mol Sci 2023; 24:14144. [PMID: 37762447 PMCID: PMC10532019 DOI: 10.3390/ijms241814144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
To move from cell to cell through plasmodesmata, many plant viruses require the concerted action of two or more movement proteins (MPs) encoded by transport gene modules of virus genomes. A tetra-cistron movement block (TCMB) is a newly discovered transport module comprising four genes. TCMB encodes three proteins, which are similar to MPs of the transport module known as the "triple gene block", and a protein unrelated to known viral MPs and containing a double-stranded RNA (dsRNA)-binding domain similar to that found in a family of cell proteins, including AtDRB4 and AtHYL1. Here, the latter TCMB protein, named vDRB for virus dsRNA-binding protein, is shown to bind both dsRNA and single-stranded RNA in vitro. In a turnip crinkle virus-based assay, vDRB exhibits the properties of a viral suppressor of RNA silencing (VSR). In the context of potato virus X infection, vDRB significantly decreases the number and size of "dark green islands", regions of local antiviral silencing, supporting the VSR function of vDRB. Nevertheless, vDRB does not exhibit the VSR properties in non-viral transient expression assays. Taken together, the data presented here indicate that vDRB is an RNA-binding protein exhibiting VSR functions in the context of viral infection.
Collapse
Affiliation(s)
- Denis A. Chergintsev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anna D. Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anastasia K. Atabekova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Alexander A. Lezzhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergei A. Golyshev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergey Y. Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| |
Collapse
|
6
|
Girardi E, Messmer M, Lopez P, Fender A, Chicher J, Chane-Woon-Ming B, Hammann P, Pfeffer S. Proteomics-based determination of double-stranded RNA interactome reveals known and new factors involved in Sindbis virus infection. RNA (NEW YORK, N.Y.) 2023; 29:361-375. [PMID: 36617674 PMCID: PMC9945444 DOI: 10.1261/rna.079270.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Viruses are obligate intracellular parasites, which depend on the host cellular machineries to replicate their genome and complete their infectious cycle. Long double-stranded (ds)RNA is a common viral by-product originating during RNA virus replication and is universally sensed as a danger signal to trigger the antiviral response. As a result, viruses hide dsRNA intermediates into viral replication factories and have evolved strategies to hijack cellular proteins for their benefit. The characterization of the host factors associated with viral dsRNA and involved in viral replication remains a major challenge to develop new antiviral drugs against RNA viruses. Here, we performed anti-dsRNA immunoprecipitation followed by mass spectrometry analysis to fully characterize the dsRNA interactome in Sindbis virus (SINV) infected human cells. Among the identified proteins, we characterized SFPQ (splicing factor, proline-glutamine rich) as a new dsRNA-associated proviral factor upon SINV infection. We showed that SFPQ depletion reduces SINV infection in human HCT116 and SK-N-BE(2) cells, suggesting that SFPQ enhances viral production. We demonstrated that the cytoplasmic fraction of SFPQ partially colocalizes with dsRNA upon SINV infection. In agreement, we proved by RNA-IP that SFPQ can bind dsRNA and viral RNA. Furthermore, we showed that overexpression of a wild-type, but not an RNA binding mutant SFPQ, increased viral infection, suggesting that RNA binding is essential for its positive effect on the virus. Overall, this study provides the community with a compendium of dsRNA-associated factors during viral infection and identifies SFPQ as a new proviral dsRNA binding protein.
Collapse
Affiliation(s)
- Erika Girardi
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| | - Mélanie Messmer
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| | - Paula Lopez
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| | - Aurélie Fender
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| | - Johana Chicher
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Plateforme Protéomique Strasbourg-Esplanade, 67084 Strasbourg France
| | - Béatrice Chane-Woon-Ming
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| | - Philippe Hammann
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Plateforme Protéomique Strasbourg-Esplanade, 67084 Strasbourg France
| | - Sébastien Pfeffer
- Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084 Strasbourg France
| |
Collapse
|
7
|
Huang X, Wei J, Wu D, Mi N, Fang S, Xiao Y, Li Y. Silencing of SlDRB1 gene reduces resistance to tomato yellow leaf curl virus (TYLCV) in tomato ( Solanum lycopersicum). PLANT SIGNALING & BEHAVIOR 2022; 17:2149942. [PMID: 36453197 PMCID: PMC9718546 DOI: 10.1080/15592324.2022.2149942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Double-stranded RNA-binding proteins are small molecules in the RNA interference (RNAi) pathway that form the RNAi machinery together with the Dicer-like protein (DCL) as a cofactor. This machinery cuts double-stranded RNA (dsRNA) to form multiple small interfering RNAs (siRNAs). Our goal was to clarify the function of DRB in tomato resistant to TYLCV. In this experiment, the expression of the SlDRB1 and SlDRB4 genes was analyzed in tomato leaves by qPCR, and the function of SlDRB1 and SlDRB4 in resistance to TYLCV was investigated by virus-induced gene silencing (VIGS). Then, peroxidase activity was determined. The results showed that the expression of SlDRB1 gradually increased after inoculation of 'dwarf tomato' plants with tomato yellow leaf curl virus (TYLCV), but this gene was suppressed after 28 days. Resistance to TYLCV was significantly weakened after silencing of the SlDRB1 gene. However, there were no significant expression differences in SlDRB4 after TYLCV inoculation. Our study showed that silencing SlDRB1 attenuated the ability of tomato plants to resist virus infection; therefore, SlDRB1 may play a key role in the defense against TYLCV in tomato plants, whereas SlDRB4 is likely not involved in this defense response. Taken together, These results suggest that the DRB gene is involved in the mechanism of antiviral activity.
Collapse
Affiliation(s)
- Xin Huang
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Jianming Wei
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Dan Wu
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Na Mi
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Sili Fang
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Yao Xiao
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| | - Yunzhou Li
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang, China
| |
Collapse
|
8
|
Bioinformatic Analysis Predicts a Novel Genetic Module Related to Triple Gene and Binary Movement Blocks of Plant Viruses: Tetra-Cistron Movement Block. Biomolecules 2022; 12:biom12070861. [PMID: 35883420 PMCID: PMC9313169 DOI: 10.3390/biom12070861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022] Open
Abstract
Previous studies have shown that the RNA genomes of some plant viruses encode two related genetic modules required for virus movement over the host body, containing two or three genes and named the binary movement block (BMB) and triple gene block (TGB), respectively. In this paper, we predict a novel putative-related movement gene module, called the tetra-cistron movement block (TCMB), in the virus-like transcriptome assemblies of the moss Dicranum scoparium and the Antarctic flowering plant Colobanthus quitensis. These TCMBs are encoded by smaller RNA components of putative two-component viruses related to plant benyviruses. Similar to the RNA2 of benyviruses, TCMB-containing RNAs have the 5′-terminal coat protein gene and include the RNA helicase gene which is followed by two small overlapping cistrons encoding hydrophobic proteins with a distant sequence similarity to the TGB2 and TGB3 proteins. Unlike TGB, TCMB also includes a fourth 5′-terminal gene preceding the helicase gene and coding for a protein showing a similarity to the double-stranded RNA-binding proteins of the DSRM AtDRB-like superfamily. Additionally, based on phylogenetic analysis, we suggest the involvement of replicative beny-like helicases in the evolution of the BMB and TCMB movement genetic modules.
Collapse
|
9
|
Jin L, Chen M, Xiang M, Guo Z. RNAi-Based Antiviral Innate Immunity in Plants. Viruses 2022; 14:v14020432. [PMID: 35216025 PMCID: PMC8875485 DOI: 10.3390/v14020432] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple antiviral immunities were developed to defend against viral infection in hosts. RNA interference (RNAi)-based antiviral innate immunity is evolutionarily conserved in eukaryotes and plays a vital role against all types of viruses. During the arms race between the host and virus, many viruses evolve viral suppressors of RNA silencing (VSRs) to inhibit antiviral innate immunity. Here, we reviewed the mechanism at different stages in RNAi-based antiviral innate immunity in plants and the counteractions of various VSRs, mainly upon infection of RNA viruses in model plant Arabidopsis. Some critical challenges in the field were also proposed, and we think that further elucidating conserved antiviral innate immunity may convey a broad spectrum of antiviral strategies to prevent viral diseases in the future.
Collapse
|
10
|
Clavel M, Lechner E, Incarbone M, Vincent T, Cognat V, Smirnova E, Lecorbeiller M, Brault V, Ziegler-Graff V, Genschik P. Atypical molecular features of RNA silencing against the phloem-restricted polerovirus TuYV. Nucleic Acids Res 2021; 49:11274-11293. [PMID: 34614168 PMCID: PMC8565345 DOI: 10.1093/nar/gkab802] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/25/2021] [Accepted: 10/04/2021] [Indexed: 11/12/2022] Open
Abstract
In plants and some animal lineages, RNA silencing is an efficient and adaptable defense mechanism against viruses. To counter it, viruses encode suppressor proteins that interfere with RNA silencing. Phloem-restricted viruses are spreading at an alarming rate and cause substantial reduction of crop yield, but how they interact with their hosts at the molecular level is still insufficiently understood. Here, we investigate the antiviral response against phloem-restricted turnip yellows virus (TuYV) in the model plant Arabidopsis thaliana. Using a combination of genetics, deep sequencing, and mechanical vasculature enrichment, we show that the main axis of silencing active against TuYV involves 22-nt vsiRNA production by DCL2, and their preferential loading into AGO1. Moreover, we identify vascular secondary siRNA produced from plant transcripts and initiated by DCL2-processed AGO1-loaded vsiRNA. Unexpectedly, and despite the viral encoded VSR P0 previously shown to mediate degradation of AGO proteins, vascular AGO1 undergoes specific post-translational stabilization during TuYV infection. Collectively, our work uncovers the complexity of antiviral RNA silencing against phloem-restricted TuYV and prompts a re-assessment of the role of its suppressor of silencing P0 during genuine infection.
Collapse
Affiliation(s)
- Marion Clavel
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Esther Lechner
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Marco Incarbone
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Timothée Vincent
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Valerie Cognat
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Ekaterina Smirnova
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Maxime Lecorbeiller
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | | | - Véronique Ziegler-Graff
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| |
Collapse
|