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Li Z, Velásquez‐Zapata V, Elmore JM, Li X, Xie W, Deb S, Tian X, Banerjee S, Jørgensen HJL, Pedersen C, Wise RP, Thordal‐Christensen H. Powdery mildew effectors AVR A1 and BEC1016 target the ER J-domain protein HvERdj3B required for immunity in barley. MOLECULAR PLANT PATHOLOGY 2024; 25:e13463. [PMID: 38695677 PMCID: PMC11064805 DOI: 10.1111/mpp.13463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/06/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024]
Abstract
The barley powdery mildew fungus, Blumeria hordei (Bh), secretes hundreds of candidate secreted effector proteins (CSEPs) to facilitate pathogen infection and colonization. One of these, CSEP0008, is directly recognized by the barley nucleotide-binding leucine-rich-repeat (NLR) receptor MLA1 and therefore is designated AVRA1. Here, we show that AVRA1 and the sequence-unrelated Bh effector BEC1016 (CSEP0491) suppress immunity in barley. We used yeast two-hybrid next-generation interaction screens (Y2H-NGIS), followed by binary Y2H and in planta protein-protein interactions studies, and identified a common barley target of AVRA1 and BEC1016, the endoplasmic reticulum (ER)-localized J-domain protein HvERdj3B. Silencing of this ER quality control (ERQC) protein increased Bh penetration. HvERdj3B is ER luminal, and we showed using split GFP that AVRA1 and BEC1016 translocate into the ER signal peptide-independently. Overexpression of the two effectors impeded trafficking of a vacuolar marker through the ER; silencing of HvERdj3B also exhibited this same cellular phenotype, coinciding with the effectors targeting this ERQC component. Together, these results suggest that the barley innate immunity, preventing Bh entry into epidermal cells, requires ERQC. Here, the J-domain protein HvERdj3B appears to be essential and can be regulated by AVRA1 and BEC1016. Plant disease resistance often occurs upon direct or indirect recognition of pathogen effectors by host NLR receptors. Previous work has shown that AVRA1 is directly recognized in the cytosol by the immune receptor MLA1. We speculate that the AVRA1 J-domain target being inside the ER, where it is inapproachable by NLRs, has forced the plant to evolve this challenging direct recognition.
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Affiliation(s)
- Zizhang Li
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
- Present address:
Institute for Bioscience and Biotechnology Research & Department of Plant Sciences and Landscape ArchitectureUniversity of MarylandRockvilleMarylandUSA
| | - Valeria Velásquez‐Zapata
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- Present address:
GreenLight Biosciences, IncResearch Triangle ParkNorth CarolinaUSA
| | - J. Mitch Elmore
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- USDA‐Agricultural Research Service, Corn Insects and Crop Genetics Research UnitAmesIowaUSA
- Present address:
USDA‐Agricultural Research Service, Cereal Disease LaboratorySt. PaulMinnesotaUSA
| | - Xuan Li
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Wenjun Xie
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Sohini Deb
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Xiao Tian
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Sagnik Banerjee
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of StatisticsIowa State UniversityAmesIowaUSA
- Present address:
Bristol Myers SquibbSan DiegoCaliforniaUSA
| | - Hans J. L. Jørgensen
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Carsten Pedersen
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Roger P. Wise
- Program in Bioinformatics & Computational BiologyIowa State UniversityAmesIowaUSA
- Department of Plant Pathology, Entomology and MicrobiologyIowa State UniversityAmesIowaUSA
- USDA‐Agricultural Research Service, Corn Insects and Crop Genetics Research UnitAmesIowaUSA
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Mirlohi S, Schott G, Imboden A, Voinnet O. An AGO10:miR165/6 module regulates meristem activity and xylem development in the Arabidopsis root. EMBO J 2024; 43:1843-1869. [PMID: 38565948 PMCID: PMC11066010 DOI: 10.1038/s44318-024-00071-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 04/04/2024] Open
Abstract
The RNA-silencing effector ARGONAUTE10 influences cell fate in plant shoot and floral meristems. ARGONAUTE10 also accumulates in the root apical meristem (RAM), yet its function(s) therein remain elusive. Here, we show that ARGONAUTE10 is expressed in the root cell initials where it controls overall RAM activity and length. ARGONAUTE10 is also expressed in the stele, where post-transcriptional regulation confines it to the root tip's pro-vascular region. There, variations in ARGONAUTE10 levels modulate metaxylem-vs-protoxylem specification. Both ARGONAUTE10 functions entail its selective, high-affinity binding to mobile miR165/166 transcribed in the neighboring endodermis. ARGONAUTE10-bound miR165/166 is degraded, likely via SMALL-RNA-DEGRADING-NUCLEASES1/2, thus reducing miR165/166 ability to silence, via ARGONAUTE1, the transcripts of cell fate-influencing transcription factors. These include PHABULOSA (PHB), which controls meristem activity in the initials and xylem differentiation in the pro-vasculature. During early germination, PHB transcription increases while dynamic, spatially-restricted transcriptional and post-transcriptional mechanisms reduce and confine ARGONAUTE10 accumulation to the provascular cells surrounding the newly-forming xylem axis. Adequate miR165/166 concentrations are thereby channeled along the ARGONAUTE10-deficient yet ARGONAUTE1-proficient axis. Consequently, inversely-correlated miR165/166 and PHB gradients form preferentially along the axis despite ubiquitous PHB transcription and widespread miR165/166 delivery inside the whole vascular cylinder.
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Affiliation(s)
- Shirin Mirlohi
- Department of Biology, Swiss Federal Institute of Technology (ETH-Zürich), Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Gregory Schott
- Department of Biology, Swiss Federal Institute of Technology (ETH-Zürich), Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - André Imboden
- Department of Biology, Swiss Federal Institute of Technology (ETH-Zürich), Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Olivier Voinnet
- Department of Biology, Swiss Federal Institute of Technology (ETH-Zürich), Universitätsstrasse 2, 8092, Zürich, Switzerland.
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Vaucheret H, Voinnet O. The plant siRNA landscape. THE PLANT CELL 2024; 36:246-275. [PMID: 37772967 PMCID: PMC10827316 DOI: 10.1093/plcell/koad253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 09/12/2023] [Accepted: 09/28/2023] [Indexed: 09/30/2023]
Abstract
Whereas micro (mi)RNAs are considered the clean, noble side of the small RNA world, small interfering (si)RNAs are often seen as a noisy set of molecules whose barbarian acronyms reflect a large diversity of often elusive origins and functions. Twenty-five years after their discovery in plants, however, new classes of siRNAs are still being identified, sometimes in discrete tissues or at particular developmental stages, making the plant siRNA world substantially more complex and subtle than originally anticipated. Focusing primarily on the model Arabidopsis, we review here the plant siRNA landscape, including transposable elements (TE)-derived siRNAs, a vast array of non-TE-derived endogenous siRNAs, as well as exogenous siRNAs produced in response to invading nucleic acids such as viruses or transgenes. We primarily emphasize the extraordinary sophistication and diversity of their biogenesis and, secondarily, the variety of their known or presumed functions, including via non-cell autonomous activities, in the sporophyte, gametophyte, and shortly after fertilization.
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Affiliation(s)
- Hervé Vaucheret
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Olivier Voinnet
- Department of Biology, Swiss Federal Institute of Technology (ETH-Zurich), 8092 Zürich, Switzerland
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Hu W, Dai Z, Liu P, Deng C, Shen W, Li Z, Cui H. The Single Distinct Leader Protease Encoded by Alpinia oxyphylla Mosaic Virus (Genus Macluravirus) Suppresses RNA Silencing Through Interfering with Double-Stranded RNA Synthesis. PHYTOPATHOLOGY 2023; 113:1103-1114. [PMID: 36576401 DOI: 10.1094/phyto-10-22-0371-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The genomic 5'-terminal regions of viruses in the family Potyviridae (potyvirids) encode two types of leader proteases: serine-protease (P1) and cysteine-protease (HCPro), which differ greatly in the arrangement and sequence composition among inter-genus viruses. Most potyvirids have the same tandemly arranged P1 and HCPro, whereas viruses in the genus Macluravirus encode a single distinct leader protease, a truncated version of HCPro with yet-unknown functions. We investigated the RNA silencing suppression (RSS) activity and its underpinning mechanism of the distinct HCPro from alpinia oxyphylla mosaic macluravirus (aHCPro). Sequence analysis revealed that macluraviral HCPros have obvious truncations in the N-terminal and middle regions when aligned to their counterparts in potyviruses (well-characterized viral suppressors of RNA silencing). Nearly all defined elements essential for the RSS activity of potyviral counterparts are not distinguished in macluraviral HCPros. Here, we demonstrated that aHCPro exhibits a similar anti-silencing activity with the potyviral counterpart. However, aHCPro fails to block both the local and systemic spreading of RNA silencing. In line, aHCPro interferes with the dsRNA synthesis, an upstream step in the RNA silencing pathway. Affinity-purification and NanoLC-MS/MS analysis revealed that aHCPro has no association with core components or their potential interactors involving in dsRNA synthesis from the protein layer. Instead, the ectopic expression of aHCPro significantly reduces the transcript abundance of RDR2, RDR6, SGS3, and SDE5. This study represents the first report on the anti-silencing function of Macluravirus-encoded HCPro and the underlying molecular mechanism.
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Affiliation(s)
- Weiyao Hu
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Zhaoji Dai
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Peilan Liu
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Changhui Deng
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Wentao Shen
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan, 571101, China
| | - Zengping Li
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Hongguang Cui
- Sanya Nanfan Research Institute, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and College of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
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Uhl S, Jang C, Frere JJ, Jordan TX, Simon AE, tenOever BR. ADAR1 Biology Can Hinder Effective Antiviral RNA Interference. J Virol 2023; 97:e0024523. [PMID: 37017521 PMCID: PMC10134826 DOI: 10.1128/jvi.00245-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/10/2023] [Indexed: 04/06/2023] Open
Abstract
Viruses constantly evolve and adapt to the antiviral defenses of their hosts. The biology of viral circumvention of these selective pressures can often be attributed to the acquisition of novel antagonistic gene products or by rapid genome change that prevents host recognition. To study viral evasion of RNA interference (RNAi)-based defenses, we established a robust antiviral system in mammalian cells using recombinant Sendai virus designed to be targeted by endogenous host microRNAs (miRNAs) with perfect complementarity. Using this system, we previously demonstrated the intrinsic ability of positive-strand RNA viruses to escape this selective pressure via homologous recombination, which was not observed in negative-strand RNA viruses. Here, we show that given extensive time, escape of miRNA-targeted Sendai virus was enabled by host adenosine deaminase acting on RNA 1 (ADAR1). Independent of the viral transcript targeted, ADAR1 editing resulted in disruption of the miRNA-silencing motif, suggesting an intolerance for extensive RNA-RNA interactions necessary for antiviral RNAi. This was further supported in Nicotiana benthamiana, where exogenous expression of ADAR1 interfered with endogenous RNAi. Together, these results suggest that ADAR1 diminishes the effectiveness of RNAi and may explain why it is absent in species that utilize this antiviral defense system. IMPORTANCE All life at the cellular level has the capacity to induce an antiviral response. Here, we examine the result of imposing the antiviral response of one branch of life onto another and find evidence for conflict. To determine the consequences of eliciting an RNAi-like defense in mammals, we applied this pressure to a recombinant Sendai virus in cell culture. We find that ADAR1, a host gene involved in regulation of the mammalian response to virus, prevented RNAi-mediated silencing and subsequently allowed for viral replication. In addition, the expression of ADAR1 in Nicotiana benthamiana, which lacks ADARs and has an endogenous RNAi system, suppresses gene silencing. These data indicate that ADAR1 is disruptive to RNAi biology and provide insight into the evolutionary relationship between ADARs and antiviral defenses in eukaryotic life.
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Affiliation(s)
- Skyler Uhl
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Microbiology | Medicine, New York University, New York, New York, USA
| | - Chanyong Jang
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, Maryland, USA
| | - Justin J. Frere
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Microbiology | Medicine, New York University, New York, New York, USA
| | - Tristan X. Jordan
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anne E. Simon
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, Maryland, USA
| | - Benjamin R. tenOever
- Department of Microbiology | Medicine, New York University, New York, New York, USA
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Xie L, Hu J, Yan Z, Li X, Wei S, Xu R, Yang W, Gu H, Zhang Q. Tree peony transcription factor PrWRI1 enhances seed oil accumulation. BMC PLANT BIOLOGY 2023; 23:127. [PMID: 36882682 PMCID: PMC9990299 DOI: 10.1186/s12870-023-04127-9] [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: 09/17/2022] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND WRINKLED1 (WRI1) encodes a transcription factor, belonging to the APETALA2 (AP2) family, and plays a key role in regulating plant oil biosynthesis. As a newly woody oil crop, tree peony (Paeonia rockii) was notable for the abundant unsaturated fatty acids in its seed oil. However, the role of WRI1 during the accumulation of P. rockii seeds oil remains largely unknown. RESULTS In this study, a new member of the WRI1 family was isolated from P. rockii and was named PrWRI1. The ORF of PrWRI1 consisted of 1269 nucleotides, encoding a putative protein of 422 amino acids, and was highly expressed in immature seeds. Subcellular localization analysis in onion inner epidermal cells showed that PrWRI1 was located at the nucleolus. Ectopic overexpression of PrWRI1 could significantly increase the total fatty acid content in Nicotiana benthamiana leaf tissue and even PUFAs in transgenic Arabidopsis thaliana seeds. Furthermore, the transcript levels of most genes related to fatty acids (FA) synthesis and triacylglycerol (TAG) assembly were also up-regulated in transgenic Arabidopsis seeds. CONCLUSIONS Together, PrWRI1 could push carbon flow to FA biosynthesis and further enhance the TAG amount in seeds with a high proportion of PUFAs.
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Affiliation(s)
- Lihang Xie
- Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450000, Henan, China
| | - Jiayuan Hu
- Sichuan Academy of Giant Panda, Chengdu, 610000, Sichuan, China
| | - Zhenguo Yan
- Academy of Agricultural Planning and Engineering, MARA, Beijing, 100000, China
| | - Xinyao Li
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450000, Henan, China
| | - Sailong Wei
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450000, Henan, China
| | - Ruilin Xu
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450000, Henan, China
| | - Weizong Yang
- College of Landscape Architecture and Art, Northwest A&F University, Yangling, 712100, Shannxi, China
| | - Huihui Gu
- Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450000, Henan, China.
| | - Qingyu Zhang
- College of Landscape Architecture and Art, Northwest A&F University, Yangling, 712100, Shannxi, China.
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Aguilar E, Lozano-Durán R. On the inhibition of RNA silencing movement by the tombusvirus P19 protein: reliance on sRNA binding and correlation with local silencing suppression. THE NEW PHYTOLOGIST 2022; 235:830-835. [PMID: 35607937 DOI: 10.1111/nph.18181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Emmanuel Aguilar
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai, 201602, China
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Campus Teatinos, Málaga, 29071, Spain
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, Tübingen, D-72076, Germany
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