1
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Serra P, Navarro B, Forment J, Gisel A, Gago-Zachert S, Di Serio F, Flores R. Expression of symptoms elicited by a hammerhead viroid through RNA silencing is related to population bottlenecks in the infected host. THE NEW PHYTOLOGIST 2023. [PMID: 37148189 DOI: 10.1111/nph.18934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/16/2023] [Indexed: 05/08/2023]
Abstract
Chlorosis is frequently incited by viroids, small nonprotein-coding, circular RNAs replicating in nuclei (family Pospiviroidae) or chloroplasts (family Avsunviroidae). Here, we investigated how chrysanthemum chlorotic mottle viroid (CChMVd, Avsunviroidae) colonizes, evolves and initiates disease. Progeny variants of natural and mutated CChMVd sequence variants inoculated in chrysanthemum plants were characterized, and plant responses were assessed by molecular assays. We showed that: chlorotic mottle induced by CChMVd reflects the spatial distribution and evolutionary behaviour in the infected host of pathogenic (containing a UUUC tetranucleotide) and nonpathogenic (lacking such a pathogenic determinant) variants; and RNA silencing is involved in the initiation of the chlorosis in symptomatic leaf sectors through a viroid-derived small RNA containing the pathogenic determinant that directs AGO1-mediated cleavage of the mRNA encoding the chloroplastic transketolase. This study provides the first evidence that colonization of leaf tissues by CChMVd is characterized by segregating variant populations differing in pathogenicity and with the ability to colonize leaf sectors (bottlenecks) and exclude other variants (superinfection exclusion). Importantly, no specific pathogenic viroid variants were found in the chlorotic spots caused by chrysanthemum stunt viroid (Pospiviroidae), thus establishing a clear distinction on how members of the two viroid families trigger chlorosis in the same host.
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Affiliation(s)
- Pedro Serra
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València), 46022, Valencia, Spain
| | - Beatriz Navarro
- Institute for Sustainable Plant Protection, National Research Council, Bari, 70122, Italy
| | - Javier Forment
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València), 46022, Valencia, Spain
| | - Andreas Gisel
- Institute for Biomedical Technologies, National Research Council, Bari, 70122, Italy
- International Institute of Tropical Agriculture, 200001, Ibadan, Nigeria
| | - Selma Gago-Zachert
- Section Microbial Biotechnology, Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120, Halle/Saale, Germany
| | - Francesco Di Serio
- Institute for Sustainable Plant Protection, National Research Council, Bari, 70122, Italy
| | - Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València), 46022, Valencia, Spain
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2
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Navarro B, Ambrós S, Serio FD, Hernández C. On the early identification and characterization of pear blister canker viroid, apple dimple fruit viroid, peach latent mosaic viroid and chrysanthemum chlorotic mottle viroid. Virus Res 2023; 323:199012. [PMID: 36436691 PMCID: PMC10194241 DOI: 10.1016/j.virusres.2022.199012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022]
Abstract
In the 90's, pear blister canker viroid (PBCVd), apple dimple fruit viroid (ADFVd), peach latent mosaic viroid (PLMVd) and chrysanthemum chlorotic mottle viroid (CChMVd) were identified and characterized in the Ricardo Flores' laboratory. In these studies, the autonomous replication of these infectious RNAs and their involvement in the elicitation of diseases in their natural hosts were also shown. Their discovery was achieved by classical approaches based on the physical purification of the viroid RNAs from polyacrylamide gels followed by the sequencing of their genomic RNAs and by bioassays to assess their autonomous replication and the fulfillment of Koch's postulates. The molecular characterization of these four viroids, including the study of their sequence variability, contributed to the establishment of the concept of quasispecies for viroids and to the development of reliable molecular diagnostic methods that have facilitated the control of the diseases they caused. Most importantly, some of these viroids became valuable experimental model systems that are still used nowadays to study structural-functional relationships in RNAs and to dissect evolutionary and pathogenic pathways underlying plant-viroid interaction. The differences between early viroid discovery strategies, relying on biological and pathogenic issues, and the current high-throughput sequencing-based approaches, that frequently allow the discovery of new viroids and viroid-like RNAs in symptomless hosts, is also discussed, clarifying why the traditional molecular and biological studies mentioned above are still required to conclusively define the nature of any novel viroid-like RNA.
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Affiliation(s)
- Beatriz Navarro
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 122/D, Bari 70126, Italy.
| | - Silvia Ambrós
- Instituto de Biología Integrativa de Sistemas I2SysBio, Consejo Superior de Investigaciones Científicas-Universitat de Valencia, C/Catedrático Agustín Escardino 9, Parque Científico, Paterna 46980, Valencia, Spain
| | - Francesco Di Serio
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 122/D, Bari 70126, Italy
| | - Carmen Hernández
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Avda, Ingeniero Fausto Elio s/n, Valencia 46011, Spain.
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3
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Manrubia S. The simple emergence of complex molecular function. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20200422. [PMID: 35599566 DOI: 10.1098/rsta.2020.0422] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
At odds with a traditional view of molecular evolution that seeks a descent-with-modification relationship between functional sequences, new functions can emerge de novo with relative ease. At early times of molecular evolution, random polymers could have sufficed for the appearance of incipient chemical activity, while the cellular environment harbours a myriad of proto-functional molecules. The emergence of function is facilitated by several mechanisms intrinsic to molecular organization, such as redundant mapping of sequences into structures, phenotypic plasticity, modularity or cooperative associations between genomic sequences. It is the availability of niches in the molecular ecology that filters new potentially functional proposals. New phenotypes and subsequent levels of molecular complexity could be attained through combinatorial explorations of currently available molecular variants. Natural selection does the rest. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.
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Affiliation(s)
- Susanna Manrubia
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain
- Systems Biology Department, National Biotechnology Centre (CSIC), c/Darwin 3, 28049 Madrid, Spain
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4
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Flores R, Navarro B, Serra P, Di Serio F. A Scenario for the Emergence of Protoviroids in the RNA World and for Their Further Evolution into Viroids and Viroid-Like RNAs by Modular Recombinations and Mutations. Virus Evol 2022; 8:veab107. [PMID: 35223083 PMCID: PMC8865084 DOI: 10.1093/ve/veab107] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/10/2021] [Accepted: 01/14/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
Viroids are tiny, circular and non-coding RNAs that are able to replicate and systemically infect plants. The smallest known pathogens, they have been proposed to represent survivors from the RNA world that likely preceded the cellular world currently dominating life on the earth. Although the small, circular and compact nature of viroid genomes, some of which are also endowed with catalytic activity mediated by hammerhead ribozymes, support this proposal, the lack of feasible evolutionary routes and the identification of hammerhead ribozymes in a large number of DNA genomes of organisms along the tree of life has led some to question such a proposal. Here, we reassess the origin and subsequent evolution of viroids by complementing phylogenetic reconstructions with molecular data, including the primary and higher-order structure of the genomic RNAs, their replication and recombination mechanisms and selected biological information. Features of some viroid-like RNAs found in plants, animal, and possibly fungi are also considered. The resulting evolutionary scenario supports the emergence of protoviroids in the RNA world, mainly as replicative modules, followed by further increase in genome complexity based on module/domain shuffling and combination, and mutation. Such a modular evolutionary scenario would have facilitated the inclusion in the protoviroid genomes of complex RNA structures (or coding sequences, as in the case of hepatitis ∂ virus and delta-like agents), likely needed for their adaptation from the RNA world to a life based on cells, thus generating the ancestors of current infectious viroids and viroid-like RNAs. Other non-infectious viroid-like RNAs, such as retroviroid-like RNA elements and retrozymes, could also be derived from protoviroids if their reverse transcription and integration into viral or eukaryotic DNA, respectively, are considered as a possible key step in their evolution. Comparison of evidence supporting a general and modular evolutionary model for viroids and viroid-like RNAs with that favoring alternative scenarios provides reasonable reasons to keep alive the hypothesis that these small RNA pathogens may be relics of a precellular world.
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Affiliation(s)
| | - Beatriz Navarro
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 122/D, Bari 70126, Italy
| | - Pedro Serra
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas–Universidad Politécnica de Valencia, Ingeniero Fausto Elio s/n, Valencia 46022, Spain
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5
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Lee BD, Neri U, Oh CJ, Simmonds P, Koonin EV. ViroidDB: a database of viroids and viroid-like circular RNAs. Nucleic Acids Res 2022; 50:D432-D438. [PMID: 34751403 PMCID: PMC8728161 DOI: 10.1093/nar/gkab974] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/01/2021] [Accepted: 10/06/2021] [Indexed: 12/31/2022] Open
Abstract
We introduce ViroidDB, a value-added database that attempts to collect all known viroid and viroid-like circular RNA sequences into a single resource. Spanning about 10 000 unique sequences, ViroidDB includes viroids, retroviroid-like elements, small circular satellite RNAs, ribozyviruses, and retrozymes. Each sequence's secondary structure, ribozyme content, and cluster membership are predicted via a custom pipeline optimized for handling circular RNAs. The data can be explored via a purpose-built user interface that features visualizations, multiple sequence alignments, and a portal for downloading bulk data. Users can browse the data by sequence type, taxon, or typo-tolerant search of metadata fields. The database is freely accessible at https://viroids.org.
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MESH Headings
- Base Sequence
- Databases, Nucleic Acid
- Internet
- Metadata
- Nucleic Acid Conformation
- Plant Diseases/virology
- Plants/virology
- RNA, Catalytic/chemistry
- RNA, Catalytic/classification
- RNA, Catalytic/genetics
- RNA, Catalytic/metabolism
- RNA, Circular/chemistry
- RNA, Circular/classification
- RNA, Circular/genetics
- RNA, Circular/metabolism
- RNA, Viral/chemistry
- RNA, Viral/classification
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Sequence Alignment
- Software
- Viroids/classification
- Viroids/genetics
- Viroids/metabolism
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Affiliation(s)
- Benjamin D Lee
- National Center for Biotechnology Information, National Library of Medicine, National Institutes Health, Bethesda, MD 20894, USA
- Nuffield Department of Medicine, University of Oxford, Oxford OX1, UK
| | - Uri Neri
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv 6997801, Israel
| | | | - Peter Simmonds
- Nuffield Department of Medicine, University of Oxford, Oxford OX1, UK
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes Health, Bethesda, MD 20894, USA
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6
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Wu J, Bisaro DM. Biased Pol II fidelity contributes to conservation of functional domains in the Potato spindle tuber viroid genome. PLoS Pathog 2020; 16:e1009144. [PMID: 33351860 PMCID: PMC7787683 DOI: 10.1371/journal.ppat.1009144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/06/2021] [Accepted: 11/10/2020] [Indexed: 01/25/2023] Open
Abstract
Accurate calculation of mutation rates for viruses and viroids is necessary for evolutionary studies and to evaluate adaptation potential. However, estimation of in vivo mutation rates is complicated by selection, which leads to loss or proliferation of certain mutations. To minimize this concern, lethal mutations, including nonsense and non-synonymous mutations, have been used to determine mutation rates for several viruses and viroids, including Potato spindle tuber viroid (PSTVd). However, this approach has limitations, including focus on a relatively small number of genome sites and the possibility that mutations may not actually be lethal or may be maintained by wild type individuals. To avoid selection bias altogether, we sequenced minus-strand PSTVd dimers from concatemeric replication intermediates. The underlying rationale is that mutations found in only one of the monomers were likely generated de novo during RNA polymerase II (Pol II) transcription of the circular plus-strand RNA genome. This approach yielded an apparent Pol II error rate of ~1/1837 nucleotides per transcription cycle, and an estimated mutation rate of ~1/919 nucleotides for a single replication cycle. Remarkably, de novo mutations were nearly absent from the most conserved, replication-critical regions of the PSTVd genome, suggesting that sequence conservation is a consequence of both essential function and template optimization for greater Pol II fidelity. Such biased fidelity may constitute a novel strategy to ensure population success while allowing abundant sampling of sequence space in other genome regions. Comparison with variants in progeny populations derived from a cloned, wild type PSTVd master sequence revealed that most de novo mutations were lost through selection. Polymerase errors are the major source of variation in virus and viroid genomes, and as a consequence polymerase error rates are major determinants of adaptation potential. Accurate calculation of in vivo mutation rates is complicated by selection. To circumvent this issue, dimeric PSTVd minus-strand replication intermediates generated in vivo by host RNA polymerase II (Pol II) were sequenced to identify de novo mutations. This analysis revealed a very high error rate for Pol II transcribing genomic PSTVd RNA, leading to an extremely high mutation rate. Remarkably, however, de novo mutations were rare in the most highly conserved, replication-critical genome regions, suggesting these sequences are selected for both function and enhanced transcription fidelity. This biased fidelity may reveal a novel strategy to ensure population survival while maximizing adaptation potential. Further, comparison of mutations identified by minus-strand dimer sequencing with mutations observed in progeny variants derived from wild type PSTVd showed that most de novo mutations were lost through selection.
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Affiliation(s)
- Jian Wu
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
| | - David M. Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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7
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Shrestha N, Bujarski JJ. Long Noncoding RNAs in Plant Viroids and Viruses: A Review. Pathogens 2020; 9:E765. [PMID: 32961969 PMCID: PMC7559573 DOI: 10.3390/pathogens9090765] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022] Open
Abstract
Infectious long-noncoding (lnc) RNAs related to plants can be of both viral and non-viral origin. Viroids are infectious plant lncRNAs that are not related to viruses and carry the circular, single-stranded, non-coding RNAs that replicate with host enzymatic activities via a rolling circle mechanism. Viroids interact with host processes in complex ways, emerging as one of the most productive tools for studying the functions of lncRNAs. Defective (D) RNAs, another category of lnc RNAs, are found in a variety of plant RNA viruses, most of which are noncoding. These are derived from and are replicated by the helper virus. D RNA-virus interactions evolve into mutually beneficial combinations, enhancing virus fitness via competitive advantages of moderated symptoms. Yet the satellite RNAs are single-stranded and include either large linear protein-coding ss RNAs, small linear ss RNAs, or small circular ss RNAs (virusoids). The satellite RNAs lack sequence homology to the helper virus, but unlike viroids need a helper virus to replicate and encapsidate. They can attenuate symptoms via RNA silencing and enhancement of host defense, but some can be lethal as RNA silencing suppressor antagonists. Moreover, selected viruses produce lncRNAs by incomplete degradation of genomic RNAs. They do not replicate but may impact viral infection, gene regulation, and cellular functions. Finally, the host plant lncRNAs can also contribute during plant-virus interactions, inducing plant defense and the regulation of gene expression, often in conjunction with micro and/or circRNAs.
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Affiliation(s)
- Nipin Shrestha
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA
| | - Józef J. Bujarski
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA
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8
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Adkar-Purushothama CR, Bolduc F, Bru P, Perreault JP. Insights Into Potato Spindle Tuber Viroid Quasi-Species From Infection to Disease. Front Microbiol 2020; 11:1235. [PMID: 32719659 PMCID: PMC7349936 DOI: 10.3389/fmicb.2020.01235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/14/2020] [Indexed: 12/31/2022] Open
Abstract
Viroids are non-coding RNA plant pathogens that are characterized by their possession of a high mutation level. Although the sequence heterogeneity in viroid infected plants is well understood, shifts in viroid population dynamics due to mutations over the course of infection remain poorly understood. In this study, the ten most abundant sequence variants of potato spindle tuber viroid RG1 (PSTVd) expressed at different time intervals in PSTVd infected tomato plants were identified by high-throughput sequencing. The sequence variants, forming a quasi-species, were subjected to both the identification of the regions favoring mutations and the effect of the mutations on viroid secondary structure and viroid derived small RNAs (vd-sRNA). At week 1 of PSTVd infection, 25% of the sequence variants were similar to the "master" sequence (i.e., the sequence used for inoculation). The frequency of the master sequence within the population increased to 70% at week 2 after PSTVd infection, and then stabilized for the rest of the disease cycle (i.e., weeks 3 and 4). While some sequence variants were abundant at week 1 after PSTVd infection, they tended to decrease in frequency over time. For example, the variants with insertions at positions 253 or 254, positions that could affect the Loop E as well as the metastable hairpin I structure that has been shown important during replication and viroid infectivity, resulted in decreased frequency. Data obtained by in silico analysis of the viroid derived small RNAs (vd-sRNA) was also analyzed. A few mutants had the potential of positively affecting the viroid's accumulation by inducing the RNA silencing of the host's defense related genes. Variants with mutations that could negatively affect viroid abundance were also identified because their derived vd-sRNA were no longer capable of targeting any host mRNA or of changing its target sequence from a host defense gene to some other non-important host gene. Together, these findings open avenues into understanding the biological role of sequence variants, this viroid's interaction with host components, stable and metastable structures generated by mutants during the course of infection, and the influence of sequence variants on stabilizing viroid population dynamics.
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Affiliation(s)
- Charith Raj Adkar-Purushothama
- RNA Group/Groupe ARN, Département de Biochimie, Faculté de Médecine des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - François Bolduc
- RNA Group/Groupe ARN, Département de Biochimie, Faculté de Médecine des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Pierrick Bru
- RNA Group/Groupe ARN, Département de Biochimie, Faculté de Médecine des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jean-Pierre Perreault
- RNA Group/Groupe ARN, Département de Biochimie, Faculté de Médecine des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Sherbrooke, QC, Canada
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9
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Tangkanchanapas P, Haegeman A, Ruttink T, Höfte M, De Jonghe K. Whole-Genome Deep Sequencing Reveals Host-Driven in-planta Evolution of Columnea Latent Viroid (CLVd) Quasi-Species Populations. Int J Mol Sci 2020; 21:ijms21093262. [PMID: 32380694 PMCID: PMC7246631 DOI: 10.3390/ijms21093262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/29/2020] [Accepted: 05/02/2020] [Indexed: 01/06/2023] Open
Abstract
Columnea latent viroid (CLVd) is one of the most serious tomato diseases. In general, viroids have high mutation rates. This generates a population of variants (so-called quasi-species) that co-exist in their host and exhibit a huge level of genetic diversity. To study the population of CLVd in individual host plants, we used amplicon sequencing using specific CLVd primers linked with a sample-specific index sequence to amplify libraries. An infectious clone of a CLVd isolate Chaipayon-1 was inoculated on different solanaceous host plants. Six replicates of the amplicon sequencing results showed very high reproducibility. On average, we obtained 133,449 CLVd reads per PCR-replicate and 79 to 561 viroid sequence variants, depending on the plant species. We identified 19 major variants (>1.0% mean relative abundance) in which a total of 16 single-nucleotide polymorphisms (SNPs) and two single nucleotide insertions were observed. All major variants contained a combination of 4 to 6 SNPs. Secondary structure prediction clustered all major variants into a tomato/bolo maka group with four loops (I, II, IV and V), and a chili pepper group with four loops (I, III, IV and V) at the terminal right domain, compared to the CLVd Chaipayon-1 which consists of five loops (I, II, III, IV and V).
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Affiliation(s)
- Parichate Tangkanchanapas
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 96, 9820 Merelbeke, Belgium; (P.T.); (A.H.); (T.R.)
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium;
| | - Annelies Haegeman
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 96, 9820 Merelbeke, Belgium; (P.T.); (A.H.); (T.R.)
| | - Tom Ruttink
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 96, 9820 Merelbeke, Belgium; (P.T.); (A.H.); (T.R.)
| | - Monica Höfte
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium;
| | - Kris De Jonghe
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burgemeester Van Gansberghelaan 96, 9820 Merelbeke, Belgium; (P.T.); (A.H.); (T.R.)
- Correspondence: ; Tel.: +32-329-2722-448
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10
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Catalán P, Elena SF, Cuesta JA, Manrubia S. Parsimonious Scenario for the Emergence of Viroid-Like Replicons De Novo. Viruses 2019; 11:v11050425. [PMID: 31075860 PMCID: PMC6563258 DOI: 10.3390/v11050425] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 01/12/2023] Open
Abstract
Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixed length, rod-like structures typical of Pospiviroidae are difficult to fix. Using different quantitative approaches, we evaluated the likelihood that RNA sequences fold into a rod-like structure and bear specific sequence motifs facilitating interactions with other molecules, e.g., RNA polymerases, RNases, and ligases. By means of numerical simulations, we show that circular RNA replicons analogous to Pospiviroidae emerge if evolution is seeded with minimal circular RNAs that grow through the gradual addition of nucleotides. Further, these rod-like replicons often maintain their structure if independent functional modules are acquired that impose selective constraints. The evolutionary scenario we propose here is consistent with the structural and biochemical properties of viroids described to date.
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Affiliation(s)
- Pablo Catalán
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain.
| | - Santiago F Elena
- Instituto de Biología Integrativa de Sistemas (I2SysBio), CSIC-Universitat de València, Paterna, 46980 València, Spain.
- The Santa Fe Institute, Santa Fe, NM 87501, USA.
| | - José A Cuesta
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain.
- Departamento de Matemáticas, Universidad Carlos III de Madrid, 28911 Leganés, Spain.
- Instituto de Biocomputación y Física de Sistemas Complejos (BiFi), Universidad de Zaragoza, 50018 Zaragoza, Spain.
- Institute of Financial Big Data (IFiBiD), Universidad Carlos III de Madrid⁻Banco de Santander, 28903 Getafe, Spain.
| | - Susanna Manrubia
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain.
- National Biotechnology Centre (CSIC), 28049 Madrid, Spain.
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11
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Hadidi A. Next-Generation Sequencing and CRISPR/Cas13 Editing in Viroid Research and Molecular Diagnostics. Viruses 2019; 11:E120. [PMID: 30699972 PMCID: PMC6409718 DOI: 10.3390/v11020120] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 12/12/2022] Open
Abstract
Viroid discovery as well as the economic significance of viroids and biological properties are presented. Next-generation sequencing (NGS) technologies combined with informatics have been applied to viroid research and diagnostics for almost a decade. NGS provides highly efficient, rapid, low-cost high-throughput sequencing of viroid genomes and of the 21⁻24 nt vd-sRNAs generated by the RNA silencing defense of the host. NGS has been utilized in various viroid studies which are presented. The discovery during the last few years that prokaryotes have heritable adaptive immunity mediated through clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated Cas proteins, have led to transformative advances in molecular biology, notably genome engineering and most recently molecular diagnostics. The potential application of the CRISPR-Cas13a system for engineering viroid interference in plants is suggested by targeting specific motifs of three economically important viroids. The CRISPR-Cas13 system has been utilized recently for the accurate detection of human RNA viruses by visual read out in 90 min or less and by paper-based assay. Multitarget RNA tests by this technology have a good potential for application as a rapid and accurate diagnostic assay for known viroids. The CRISPR/Cas system will work only for known viroids in contrast to NGS, but it should be much faster.
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Affiliation(s)
- Ahmed Hadidi
- United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA.
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12
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Abstract
Many recent studies have demonstrated that several known and unknown viruses infect many horticultural plants. However, the elucidation of a viral population and the understanding of the genetic complexity of viral genomes in a single plant are rarely reported. Here, we conducted metatranscriptome analyses using six different peach trees representing six individual peach cultivars. We identified six viruses including five viruses in the family Betaflexiviridae and a novel virus belonging to the family Tymoviridae as well as two viroids. The number of identified viruses and viroids in each transcriptome ranged from one to six. We obtained 18 complete or nearly complete genomes for six viruses and two viroids using transcriptome data. Furthermore, we analyzed single nucleotide variations for individual viral genomes. In addition, we analyzed the amount of viral RNA and copy number for identified viruses and viroids. Some viruses or viroids were commonly present in different cultivars; however, the list of infected viruses and viroids in each cultivar was different. Taken together, our study reveals the viral population in a single peach tree and a comprehensive overview for the diversities of viral communities in different peach cultivars.
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13
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Jo Y, Choi H, Kim SM, Kim SL, Lee BC, Cho WK. The pepper virome: natural co-infection of diverse viruses and their quasispecies. BMC Genomics 2017; 18:453. [PMID: 28595635 PMCID: PMC5465472 DOI: 10.1186/s12864-017-3838-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 06/01/2017] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The co-infection of diverse viruses in a host plant is common; however, little is known about viral populations and their quasispecies in the host. RESULTS Here, we report the first pepper viromes that were co-infected by different types of viral genomes. The pepper viromes are dominated by geminivirus DNA-A followed by a novel carlavirus referred to as Pepper virus A. The two pepper cultivars share similar viral populations and replications. However, the quasispecies for double-stranded RNA virus and two satellite DNAs were heterogeneous and homogenous in susceptible and resistant cultivars, respectively, indicating the quasispecies of an individual virus depends on the host. CONCLUSIONS Taken together, we provide the first evidence that the host plant resistant to viruses has an unrevealed antiviral system, affecting viral quasispecies, not replication.
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Affiliation(s)
- Yeonhwa Jo
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hoseong Choi
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Sang-Min Kim
- Crop Foundation Division, National Institute of Crop Science, RDA, Wanju, 55365, South Korea
| | - Sun-Lim Kim
- Crop Foundation Division, National Institute of Crop Science, RDA, Wanju, 55365, South Korea
| | - Bong Choon Lee
- Crop Foundation Division, National Institute of Crop Science, RDA, Wanju, 55365, South Korea
| | - Won Kyong Cho
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea. .,The Taejin Genome Institute, Gadam-gil 61, Hoeongseong, 25239, Republic of Korea.
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14
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Suzuki T, Fujibayashi M, Hataya T, Taneda A, He YH, Tsushima T, Duraisamy GS, Siglová K, Matoušek J, Sano T. Characterization of host-dependent mutations of apple fruit crinkle viroid replicating in newly identified experimental hosts suggests maintenance of stem-loop structures in the left-hand half of the molecule is important for replication. J Gen Virol 2017; 98:506-516. [PMID: 28005527 DOI: 10.1099/jgv.0.000693] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Apple fruit crinkle viroid (AFCVd) is a tentative member of the genus Apscaviroid, family Pospiviroidae. AFCVd has a narrow host range and is known to infect apple, hop and persimmon as natural hosts. In this study, tomato, cucumber and wild hop have been identified as new experimental herbaceous hosts. Foliar symptoms were very mild or virtually undetectable, but fruits of infected tomato were small, cracked and distorted. These symptoms resemble those observed on some AFCVd-sensitive apple cultivars. After transfer to tomato, cucumber and wild hop, sequence changes were detected in a natural AFCVd isolate from hop, and major variants in tomato, cucumber and wild hop differed in 10, 8 or 2 nucleotides, respectively, from the predominant one in the inoculum. The major variants in tomato and cucumber were almost identical, and the one in wild hop was very similar to the one in cultivated hop. Detailed analyses of the host-dependent sequence changes that appear in a naturally occurring AFCVd isolate from hop after transfer to tomato using small RNA deep sequence data and infectivity studies with dimeric RNA transcripts followed by progeny analysis indicate that the major AFCVd variant in tomato emerged by selection of a minor variant present in the inoculum (i.e. hop) followed by one to two host-dependent de novo mutations. Comparison of the secondary structures of major variants in hop, tomato and persimmon after transfer to tomato suggested that maintenance of stem-loop structures in the left-hand half of the molecule is critical for infection.
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Affiliation(s)
- Takahiro Suzuki
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
| | - Misato Fujibayashi
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
| | - Tatsuji Hataya
- Laboratory of Pathogen-Plant Interactions, Research Faculty of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan
| | - Akito Taneda
- Graduate School of Science and Technology, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
| | - Ying-Hong He
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
| | - Taro Tsushima
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
| | - Ganesh Selvaraj Duraisamy
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic
| | - Kristyna Siglová
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic.,University of South Bohemia, Faculty of Science, Branišovská 31, České Budějovice 370 05, Czech Republic
| | - Jaroslav Matoušek
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic
| | - Teruo Sano
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan
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15
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Brass JRJ, Owens RA, Matoušek J, Steger G. Viroid quasispecies revealed by deep sequencing. RNA Biol 2017; 14:317-325. [PMID: 28027000 PMCID: PMC5367258 DOI: 10.1080/15476286.2016.1272745] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/04/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022] Open
Abstract
Viroids are non-coding single-stranded circular RNA molecules that replicate autonomously in infected host plants causing mild to lethal symptoms. Their genomes contain about 250-400 nucleotides, depending on viroid species. Members of the family Pospiviroidae, like the Potato spindle tuber viroid (PSTVd), replicate via an asymmetric rolling-circle mechanism using the host DNA-dependent RNA-Polymerase II in the nucleus, while members of Avsunviroidae are replicated in a symmetric rolling-circle mechanism probably by the nuclear-encoded polymerase in chloroplasts. Viroids induce the production of viroid-specific small RNAs (vsRNA) that can direct (post-)transcriptional gene silencing against host transcripts or genomic sequences. Here, we used deep-sequencing to analyze vsRNAs from plants infected with different PSTVd variants to elucidate the PSTVd quasipecies evolved during infection. We recovered several novel as well as previously known PSTVd variants that were obviously competent in replication and identified common strand-specific mutations. The calculated mean error rate per nucleotide position was less than [Formula: see text], quite comparable to the value of [Formula: see text] reported for a member of Avsunviroidae. The resulting error threshold allows the synthesis of longer-than-unit-length replication intermediates as required by the asymmetric rolling-circle mechanism of members of Pospiviroidae.
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Affiliation(s)
- Joseph R. J. Brass
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Robert A. Owens
- United States Department of Agriculture, Agricultural Research Service, Molecular Plant Pathology Laboratory, Beltsville, MD, USA
| | - Jaroslav Matoušek
- Biology Centre, CAS, v. v. i., Institute of Plant Molecular Biology, Branišovská, České Budějovice, Czech Republic
| | - Gerhard Steger
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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16
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Serra P, Bertolini E, Martínez MC, Cambra M, Flores R. Interference between variants of peach latent mosaic viroid reveals novel features of its fitness landscape: implications for detection. Sci Rep 2017; 7:42825. [PMID: 28211491 PMCID: PMC5314366 DOI: 10.1038/srep42825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/13/2017] [Indexed: 12/05/2022] Open
Abstract
Natural populations of peach latent mosaic viroid (PLMVd) are complex mixtures of variants. During routine testing, TaqMan rtRT-PCR and RNA gel-blot hybridization produced discordant results with some PLMVd isolates. Analysis of the corresponding populations showed that they were exclusively composed of variants (of class II) with a structural domain different from that of the reference and many other variants (of class I) targeted by the TaqMan rtRT-PCR probe. Bioassays in peach revealed that a representative PLMVd variant of class II replicated without symptoms, generated a progeny with low nucleotide diversity, and, intriguingly, outcompeted a representative symptomatic variant of class I when co-inoculated in equimolecular amounts. A number of informative positions associated with the higher fitness of variants of class II have been identified, and novel sets of primers and probes for universal or specific TaqMan rtRT-PCR detection of PLMVd variants have been designed and tested.
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Affiliation(s)
- Pedro Serra
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Spain
| | - Edson Bertolini
- Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
- Departamento de Fitossanidade, Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - M. Carmen Martínez
- Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Mariano Cambra
- Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Spain
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17
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Hadidi A, Flores R, Candresse T, Barba M. Next-Generation Sequencing and Genome Editing in Plant Virology. Front Microbiol 2016; 7:1325. [PMID: 27617007 PMCID: PMC4999435 DOI: 10.3389/fmicb.2016.01325] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/11/2016] [Indexed: 01/18/2023] Open
Abstract
Next-generation sequencing (NGS) has been applied to plant virology since 2009. NGS provides highly efficient, rapid, low cost DNA, or RNA high-throughput sequencing of the genomes of plant viruses and viroids and of the specific small RNAs generated during the infection process. These small RNAs, which cover frequently the whole genome of the infectious agent, are 21-24 nt long and are known as vsRNAs for viruses and vd-sRNAs for viroids. NGS has been used in a number of studies in plant virology including, but not limited to, discovery of novel viruses and viroids as well as detection and identification of those pathogens already known, analysis of genome diversity and evolution, and study of pathogen epidemiology. The genome engineering editing method, clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has been successfully used recently to engineer resistance to DNA geminiviruses (family, Geminiviridae) by targeting different viral genome sequences in infected Nicotiana benthamiana or Arabidopsis plants. The DNA viruses targeted include tomato yellow leaf curl virus and merremia mosaic virus (begomovirus); beet curly top virus and beet severe curly top virus (curtovirus); and bean yellow dwarf virus (mastrevirus). The technique has also been used against the RNA viruses zucchini yellow mosaic virus, papaya ringspot virus and turnip mosaic virus (potyvirus) and cucumber vein yellowing virus (ipomovirus, family, Potyviridae) by targeting the translation initiation genes eIF4E in cucumber or Arabidopsis plants. From these recent advances of major importance, it is expected that NGS and CRISPR-Cas technologies will play a significant role in the very near future in advancing the field of plant virology and connecting it with other related fields of biology.
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Affiliation(s)
- Ahmed Hadidi
- United States Department of Agriculture – Agricultural Research ServiceBeltsville, MD, USA
| | - Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia–Consejo Superior de Investigaciones CientíficasValencia, Spain
| | - Thierry Candresse
- UMR 1332 Biologie du Fruit et Pathologie, Institut National de la Recherche Agronomique, Université de BordeauxBordeaux, France
| | - Marina Barba
- Consiglio per la Ricerca in Agricoltura e l’analisi dell’Economia Agraria, Centro di Ricerca per la Patologia VegetaleRome, Italy
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18
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Abstract
Mature viroids consist of a noncoding, covalently closed circular RNA that is able to autonomously infect respective host plants. Thus, they must utilize proteins of the host for most biological functions such as replication, processing, transport, and pathogenesis. Therefore, viroids can be regarded as minimal parasites of the host machinery. They have to present to the host machinery the appropriate signals based on either their sequence or their structure. Here, we summarize such sequence and structural features critical for the biological functions of viroids.
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Affiliation(s)
- Gerhard Steger
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
| | - Jean-Pierre Perreault
- Département de biochimie, Faculté de médecine et des sciences de la santé, Pavillon de recherche appliqueé sur le cancer, Université de Sherbrooke, Québec, Canada.
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19
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Jo Y, Choi H, Kyong Cho J, Yoon JY, Choi SK, Kyong Cho W. In silico approach to reveal viral populations in grapevine cultivar Tannat using transcriptome data. Sci Rep 2015; 5:15841. [PMID: 26508692 PMCID: PMC4623741 DOI: 10.1038/srep15841] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/01/2015] [Indexed: 11/09/2022] Open
Abstract
Viruses are ubiquitous and present in a wide range of settings, from living organisms to various environments. Although viruses are regarded as important pathogens in higher plants, viral populations in specific host plants have not yet been fully examined. This study revealed viral populations in grape berries obtained from a cultivar from a single vineyard using currently available grapevine transcriptomes. Eight viruses and two viroids were identified using 11 grapevine libraries. Virus-associated sequences in each transcriptome ranged from 0.2% (seed) to 8.8% (skin). The amount of viral RNAs and virus copy numbers was quantified, thus revealing the dominant virus or viroid in each individual library. In addition, five viral genomes were successfully assembled de novo using transcriptome data. Phylogenetic analyses revealed that the viruses and viroids might have originated from Europe, along with the host. Single nucleotide variation studies revealed the quasispecies of RNA viruses. Taken together, this study defines complex viral populations in three different grape tissues from a single vineyard.
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Affiliation(s)
- Yeonhwa Jo
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hoseong Choi
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Jin Kyong Cho
- Department of Fruit Tree, Korea National College of Agriculture and Fisheries, Jeonju, 560-500, Republic of Korea
| | - Ju-Yeon Yoon
- Virology Unit, Department of Horticultural Environment, National Institute of Horticultural and Herbal Science, RDA, Wan-Ju, 565-852, Republic of Korea
| | - Seung-Kook Choi
- Virology Unit, Department of Horticultural Environment, National Institute of Horticultural and Herbal Science, RDA, Wan-Ju, 565-852, Republic of Korea
| | - Won Kyong Cho
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
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20
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What has been happening with viroids? Virus Genes 2014; 49:175-84. [DOI: 10.1007/s11262-014-1110-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 08/18/2014] [Indexed: 12/18/2022]
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