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Bader S, Tuller T. Advanced computational predictive models of miRNA-mRNA interaction efficiency. Comput Struct Biotechnol J 2024; 23:1740-1754. [PMID: 38689718 PMCID: PMC11058727 DOI: 10.1016/j.csbj.2024.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/06/2024] [Accepted: 04/07/2024] [Indexed: 05/02/2024] Open
Abstract
The modeling of miRNA-mRNA interactions holds significant implications for synthetic biology and human health. However, this research area presents specific challenges due to the multifaceted nature of mRNA downregulation by miRNAs, influenced by numerous factors including competition or synergism among miRNAs and mRNAs. In this study, we present an improved computational model for predicting miRNA-mRNA interactions, addressing aspects not previously modeled. Firstly, we integrated a novel set of features that significantly enhanced the predictor's performance. Secondly, we demonstrated the cell-specific nature of certain aspects of miRNA-mRNA interactions, highlighting the importance of designing models tailored to specific cell types for improved accuracy. Moreover, we introduce a miRNA binding site interaction model (miBSIM) that, for the first time, accounts for both the distribution of miRNA binding sites along the mRNA and their respective strengths in regulating mRNA stability. Our analysis suggests that distant miRNA sites often compete with each other, revealing the intricate interplay of binding site interactions. Overall, our new predictive model shows a significant improvement of up to 6.43% over previous models in the field. The code of our model is available at https://www.cs.tau.ac.il/~tamirtul/miBSIM.
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Affiliation(s)
- Sharon Bader
- Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv, Israel
- The Segol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
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2
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Zaheer U, Munir F, Salum YM, He W. Function and regulation of plant ARGONAUTE proteins in response to environmental challenges: a review. PeerJ 2024; 12:e17115. [PMID: 38560454 PMCID: PMC10979746 DOI: 10.7717/peerj.17115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Environmental stresses diversely affect multiple processes related to the growth, development, and yield of many crops worldwide. In response, plants have developed numerous sophisticated defense mechanisms at the cellular and subcellular levels to react and adapt to biotic and abiotic stressors. RNA silencing, which is an innate immune mechanism, mediates sequence-specific gene expression regulation in higher eukaryotes. ARGONAUTE (AGO) proteins are essential components of the RNA-induced silencing complex (RISC). They bind to small noncoding RNAs (sRNAs) and target complementary RNAs, causing translational repression or triggering endonucleolytic cleavage pathways. In this review, we aim to illustrate the recently published molecular functions, regulatory mechanisms, and biological roles of AGO family proteins in model plants and cash crops, especially in the defense against diverse biotic and abiotic stresses, which could be helpful in crop improvement and stress tolerance in various plants.
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Affiliation(s)
- Uroosa Zaheer
- Plant Protection, State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Faisal Munir
- Plant Protection, State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Yussuf Mohamed Salum
- Plant Protection, State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Weiyi He
- Plant Protection, State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Plant Protection, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
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3
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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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4
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Gruber C, Gursinsky T, Gago-Zachert S, Pantaleo V, Behrens SE. Effective Antiviral Application of Antisense in Plants by Exploiting Accessible Sites in the Target RNA. Int J Mol Sci 2023; 24:17153. [PMID: 38138982 PMCID: PMC10743417 DOI: 10.3390/ijms242417153] [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: 10/18/2023] [Revised: 12/01/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023] Open
Abstract
Antisense oligodeoxynucleotides (ASOs) have long been used to selectively inhibit or modulate gene expression at the RNA level, and some ASOs are approved for clinical use. However, the practicability of antisense technologies remains limited by the difficulty of reliably predicting the sites accessible to ASOs in complex folded RNAs. Recently, we applied a plant-based method that reproduces RNA-induced RNA silencing in vitro to reliably identify sites in target RNAs that are accessible to small interfering RNA (siRNA)-guided Argonaute endonucleases. Here, we show that this method is also suitable for identifying ASOs that are effective in DNA-induced RNA silencing by RNases H. We show that ASOs identified in this way that target a viral genome are comparably effective in protecting plants from infection as siRNAs with the corresponding sequence. The antiviral activity of the ASOs could be further enhanced by chemical modification. This led to two important conclusions: siRNAs and ASOs that can effectively knock down complex RNA molecules can be identified using the same approach, and ASOs optimized in this way could find application in crop protection. The technology developed here could be useful not only for effective RNA silencing in plants but also in other organisms.
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Affiliation(s)
- Cornelia Gruber
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany; (C.G.); (T.G.); (S.G.-Z.)
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany; (C.G.); (T.G.); (S.G.-Z.)
| | - Selma Gago-Zachert
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany; (C.G.); (T.G.); (S.G.-Z.)
| | - Vitantonio Pantaleo
- Institute for Sustainable Plant Protection, Department of Biology, Agricultural and Food Sciences National Research Council, Bari Unit, I-70126 Bari, Italy;
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany; (C.G.); (T.G.); (S.G.-Z.)
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5
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Leonetti P, Consiglio A, Arendt D, Golbik RP, Rubino L, Gursinsky T, Behrens SE, Pantaleo V. Exogenous and endogenous dsRNAs perceived by plant Dicer-like 4 protein in the RNAi-depleted cellular context. Cell Mol Biol Lett 2023; 28:64. [PMID: 37550627 PMCID: PMC10405411 DOI: 10.1186/s11658-023-00469-2] [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: 05/02/2023] [Accepted: 06/24/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND In plants, RNase III Dicer-like proteins (DCLs) act as sensors of dsRNAs and process them into short 21- to 24-nucleotide (nt) (s)RNAs. Plant DCL4 is involved in the biogenesis of either functional endogenous or exogenous (i.e. viral) short interfering (si)RNAs, thus playing crucial antiviral roles. METHODS In this study we expressed plant DCL4 in Saccharomyces cerevisiae, an RNAi-depleted organism, in which we could highlight the role of dicing as neither Argonautes nor RNA-dependent RNA polymerase is present. We have therefore tested the DCL4 functionality in processing exogenous dsRNA-like substrates, such as a replicase-assisted viral replicon defective-interfering RNA and RNA hairpin substrates, or endogenous antisense transcripts. RESULTS DCL4 was shown to be functional in processing dsRNA-like molecules in vitro and in vivo into 21- and 22-nt sRNAs. Conversely, DCL4 did not efficiently process a replicase-assisted viral replicon in vivo, providing evidence that viral RNAs are not accessible to DCL4 in membranes associated in active replication. Worthy of note, in yeast cells expressing DCL4, 21- and 22-nt sRNAs are associated with endogenous loci. CONCLUSIONS We provide new keys to interpret what was studied so far on antiviral DCL4 in the host system. The results all together confirm the role of sense/antisense RNA-based regulation of gene expression, expanding the sense/antisense atlas of S. cerevisiae. The results described herein show that S. cerevisiae can provide insights into the functionality of plant dicers and extend the S. cerevisiae tool to new biotechnological applications.
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Affiliation(s)
- Paola Leonetti
- Department of Biology, Agricultural and Food Sciences, National Research Council, Institute for Sustainable Plant Protection, Bari Unit, Bari, Italy
| | - Arianna Consiglio
- Department of Biomedical Sciences, National Research Council, Institute for Biomedical Technologies, Bari Unit, Bari, Italy
| | - Dennis Arendt
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Halle Saale, Germany
| | - Ralph Peter Golbik
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Halle Saale, Germany
| | - Luisa Rubino
- Department of Biology, Agricultural and Food Sciences, National Research Council, Institute for Sustainable Plant Protection, Bari Unit, Bari, Italy
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Halle Saale, Germany
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Halle Saale, Germany
| | - Vitantonio Pantaleo
- Department of Biology, Agricultural and Food Sciences, National Research Council, Institute for Sustainable Plant Protection, Bari Unit, Bari, Italy.
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6
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Liu M, Wu H, Hong N, Kang B, Peng B, Liu L, Gu Q. Argonaute 1 and 5 proteins play crucial roles in the defence against cucumber green mottle mosaic virus in watermelon. MOLECULAR PLANT PATHOLOGY 2023; 24:961-972. [PMID: 37118922 PMCID: PMC10346368 DOI: 10.1111/mpp.13344] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
RNA silencing, a core part of plants' antiviral defence, requires the ARGONAUTE, DICER-like, and RNA-dependent RNA polymerase proteins. However, how these proteins contribute to watermelon's RNA interference (RNAi) pathway response to cucumber green mottle mosaic virus (CGMMV) has not been characterized. Here, we identify seven ClAGO, four ClDCL, and 11 ClRDR genes in watermelon and analyse their expression profiles when infected with CGMMV. ClAGO1 and ClAGO5 expression levels were highly induced by CGMMV infection. The results of ClAGO1 and ClAGO5 overexpression and silencing experiments suggest that these genes play central roles in watermelon's antiviral defence. Furthermore, co-immunoprecipitation and bimolecular fluorescence complementation experiments showed that ClAGO1 interacts with ClAGO5 in vivo, suggesting that ClAGO1 and ClAGO5 co-regulate watermelon defence against CGMMV infection. We also identified the ethylene response factor (ERF) binding site in the promoters of the ClAGO1 and ClAGO5 genes, and ethylene (ETH) treatment significantly increased ClAGO5 expression. Two ERF genes (Cla97C08G147180 and Cla97C06G122830) closely related to ClAGO5 expression were identified using co-expression analysis. Subcellular localization revealed that two ERFs and ClAGO5 predominantly localize at the nucleus, suggesting that enhancement of resistance to CGMMV by ETH is probably achieved through ClAGO5 but not ClAGO1. Our findings reveal aspects of the mechanisms underlying RNA silencing in watermelon against CGMMV.
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Affiliation(s)
- Mei Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Huijie Wu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
| | - Ni Hong
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Baoshan Kang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
| | - Bin Peng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
| | - Liming Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
| | - Qinsheng Gu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research InstituteChinese Academy of Agricultural SciencesZhengzhouChina
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7
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Ding SW. Transgene Silencing, RNA Interference, and the Antiviral Defense Mechanism Directed by Small Interfering RNAs. PHYTOPATHOLOGY 2023; 113:616-625. [PMID: 36441873 DOI: 10.1094/phyto-10-22-0358-ia] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
One important discovery in plant pathology over recent decades is the natural antiviral defense mechanism mediated by RNA interference (RNAi). In antiviral RNAi, virus infection triggers Dicer processing of virus-specific double-stranded RNA into small interfering RNAs (siRNAs). Frequently, further amplified by host enzyme and cofactors, these virus-derived siRNAs direct specific virus clearance in an Argonaute protein-containing effector complex. The siRNAs derived from viruses and viroids accumulate to very high levels during infection. Because they overlap extensively in nucleotide sequence, this allows for deep sequencing and bioinformatics assembly of total small RNAs for rapid discovery and identification of viruses and viroids. Antiviral RNAi acts as the primary defense mechanism against both RNA and DNA viruses in plants, yet viruses still successfully infect plants. They do so because all currently recognized plant viruses combat the RNAi response by encoding at least one protein as a viral suppressor of RNAi (VSR) required for infection, even though plant viruses have small genome sizes with a limited coding capacity. This review article will recapitulate the key findings that have revealed the genetic pathway for the biogenesis and antiviral activity of viral siRNAs and the specific role of VSRs in infection by antiviral RNAi suppression. Moreover, early pioneering studies on transgene silencing, RNAi, and virus-plant/virus-virus interactions paved the road to the discovery of antiviral RNAi.
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Affiliation(s)
- Shou-Wei Ding
- Department of Microbiology & Plant Pathology and Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA
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8
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Akbarimotlagh M, Azizi A, Shams-Bakhsh M, Jafari M, Ghasemzadeh A, Palukaitis P. Critical points for the design and application of RNA silencing constructs for plant virus resistance. Adv Virus Res 2023; 115:159-203. [PMID: 37173065 DOI: 10.1016/bs.aivir.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Control of plant virus diseases is a big challenge in agriculture as is resistance in plant lines to infection by viruses. Recent progress using advanced technologies has provided fast and durable alternatives. One of the most promising techniques against plant viruses that is cost-effective and environmentally safe is RNA silencing or RNA interference (RNAi), a technology that could be used alone or along with other control methods. To achieve the goals of fast and durable resistance, the expressed and target RNAs have been examined in many studies, with regard to the variability in silencing efficiency, which is regulated by various factors such as target sequences, target accessibility, RNA secondary structures, sequence variation in matching positions, and other intrinsic characteristics of various small RNAs. Developing a comprehensive and applicable toolbox for the prediction and construction of RNAi helps researchers to achieve the acceptable performance level of silencing elements. Although the attainment of complete prediction of RNAi robustness is not possible, as it also depends on the cellular genetic background and the nature of the target sequences, some important critical points have been discerned. Thus, the efficiency and robustness of RNA silencing against viruses can be improved by considering the various parameters of the target sequence and the construct design. In this review, we provide a comprehensive treatise regarding past, present and future prospective developments toward designing and applying RNAi constructs for resistance to plant viruses.
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Affiliation(s)
- Masoud Akbarimotlagh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Abdolbaset Azizi
- Department of Plant Protection, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran.
| | - Masoud Shams-Bakhsh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Majid Jafari
- Department of Plant Protection, Higher Education Complex of Saravan, Saravan, Iran
| | - Aysan Ghasemzadeh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran, Iran
| | - Peter Palukaitis
- Department of Horticulture Sciences, Seoul Women's University, Seoul, Republic of Korea.
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Comparative Plant Transcriptome Profiling of Arabidopsis thaliana Col-0 and Camelina sativa var. Celine Infested with Myzus persicae Aphids Acquiring Circulative and Noncirculative Viruses Reveals Virus- and Plant-Specific Alterations Relevant to Aphid Feeding Behavior and Transmission. Microbiol Spectr 2022; 10:e0013622. [PMID: 35856906 PMCID: PMC9430646 DOI: 10.1128/spectrum.00136-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evidence is accumulating that plant viruses alter host plant traits in ways that modify their insect vectors' behavior. These alterations often enhance virus transmission, which has led to the hypothesis that these effects are manipulations caused by viral adaptation. However, we lack a mechanistic understanding of the genetic basis of these indirect, plant-mediated effects on vectors, their dependence on the plant host, and their relation to the mode of virus transmission. Transcriptome profiling of Arabidopsis thaliana and Camelina sativa plants infected with turnip yellows virus (TuYV) or cauliflower mosaic virus (CaMV) and infested with the common aphid vector Myzus persicae revealed strong virus- and host-specific differences in gene expression patterns. CaMV infection caused more severe effects on the phenotype of both plant hosts than did TuYV infection, and the severity of symptoms correlated strongly with the proportion of differentially expressed genes, especially photosynthesis genes. Accordingly, CaMV infection modified aphid behavior and fecundity more strongly than did infection with TuYV. Overall, infection with CaMV, relying on the noncirculative transmission mode, tends to have effects on metabolic pathways, with strong potential implications for insect vector-plant host interactions (e.g., photosynthesis, jasmonic acid, ethylene, and glucosinolate biosynthetic processes), while TuYV, using the circulative transmission mode, alters these pathways only weakly. These virus-induced deregulations of genes that are related to plant physiology and defense responses might impact both aphid probing and feeding behavior on infected host plants, with potentially distinct effects on virus transmission. IMPORTANCE Plant viruses change the phenotype of their plant hosts. Some of the changes impact interactions of the plant with insects that feed on the plants and transmit these viruses. These modifications may result in better virus transmission. We examine here the transcriptomes of two plant species infected with two viruses with different transmission modes to work out whether there are plant species-specific and transmission mode-specific transcriptome changes. Our results show that both are the case.
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Rössner C, Lotz D, Becker A. VIGS Goes Viral: How VIGS Transforms Our Understanding of Plant Science. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:703-728. [PMID: 35138878 DOI: 10.1146/annurev-arplant-102820-020542] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Virus-induced gene silencing (VIGS) has developed into an indispensable approach to gene function analysis in a wide array of species, many of which are not amenable to stable genetic transformation. VIGS utilizes the posttranscriptional gene silencing (PTGS) machinery of plants to restrain viral infections systemically and is used to downregulate the plant's endogenous genes. Here, we review the molecular mechanisms of DNA- and RNA-virus-based VIGS, its inherent connection to PTGS, and what is known about the systemic spread of silencing. Recently, VIGS-based technologies have been expanded to enable not only gene silencing but also overexpression [virus-induced overexpression (VOX)], genome editing [virus-induced genome editing (VIGE)], and host-induced gene silencing (HIGS). These techniques expand the genetic toolbox for nonmodel organisms even more. Further, we illustrate the versatility of VIGS and the methods derived from it in elucidating molecular mechanisms, using tomato fruit ripening and programmed cell death as examples. Finally, we discuss challenges of and future perspectives on the use of VIGS to advance gene function analysis in nonmodel plants in the postgenomic era.
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Affiliation(s)
- Clemens Rössner
- Institute of Botany, Justus-Liebig University Gießen, Gießen, Germany;
| | - Dominik Lotz
- Institute of Botany, Justus-Liebig University Gießen, Gießen, Germany;
| | - Annette Becker
- Institute of Botany, Justus-Liebig University Gießen, Gießen, Germany;
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11
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Pertermann R, Golbik RP, Tamilarasan S, Gursinsky T, Gago-Zachert S, Pantaleo V, Thondorf I, Behrens SE. RNA and Protein Determinants Mediate Differential Binding of miRNAs by a Viral Suppressor of RNA Silencing Thus Modulating Antiviral Immune Responses in Plants. Int J Mol Sci 2022; 23:4977. [PMID: 35563369 PMCID: PMC9103804 DOI: 10.3390/ijms23094977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 01/27/2023] Open
Abstract
Many plant viruses express suppressor proteins (VSRs) that can inhibit RNA silencing, a central component of antiviral plant immunity. The most common activity of VSRs is the high-affinity binding of virus-derived siRNAs and thus their sequestration from the silencing process. Since siRNAs share large homologies with miRNAs, VSRs like the Tombusvirus p19 may also bind miRNAs and in this way modulate cellular gene expression at the post-transcriptional level. Interestingly, the binding affinity of p19 varies considerably between different miRNAs, and the molecular determinants affecting this property have not yet been adequately characterized. Addressing this, we analyzed the binding of p19 to the miRNAs 162 and 168, which regulate the expression of the important RNA silencing constituents Dicer-like 1 (DCL1) and Argonaute 1 (AGO1), respectively. p19 binds miRNA162 with similar high affinity as siRNA, whereas the affinity for miRNA168 is significantly lower. We show that specific molecular features, such as mismatches and 'G-U wobbles' on the RNA side and defined amino acid residues on the VSR side, mediate this property. Our observations highlight the remarkable adaptation of VSR binding affinities to achieve differential effects on host miRNA activities. Moreover, they show that even minimal changes, i.e., a single base pair in a miRNA duplex, can have significant effects on the efficiency of the plant antiviral immune response.
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Affiliation(s)
- Robert Pertermann
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Ralph Peter Golbik
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Selvaraj Tamilarasan
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Selma Gago-Zachert
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Vitantonio Pantaleo
- Department of Biology, Agricultural and Food Sciences, Institute for Sustainable Plant Protection, Bari Unit, CNR, 70126 Bari, Italy;
| | - Iris Thondorf
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Saale, 06120 Halle, Germany; (R.P.); (R.P.G.); (S.T.); (T.G.); (S.G.-Z.); (I.T.)
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12
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Li Z, Li W, Guo M, Liu S, Liu L, Yu Y, Mo B, Chen X, Gao L. Origin, evolution and diversification of plant ARGONAUTE proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:1086-1097. [PMID: 34845788 PMCID: PMC9208301 DOI: 10.1111/tpj.15615] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/13/2021] [Accepted: 11/22/2021] [Indexed: 05/26/2023]
Abstract
Argonaute (AGO) proteins are central players in RNA interference in eukaryotes. They associate with small RNAs (sRNA) and lead to transcriptional or posttranscriptional silencing of targets, thereby regulating diverse biological processes. The molecular and biological functions of AGO proteins have been extensively characterized, particularly in a few angiosperm species, leading to the recognition that the AGO family has expanded to accommodate diverse sRNAs thereby performing diverse biological functions. However, understanding of the expansion of AGO proteins in plants is still limited, due to a dearth of knowledge of AGO proteins in green algal groups. Here, we identified more than 2900 AGO proteins from 244 plant species, including green algae, and performed a large-scale phylogenetic analysis. The phylogeny shows that the plant AGO family gave rise to four clades after the emergence of hydrobiontic algae and prior to the emergence of land plants. Subsequent parallel expansion in ferns and angiosperms resulted in eight main clades in angiosperms: AGO2, AGO7, AGO6, AGO4, AGO1, AGO10a, AGO10b and AGO5. On the basis of this phylogeny, we identified two novel AGO4 orthologs that Arabidopsis does not have, and redefined AGO10, which is composed of AGO10a and AGO10b. Finally, we propose a hypothetical evolutionary model of AGO proteins in plants. Our studies provide a deeper understanding of the phylogenetic relationships of AGO family members in the green lineage, which would help to further reveal their roles as RNAi effectors.
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Affiliation(s)
- Zancong Li
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Wenqi Li
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Mingxi Guo
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Simu Liu
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Lin Liu
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Yu Yu
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Beixin Mo
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Xuemei Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Lei Gao
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
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13
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Yang L, Chen Y, Liu N, Lu Y, Ma W, Yang Z, Gan W, Li D. CircMET promotes tumor proliferation by enhancing CDKN2A mRNA decay and upregulating SMAD3. Mol Cancer 2022; 21:23. [PMID: 35042525 PMCID: PMC8764797 DOI: 10.1186/s12943-022-01497-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 01/03/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Functions of CircMET (hsa_circ_0082002) which is a circular RNA and derived from MET gene remain understood incompletely. In the present study, Xp11.2 translocation/NONO-TFE3 fusion renal cell carcinoma (NONO-TFE3 tRCC) with up-regulated CircMET was employed to investigate its mechanism in cancer progression and post-transcriptional regulation. METHODS FISH and real-time PCR were performed to explore the expression and localization circMET in NONO-TFE3 tRCC tissues and cells. The functions of circMET in tRCC were investigated by proliferation analysis, EdU staining, colony and sphere formation assay. The regulatory mechanisms among circMET, CDKN2A and SMAD3 were investigated by luciferase assay, RNA immunoprecipitation, RNA pulldown and targeted RNA demethylation system. RESULTS The expression of circMET was upregulated by NONO-TFE3 fusion in NONO-TFE3 tRCC tissues and cells, and overexpression of circMET significantly promoted the growth of NONO-TFE3 tRCC. Mechanistic studies revealed that circMET was delivered to cytosol by YTHDC1 in N6-methyladenosine (m6A)-depend manner. CircMET enhances mRNA decay of CDKN2A by direct interaction and recruitment of YTHDF2. Meanwhile, circMET competitively absorbed miR-1197 and prevented those from SMAD3 mRNA. CONCLUSIONS CircMET promotes the development of NONO-TFE3 tRCC, and the regulation to both CDKN2A and SMAD3 of circMET was revealed. CircMET has the potential to serve as a novel target for the molecular therapy of NONO-TFE3 tRCC as well as the other cancer with high-expressing circMET.
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Affiliation(s)
- Lei Yang
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Yi Chen
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Ning Liu
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Yanwen Lu
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Wenliang Ma
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Zhenhao Yang
- Department of Urology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210008, Jiangsu, China
| | - Weidong Gan
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China.
| | - Dongmei Li
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China. .,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China.
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14
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Jiao Y, Zhao X, Hao K, Gao X, Xing D, Wang Z, An M, Xia Z, Wu Y. Characterization of small interfering RNAs derived from pepper mild mottle virus in infected pepper plants by high-throughput sequencing. Virus Res 2022; 307:198607. [PMID: 34688783 DOI: 10.1016/j.virusres.2021.198607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/12/2021] [Accepted: 10/17/2021] [Indexed: 11/25/2022]
Abstract
Pepper mild mottle virus (PMMoV) infects pepper plants and induces severe yield losses in China. However, the molecular interaction between PMMoV and pepper plants is largely unknown. RNA silencing is a eukaryotically conserved mechanism against viruses mediated by virus-derived small interfering RNAs (vsiRNAs) in plants. In this study, the profiles of vsiRNAs from PMMoV in infected pepper plants were obtained by high-throughput sequencing. The results showed that vsiRNAs were predominantly 21 and 22 nucleotides (nts) in length, and had a U bias at the 5'-terminal. The single-nucleotide resolution maps revealed that vsiRNAs were heterogeneously distributed throughout PMMoV genomic RNAs and hotspots of sense and antisense strands were mainly located in the RdRp and CP coding regions. The host transcripts targeted by vsiRNAs were predicted and they are mainly involved in physiological pathways related to stress response, cell regulation, and metabolism process. In addition, PMMoV infection induced significant up-regulation of CaAGO1a/1b/2, CaDCL2 and CaRDR1 gene transcripts in pepper plants, which are important components involved in antiviral RNA silencing pathway. Taken together, our results suggest the possible roles of vsiRNAs in PMMoV-pepper interactions.
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Affiliation(s)
- Yubing Jiao
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China; Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Xiuxiang Zhao
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Kaiqiang Hao
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Xinran Gao
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Dan Xing
- Institute of Pepper, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China
| | - Zhiping Wang
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Mengnan An
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Zihao Xia
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
| | - Yuanhua Wu
- Liaoning Key Laboratory of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
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15
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Zhao S, Wu J. Rapid and Specific Purification of Argonaute-Small RNA Complexes from Rice for Slicer Activity. Methods Mol Biol 2022; 2400:139-147. [PMID: 34905198 DOI: 10.1007/978-1-0716-1835-6_14] [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: 06/14/2023]
Abstract
Argonaute (AGO) proteins associate with small RNAs (sRNAs) to form an RNA-induced silencing complex (RISC). The ribonuclease (slicer) activity of AGOs is required for the sRNA-complementary target cleavage, which is important for RISC-mediated RNA silencing, especially in plants. Sequencing small RNAs is an obvious choice to understand their expression and downstream effects. It also provides an opportunity to identify novel and polymorphic miRNAs. Recently, we have successfully reconstituted rice (Oryza sativa) AGO1a slicer assays in vitro that are able to recapitulate in vivo miRNA-guided cleavage activity. Here we provide a detailed protocol for the purification of OsAGO1a-sRNA complexes and further slicer assays, small RNA sequencing and bioinformatic analysis. This protocol can be readily adapted for the purification and subsequent analyses of the AGO complexes in other plants.
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Affiliation(s)
- Shanshan Zhao
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jianguo Wu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.
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16
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Tarquini G, Pagliari L, Ermacora P, Musetti R, Firrao G. Trigger and Suppression of Antiviral Defenses by Grapevine Pinot Gris Virus (GPGV): Novel Insights into Virus-Host Interaction. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1010-1023. [PMID: 33983824 DOI: 10.1094/mpmi-04-21-0078-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Grapevine Pinot gris virus (GPGV) is an emerging trichovirus that has been putatively associated with a novel grapevine disease known as grapevine leaf mottling and deformation (GLMD). Yet the role of GPGV in GLMD disease is poorly understood, since it has been detected both in symptomatic and symptomless grapevines. We exploited a recently constructed GPGV infectious clone (pRI::GPGV-vir) to induce an antiviral response in Nicotiana benthamiana plants. In silico prediction of virus-derived small interfering RNAs and gene expression analyses revealed the involvement of DCL4, AGO5, and RDR6 genes during GPGV infection, suggesting the activation of the posttranscriptional gene-silencing (PTGS) pathway as a plant antiviral defense. PTGS suppression assays in transgenic N. benthamiana 16c plants revealed the ability of the GPGV coat protein to suppress RNA silencing. This work provides novel insights on the interaction between GPGV and its host, revealing the ability of the virus to trigger and suppress antiviral RNA silencing.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Giulia Tarquini
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine I-33100, Italy
| | - Laura Pagliari
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine I-33100, Italy
| | - Paolo Ermacora
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine I-33100, Italy
| | - Rita Musetti
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine I-33100, Italy
| | - Giuseppe Firrao
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine I-33100, Italy
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17
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Sakurai Y, Baeg K, Lam AYW, Shoji K, Tomari Y, Iwakawa HO. Cell-free reconstitution reveals the molecular mechanisms for the initiation of secondary siRNA biogenesis in plants. Proc Natl Acad Sci U S A 2021; 118:e2102889118. [PMID: 34330830 PMCID: PMC8346886 DOI: 10.1073/pnas.2102889118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Secondary small interfering RNA (siRNA) production, triggered by primary small RNA targeting, is critical for proper development and antiviral defense in many organisms. RNA-dependent RNA polymerase (RDR) is a key factor in this pathway. However, how RDR specifically converts the targets of primary small RNAs into double-stranded RNA (dsRNA) intermediates remains unclear. Here, we develop an in vitro system that allows for dissection of the molecular mechanisms underlying the production of trans-acting siRNAs, a class of plant secondary siRNAs that play roles in organ development and stress responses. We find that a combination of the dsRNA-binding protein, SUPPRESSOR OF GENE SILENCING3; the putative nuclear RNA export factor, SILENCING DEFECTIVE5, primary small RNA, and Argonaute is required for physical recruitment of RDR6 to target RNAs. dsRNA synthesis by RDR6 is greatly enhanced by the removal of the poly(A) tail, which can be achieved by the cleavage at a second small RNA-binding site bearing appropriate mismatches. Importantly, when the complementarity of the base pairing at the second target site is too strong, the small RNA-Argonaute complex remains at the cleavage site, thereby blocking the initiation of dsRNA synthesis by RDR6. Our data highlight the light and dark sides of double small RNA targeting in the secondary siRNA biogenesis.
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Affiliation(s)
- Yuriki Sakurai
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Kyungmin Baeg
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Andy Y W Lam
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Keisuke Shoji
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yukihide Tomari
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan;
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hiro-Oki Iwakawa
- Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan;
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
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18
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Leonetti P, Ghasemzadeh A, Consiglio A, Gursinsky T, Behrens S, Pantaleo V. Endogenous activated small interfering RNAs in virus-infected Brassicaceae crops show a common host gene-silencing pattern affecting photosynthesis and stress response. THE NEW PHYTOLOGIST 2021; 229:1650-1664. [PMID: 32945560 PMCID: PMC7821159 DOI: 10.1111/nph.16932] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/04/2020] [Indexed: 05/14/2023]
Abstract
Viral infections are accompanied by a massive production of small interfering RNAs (siRNAs) of plant origin, such as virus-activated (va)siRNAs, which drive the widespread silencing of host gene expression, and whose effects in plant pathogen interactions remain unknown. By combining phenotyping and molecular analyses, we characterized vasiRNAs that are associated with typical mosaic symptoms of cauliflower mosaic virus infection in two crops, turnip (Brassica rapa) and oilseed rape (Brassica napus), and the reference plant Arabidopsis thaliana. We identified 15 loci in the three infected plant species, whose transcripts originate vasiRNAs. These loci appear to be generally affected by virus infections in Brassicaceae and encode factors that are centrally involved in photosynthesis and stress response, such as Rubisco activase (RCA), senescence-associated protein, heat shock protein HSP70, light harvesting complex, and membrane-related protein CP5. During infection, the expression of these factors is significantly downregulated, suggesting that their silencing is a central component of the plant's response to virus infections. Further findings indicate an important role for 22 nt long vasiRNAs in the plant's endogenous RNA silencing response. Our study considerably enhances knowledge about the new class of vasiRNAs that are triggered in virus-infected plants and will help to advance strategies for the engineering of gene clusters involved in the development of crop diseases.
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Affiliation(s)
- Paola Leonetti
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
| | - Aysan Ghasemzadeh
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
- Department of Plant PathologyFaculty of AgricultureTarbiat Modares UniversityTehran14115‐111Iran
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Arianna Consiglio
- Department of Biomedical SciencesInstitute for Biomedical TechnologiesBari UnitCNRBari70126Italy
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Sven‐Erik Behrens
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Vitantonio Pantaleo
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
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19
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Silva-Martins G, Bolaji A, Moffett P. What does it take to be antiviral? An Argonaute-centered perspective on plant antiviral defense. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6197-6210. [PMID: 32835379 DOI: 10.1093/jxb/eraa377] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
RNA silencing is a major mechanism of constitutive antiviral defense in plants, mediated by a number of proteins, including the Dicer-like (DCL) and Argonaute (AGO) endoribonucleases. Both DCL and AGO protein families comprise multiple members. In particular, the AGO protein family has expanded considerably in different plant lineages, with different family members having specialized functions. Although the general mode of action of AGO proteins is well established, the properties that make different AGO proteins more or less efficient at targeting viruses are less well understood. In this report, we review methodologies used to study AGO antiviral activity and current knowledge about which AGO family members are involved in antiviral defense. In addition, we discuss what is known about the different properties of AGO proteins thought to be associated with this function.
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Affiliation(s)
| | - Ayooluwa Bolaji
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
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20
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Kwon J, Kasai A, Maoka T, Masuta C, Sano T, Nakahara KS. RNA silencing-related genes contribute to tolerance of infection with potato virus X and Y in a susceptible tomato plant. Virol J 2020; 17:149. [PMID: 33032637 PMCID: PMC7542965 DOI: 10.1186/s12985-020-01414-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 09/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In plants, the RNA silencing system functions as an antiviral defense mechanism following its induction with virus-derived double-stranded RNAs. This occurs through the action of RNA silencing components, including Dicer-like (DCL) nucleases, Argonaute (AGO) proteins, and RNA-dependent RNA polymerases (RDR). Plants encode multiple AGOs, DCLs, and RDRs. The functions of these components have been mainly examined in Arabidopsis thaliana and Nicotiana benthamiana. In this study, we investigated the roles of DCL2, DCL4, AGO2, AGO3 and RDR6 in tomato responses to viral infection. For this purpose, we used transgenic tomato plants (Solanum lycopersicum cv. Moneymaker), in which the expression of these genes were suppressed by double-stranded RNA-mediated RNA silencing. METHODS We previously created multiple DCL (i.e., DCL2 and DCL4) (hpDCL2.4) and RDR6 (hpRDR6) knockdown transgenic tomato plants and here additionally did multiple AGO (i.e., AGO2 and AGO3) knockdown plants (hpAGO2.3), in which double-stranded RNAs cognate to these genes were expressed to induce RNA silencing to them. Potato virus X (PVX) and Y (PVY) were inoculated onto these transgenic tomato plants, and the reactions of these plants to the viruses were investigated. In addition to observation of symptoms, viral coat protein and genomic RNA were detected by western and northern blotting and reverse transcription-polymerase chain reaction (RT-PCR). Host mRNA levels were investigated by quantitative RT-PCR. RESULTS Following inoculation with PVX, hpDCL2.4 plants developed a more severe systemic mosaic with leaf curling compared with the other inoculated plants. Systemic necrosis was also observed in hpAGO2.3 plants. Despite the difference in the severity of symptoms, the accumulation of PVX coat protein (CP) and genomic RNA in the uninoculated upper leaves was not obviously different among hpDCL2.4, hpRDR6, and hpAGO2.3 plants and the empty vector-transformed plants. Moneymaker tomato plants were asymptomatic after infection with PVY. However, hpDCL2.4 plants inoculated with PVY developed symptoms, including leaf curling. Consistently, PVY CP was detected in the uninoculated symptomatic upper leaves of hpDCL2.4 plants through western blotting. Of note, PVY CP was rarely detected in other asymptomatic transgenic or wild-type plants. However, PVY was detected in the uninoculated upper leaves of all the inoculated plants using reverse transcription-polymerase chain reactions. These findings indicated that PVY systemically infected asymptomatic Moneymaker tomato plants at a low level (i.e., no detection of CP via western blotting). CONCLUSION Our results indicate that the tomato cultivar Moneymaker is susceptible to PVX and shows mild mosaic symptoms, whereas it is tolerant and asymptomatic to systemic PVY infection with a low virus titer. In contrast, in hpDCL2.4 plants, PVX-induced symptoms became more severe and PVY infection caused symptoms. These results indicate that DCL2, DCL4, or both contribute to tolerance to infection with PVX and PVY. PVY CP and genomic RNA accumulated to a greater extent in DCL2.4-knockdown plants. Hence, the contribution of these DCLs to tolerance to infection with PVY is at least partly attributed to their roles in anti-viral RNA silencing, which controls the multiplication of PVY in tomato plants. The necrotic symptoms observed in the PVX-infected hpAGO2.3 plants suggest that AGO2, AGO3 or both are also distinctly involved in tolerance to infection with PVX.
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Affiliation(s)
- Joon Kwon
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan
| | - Atsushi Kasai
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, 036-8561, Japan
| | - Tetsuo Maoka
- Division of Agro-Environmental Research, Hokkaido Agricultural Research Center, NARO, Sapporo, Hokkaido, 062-8555, Japan
| | - Chikara Masuta
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan.,Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan
| | - Teruo Sano
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, 036-8561, Japan
| | - Kenji S Nakahara
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan. .,Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan.
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21
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Li T, Gonzalez N, Inzé D, Dubois M. Emerging Connections between Small RNAs and Phytohormones. TRENDS IN PLANT SCIENCE 2020; 25:912-929. [PMID: 32381482 DOI: 10.1016/j.tplants.2020.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 05/20/2023]
Abstract
Small RNAs (sRNAs), mainly including miRNAs and siRNAs, are ubiquitous in eukaryotes. sRNAs mostly negatively regulate gene expression via (post-)transcriptional gene silencing through DNA methylation, mRNA cleavage, or translation inhibition. The mechanisms of sRNA biogenesis and function in diverse biological processes, as well as the interactions between sRNAs and environmental factors, like (a)biotic stress, have been deeply explored. Phytohormones are central in the plant's response to stress, and multiple recent studies highlight an emerging role for sRNAs in the direct response to, or the regulation of, plant hormonal pathways. In this review, we discuss recent progress on the unraveling of crossregulation between sRNAs and nine plant hormones.
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Affiliation(s)
- Ting Li
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Nathalie Gonzalez
- INRAE, Université de Bordeaux, UMR1332 Biologie du fruit et Pathologie, F-33882 Villenave d'Ornon cedex, France
| | - Dirk Inzé
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium.
| | - Marieke Dubois
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
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22
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Nigam D, LaTourrette K, Garcia-Ruiz H. Mutations in virus-derived small RNAs. Sci Rep 2020; 10:9540. [PMID: 32533016 PMCID: PMC7293216 DOI: 10.1038/s41598-020-66374-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 05/18/2020] [Indexed: 02/03/2023] Open
Abstract
RNA viruses exist as populations of genome variants. Virus-infected plants accumulate 21–24 nucleotide small interfering RNAs (siRNAs) derived from viral RNA (virus-derived siRNAs) through gene silencing. This paper describes the profile of mutations in virus-derived siRNAs for three members of the family Potyviridae: Turnip mosaic virus (TuMV), Papaya ringspot virus (PRSV) and Wheat streak mosaic virus (WSMV). For TuMV in Arabidopsis thaliana, profiles were obtained for mechanically inoculated rosette leaves and systemically infected cauline leaves and inflorescence. Results are consistent with selection pressure on the viral genome imposed by local and systemic movement. By genetically removing gene silencing in the plant and silencing suppression in the virus, our results showed that antiviral gene silencing imposes selection in viral populations. Mutations in siRNAs derived from a PRSV coat protein transgene in the absence of virus replication showed the contribution of cellular RNA-dependent RNA polymerases to the generation of mutations in virus-derived siRNAs. Collectively, results are consistent with two sources of mutations in virus-derived siRNAs: viral RNA-dependent RNA polymerases responsible for virus replication and cellular RNA-dependent RNA polymerases responsible for gene silencing amplification.
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Affiliation(s)
- Deepti Nigam
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Nebraska, United States of America
| | - Katherine LaTourrette
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Nebraska, United States of America
| | - Hernan Garcia-Ruiz
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Nebraska, United States of America.
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23
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Cisneros AE, Carbonell A. Artificial Small RNA-Based Silencing Tools for Antiviral Resistance in Plants. PLANTS 2020; 9:plants9060669. [PMID: 32466363 PMCID: PMC7356032 DOI: 10.3390/plants9060669] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/05/2023]
Abstract
Artificial small RNAs (art-sRNAs), such as artificial microRNAs (amiRNAs) and synthetic trans-acting small interfering RNAs (syn-tasiRNAs), are highly specific 21-nucleotide small RNAs designed to recognize and silence complementary target RNAs. Art-sRNAs are extensively used in gene function studies or for improving crops, particularly to protect plants against viruses. Typically, antiviral art-sRNAs are computationally designed to target one or multiple sites in viral RNAs with high specificity, and art-sRNA constructs are generated and introduced into plants that are subsequently challenged with the target virus(es). Numerous studies have reported the successful application of art-sRNAs to induce resistance against a large number of RNA and DNA viruses in model and crop species. However, the application of art-sRNAs as an antiviral tool has limitations, such as the difficulty to predict the efficacy of a particular art-sRNA or the emergence of virus variants with mutated target sites escaping to art-sRNA-mediated degradation. Here, we review the different classes, features, and uses of art-sRNA-based tools to induce antiviral resistance in plants. We also provide strategies for the rational design of antiviral art-sRNAs and discuss the latest advances in developing art-sRNA-based methodologies for enhanced resistance to plant viruses.
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Abstract
Protection against microbial infection in eukaryotes is provided by diverse cellular and molecular mechanisms. Here, we present a comparative view of the antiviral activity of virus-derived small interfering RNAs in fungi, plants, invertebrates and mammals, detailing the mechanisms for their production, amplification and activity. We also highlight the recent discovery of viral PIWI-interacting RNAs in animals and a new role for mobile host and pathogen small RNAs in plant defence against eukaryotic pathogens. In turn, viruses that infect plants, insects and mammals, as well as eukaryotic pathogens of plants, have evolved specific virulence proteins that suppress RNA interference (RNAi). Together, these advances suggest that an antimicrobial function of the RNAi pathway is conserved across eukaryotic kingdoms.
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25
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Gago-Zachert S, Schuck J, Weinholdt C, Knoblich M, Pantaleo V, Grosse I, Gursinsky T, Behrens SE. Highly efficacious antiviral protection of plants by small interfering RNAs identified in vitro. Nucleic Acids Res 2019; 47:9343-9357. [PMID: 31433052 PMCID: PMC6755098 DOI: 10.1093/nar/gkz678] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 06/21/2019] [Accepted: 08/02/2019] [Indexed: 01/09/2023] Open
Abstract
In response to a viral infection, the plant’s RNA silencing machinery processes viral RNAs into a huge number of small interfering RNAs (siRNAs). However, a very few of these siRNAs actually interfere with viral replication. A reliable approach to identify these immunologically effective siRNAs (esiRNAs) and to define the characteristics underlying their activity has not been available so far. Here, we develop a novel screening approach that enables a rapid functional identification of antiviral esiRNAs. Tests on the efficacy of such identified esiRNAs of a model virus achieved a virtual full protection of plants against a massive subsequent infection in transient applications. We find that the functionality of esiRNAs depends crucially on two properties: the binding affinity to Argonaute proteins and the ability to access the target RNA. The ability to rapidly identify functional esiRNAs could be of great benefit for all RNA silencing-based plant protection measures against viruses and other pathogens.
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Affiliation(s)
- Selma Gago-Zachert
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany.,Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Halle/Saale D-06120, Germany
| | - Jana Schuck
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
| | - Claus Weinholdt
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
| | - Marie Knoblich
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
| | - Vitantonio Pantaleo
- Institute for Sustainable Plant Protection-Consiglio Nazionale delle Ricerche, Research Unit of Bari, Bari I-70126, Italy
| | - Ivo Grosse
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig D-04103, Germany
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
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26
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Abstract
Plant virus genome replication and movement is dependent on host resources and factors. However, plants respond to virus infection through several mechanisms, such as autophagy, ubiquitination, mRNA decay and gene silencing, that target viral components. Viral factors work in synchrony with pro-viral host factors during the infection cycle and are targeted by antiviral responses. Accordingly, establishment of virus infection is genetically determined by the availability of the pro-viral factors necessary for genome replication and movement, and by the balance between plant defence and viral suppression of defence responses. Sequential requirement of pro-viral factors and the antagonistic activity of antiviral factors suggest a two-step model to explain plant-virus interactions. At each step of the infection process, host factors with antiviral activity have been identified. Here we review our current understanding of host factors with antiviral activity against plant viruses.
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Affiliation(s)
- Hernan Garcia‐Ruiz
- Nebraska Center for Virology, Department of Plant PathologyUniversity of Nebraska‐LincolnLincolnNE68503USA
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27
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Huang YW, Hu CC, Tsai CH, Lin NS, Hsu YH. Nicotiana benthamiana Argonaute10 plays a pro-viral role in Bamboo mosaic virus infection. THE NEW PHYTOLOGIST 2019; 224:804-817. [PMID: 31283838 DOI: 10.1111/nph.16048] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/28/2019] [Indexed: 05/16/2023]
Abstract
RNA silencing is a major defense mechanism against invading viruses in plants. Argonaute proteins (AGOs) are the key players in RNA silencing. The number of AGO family members involved varies depending on the plant species and they play distinct or sometimes redundant roles in antiviral defense. By using a virus-induced gene silencing technique, it was found that Nicotiana benthamiana AGO1 restricted Bamboo mosaic virus (BaMV) accumulation, but NbAGO10, the closest paralog of NbAGO1, positively regulated BaMV accumulation. Immunoprecipitation assay revealed BaMV virus-derived small interfering RNAs (vsiRNAs) in NbAGO10 complexes. Transient overexpression of NbAGO10 increased BaMV RNA accumulation, but with co-expression of NbAGO1, BaMV RNA accumulation was reduced, which suggests that NbAGO10 may have competed with NbAGO1 for sequestering BaMV vsiRNA and prevented the formation of RNA-induced silencing complexes. In addition, overexpression of NbAGO10 decreased BaMV vsiRNA accumulation. A host enzyme, small RNA degrading nuclease 1 (SDN1), also was found to interact with NbAGO10 on in vivo pull-down assay. Silencing of SDN1 elevated BaMV vsiRNA level and decreased BaMV RNA accumulation in N. benthamiana, indicating that NbAGO10 might recruit SDN1 for BaMV vsiRNA degradation. The results herein suggested that NbAGO10 plays a pro-viral role by BaMV vsiRNA sequestration and degradation.
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Affiliation(s)
- Ying Wen Huang
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chung Chi Hu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Ching Hsiu Tsai
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Na Sheng Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Yau Heiu Hsu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
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28
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Zheng X, Fahlgren N, Abbasi A, Berry JC, Carrington JC. Antiviral ARGONAUTEs Against Turnip Crinkle Virus Revealed by Image-Based Trait Analysis. PLANT PHYSIOLOGY 2019; 180:1418-1435. [PMID: 31043494 PMCID: PMC6752898 DOI: 10.1104/pp.19.00121] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/21/2019] [Indexed: 05/18/2023]
Abstract
RNA-based silencing functions as an important antiviral immunity mechanism in plants. Plant viruses evolved to encode viral suppressors of RNA silencing (VSRs) that interfere with the function of key components in the silencing pathway. As effectors in the RNA silencing pathway, ARGONAUTE (AGO) proteins are targeted by some VSRs, such as that encoded by Turnip crinkle virus (TCV). A VSR-deficient TCV mutant was used to identify AGO proteins with antiviral activities during infection. A quantitative phenotyping protocol using an image-based color trait analysis pipeline on the PlantCV platform, with temporal red, green, and blue imaging and a computational segmentation algorithm, was used to measure plant disease after TCV inoculation. This process captured and analyzed growth and leaf color of Arabidopsis (Arabidopsis thaliana) plants in response to virus infection over time. By combining this quantitative phenotypic data with molecular assays to detect local and systemic virus accumulation, AGO2, AGO3, and AGO7 were shown to play antiviral roles during TCV infection. In leaves, AGO2 and AGO7 functioned as prominent nonadditive, anti-TCV effectors, whereas AGO3 played a minor role. Other AGOs were required to protect inflorescence tissues against TCV. Overall, these results indicate that distinct AGO proteins have specialized, modular roles in antiviral defense across different tissues, and demonstrate the effectiveness of image-based phenotyping to quantify disease progression.
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Affiliation(s)
- Xingguo Zheng
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Noah Fahlgren
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Arash Abbasi
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Jeffrey C Berry
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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29
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Wang Z, Wang Y, Liu T, Wang Y, Zhang W. Effects of the PIWI/MID domain of Argonaute protein on the association of miRNAi's seed base with the target. RNA (NEW YORK, N.Y.) 2019; 25:620-629. [PMID: 30770397 PMCID: PMC6467011 DOI: 10.1261/rna.069328.118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 02/01/2019] [Indexed: 05/24/2023]
Abstract
The small interfering RNAs (siRNA) or microRNAs (miRNA) incorporated into the RNA-induced silencing complex with the Argonaute (Ago) protein associates with target mRNAs through base-pairing, which leads to the cleavage or knockdown of the target mRNA. The seed region of the s(m)iRNA is crucial for target recognition. In this work, a molecular dynamic simulation was utilized to study the thermodynamics and kinetic properties of the third seed base binding to the target in the presence of the PIWI/MID domain of Ago. The results showed that in the presence of the PIWI/MID domain, the entropy and enthalpy changes for the association of the seed base with the target were smaller than those in the absence of protein. The binding affinity was increased due to the reduced entropy penalty, which resulted from the preorganization of the seed base into the A-helix form. In the presence of the protein, the association barrier resulting from the unfavorable entropy loss and the dissociation barrier coming from the destruction of hydrogen bonding and base-stacking interactions were lower than those in the absence of the protein. These results indicate that the seed region is crucial for fast recognition and association with the correct target.
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Affiliation(s)
- Zhen Wang
- Department of Physics, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Yanli Wang
- Department of Physics, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Taigang Liu
- Department of Physics, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Yujie Wang
- Department of Physics, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Wenbing Zhang
- Department of Physics, Wuhan University, Wuhan, Hubei 430072, P.R. China
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30
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Xia Z, Zhao Z, Jiao Z, Xu T, Wu Y, Zhou T, Fan Z. Virus-Derived Small Interfering RNAs Affect the Accumulations of Viral and Host Transcripts in Maize. Viruses 2018; 10:v10120664. [PMID: 30477197 PMCID: PMC6315483 DOI: 10.3390/v10120664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 12/18/2022] Open
Abstract
RNA silencing is a conserved surveillance mechanism against invading viruses in plants, which involves the production of virus-derived small interfering RNAs (vsiRNAs) that play essential roles in the silencing of viral RNAs and/or specific host transcripts. However, how vsiRNAs function to target viral and/or host transcripts is poorly studied, especially in maize (Zea mays L.). In this study, a degradome library constructed from Sugarcane mosaic virus (SCMV)-inoculated maize plants was analyzed to identify the cleavage sites in viral and host transcripts mainly produced by vsiRNAs. The results showed that 42 maize transcripts were possibly cleaved by vsiRNAs, among which several were involved in chloroplast functions and in biotic and abiotic stresses. In addition, more than 3000 cleavage sites possibly produced by vsiRNAs were identified in positive-strand RNAs of SCMV, while there were only four cleavage sites in the negative-strand RNAs. To determine the roles of vsiRNAs in targeting viral RNAs, six vsiRNAs were expressed in maize protoplast based on artificial microRNAs (amiRNAs), of which four could efficiently inhibit the accumulations of SCMV RNAs. These results provide new insights into the genetic manipulation of maize with resistance against virus infection by using amiRNA as a more predictable and useful approach.
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Affiliation(s)
- Zihao Xia
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
| | - Zhenxing Zhao
- State Key Laboratory of Agro-Biotechnology and Key Laboratory of Pest Monitoring and Green Management-MOA, China Agricultural University, Beijing 100193, China.
| | - Zhiyuan Jiao
- State Key Laboratory of Agro-Biotechnology and Key Laboratory of Pest Monitoring and Green Management-MOA, China Agricultural University, Beijing 100193, China.
| | - Tengzhi Xu
- State Key Laboratory of Agro-Biotechnology and Key Laboratory of Pest Monitoring and Green Management-MOA, China Agricultural University, Beijing 100193, China.
| | - Yuanhua Wu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
| | - Tao Zhou
- State Key Laboratory of Agro-Biotechnology and Key Laboratory of Pest Monitoring and Green Management-MOA, China Agricultural University, Beijing 100193, China.
| | - Zaifeng Fan
- State Key Laboratory of Agro-Biotechnology and Key Laboratory of Pest Monitoring and Green Management-MOA, China Agricultural University, Beijing 100193, China.
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31
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Pooggin MM. Small RNA-Omics for Plant Virus Identification, Virome Reconstruction, and Antiviral Defense Characterization. Front Microbiol 2018; 9:2779. [PMID: 30524398 PMCID: PMC6256188 DOI: 10.3389/fmicb.2018.02779] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/30/2018] [Indexed: 11/13/2022] Open
Abstract
RNA interference (RNAi)-based antiviral defense generates small interfering RNAs that represent the entire genome sequences of both RNA and DNA viruses as well as viroids and viral satellites. Therefore, deep sequencing and bioinformatics analysis of small RNA population (small RNA-ome) allows not only for universal virus detection and genome reconstruction but also for complete virome reconstruction in mixed infections. Viral infections (like other stress factors) can also perturb the RNAi and gene silencing pathways regulating endogenous gene expression and repressing transposons and host genome-integrated endogenous viral elements which can potentially be released from the genome and contribute to disease. This review describes the application of small RNA-omics for virus detection, virome reconstruction and antiviral defense characterization in cultivated and non-cultivated plants. Reviewing available evidence from a large and ever growing number of studies of naturally or experimentally infected hosts revealed that all families of land plant viruses, their satellites and viroids spawn characteristic small RNAs which can be assembled into contigs of sufficient length for virus, satellite or viroid identification and for exhaustive reconstruction of complex viromes. Moreover, the small RNA size, polarity and hotspot profiles reflect virome interactions with the plant RNAi machinery and allow to distinguish between silent endogenous viral elements and their replicating episomal counterparts. Models for the biogenesis and functions of small interfering RNAs derived from all types of RNA and DNA viruses, satellites and viroids as well as endogenous viral elements are presented and discussed.
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Affiliation(s)
- Mikhail M. Pooggin
- Institut National de la Recherche Agronomique, UMR BGPI, Montpellier, France
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32
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Lee CH, Carroll BJ. Evolution and Diversification of Small RNA Pathways in Flowering Plants. PLANT & CELL PHYSIOLOGY 2018; 59:2169-2187. [PMID: 30169685 DOI: 10.1093/pcp/pcy167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/30/2018] [Indexed: 06/08/2023]
Abstract
Small regulatory RNAs guide gene silencing at the DNA or RNA level through repression of complementary sequences. The two main forms of small RNAs are microRNA (miRNA) and small interfering RNA (siRNAs), which are generated from the processing of different forms of double-stranded RNA (dsRNA) precursors. These two forms of small regulatory RNAs function in distinct but overlapping gene silencing pathways in plants. Gene silencing pathways in eukaryotes evolved from an ancient prokaryotic mechanism involved in genome defense against invasive genetic elements, but has since diversified to also play a crucial role in regulation of endogenous gene expression. Here, we review the biogenesis of the different forms of small RNAs in plants, including miRNAs, phased, secondary siRNAs (phasiRNAs) and heterochromatic siRNAs (hetsiRNAs), with a focus on their functions in genome defense, transcriptional and post-transcriptional gene silencing, RNA-directed DNA methylation, trans-chromosomal methylation and paramutation. We also discuss the important role that gene duplication has played in the functional diversification of gene silencing pathways in plants, and we highlight recently discovered components of gene silencing pathways in plants.
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Affiliation(s)
- Chin Hong Lee
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
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33
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Paudel DB, Ghoshal B, Jossey S, Ludman M, Fatyol K, Sanfaçon H. Expression and antiviral function of ARGONAUTE 2 in Nicotiana benthamiana plants infected with two isolates of tomato ringspot virus with varying degrees of virulence. Virology 2018; 524:127-139. [PMID: 30195250 DOI: 10.1016/j.virol.2018.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/16/2018] [Accepted: 08/19/2018] [Indexed: 11/23/2022]
Abstract
ARGONAUTEs (notably AGO1 and AGO2) are effectors of plant antiviral RNA silencing. AGO1 was shown to be required for the temperature-dependent symptom recovery of Nicotiana benthamiana plants infected with tomato ringspot virus (isolate ToRSV-Rasp1) at 27 °C. In this study, we show that symptom recovery from isolate ToRSV-GYV shares similar hallmarks of antiviral RNA silencing but occurs at a wider range of temperatures (21-27 °C). At 21 °C, an early spike in AGO2 mRNAs accumulation was observed in plants infected with either ToRSV-Rasp1 or ToRSV-GYV but the AGO2 protein was only consistently detected in ToRSV-GYV infected plants. Symptom recovery from ToRSV-GYV at 21 °C was not prevented in an ago2 mutant or by silencing of AGO1 or AGO2. We conclude that other factors (possibly other AGOs) contribute to symptom recovery under these conditions. The results also highlight distinct expression patterns of AGO2 in response to ToRSV isolates and environmental conditions.
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Affiliation(s)
- Dinesh Babu Paudel
- Dept of Botany, University of British Columbia, 3529-6270 University Blvd, Vancouver, BC, Canada V6T 1Z4
| | - Basudev Ghoshal
- Dept of Botany, University of British Columbia, 3529-6270 University Blvd, Vancouver, BC, Canada V6T 1Z4
| | - Sushma Jossey
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, PO Box 5000, 4200 Highway 97, Summerland, BC, Canada V0H 1Z0
| | - Marta Ludman
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Center, Szent-Györgyi Albert u. 4, Gödöllő 2100, Hungary
| | - Karoly Fatyol
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Center, Szent-Györgyi Albert u. 4, Gödöllő 2100, Hungary
| | - Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, PO Box 5000, 4200 Highway 97, Summerland, BC, Canada V0H 1Z0.
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34
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Li Z, Zhang T, Huang X, Zhou G. Impact of Two Reoviruses and Their Coinfection on the Rice RNAi System and vsiRNA Production. Viruses 2018; 10:v10110594. [PMID: 30380782 PMCID: PMC6267445 DOI: 10.3390/v10110594] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/20/2018] [Accepted: 10/27/2018] [Indexed: 12/13/2022] Open
Abstract
Both Southern rice black-streaked dwarf virus (SRBSDV) and Rice ragged stunt virus (RRSV) belong to the family Reoviridae, and synergistic infection of these two viruses commonly occurs in the field. This study revealed that both SRBSDV and RRSV affect the RNA interference (RNAi) pathway and form different virus-derived interfering RNA (vsiRNA) profiles in rice. Co-infection of rice by SRBSDV and RRSV up-regulated the expression of rice DICER-like (DCL) proteins but down-regulated the expression of rice RNA-dependent RNA polymerases (RDRs), and the accumulation of vsiRNAs of either RBSDV or RRSV was decreased compared with that in singly infected plants. The majority of SRBSDV vsiRNAs were 21 nt or 22 nt in length, whether plants were singly infected with SRBSDV or co-infected with RRSV. On the other hand, the majority of RRSV vsiRNAs were 20 nt, 21 nt, or 22 nt in length, among which those 20 nt in length accounted for the largest proportion; co-infection with SRBSDV further increased the proportion of 20 nt vsiRNAs and decreased the proportion of 21 nt vsiRNAs. Co-infection had no effects on the strand favoritism and hot spots of the vsiRNAs, but changed the bias of the 5′ terminal nucleotide significantly. This study provides a reference for further study on the pathogenesis and synergistic mechanism of SRBSDV and RRSV.
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Affiliation(s)
- Zhanbiao Li
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
- Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China.
| | - Tong Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
- Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China.
| | - Xiuqin Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
- Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China.
| | - Guohui Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
- Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China.
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35
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Chiumenti M, Catacchio CR, Miozzi L, Pirovano W, Ventura M, Pantaleo V. A Short Indel-Lacking-Resistance Gene Triggers Silencing of the Photosynthetic Machinery Components Through TYLCSV-Associated Endogenous siRNAs in Tomato. FRONTIERS IN PLANT SCIENCE 2018; 9:1470. [PMID: 30364213 PMCID: PMC6193080 DOI: 10.3389/fpls.2018.01470] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 09/19/2018] [Indexed: 05/27/2023]
Abstract
Plant viruses modify gene expression in infected tissues by altering the micro (mi)RNA-mediated regulation of genes. Among conserved miRNA targets there are transcripts coding for transcription factors, RNA silencing core, and disease-resistance proteins. Paralogs in these gene families are widely present in plant genomes and are known to respond differently to miRNA-mediated regulation during plant virus infections. Using genome-wide approaches applied to Solanum lycopersicum infected by a nuclear-replicating virus, we highlighted miRNA-mediated cleavage events that could not be revealed in virus-free systems. Among them we confirmed miR6024 targeting and cleavage of RX-coiled-coil (RX-CC), nucleotide binding site (NBS), leucine-rich (LRR) mRNA. Cleavage of paralogs was associated with short indels close to the target sites, indicating a general functional significance of indels in fine-tuning gene expression in plant-virus interaction. miR6024-mediated cleavage, uniquely in virus-infected tissues, triggers the production of several 21-22 nt secondary siRNAs. These secondary siRNAs, rather than being involved in the cascade regulation of other NBS-LRR paralogs, explained cleavages of several mRNAs annotated as defence-related proteins and components of the photosynthetic machinery. Outputs of these data explain part of the phenotype plasticity in plants, including the appearance of yellowing symptoms in the viral pathosystem.
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Affiliation(s)
- Michela Chiumenti
- Institute for Sustainable Plant Protection of the National Research Council, Research Unit of Bari, Bari, Italy
| | | | - Laura Miozzi
- Institute for Sustainable Plant Protection of the National Research Council, Research Unit of Turin, Turin, Italy
| | | | - Mario Ventura
- Dipartimento di Biologia, Università degli Studi di Bari Aldo Moro, Bari, Italy
| | - Vitantonio Pantaleo
- Institute for Sustainable Plant Protection of the National Research Council, Research Unit of Bari, Bari, Italy
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Turco S, Golyaev V, Seguin J, Gilli C, Farinelli L, Boller T, Schumpp O, Pooggin MM. Small RNA-Omics for Virome Reconstruction and Antiviral Defense Characterization in Mixed Infections of Cultivated Solanum Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:707-723. [PMID: 29424662 DOI: 10.1094/mpmi-12-17-0301-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In plants, RNA silencing-based antiviral defense generates viral small RNAs (sRNAs) faithfully representing the viral genomes. We employed sRNA sequencing and bioinformatics (sRNA-omics) to characterize antiviral defense and to reconstruct the full genomic sequences and their variants in the evolving viral quasispecies in cultivated solanaceous plants carrying mixed infections. In naturally infected Solanum tuberosum (potato), one case study revealed a virome comprising Potato virus Y (genus Potyvirus) and Potato virus X (genus Potexvirus), which was reconstructed by de novo-assembling separate genome-size sRNA contigs. Another case study revealed a virome comprising NTN and O strains of Potato virus Y, whose sRNAs assembled in chimeric contigs, which could be disentangled on the basis of reference genome sequences. Both viromes were stable in vegetative potato progeny. In a cross-protection trial of Solanum lycopersicum (tomato), the supposedly protective mild strain CH2 of Pepino mosaic virus (genus Potexvirus) was tested for protection against strain LP of the same virus. Reciprocal mechanical inoculations eventually resulted in co-infection of all individual plants with CH2 and LP strains, reconstructed as separate sRNA contigs. LP invasions into CH2-preinfected plants and vice versa were accompanied by alterations of consensus genome sequences in viral quasispecies, indicating a potential risk of cross-protection measures. Additionally, the study also revealed, by reconstruction from sRNAs, the presence of the mechanically nontransmissible Southern tomato virus (genus Amalgavirus) in some plants. Our in-depth analysis of sRNA sizes, 5'-nucleotide frequencies and hotspot maps revealed similarities in sRNA-generating mechanisms in potato and tomato, differential silencing responses to virome components and potential for sRNA-directed cross-targeting between viral strains which could not, however, prevent the formation of stable viromes.
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Affiliation(s)
- Silvia Turco
- 1 Department of Environmental Sciences, Botany, Zurich-Basel Plant Science Center, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
| | - Victor Golyaev
- 1 Department of Environmental Sciences, Botany, Zurich-Basel Plant Science Center, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
| | - Jonathan Seguin
- 1 Department of Environmental Sciences, Botany, Zurich-Basel Plant Science Center, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
| | | | | | - Thomas Boller
- 1 Department of Environmental Sciences, Botany, Zurich-Basel Plant Science Center, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
| | | | - Mikhail M Pooggin
- 1 Department of Environmental Sciences, Botany, Zurich-Basel Plant Science Center, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
- 5 INRA, UMR BGPI, 34398 Montpellier, France
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Pertermann R, Tamilarasan S, Gursinsky T, Gambino G, Schuck J, Weinholdt C, Lilie H, Grosse I, Golbik RP, Pantaleo V, Behrens SE. A Viral Suppressor Modulates the Plant Immune Response Early in Infection by Regulating MicroRNA Activity. mBio 2018; 9:e00419-18. [PMID: 29691336 PMCID: PMC5915741 DOI: 10.1128/mbio.00419-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/28/2018] [Indexed: 02/06/2023] Open
Abstract
Many viral suppressors (VSRs) counteract antiviral RNA silencing, a central component of the plant's immune response by sequestration of virus-derived antiviral small interfering RNAs (siRNAs). Here, we addressed how VSRs affect the activities of cellular microRNAs (miRNAs) during a viral infection by characterizing the interactions of two unrelated VSRs, the Tombusvirus p19 and the Cucumovirus 2b, with miRNA 162 (miR162), miR168, and miR403. These miRNAs regulate the expression of the important silencing factors Dicer-like protein 1 (DCL1) and Argonaute proteins 1 and 2 (AGO1 and AGO2), respectively. Interestingly, while the two VSRs showed similar binding profiles, the miRNAs were bound with significantly different affinities, for example, with the affinity of miR162 greatly exceeding that of miR168. In vitro silencing experiments revealed that p19 and 2b affect miRNA-mediated silencing of the DCL1, AGO1, and AGO2 mRNAs in strict accordance with the VSR's miRNA-binding profiles. In Tombusvirus-infected plants, the miRNA-binding behavior of p19 closely corresponded to that in vitro Most importantly, in contrast to controls with a Δp19 virus, infections with wild-type (wt) virus led to changes of the levels of the miRNA-targeted mRNAs, and these changes correlated with the miRNA-binding preferences of p19. This was observed exclusively in the early stage of infection when viral genomes are proposed to be susceptible to silencing and viral siRNA (vsiRNA) concentrations are low. Accordingly, our study suggests that differential binding of miRNAs by VSRs is a widespread viral mechanism to coordinately modulate cellular gene expression and the antiviral immune response during infection initiation.IMPORTANCE Plant viruses manipulate their hosts in various ways. Viral suppressor proteins (VSRs) interfere with the plant's immune response by sequestering small, antivirally acting vsiRNAs, which are processed from viral RNAs during the plant's RNA-silencing response. Here, we examined the effects of VSRs on cellular microRNAs (miRNAs), which show a high degree of similarity with vsiRNAs. Binding experiments with two unrelated VSRs and three important regulatory miRNAs revealed that the proteins exhibit similar miRNA-binding profiles but bind different miRNAs at considerably different affinities. Most interestingly, experiments in plants showed that in the early infection phase, the Tombusvirus VSR p19 modulates the activity of these miRNAs on their target mRNAs very differently and that this differential regulation strictly correlates with the binding affinities of p19 for the respective miRNAs. Our data suggest that VSRs may specifically control plant gene expression and the early immune response by differential sequestration of miRNAs.
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Affiliation(s)
- Robert Pertermann
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Selvaraj Tamilarasan
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Giorgio Gambino
- Institute for Sustainable Plant Protection-Consiglio Nazionale delle Ricerche, Turin, Italy
| | - Jana Schuck
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Claus Weinholdt
- Institute of Informatics, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Hauke Lilie
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Ivo Grosse
- Institute of Informatics, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Ralph Peter Golbik
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Vitantonio Pantaleo
- Institute for Sustainable Plant Protection-Consiglio Nazionale delle Ricerche, Research Unit of Bari, Bari, Italy
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
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Tomato Spotted Wilt Virus NSs Protein Supports Infection and Systemic Movement of a Potyvirus and Is a Symptom Determinant. Viruses 2018. [PMID: 29538326 PMCID: PMC5869522 DOI: 10.3390/v10030129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Plant viruses are inducers and targets of antiviral RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressor proteins that interfere with antiviral RNA silencing. The NSs protein is an RNA silencing suppressor in orthotospoviruses, such as the tomato spotted wilt virus (TSWV). The mechanism of RNA silencing suppression by NSs and its role in virus infection and movement are poorly understood. Here, we cloned and tagged TSWV NSs and expressed it from a GFP-tagged turnip mosaic virus (TuMV-GFP) carrying either a wild-type or suppressor-deficient (AS9) helper component proteinase (HC-Pro). When expressed in cis, NSs restored pathogenicity and promoted systemic infection of suppressor-deficient TuMV-AS9-GFP in Nicotiana benthamiana and Arabidopsis thaliana. Inactivating mutations were introduced in NSs RNA-binding domain one. A genetic analysis with active and suppressor-deficient NSs, in combination with wild-type and mutant plants lacking essential components of the RNA silencing machinery, showed that the NSs insert is stable when expressed from a potyvirus. NSs can functionally replace potyviral HC-Pro, condition virus susceptibility, and promote systemic infection and symptom development by suppressing antiviral RNA silencing through a mechanism that partially overlaps that of potyviral HC-Pro. The results presented provide new insight into the mechanism of silencing suppression by NSs and its effect on virus infection.
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Odokonyero D, Mendoza MR, Moffett P, Scholthof HB. Tobacco rattle virus (TRV)-Mediated Silencing of Nicotiana benthamiana ARGONAUTES (NbAGOs) Reveals New Antiviral Candidates and Dominant Effects of TRV-NbAGO1. PHYTOPATHOLOGY 2017; 107:977-987. [PMID: 28636437 DOI: 10.1094/phyto-02-17-0049-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The objective of this study was to determine the contribution of different ARGONAUTE proteins in Nicotiana benthamiana (NbAGOs) to the defense against silencing sensitive GFP-expressing viral constructs based on Tomato bushy stunt virus (TBSV) (Tombusvirus), Sunn-hemp mosaic virus (Tobamovirus), and Foxtail mosaic virus (Potexvirus). Upon Tobacco rattle virus (TRV)-mediated down-regulation of NbAGO1, 4, 5, or 6, no effects were noted on susceptibility to any virus construct, whereas knockdown of NbAGO2 specifically prevented silencing of P19-defective TBSV (TGdP19). Down-regulation of a new gene referred to as NbAGO5L showed some reduced silencing for TGdP19 but not for the other two virus constructs, whereas silencing of NbAGO7 gave rise to a subtle increase in susceptibility to all three viruses. Co-infiltrating different TRV-NbAGO constructs simultaneously did not enhance virus susceptibility. However, an unexpected finding was that whenever the TRV-NbAGO1 construct was present, this compromised silencing of genes targeted by co-infiltrated constructs, as shown upon co-infiltration of TRV-NbAGO1 with either TRV-NbAGO2 or TRV-Sul (targeting Magnesium chelatase I). Only after a prolonged period (approximately 2 months) did TRV-Sul-mediated systemic bleaching occur in these co-infected plants, suggesting that TRV-NbAGO1 hinders the silencing ability of other TRV-NbAGO constructs. In conclusion, this study revealed new antiviral NbAGOs and dominant effects of silencing NbAGO1.
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Affiliation(s)
- Denis Odokonyero
- First, second, and fourth authors: Department of Plant Pathology and Microbiology, Texas A&M University, College Station; and third author: Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Maria R Mendoza
- First, second, and fourth authors: Department of Plant Pathology and Microbiology, Texas A&M University, College Station; and third author: Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Peter Moffett
- First, second, and fourth authors: Department of Plant Pathology and Microbiology, Texas A&M University, College Station; and third author: Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Herman B Scholthof
- First, second, and fourth authors: Department of Plant Pathology and Microbiology, Texas A&M University, College Station; and third author: Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Kovalev N, Inaba JI, Li Z, Nagy PD. The role of co-opted ESCRT proteins and lipid factors in protection of tombusviral double-stranded RNA replication intermediate against reconstituted RNAi in yeast. PLoS Pathog 2017; 13:e1006520. [PMID: 28759634 PMCID: PMC5552349 DOI: 10.1371/journal.ppat.1006520] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 08/10/2017] [Accepted: 07/07/2017] [Indexed: 01/28/2023] Open
Abstract
Reconstituted antiviral defense pathway in surrogate host yeast is used as an intracellular probe to further our understanding of virus-host interactions and the role of co-opted host factors in formation of membrane-bound viral replicase complexes in protection of the viral RNA against ribonucleases. The inhibitory effect of the RNA interference (RNAi) machinery of S. castellii, which only consists of the two-component DCR1 and AGO1 genes, was measured against tomato bushy stunt virus (TBSV) in wild type and mutant yeasts. We show that deletion of the co-opted ESCRT-I (endosomal sorting complexes required for transport I) or ESCRT-III factors makes TBSV replication more sensitive to the RNAi machinery in yeast. Moreover, the lack of these pro-viral cellular factors in cell-free extracts (CFEs) used for in vitro assembly of the TBSV replicase results in destruction of dsRNA replication intermediate by a ribonuclease at the 60 min time point when the CFE from wt yeast has provided protection for dsRNA. In addition, we demonstrate that co-opted oxysterol-binding proteins and membrane contact sites, which are involved in enrichment of sterols within the tombusvirus replication compartment, are required for protection of viral dsRNA. We also show that phosphatidylethanolamine level influences the formation of RNAi-resistant replication compartment. In the absence of peroxisomes in pex3Δ yeast, TBSV subverts the ER membranes, which provide as good protection for TBSV dsRNA against RNAi or ribonucleases as the peroxisomal membranes in wt yeast. Altogether, these results demonstrate that co-opted protein factors and usurped lipids are exploited by tombusviruses to build protective subcellular environment against the RNAi machinery and possibly other cellular ribonucleases. Positive-strand RNA viruses build membranous replication compartment to support their replication in the infected hosts. One of the proposed functions of the usurped subcellular membranes is to protect the viral RNA from recognition and destruction by various cellular RNA sensors and ribonucleases. To answer this fundamental question on the putative role of co-opted host factors and membranes in protecting the viral double-stranded RNA replication intermediate during replication, the authors took advantage of yeast (Saccharomyces cerevisiae), which lacks the conserved RNAi machinery, as a surrogate host for TBSV. The reconstituted RNAi machinery from S. castellii in S. cerevisiae was used as an intracellular probe to study the effect of various co-opted cellular proteins and lipids on the formation of RNAi-insensitive replication compartment. Overall, the authors demonstrate the interaction between the RNAi machinery and the viral replicase complex, and the essential roles of usurped host factors in protecting the viral dsRNA replication intermediate from RNAi-based degradation.
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Affiliation(s)
- Nikolay Kovalev
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jun-ichi Inaba
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhenghe Li
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
- Institute of Biotechnology, State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, P. R. China
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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Zhou B, Zeng L. Elucidating the role of highly homologous Nicotiana benthamiana ubiquitin E2 gene family members in plant immunity through an improved virus-induced gene silencing approach. PLANT METHODS 2017; 13:59. [PMID: 28736574 PMCID: PMC5521103 DOI: 10.1186/s13007-017-0210-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/17/2017] [Indexed: 05/29/2023]
Abstract
BACKGROUND Virus-induced gene silencing (VIGS) has been used in many plant species as an attractive post transcriptional gene silencing (PTGS) method for studying gene function either individually or at large-scale in a high-throughput manner. However, the specificity and efficiency for knocking down members of a highly homologous gene family have remained to date a significant challenge in VIGS due to silencing of off-targets. RESULTS Here we present an improved method for the selection and evaluation of gene fragments used for VIGS to specifically and efficiently knock down members of a highly homologous gene family. Using this method, we knocked down twelve and four members, respectively of group III of the gene family encoding ubiquitin-conjugating enzymes (E2) in Nicotiana benthamiana. Assays using these VIGS-treated plants revealed that the group III E2s are essential for plant development, plant immunity-associated reactive oxygen species (ROS) production, expression of the gene NbRbohB that is required for ROS production, and suppression of immunity-associated programmed cell death (PCD) by AvrPtoB, an effector protein of the bacterial pathogen Pseudomons syringae. Moreover, functional redundancy for plant development and ROS production was found to exist among members of group III E2s. CONCLUSIONS We have found that employment of a gene fragment as short as approximately 70 base pairs (bp) that contains at least three mismatched nucleotides to other genes within any 21-bp sequences prevents silencing of off-target(s) in VIGS. This improved approach in the selection and evaluation of gene fragments allows for specific and efficient knocking down of highly homologous members of a gene family. Using this approach, we implicated N. benthamiana group III E2s in plant development, immunity-associated ROS production, and suppression of multiple immunity-associated PCD by AvrPtoB. We also unraveled functional redundancy among group III members in their requirement for plant development and plant immunity-associated ROS production.
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Affiliation(s)
- Bangjun Zhou
- Center for Plant Science Innovation, Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583 USA
| | - Lirong Zeng
- Center for Plant Science Innovation, Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583 USA
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha, 410128 China
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Iki T, Tschopp MA, Voinnet O. Biochemical and genetic functional dissection of the P38 viral suppressor of RNA silencing. RNA (NEW YORK, N.Y.) 2017; 23:639-654. [PMID: 28148824 PMCID: PMC5393175 DOI: 10.1261/rna.060434.116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 01/25/2017] [Indexed: 05/08/2023]
Abstract
Phytoviruses encode viral suppressors of RNA silencing (VSRs) to counteract the plant antiviral silencing response, which relies on virus-derived small interfering (si)RNAs processed by Dicer RNaseIII enzymes and subsequently loaded into ARGONAUTE (AGO) effector proteins. Here, a tobacco cell-free system was engineered to recapitulate the key steps of antiviral RNA silencing and, in particular, the most upstream double-stranded (ds)RNA processing reaction, not kinetically investigated thus far in the context of plant VSR studies. Comparative biochemical analyses of distinct VSRs in the reconstituted assay showed that in all cases tested, VSR interactions with siRNA duplexes inhibited the loading, but not the activity, of antiviral AGO1 and AGO2. Turnip crinkle virus P38 displayed the additional and unique property to bind both synthetic and RNA-dependent-RNA-polymerase-generated long dsRNAs, and inhibited the processing into siRNAs. Single amino acid substitutions in P38 could dissociate dsRNA-processing from AGO-loading inhibition in vitro and in vivo, illustrating dual-inhibitory strategies discriminatively deployed within a single viral protein, which, we further show, are bona fide suppressor functions that evolved independently of the conserved coat protein function of P38.
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Affiliation(s)
- Taichiro Iki
- Department of Biology, Swiss Federal Institute of Technology (ETH), 8092 Zürich, Switzerland
| | - Marie-Aude Tschopp
- Department of Biology, Swiss Federal Institute of Technology (ETH), 8092 Zürich, Switzerland
| | - Olivier Voinnet
- Department of Biology, Swiss Federal Institute of Technology (ETH), 8092 Zürich, Switzerland
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43
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Alazem M, He MH, Moffett P, Lin NS. Abscisic Acid Induces Resistance against Bamboo Mosaic Virus through Argonaute2 and 3. PLANT PHYSIOLOGY 2017; 174:339-355. [PMID: 28270624 PMCID: PMC5411131 DOI: 10.1104/pp.16.00015] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/03/2017] [Indexed: 05/21/2023]
Abstract
Plant resistance to pathogens is tuned by defense-related hormones. Of these, abscisic acid (ABA) is well documented to moderate resistance against fungi and bacteria. However, ABA's contribution to resistance against viruses is pleiotropic. ABA affects callose deposition at plasmodesmata (therefore hindering the viral cell-to-cell movement), but here, we show that when callose synthase is down-regulated, ABA still induces resistance against infection with Bamboo mosaic virus (BaMV). By examining the potential connections between the ABA and RNA-silencing pathways in Arabidopsis (Arabidopsis thaliana), we showed that ABA regulates the expression of almost the whole ARGONAUTE (AGO) gene family, of which some are required for plant resistance against BaMV Our data show that BaMV infection and ABA treatment regulate the same set of AGOs, with positive effects on AGO1, AGO2, and AGO3, no effect on AGO7, and negative effects on AGO4 and AGO10 The BaMV-mediated regulation of AGO1, AGO2, and AGO3 is ABA dependent, because the accumulation of these AGOs in BaMV-infected ABA mutants did not reach the levels observed in infected wild-type plants. In addition, the AGO1-miR168a complex is dispensable for BaMV resistance, while AGO2 and AGO3 were important for ABA-mediated resistance. While most ago mutants showed increased susceptibility to BaMV infection (except ago10), ago1-27 showed reduced BaMV titers, which was attributed to the up-regulated levels of AGO2, AGO3, and AGO4 We have established that ABA regulates the expression of several members of the AGO family, and this regulation partially contributes to ABA-mediated resistance against BaMV These findings reveal another role for ABA in plants.
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Affiliation(s)
- Mazen Alazem
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China (M.A., M.-H.H., N.-S.L.); and
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1 (P.M.)
| | - Meng-Hsun He
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China (M.A., M.-H.H., N.-S.L.); and
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1 (P.M.)
| | - Peter Moffett
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China (M.A., M.-H.H., N.-S.L.); and
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1 (P.M.)
| | - Na-Sheng Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China (M.A., M.-H.H., N.-S.L.); and
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1 (P.M.)
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Iki T, Ishikawa M, Yoshikawa M. In Vitro Formation of Plant RNA-Induced Silencing Complexes Using an Extract of Evacuolated Tobacco Protoplasts. Methods Mol Biol 2017; 1640:39-53. [PMID: 28608333 DOI: 10.1007/978-1-4939-7165-7_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Small RNA-mediated gene silencing is involved in a variety of biological processes among many eukaryotic organisms. The silencing effector, generally referred to as RNA-induced silencing complex (RISC), comprises an ARGONAUTE (AGO) protein and a small single-stranded guide RNA in its core. RISCs recognize target genes containing sequences complementary to the guide RNA and repress their expression transcriptionally or posttranscriptionally. In vitro systems that recapitulate RISC assembly are useful not only to decipher the molecular mechanisms underlying the assembly process itself but also to dissect the downstream silencing pathways mediated by RISCs. Here, we describe a method for in vitro plant RISC assembly, which relies on an extract of evacuolated protoplasts derived from Nicotiana tabacum BY-2 suspension-cultured cells. In this extract, synthetic duplexes of small RNAs are incorporated into AGO proteins that are synthesized by in vitro translation, and then duplex unwinding and selective strand elimination result in formation of mature RISCs.
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Affiliation(s)
- Taichiro Iki
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Masayuki Ishikawa
- Division of Plant and Microbial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 2-1-2 Kannondai, Tsukuba, ITsukuba, 305-8602, Ibaraki, Japan
| | - Manabu Yoshikawa
- Division of Plant and Microbial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 2-1-2 Kannondai, Tsukuba, ITsukuba, 305-8602, Ibaraki, Japan.
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45
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Ma W, Gabriel TS, Martis MM, Gursinsky T, Schubert V, Vrána J, Doležel J, Grundlach H, Altschmied L, Scholz U, Himmelbach A, Behrens SE, Banaei-Moghaddam AM, Houben A. Rye B chromosomes encode a functional Argonaute-like protein with in vitro slicer activities similar to its A chromosome paralog. THE NEW PHYTOLOGIST 2017; 213:916-928. [PMID: 27468091 DOI: 10.1111/nph.14110] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/18/2016] [Indexed: 05/21/2023]
Abstract
B chromosomes (Bs) are supernumerary, dispensable parts of the nuclear genome, which appear in many different species of eukaryote. So far, Bs have been considered to be genetically inert elements without any functional genes. Our comparative transcriptome analysis and the detection of active RNA polymerase II (RNAPII) in the proximity of B chromatin demonstrate that the Bs of rye (Secale cereale) contribute to the transcriptome. In total, 1954 and 1218 B-derived transcripts with an open reading frame were expressed in generative and vegetative tissues, respectively. In addition to B-derived transposable element transcripts, a high percentage of short transcripts without detectable similarity to known proteins and gene fragments from A chromosomes (As) were found, suggesting an ongoing gene erosion process. In vitro analysis of the A- and B-encoded AGO4B protein variants demonstrated that both possess RNA slicer activity. These data demonstrate unambiguously the presence of a functional AGO4B gene on Bs and that these Bs carry both functional protein coding genes and pseudogene copies. Thus, B-encoded genes may provide an additional level of gene control and complexity in combination with their related A-located genes. Hence, physiological effects, associated with the presence of Bs, may partly be explained by the activity of B-located (pseudo)genes.
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Affiliation(s)
- Wei Ma
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Tobias Sebastian Gabriel
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Mihaela Maria Martis
- Institute of Bioinformatics and Systems Biology/Munich Information Center for Protein Sequences, Helmholtz Center Munich, German Research Center for Environmental Health, 85764, Neuherberg, Germany
- National Bioinformatics Infrastructure Sweden, Department of Clinical and Experimental Medicine, Linköping University, SE-558185, Linköping, Sweden
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Faculty of Life Sciences, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120, Halle/Saale, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Jan Vrána
- Institute of Experimental Botany, Center of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 78371, Olomouc, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany, Center of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 78371, Olomouc, Czech Republic
| | - Heidrun Grundlach
- Institute of Bioinformatics and Systems Biology/Munich Information Center for Protein Sequences, Helmholtz Center Munich, German Research Center for Environmental Health, 85764, Neuherberg, Germany
| | - Lothar Altschmied
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Uwe Scholz
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Axel Himmelbach
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Faculty of Life Sciences, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120, Halle/Saale, Germany
| | - Ali Mohammad Banaei-Moghaddam
- Department of Biochemistry, Institute of Biochemistry and Biophysics (IBB), University of Tehran, PO Box 13145-1384, Tehran, Iran
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, 06466, Stadt Seeland, Germany
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46
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Iki T. Messages on small RNA duplexes in plants. JOURNAL OF PLANT RESEARCH 2017; 130:7-16. [PMID: 27878651 DOI: 10.1007/s10265-016-0876-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 10/12/2016] [Indexed: 06/06/2023]
Abstract
Small RNA-mediated gene silencing encompasses diverse developmental events, stress responses, defense against pathogens, and maintenance of genome integrity. Extensive studies in model organisms have unveiled the molecular mechanisms underpinning the RNA silencing phenomena, and the accumulating knowledge have characterized the intricate pathways and the repertoire of proteins responsible for the actions of small RNAs characterized as microRNAs (miRNAs) or small interfering RNAs (siRNAs). Although the single-stranded, matured guide small RNAs direct the effector ribonucleoprotein complexes to induce gene silencing in sequence-specific manner, the double-stranded intermediate, the small RNA duplexes, which are processed as nascent products of the RNase III enzyme activities, act as key to determine the downstream molecular pathways and the fate of small RNAs. Based at the small RNA duplex-centered view, this review describes the recent advances in understanding the small RNA pathways in plants.
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Affiliation(s)
- Taichiro Iki
- Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka, 565-0871, Japan.
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Brosseau C, El Oirdi M, Adurogbangba A, Ma X, Moffett P. Antiviral Defense Involves AGO4 in an Arabidopsis-Potexvirus Interaction. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:878-888. [PMID: 27762650 DOI: 10.1094/mpmi-09-16-0188-r] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In plants, RNA silencing regulates gene expression through the action of Dicer-like (DCL) and Argonaute (AGO) proteins via micro RNAs and RNA-dependent DNA methylation (RdDM). In addition, RNA silencing functions as an antiviral defense mechanism by targeting virus-derived double-stranded RNA. Plants encode multiple AGO proteins with specialized functions, including AGO4-like proteins that affect RdDM and AGO2, AGO5, and AGO1, which have antiviral activities. Here, we show that AGO4 is also required for defense against the potexvirus Plantago asiatica mosaic virus (PlAMV), most likely independent of RdDM components such as DCL3, Pol IV, and Pol V. Transient assays showed that AGO4 has direct antiviral activity on PlAMV and, unlike RdDM, this activity does not require nuclear localization of AGO4. Furthermore, although PlAMV infection causes a decrease in AGO4 expression, PlAMV causes a change in AGO4 localization from a largely nuclear to a largely cytoplasmic distribution. These results indicate an important role for AGO4 in targeting plant RNA viruses as well as demonstrating novel mechanisms of regulation of and by AGO4, independent of its canonical role in regulating gene expression by RdDM.
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Affiliation(s)
- Chantal Brosseau
- 1 Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Mohamed El Oirdi
- 1 Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
- 2 Current address: Department of Biology, PYD, King Faisal University, Al Hasa, Kingdom of Saudi Arabia; and
| | - Ayooluwa Adurogbangba
- 1 Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Xiaofang Ma
- 1 Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
- 3 College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China
| | - Peter Moffett
- 1 Centre SÈVE, Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
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48
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Liu J, Zhang X, Yang Y, Hong N, Wang G, Wang A, Wang L. Characterization of virus-derived small interfering RNAs in Apple stem grooving virus-infected in vitro-cultured Pyrus pyrifolia shoot tips in response to high temperature treatment. Virol J 2016; 13:166. [PMID: 27716257 PMCID: PMC5053029 DOI: 10.1186/s12985-016-0625-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 09/27/2016] [Indexed: 11/10/2022] Open
Abstract
Background Heat treatment (known as thermotherapy) together with in vitro culture of shoot meristem tips is a commonly used technology to obtain virus-free germplasm for the effective control of virus diseases in fruit trees. RNA silencing as an antiviral defense mechanism has been implicated in this process. To understand if high temperature-mediated acceleration of the host antiviral gene silencing system in the meristem tip facilitates virus-derived small interfering RNAs (vsiRNA) accumulation to reduce the viral RNA titer in the fruit tree meristem tip cells, we used the Apple stem grooving virus (ASGV)–Pyrus pyrifolia pathosystem to explore the possible roles of vsiRNA in thermotherapy. Results At first we determined the full-length genome sequence of the ASGV-Js2 isolate and then profiled vsiRNAs in the meristem tip of in vitro-grown pear (cv. ‘Jinshui no. 2’) shoots infected by ASGV-Js2 and cultured at 24 and 37 °C. A total of 7,495 and 7,949 small RNA reads were obtained from the tips of pear shoots cultured at 24 and 37 °C, respectively. Mapping of the vsiRNAs to the ASGV-Js2 genome revealed that they were unevenly distributed along the ASGV-Js2 genome, and that 21- and 22-nt vsiRNAs preferentially accumulated at both temperatures. The 5′-terminal nucleotides of ASGV-specific siRNAs in the tips cultured under different temperatures had a similar distribution pattern, and the nucleotide U was the most frequent. RT-qPCR analyses suggested that viral genome accumulation was drastically compromised at 37 °C compared to 24 °C, which was accompanied with the elevated levels of vsiRNAs at 37 °C. As plant Dicer-like proteins (DCLs), Argonaute proteins (AGOs), and RNA-dependent RNA polymerases (RDRs) are implicated in vsiRNA biogenesis, we also cloned the partial sequences of PpDCL2,4, PpAGO1,2,4 and PpRDR1 genes, and found their expression levels were up-regulated in the ASGV-infected pear shoots at 37 °C. Conclusions Collectively, these results showed that upon high temperature treatment, the ASGV-infected meristem shoot tips up-regulated the expression of key genes in the RNA silencing pathway, induced the biogenesis of vsiRNAs and inhibited viral RNA accumulation. This study represents the first report on the characterization of the vsiRNA population in pear plants infected by ASGV-Js2, in response to high temperature treatment. Electronic supplementary material The online version of this article (doi:10.1186/s12985-016-0625-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan Liu
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, 430070, People's Republic of China.,Laboratory of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, 430070, People's Republic of China
| | - XueJiao Zhang
- Shihezi University, Shihezi City, Xinjiang Uyghur Autonomous Region, 832003, People's Republic of China
| | - YueKun Yang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, 430070, People's Republic of China.,Laboratory of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, 430070, People's Republic of China
| | - Ni Hong
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, 430070, People's Republic of China.,Laboratory of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, 430070, People's Republic of China
| | - GuoPing Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, 430070, People's Republic of China.,Laboratory of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, 430070, People's Republic of China
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4 T3, Canada
| | - LiPing Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, 430070, People's Republic of China. .,Laboratory of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, 430070, People's Republic of China.
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49
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Palma-Martínez I, Guerrero-Mandujano A, Ruiz-Ruiz MJ, Hernández-Cortez C, Molina-López J, Bocanegra-García V, Castro-Escarpulli G. Active Shiga-Like Toxin Produced by Some Aeromonas spp., Isolated in Mexico City. Front Microbiol 2016; 7:1552. [PMID: 27757103 PMCID: PMC5048074 DOI: 10.3389/fmicb.2016.01552] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/16/2016] [Indexed: 12/29/2022] Open
Abstract
RNA silencing is a conserved mechanism that utilizes small RNAs (sRNAs) to direct the regulation of gene expression at the transcriptional or post-transcriptional level. Plants utilizing RNA silencing machinery to defend pathogen infection was first identified in plant–virus interaction and later was observed in distinct plant–pathogen interactions. RNA silencing is not only responsible for suppressing RNA accumulation and movement of virus and viroid, but also facilitates plant immune responses against bacterial, oomycete, and fungal infection. Interestingly, even the same plant sRNA can perform different roles when encounters with different pathogens. On the other side, pathogens counteract by generating sRNAs that directly regulate pathogen gene expression to increase virulence or target host genes to facilitate pathogen infection. Here, we summarize the current knowledge of the characterization and biogenesis of host- and pathogen-derived sRNAs, as well as the different RNA silencing machineries that plants utilize to defend against different pathogens. The functions of these sRNAs in defense and counter-defense and their mechanisms for regulation during different plant–pathogen interactions are also discussed.
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Affiliation(s)
- Ingrid Palma-Martínez
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
| | - Andrea Guerrero-Mandujano
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
| | - Manuel J Ruiz-Ruiz
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio Central de Análisis Clínicos Unidad Médica de Alta Especialidad Hospital de Pediatría "Silvestre Frenk Freund," Centro Médico Nacional Siglo XXIMexico City, Mexico
| | - Cecilia Hernández-Cortez
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio de Bioquímica Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico
| | - José Molina-López
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| | | | - Graciela Castro-Escarpulli
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
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50
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Garcia-Ruiz H, Ruiz MTG, Peralta SMG, Gabriel CBM, El-Mounadi K. Mechanisms, applications, and perspectives of antiviral RNA silencing in plants. ACTA ACUST UNITED AC 2016; 34. [PMID: 28890589 DOI: 10.18781/r.mex.fit.1606-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Viral diseases of plants cause important economic losses due to reduction in crop quality and quantity to the point of threatening food security in some countries. Given the reduced availability of natural sources, genetic resistance to viruses has been successfully engineered for some plant-virus combinations. A sound understanding of the basic mechanisms governing plant-virus interactions, including antiviral RNA silencing, is the foundation to design better management strategies and biotechnological approaches to engineer and implement antiviral resistance in plants. In this review, we present current molecular models to explain antiviral RNA silencing and its application in basic plant research, biotechnology and genetic engineering.
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Affiliation(s)
- Hernan Garcia-Ruiz
- Department of Plant Pathology, Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583 USA
| | | | | | | | - Kautar El-Mounadi
- Department of Biology, Kuztown University of Pennsylvania, Kuztown, PA 19530 USA
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