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Wang Y, Shi Y, Li H, Chang J. Understanding Citrus Viroid Interactions: Experience and Prospects. Viruses 2024; 16:577. [PMID: 38675919 PMCID: PMC11053686 DOI: 10.3390/v16040577] [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: 03/10/2024] [Revised: 03/28/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
Citrus is the natural host of at least eight viroid species, providing a natural platform for studying interactions among viroids. The latter manifests as antagonistic or synergistic phenomena. The antagonistic effect among citrus viroids intuitively leads to reduced symptoms caused by citrus viroids, while the synergistic effect leads to an increase in symptom severity. The interaction phenomenon is complex and interesting, and a deep understanding of the underlying mechanisms induced during this viroid interaction is of great significance for the prevention and control of viroid diseases. This paper summarizes the research progress of citrus viroids in recent years, focusing on the interaction phenomenon and analyzing their interaction mechanisms. It points out the core role of the host RNA silencing mechanism and viroid-derived siRNA (vd-siRNA), and provides suggestions for future research directions.
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Affiliation(s)
- Yafei Wang
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China; (Y.S.); (H.L.); (J.C.)
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2
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Cisneros AE, Lisón P, Campos L, López-Tubau JM, Altabella T, Ferrer A, Daròs JA, Carbonell A. Down-regulation of tomato STEROL GLYCOSYLTRANSFERASE 1 perturbs plant development and facilitates viroid infection. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:1564-1578. [PMID: 36111947 PMCID: PMC10010610 DOI: 10.1093/jxb/erac361] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Potato spindle tuber viroid (PSTVd) is a plant pathogen naturally infecting economically important crops such as tomato (Solanum lycopersicum). Here, we aimed to engineer tomato plants highly resistant to PSTVd and developed several S. lycopersicum lines expressing an artificial microRNA (amiRNA) against PSTVd (amiR-PSTVd). Infectivity assays revealed that amiR-PSTVd-expressing lines were not resistant but instead hypersusceptible to the viroid. A combination of phenotypic, molecular, and metabolic analyses of amiRNA-expressing lines non-inoculated with the viroid revealed that amiR-PSTVd was accidentally silencing the tomato STEROL GLYCOSYLTRANSFERASE 1 (SlSGT1) gene, which caused late developmental and reproductive defects such as leaf epinasty, dwarfism, or reduced fruit size. Importantly, two independent transgenic tomato lines each expressing a different amiRNA specifically designed to target SlSGT1 were also hypersusceptible to PSTVd, thus demonstrating that down-regulation of SlSGT1 was responsible for the viroid-hypersusceptibility phenotype. Our results highlight the role of sterol glycosyltransferases in proper plant development and indicate that the imbalance of sterol glycosylation levels favors viroid infection, most likely by facilitating viroid movement.
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Affiliation(s)
- Adriana E Cisneros
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València), 46022 Valencia, Spain
| | - Purificación Lisón
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València), 46022 Valencia, Spain
| | - Laura Campos
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València), 46022 Valencia, Spain
| | - Joan Manel López-Tubau
- Centre for Research in Agricultural Genomics (CSIC-IRTA-IAB-UB), Bellaterra, Barcelona, Spain
| | - Teresa Altabella
- Centre for Research in Agricultural Genomics (CSIC-IRTA-IAB-UB), Bellaterra, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain
| | - Albert Ferrer
- Centre for Research in Agricultural Genomics (CSIC-IRTA-IAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València), 46022 Valencia, Spain
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3
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Di Serio F, Owens RA, Navarro B, Serra P, Martínez de Alba ÁE, Delgado S, Carbonell A, Gago-Zachert S. Role of RNA silencing in plant-viroid interactions and in viroid pathogenesis. Virus Res 2023; 323:198964. [PMID: 36223861 PMCID: PMC10194176 DOI: 10.1016/j.virusres.2022.198964] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/04/2022] [Accepted: 10/07/2022] [Indexed: 11/05/2022]
Abstract
Viroids are small, single-stranded, non-protein coding and circular RNAs able to infect host plants in the absence of any helper virus. They may elicit symptoms in their hosts, but the underlying molecular pathways are only partially known. Here we address the role of post-transcriptional RNA silencing in plant-viroid-interplay, with major emphasis on the involvement of this sequence-specific RNA degradation mechanism in both plant antiviroid defence and viroid pathogenesis. This review is a tribute to the memory of Dr. Ricardo Flores, who largely contributed to elucidate this and other molecular mechanisms involved in plant-viroid interactions.
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Affiliation(s)
- Francesco Di Serio
- Institute for Sustainable Plant Protection, National Research Council, Bari 70122, Italy.
| | - Robert A Owens
- Molecular Plant Pathology Laboratory, US Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Beatriz Navarro
- Institute for Sustainable Plant Protection, National Research Council, Bari 70122, Italy
| | - Pedro Serra
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València), Valencia 46022, Spain
| | - Ángel Emilio Martínez de Alba
- Institute for Agribiotechnology Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, Villamayor 37185, Salamanca, Spain
| | - Sonia Delgado
- Instituto Agroforestal Mediterráneo (IAM-UPV), Camino de Vera, s/n 46022, Valencia, Spain
| | - Alberto Carbonell
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València), Valencia 46022, Spain
| | - Selma Gago-Zachert
- Institute of Biochemistry and Biotechnology, Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale 06120, Germany
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4
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Carbonell A. RNAi tools for controlling viroid diseases. Virus Res 2022; 313:198729. [DOI: 10.1016/j.virusres.2022.198729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/02/2022] [Accepted: 03/05/2022] [Indexed: 12/01/2022]
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5
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Dalakouras A, Vlachostergios D. Epigenetic approaches to crop breeding: current status and perspectives. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5356-5371. [PMID: 34017985 DOI: 10.1093/jxb/erab227] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/18/2021] [Indexed: 05/10/2023]
Abstract
In order to tackle the cumulative adverse effects of global climate change, reduced farmland, and heightened needs of an ever-increasing world population, modern agriculture is in urgent search of solutions that can ensure world food security and sustainable development. Classical crop breeding is still a powerful method to obtain crops with valued agronomical traits, but its potential is gradually being compromised by the menacing decline of genetic variation. Resorting to the epigenome as a source of variation could serve as a promising alternative. Here, we discuss current status of epigenetics-mediated crop breeding (epibreeding), highlight its advances and limitations, outline currently available methodologies, and propose novel RNA-based strategies to modify the epigenome in a gene-specific and transgene-free manner.
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Affiliation(s)
- Athanasios Dalakouras
- Institute of Industrial and Forage Crops, HAO-DEMETER, 41335 Larissa, Greece
- Institute of Plant Breeding and Genetic Resources, HAO-DEMETER, 57001 Thessaloniki, Greece
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6
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Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants. Cells 2021; 10:cells10051187. [PMID: 34067940 PMCID: PMC8152041 DOI: 10.3390/cells10051187] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/11/2022] Open
Abstract
Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.
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Potrokhov A, Sosnovska D, Ovcharenko O, Budzanivska I, Rudas V, Kuchuk M. Increased ribonuclease activity in Solanum tuberosum L. transformed with heterologous genes of apoplastic ribonucleases as a putative approach for production of virus resistant plants. ACTA ACUST UNITED AC 2021; 45:79-87. [PMID: 33597824 PMCID: PMC7877712 DOI: 10.3906/biy-2007-87] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/01/2020] [Indexed: 01/09/2023]
Abstract
Viral pathogens seriously decrease the yield of potato (Solanum tuberosum L.) –an important agricultural crop. Therefore, there is a demand for potato cultivars resistant to multiple viruses. Ribonucleases (RNases) are supposed to be engaged to antiviral response in plants. Heterologous RNase gene expression provides a tool for production of cultivars with multiple resistance to viruses and viroids. Transgenic potato cultivars Luhivs’ka and Lasynak with heterologous genes bov and ZRNase II of apoplastic RNases from Bos taurus and Zinniaelegans respectively were obtained via Agrobacterium-mediated transformation. The presence of bov and ZRNase II transgenes was confirmed by PCR analysis. RNase activity was examined by modified Oleshko method. Plants with heterologous ribonuclease genes had higher level of RNase activity compared to nontransgenic ones. Transgenic plants inoculated with Potato virus Y, PVY (genus Potyvirus, family Potyviridae) demonstrated delayed and less severe symptoms of viral infection. DAS-ELISA confirmed the presence of viral antigens both in transformed and control plants. Visual manifestations of viral infection in transgenic potatoes were milder than in control plants and their development was delayed, but complete elimination of the virus did not occur.
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Affiliation(s)
- Andrii Potrokhov
- Institute of Cell Biology and Genetic Engineering NAS Ukraine, Kyiv Ukraine
| | - Daria Sosnovska
- Virology Department, Educational and Scientific Center, Institute of Biology and Medicine of Taras Shevchenko National University of Kyiv, Kyiv Ukraine
| | - Olga Ovcharenko
- Institute of Cell Biology and Genetic Engineering NAS Ukraine, Kyiv Ukraine
| | - Irena Budzanivska
- Virology Department, Educational and Scientific Center, Institute of Biology and Medicine of Taras Shevchenko National University of Kyiv, Kyiv Ukraine
| | - Volodymyr Rudas
- Institute of Cell Biology and Genetic Engineering NAS Ukraine, Kyiv Ukraine
| | - Mykola Kuchuk
- Institute of Cell Biology and Genetic Engineering NAS Ukraine, Kyiv Ukraine
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Marwal A, Gaur RK. Host Plant Strategies to Combat Against Viruses Effector Proteins. Curr Genomics 2020; 21:401-410. [PMID: 33093803 PMCID: PMC7536791 DOI: 10.2174/1389202921999200712135131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 02/02/2023] Open
Abstract
Viruses are obligate parasites that exist in an inactive state until they enter the host body. Upon entry, viruses become active and start replicating by using the host cell machinery. All plant viruses can augment their transmission, thus powering their detrimental effects on the host plant. To diminish infection and diseases caused by viruses, the plant has a defence mechanism known as pathogenesis-related biochemicals, which are metabolites and proteins. Proteins that ultimately prevent pathogenic diseases are called R proteins. Several plant R genes (that confirm resistance) and avirulence protein (Avr) (pathogen Avr gene-encoded proteins [effector/elicitor proteins involved in pathogenicity]) molecules have been identified. The recognition of such a factor results in the plant defence mechanism. During plant viral infection, the replication and expression of a viral molecule lead to a series of a hypersensitive response (HR) and affect the host plant's immunity (pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity). Avr protein renders the host RNA silencing mechanism and its innate immunity, chiefly known as silencing suppressors towards the plant defensive machinery. This is a strong reply to the plant defensive machinery by harmful plant viruses. In this review, we describe the plant pathogen resistance protein and how these proteins regulate host immunity during plant-virus interactions. Furthermore, we have discussed regarding ribosome-inactivating proteins, ubiquitin proteasome system, translation repression (nuclear shuttle protein interacting kinase 1), DNA methylation, dominant resistance genes, and autophagy-mediated protein degradation, which are crucial in antiviral defences.
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Affiliation(s)
- Avinash Marwal
- 1Department of Biotechnology, Vigyan Bhawan - Block B, New Campus, Mohanlal Sukhadia University, Udaipur, Rajasthan - 313001, India; 2Department of Biotechnology, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, Uttar Pradesh - 273009, India
| | - Rajarshi Kumar Gaur
- 1Department of Biotechnology, Vigyan Bhawan - Block B, New Campus, Mohanlal Sukhadia University, Udaipur, Rajasthan - 313001, India; 2Department of Biotechnology, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, Uttar Pradesh - 273009, India
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9
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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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Dalakouras A, Wassenegger M, Dadami E, Ganopoulos I, Pappas ML, Papadopoulou K. Genetically Modified Organism-Free RNA Interference: Exogenous Application of RNA Molecules in Plants. PLANT PHYSIOLOGY 2020; 182:38-50. [PMID: 31285292 PMCID: PMC6945881 DOI: 10.1104/pp.19.00570] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 06/28/2019] [Indexed: 05/08/2023]
Abstract
The latest advances in the field exogenous application of RNA molecules in plants help to protect and modify them through RNA interference (RNAi).
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Affiliation(s)
- Athanasios Dalakouras
- University of Thessaly, Department of Biochemistry and Biotechnology, 41500 Larissa, Greece
- Institute of Plant Breeding and Genetic Resources Hellenic Agricultural Organization (ELGO)-DEMETER, 57001 Thessaloniki, Greece
| | - Michael Wassenegger
- RLP AgroScience, Alplanta Institute for Plant Research, 67435 Neustadt an der Weinstrasse, Germany
| | - Elena Dadami
- University of Thessaly, Department of Biochemistry and Biotechnology, 41500 Larissa, Greece
| | - Ioannis Ganopoulos
- Institute of Plant Breeding and Genetic Resources Hellenic Agricultural Organization (ELGO)-DEMETER, 57001 Thessaloniki, Greece
| | - Maria L Pappas
- Democritus University of Thrace, Department of Agricultural Development, 68200 Orestiada, Greece
| | - Kalliope Papadopoulou
- University of Thessaly, Department of Biochemistry and Biotechnology, 41500 Larissa, Greece
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11
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Suzuki T, Ikeda S, Kasai A, Taneda A, Fujibayashi M, Sugawara K, Okuta M, Maeda H, Sano T. RNAi-Mediated Down-Regulation of Dicer-Like 2 and 4 Changes the Response of 'Moneymaker' Tomato to Potato Spindle Tuber Viroid Infection from Tolerance to Lethal Systemic Necrosis, Accompanied by Up-Regulation of miR398, 398a-3p and Production of Excessive Amount of Reactive Oxygen Species. Viruses 2019; 11:v11040344. [PMID: 31013904 PMCID: PMC6521110 DOI: 10.3390/v11040344] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 12/14/2022] Open
Abstract
To examine the role of RNA silencing in plant defenses against viroids, a Dicer-like 2 and 4 (DCL2&4)–double knockdown transgenic tomato plant line, 72E, was created. The expression of endogenous SlDCL2s and SlDCL4 in line 72E decreased to about a half that of the empty cassette line, EC. When challenged with potato spindle tuber viroid (PSTVd), line 72E showed significantly higher levels of PSTVd accumulation early in the course of the infection and lethal systemic necrosis late in the infection. The size distribution of PSTVd-derived small RNAs was significantly different with the number of RNAs of 21 and 22 nucleotides (nt) in line 72E, at approximately 66.7% and 5% of those in line EC, respectively. Conversely, the numbers of 24 nt species increased by 1100%. Furthermore, expression of the stress-responsive microRNA species miR398 and miR398a-3p increased 770% and 868% in the PSTVd-infected line 72E compared with the PSTVd-infected EC. At the same time, the expression of cytosolic and chloroplast-localized Cu/Zn-superoxide dismutase 1 and 2 (SOD1 and SOD2) and the copper chaperon for SOD (CCS1) mRNAs, potential targets of miR398 or 398a-3p, decreased significantly in the PSTVd-infected line 72E leaves, showing necrosis. In concert with miR398 and 398a-3p, SODs control the detoxification of reactive oxygen species (ROS) generated in cells. Since high levels of ROS production were observed in PSTVd-infected line 72E plants, it is likely that the lack of full dicer-likes (DCL) activity in these plants made them unable to control excessive ROS production after PSTVd infection, as disruption in the ability of miR398 and miR398a-3p to regulate SODs resulted in the development of lethal systemic necrosis.
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Affiliation(s)
- Takahiro Suzuki
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
- Union Graduate School of Agricultural Sciences, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
| | - Sho Ikeda
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
| | - Atsushi Kasai
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
| | - Akito Taneda
- Graduate School of Science and Technology, 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.
| | - Kohei Sugawara
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
| | - Maki Okuta
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
| | - Hayato Maeda
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
| | - Teruo Sano
- Faculty of Agriculture and Life Science, Hirosaki University, Bunkyo-cho 3, Hirosaki 036-8561, Japan.
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12
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Chrysanthemum Stunt Viroid Resistance in Chrysanthemum. Viruses 2018; 10:v10120719. [PMID: 30562919 PMCID: PMC6315827 DOI: 10.3390/v10120719] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 12/17/2022] Open
Abstract
Chrysanthemum stunt viroid (CSVd) is one of the most severe threats in Chrysanthemum morifolium production. Over the last decade, several studies have reported the natural occurrence of CSVd resistance in chrysanthemum germplasms. Such CSVd-resistant germplasms are desirable for the stable production of chrysanthemum plants. Current surveys include finding new resistant chrysanthemum cultivars, breeding, and revealing resistant mechanisms. We review the progress, from discovery to current status, of CSVd-resistance studies, while introducing information on the improvement of associated inoculation and diagnostic techniques.
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Potato Spindle Tuber Viroid Modulates Its Replication through a Direct Interaction with a Splicing Regulator. J Virol 2018; 92:JVI.01004-18. [PMID: 30068655 DOI: 10.1128/jvi.01004-18] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/29/2018] [Indexed: 12/13/2022] Open
Abstract
Viroids are circular noncoding RNAs (ncRNAs) that infect plants. Despite differences in the genetic makeup and biogenesis, viroids and various long ncRNAs all rely on RNA structure-based interactions with cellular factors for function. Viroids replicating in the nucleus utilize DNA-dependent RNA polymerase II for transcription, a process that involves a unique splicing form of transcription factor IIIA (TFIIIA-7ZF). Here, we provide evidence showing that potato spindle tuber viroid (PSTVd) interacts with a TFIIIA splicing regulator (ribosomal protein L5 [RPL5]) in vitro and in vivo PSTVd infection compromises the regulatory role of RPL5 over splicing of TFIIIA transcripts, while ectopic expression of RPL5 reduces TFIIIA-7ZF expression and attenuates PSTVd accumulation. Furthermore, we illustrate that the RPL5 binding site on the PSTVd genome resides in the central conserved region critical for replication. Together, our data suggest that viroids can regulate their own replication and modulate specific regulatory factors leading to splicing changes in only one or a few genes. This study also has implications for understanding the functional mechanisms of ncRNAs and elucidating the global splicing changes in various host-pathogen interactions.IMPORTANCE Viroids are the smallest replicons among all living entities. As circular noncoding RNAs, viroids can replicate and spread in plants, often resulting in disease symptoms. Potato spindle tuber viroid (PSTVd), the type species of nuclear-replicating viroids, requires a unique splicing form of transcription factor IIIA (TFIIIA-7ZF) for its propagation. Here, we provide evidence showing that PSTVd directly interacts with a splicing regulator, RPL5, to favor the expression of TFIIIA-7ZF, thereby promoting viroid replication. This finding provides new insights to better understand viroid biology and sheds light on the noncoding RNA-based regulation of splicing. Our discovery also establishes RPL5 as a novel negative factor regulating viroid replication in the nucleus and highlights a potential means for viroid control.
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Islam W, Noman A, Qasim M, Wang L. Plant Responses to Pathogen Attack: Small RNAs in Focus. Int J Mol Sci 2018; 19:E515. [PMID: 29419801 PMCID: PMC5855737 DOI: 10.3390/ijms19020515] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/04/2018] [Accepted: 02/05/2018] [Indexed: 12/25/2022] Open
Abstract
Small RNAs (sRNA) are a significant group of gene expression regulators for multiple biological processes in eukaryotes. In plants, many sRNA silencing pathways produce extensive array of sRNAs with specialized roles. The evidence on record advocates for the functions of sRNAs during plant microbe interactions. Host sRNAs are reckoned as mandatory elements of plant defense. sRNAs involved in plant defense processes via different pathways include both short interfering RNA (siRNA) and microRNA (miRNA) that actively regulate immunity in response to pathogenic attack via tackling pathogen-associated molecular patterns (PAMPs) and other effectors. In response to pathogen attack, plants protect themselves with the help of sRNA-dependent immune systems. That sRNA-mediated plant defense responses play a role during infections is an established fact. However, the regulations of several sRNAs still need extensive research. In this review, we discussed the topical advancements and findings relevant to pathogen attack and plant defense mediated by sRNAs. We attempted to point out diverse sRNAs as key defenders in plant systems. It is hoped that sRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases.
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Affiliation(s)
- Waqar Islam
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Ali Noman
- Department of Botany, Government College University, Faisalabad 38040, Pakistan.
- College of Crop Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Muhammad Qasim
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Liande Wang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Nabeshima T, Doi M, Hosokawa M. Comparative Analysis of Chrysanthemum Stunt Viroid Accumulation and Movement in Two Chrysanthemum ( Chrysanthemum morifolium) Cultivars with Differential Susceptibility to the Viroid Infection. FRONTIERS IN PLANT SCIENCE 2017; 8:1940. [PMID: 29250083 PMCID: PMC5715398 DOI: 10.3389/fpls.2017.01940] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
Chrysanthemum stunt viroid (CSVd) was inoculated into two chrysanthemum (Chrysanthemum morifolium) cultivars, the CSVd-susceptible cultivar Piato and the CSVd-resistant cultivar Mari Kazaguruma. For CSVd inoculation, grafting and Agrobacterium-mediated inoculation were used. In grafting experiments, CSVd was detectable in Mari Kazaguruma after grafting onto infected Piato, but after removal of infected rootstocks, CSVd could not be detected in the uppermost leaves. In agroinfection experiments, CSVd systemic infection was observed in Piato but not in Mari Kazaguruma. However, agro-inoculated leaves of Mari Kazaguruma accumulated circular CSVd RNA to levels equivalent to those in Piato at 7 days post-inoculation. In situ detection of CSVd in inoculated leaves revealed that CSVd was absent in phloem of Mari Kazaguruma, while CSVd strongly localized to this site in Piato. We hypothesize that CSVd resistance in Mari Kazaguruma relates not to CSVd replication but to CSVd movement in leaves.
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Flores R, Navarro B, Kovalskaya N, Hammond RW, Di Serio F. Engineering resistance against viroids. Curr Opin Virol 2017; 26:1-7. [PMID: 28738223 DOI: 10.1016/j.coviro.2017.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/28/2017] [Accepted: 07/05/2017] [Indexed: 01/19/2023]
Abstract
Viroids, the smallest infectious agents endowed with autonomous replication, are tiny single-stranded circular RNAs (∼250 to 400nt) without protein-coding ability that, despite their simplicity, infect and often cause disease in herbaceous and woody plants of economic relevance. To mitigate the resulting losses, several strategies have been developed, the most effective of which include: firstly, search for naturally resistant cultivars and breeding for resistance, secondly, induced resistance by pre-infection with mild strains, thirdly, ribonucleases targeting double-stranded RNAs and catalytic antibodies endowed with intrinsic ribonuclease activity, fourthly, antisense, and sense, RNAs, fifthly, catalytic antisense RNAs derived from hammerhead ribozymes, and sixthly, hairpin RNAs and artificial small RNAs for RNA interference. The mechanisms underpinning these strategies, most of which have been implemented via genetic transformation, together with their present results and future potential, are the subject of this review.
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Affiliation(s)
- Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Valencia 46022, Spain.
| | - Beatriz Navarro
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, 70126 Bari, Italy
| | - Natalia Kovalskaya
- Molecular Plant Pathology Laboratory, USDA-ARS-BARC, Beltsville, MD 20705, USA
| | - Rosemarie W Hammond
- Molecular Plant Pathology Laboratory, USDA-ARS-BARC, Beltsville, MD 20705, USA
| | - Francesco Di Serio
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, 70126 Bari, Italy
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Carbonell A, Daròs J. Artificial microRNAs and synthetic trans-acting small interfering RNAs interfere with viroid infection. MOLECULAR PLANT PATHOLOGY 2017; 18:746-753. [PMID: 28026103 PMCID: PMC6638287 DOI: 10.1111/mpp.12529] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/14/2016] [Accepted: 12/17/2016] [Indexed: 05/18/2023]
Abstract
Artificial microRNAs (amiRNAs) and synthetic trans-acting small interfering RNAs (syn-tasiRNAs) are two classes of artificial small RNAs (sRNAs) engineered to silence endogenous transcripts as well as viral RNAs in plants. Here, we explore the possibility of using amiRNAs and syn-tasiRNAs to specifically interfere with infections by viroids, small (250-400-nucleotide) non-coding circular RNAs with compact secondary structure infecting a wide range of plant species. The combined use of recent high-throughput methods for artificial sRNA construct generation and the Potato spindle tuber viroid (PSTVd)-Nicotiana benthamiana pathosystem allowed for the simple and time-effective screening of multiple artificial sRNAs targeting sites distributed along PSTVd RNAs of (+) or (-) polarity. The majority of amiRNAs were highly active in agroinfiltrated leaves when co-expressed with an infectious PSTVd transcript, as were syn-tasiRNAs derived from a construct including the five most effective amiRNA sequences. A comparative analysis showed that the effects of the most effective amiRNA and of the syn-tasiRNAs were similar in agroinfiltrated leaves, as well as in upper non-agroinfiltrated leaves in which PSTVd accumulation was significantly delayed. These results suggest that amiRNAs and syn-tasiRNAs can be used effectively to control viroid infections in plants.
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Affiliation(s)
- Alberto Carbonell
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas‐Universidad Politécnica de Valencia)Valencia46022Spain
| | - José‐Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas‐Universidad Politécnica de Valencia)Valencia46022Spain
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