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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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Animasaun DA, Lawrence JA. Antisense RNA (asRNA) technology: the concept and applications in crop improvement and sustainable agriculture. Mol Biol Rep 2023; 50:9545-9557. [PMID: 37755651 DOI: 10.1007/s11033-023-08814-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023]
Abstract
Antisense RNA (asRNA) technology is a method used to silence genes and inhibit their expression. Gene function relies on expression, which follows the central dogma of molecular biology. The use of asRNA can regulate gene expression by targeting specific mRNAs, which can result in changes in phenotype, disease resistance, and other traits associated with protein expression profiles. This technology uses short, single-stranded oligonucleotide strands that are complementary to the targeted mRNA. Manipulating and regulating protein expression during its translation can either knock out or knock down the expression of a gene of interest. Therefore, functional genomics can benefit from this technology since it allows for the regulation of protein expression. In this review, we discuss the concept, and applications of asRNA technology which include delaying ripening, prolonging shelf life, biofortification, and increasing biotic and abiotic resistance among others in crop improvement and sustainable agriculture.
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Affiliation(s)
- David Adedayo Animasaun
- Department of Plant Biology, Faculty of Life Sciences, University of Ilorin, P.M.B. 1515, Ilorin, Kwara State, Nigeria.
- Plant Tissue Culture Lab, Central Research Laboratories, University of Ilorin, P.M.B.1515, Ilorin, Kwara State, Nigeria.
| | - Judith Amaka Lawrence
- Department of Plant Biology, Faculty of Life Sciences, University of Ilorin, P.M.B. 1515, Ilorin, Kwara State, Nigeria.
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3
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Jiang C, Li Z, Zheng L, Yu Y, Niu D. Small RNAs: Efficient and miraculous effectors that play key roles in plant-microbe interactions. MOLECULAR PLANT PATHOLOGY 2023; 24:999-1013. [PMID: 37026481 PMCID: PMC10346379 DOI: 10.1111/mpp.13329] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
Plants' response to pathogens is highly complex and involves changes at different levels, such as activation or repression of a vast array of genes. Recently, many studies have demonstrated that many RNAs, especially small RNAs (sRNAs), are involved in genetic expression and reprogramming affecting plant-pathogen interactions. The sRNAs, including short interfering RNAs and microRNAs, are noncoding RNA with 18-30 nucleotides, and are recognized as key genetic and epigenetic regulators. In this review, we summarize the new findings about defence-related sRNAs in the response to pathogens and our current understanding of their effects on plant-pathogen interactions. The main content of this review article includes the roles of sRNAs in plant-pathogen interactions, cross-kingdom sRNA trafficking between host and pathogen, and the application of RNA-based fungicides for plant disease control.
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Affiliation(s)
- Chun‐Hao Jiang
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Integrated Management of Crop Disease and Pests, Ministry of Education/Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture/Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
- Engineering Center of Bioresource Pesticide in Jiangsu ProvinceNanjingChina
| | - Zi‐Jie Li
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Integrated Management of Crop Disease and Pests, Ministry of Education/Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture/Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
- Engineering Center of Bioresource Pesticide in Jiangsu ProvinceNanjingChina
| | - Li‐Yu Zheng
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Integrated Management of Crop Disease and Pests, Ministry of Education/Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture/Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
- Engineering Center of Bioresource Pesticide in Jiangsu ProvinceNanjingChina
| | - Yi‐Yang Yu
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Integrated Management of Crop Disease and Pests, Ministry of Education/Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture/Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
- Engineering Center of Bioresource Pesticide in Jiangsu ProvinceNanjingChina
| | - Dong‐Dong Niu
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Integrated Management of Crop Disease and Pests, Ministry of Education/Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture/Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjingChina
- Engineering Center of Bioresource Pesticide in Jiangsu ProvinceNanjingChina
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4
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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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5
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Ortolá B, Daròs JA. Viroids: Non-Coding Circular RNAs Able to Autonomously Replicate and Infect Higher Plants. BIOLOGY 2023; 12:biology12020172. [PMID: 36829451 PMCID: PMC9952643 DOI: 10.3390/biology12020172] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023]
Abstract
Viroids are a unique type of infectious agent, exclusively composed of a relatively small (246-430 nt), highly base-paired, circular, non-coding RNA. Despite the small size and non-coding nature, the more-than-thirty currently known viroid species infectious of higher plants are able to autonomously replicate and move systemically through the host, thereby inducing disease in some plants. After recalling viroid discovery back in the late 60s and early 70s of last century and discussing current hypotheses about their evolutionary origin, this article reviews our current knowledge about these peculiar infectious agents. We describe the highly base-paired viroid molecules that fold in rod-like or branched structures and viroid taxonomic classification in two families, Pospiviroidae and Avsunviroidae, likely gathering nuclear and chloroplastic viroids, respectively. We review current knowledge about viroid replication through RNA-to-RNA rolling-circle mechanisms in which host factors, notably RNA transporters, RNA polymerases, RNases, and RNA ligases, are involved. Systemic movement through the infected plant, plant-to-plant transmission and host range are also discussed. Finally, we focus on the mechanisms of viroid pathogenesis, in which RNA silencing has acquired remarkable importance, and also for the initiation of potential biotechnological applications of viroid molecules.
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6
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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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7
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Villegas-Estrada B, Sánchez MA, Valencia-Jiménez A. Foliar Infiltration of Virus-Derived Small Hairpin RNAs Triggers the RNAi Mechanism against the Cucumber Mosaic Virus. Int J Mol Sci 2022; 23:4938. [PMID: 35563329 PMCID: PMC9104436 DOI: 10.3390/ijms23094938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/14/2022] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
Post-transcriptional gene silencing (PTGS) is an evolutionarily conserved plant defense mechanism against viruses. This paper aimed to evaluate a dsDNA construct (77 bp) as a template for in vitro production of virus-derived artificial small hairpin RNAs (shRNAs) and test for their potential to trigger the RNAi mechanism in Nicotiana benthamiana plants against CMV after their foliar infiltration. This approach allowed for the production of significant amounts of shRNAs (60-mers) quickly and easily. The gene silencing was confirmed using polymerase chain reaction (PCR), immunological-based assays, and real-time PCR (qPCR). The highest levels of gene silencing were recorded for mRNAs coding for replication protein (ORF1a), the viral suppressor of RNA silencing (ORF2b), and the capsid protein (ORF3b), with 98, 94, and 70% of total transcript silencing, respectively. This protocol provides an alternative to producing significant shRNAs that can effectively trigger the RNAi mechanism against CMV.
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Affiliation(s)
| | | | - Arnubio Valencia-Jiménez
- Departamento de Producción Agropecuaria, Universidad de Caldas, Manizales 170004, Caldas, Colombia;
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8
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Advances in RNA-Silencing-Related Resistance against Viruses in Potato. Genes (Basel) 2022; 13:genes13050731. [PMID: 35627117 PMCID: PMC9141481 DOI: 10.3390/genes13050731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/20/2022] [Accepted: 04/20/2022] [Indexed: 12/16/2022] Open
Abstract
Potato is a major food crop that has the potential to feed the increasing global population. Potato is the fourth most important crop and a staple food for many people worldwide. The traditional breeding of potato poses many challenges because of its autotetraploid nature and its tendency toward inbreeding depression. Moreover, potato crops suffer considerable production losses because of infections caused by plant viruses. In this context, RNA silencing technology has been successfully applied in model and crop species. In this review, we describe the RNA interference (RNAi) mechanisms, including small-interfering RNA, microRNA, and artificial microRNA, which may be used to engineer resistance against potato viruses. We also explore the latest advances in the development of antiviral strategies to enhance resistance against potato virus X, potato virus Y, potato virus A, potato leafroll virus, and potato spindle tuber viroid. Furthermore, the challenges in RNAi that need to be overcome are described in this review. Altogether, this report would be insightful for the researchers attempting to understand the RNAi-mediated resistance against viruses in potato.
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9
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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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10
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In Memoriam of Ricardo Flores: The Career, Achievements, and Legacy of an inspirational plant virologist. Virus Res 2022. [DOI: 10.1016/j.virusres.2022.198718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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11
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Hajieghrari B, Farrokhi N. Plant RNA-mediated gene regulatory network. Genomics 2021; 114:409-442. [PMID: 34954000 DOI: 10.1016/j.ygeno.2021.12.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/21/2021] [Accepted: 12/20/2021] [Indexed: 11/26/2022]
Abstract
Not all transcribed RNAs are protein-coding RNAs. Many of them are non-protein-coding RNAs in diverse eukaryotes. However, some of them seem to be non-functional and are resulted from spurious transcription. A lot of non-protein-coding transcripts have a significant function in the translation process. Gene expressions depend on complex networks of diverse gene regulatory pathways. Several non-protein-coding RNAs regulate gene expression in a sequence-specific system either at the transcriptional level or post-transcriptional level. They include a significant part of the gene expression regulatory network. RNA-mediated gene regulation machinery is evolutionarily ancient. They well-evolved during the evolutionary time and are becoming much more complex than had been expected. In this review, we are trying to summarizing the current knowledge in the field of RNA-mediated gene silencing.
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Affiliation(s)
- Behzad Hajieghrari
- Department of Agricultural Biotechnology, College of Agriculture, Jahrom University, Jahrom, Iran.
| | - Naser Farrokhi
- Department of Cell, Molecular Biology Faculty of Life Sciences, Biotechnology, Shahid Beheshti University, G. C Evin, Tehran, Iran.
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12
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Kaur R, Choudhury A, Chauhan S, Ghosh A, Tiwari R, Rajam MV. RNA interference and crop protection against biotic stresses. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2357-2377. [PMID: 34744371 PMCID: PMC8526635 DOI: 10.1007/s12298-021-01064-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 08/14/2021] [Accepted: 09/07/2021] [Indexed: 05/26/2023]
Abstract
RNA interference (RNAi) is a universal phenomenon of RNA silencing or gene silencing with broader implications in important physiological and developmental processes of most eukaryotes, including plants. Small RNA (sRNA) are the critical drivers of the RNAi machinery that ensures down-regulation of the target genes in a homology-dependent manner and includes small-interfering RNAs (siRNAs) and micro RNAs (miRNAs). Plant researchers across the globe have exploited the powerful technique of RNAi to execute targeted suppression of desired genes in important crop plants, with an intent to improve crop protection against pathogens and pests for sustainable crop production. Biotic stresses cause severe losses to the agricultural productivity leading to food insecurity for future generations. RNAi has majorly contributed towards the development of designer crops that are resilient towards the various biotic stresses such as viruses, bacteria, fungi, insect pests, and nematodes. This review summarizes the recent progress made in the RNAi-mediated strategies against these biotic stresses, along with new insights on the future directions in research involving RNAi for crop protection.
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Affiliation(s)
- Ranjeet Kaur
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Aparajita Choudhury
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Sambhavana Chauhan
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Arundhati Ghosh
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Ruby Tiwari
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Manchikatla Venkat Rajam
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
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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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14
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Naoi T, Hataya T. Tolerance Even to Lethal Strain of Potato Spindle Tuber Viroid Found in Wild Tomato Species Can Be Introduced by Crossing. PLANTS 2021; 10:plants10030575. [PMID: 33803660 PMCID: PMC8003082 DOI: 10.3390/plants10030575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022]
Abstract
To date, natural resistance or tolerance, which can be introduced into crops by crossing, to potato spindle tuber viroid (PSTVd) has not been reported. Additionally, responses to PSTVd infection in many wild tomato species, including some species that can be crossed with PSTVd-susceptible cultivated tomatoes (Solanum lycopersicum var. lycoperaicum), have not been ascertained. The aim of this study was to evaluate responses to PSTVd infection including resistance and tolerance. Accordingly, we inoculated several cultivated and wild tomato species with intermediate and lethal strains of PSTVd. None of the host plants exhibited sufficient resistance to PSTVd to render systemic infection impossible; however, these plants displayed other responses, including tolerance. Further analysis of PSTVd accumulation revealed low accumulation of PSTVd in two wild species, exhibiting high tolerance, even to the lethal strain. Additionally, F1 hybrids generated by crossing a PSTVd-sensitive wild tomato (Solanum lycopersicum var. cerasiforme) with these wild relatives also exhibited tolerance to the lethal PSTVd strain, which is accompanied by low PSTVd accumulation during early infection. These results indicate that the tolerance toward PSTVd in wild species is a dominant trait and can be utilized for tomato breeding by crossing.
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Affiliation(s)
- Takashi Naoi
- Pathogen-Plant Interactions, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan;
| | - Tatsuji Hataya
- Pathogen-Plant Interactions, Research Faculty of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan
- Correspondence:
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15
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Flores R, Navarro B, Delgado S, Serra P, Di Serio F. Viroid pathogenesis: a critical appraisal of the role of RNA silencing in triggering the initial molecular lesion. FEMS Microbiol Rev 2021; 44:386-398. [PMID: 32379313 DOI: 10.1093/femsre/fuaa011] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 05/06/2020] [Indexed: 12/15/2022] Open
Abstract
The initial molecular lesions through which viroids, satellite RNAs and viruses trigger signal cascades resulting in plant diseases are hotly debated. Since viroids are circular non-protein-coding RNAs of ∼250-430 nucleotides, they appear very convenient to address this issue. Viroids are targeted by their host RNA silencing defense, generating viroid-derived small RNAs (vd-sRNAs) that are presumed to direct Argonaute (AGO) proteins to inactivate messenger RNAs, thus initiating disease. Here, we review the existing evidence. Viroid-induced symptoms reveal a distinction. Those attributed to vd-sRNAs from potato spindle tuber viroid and members of the family Pospiviroidae (replicating in the nucleus) are late, non-specific and systemic. In contrast, those attributed to vd-sRNAs from peach latent mosaic viroid (PLMVd) and other members of the family Avsunviroidae (replicating in plastids) are early, specific and local. Remarkably, leaf sectors expressing different PLMVd-induced chloroses accumulate viroid variants with specific pathogenic determinants. Some vd-sRNAs containing such determinant guide AGO1-mediated cleavage of mRNAs that code for proteins regulating chloroplast biogenesis/development. Therefore, the initial lesions and the expected phenotypes are connected by short signal cascades, hence supporting a cause-effect relationship. Intriguingly, one virus satellite RNA initiates disease through a similar mechanism, whereas in the Pospiviroidae and in plant viruses the situation remains uncertain.
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Affiliation(s)
- Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV), Avenida de los Naranjos s/n 46010, Valencia, Spain
| | - Beatriz Navarro
- Istituto per la Protezione Sostenibile delle Piante, Via Amendola 122/D, 70126 Bari, Italy
| | - Sonia Delgado
- Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV), Avenida de los Naranjos s/n 46010, Valencia, Spain
| | - Pedro Serra
- Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV), Avenida de los Naranjos s/n 46010, Valencia, Spain
| | - Francesco Di Serio
- Istituto per la Protezione Sostenibile delle Piante, Via Amendola 122/D, 70126 Bari, Italy
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16
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Salava H, Thula S, Mohan V, Kumar R, Maghuly F. Application of Genome Editing in Tomato Breeding: Mechanisms, Advances, and Prospects. Int J Mol Sci 2021; 22:E682. [PMID: 33445555 PMCID: PMC7827871 DOI: 10.3390/ijms22020682] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 12/19/2022] Open
Abstract
Plants regularly face the changing climatic conditions that cause biotic and abiotic stress responses. The abiotic stresses are the primary constraints affecting crop yield and nutritional quality in many crop plants. The advances in genome sequencing and high-throughput approaches have enabled the researchers to use genome editing tools for the functional characterization of many genes useful for crop improvement. The present review focuses on the genome editing tools for improving many traits such as disease resistance, abiotic stress tolerance, yield, quality, and nutritional aspects of tomato. Many candidate genes conferring tolerance to abiotic stresses such as heat, cold, drought, and salinity stress have been successfully manipulated by gene modification and editing techniques such as RNA interference, insertional mutagenesis, and clustered regularly interspaced short palindromic repeat (CRISPR/Cas9). In this regard, the genome editing tools such as CRISPR/Cas9, which is a fast and efficient technology that can be exploited to explore the genetic resources for the improvement of tomato and other crop plants in terms of stress tolerance and nutritional quality. The review presents examples of gene editing responsible for conferring both biotic and abiotic stresses in tomato simultaneously. The literature on using this powerful technology to improve fruit quality, yield, and nutritional aspects in tomato is highlighted. Finally, the prospects and challenges of genome editing, public and political acceptance in tomato are discussed.
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Affiliation(s)
- Hymavathi Salava
- Department of Plant Sciences, University of Hyderabad, Hyderabad 500064, India;
| | - Sravankumar Thula
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic;
| | - Vijee Mohan
- Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA;
| | - Rahul Kumar
- Plant Translational Research Laboratory, Department of Plant Sciences, University of Hyderabad, Hyderabad 500064, India;
| | - Fatemeh Maghuly
- Plant Functional Genomics, Institute of Molecular Biotechnology, Department of Biotechnology, BOKU-VIBT, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
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17
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Adkar-Purushothama CR, Perreault JP. Impact of Nucleic Acid Sequencing on Viroid Biology. Int J Mol Sci 2020; 21:ijms21155532. [PMID: 32752288 PMCID: PMC7432327 DOI: 10.3390/ijms21155532] [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: 07/05/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/26/2022] Open
Abstract
The early 1970s marked two breakthroughs in the field of biology: (i) The development of nucleotide sequencing technology; and, (ii) the discovery of the viroids. The first DNA sequences were obtained by two-dimensional chromatography which was later replaced by sequencing using electrophoresis technique. The subsequent development of fluorescence-based sequencing method which made DNA sequencing not only easier, but many orders of magnitude faster. The knowledge of DNA sequences has become an indispensable tool for both basic and applied research. It has shed light biology of viroids, the highly structured, circular, single-stranded non-coding RNA molecules that infect numerous economically important plants. Our understanding of viroid molecular biology and biochemistry has been intimately associated with the evolution of nucleic acid sequencing technologies. With the development of the next-generation sequence method, viroid research exponentially progressed, notably in the areas of the molecular mechanisms of viroids and viroid diseases, viroid pathogenesis, viroid quasi-species, viroid adaptability, and viroid–host interactions, to name a few examples. In this review, the progress in the understanding of viroid biology in conjunction with the improvements in nucleotide sequencing technology is summarized. The future of viroid research with respect to the use of third-generation sequencing technology is also briefly envisaged.
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Qin T, Hao W, Sun R, Li Y, Wang Y, Wei C, Dong T, Wu B, Dong N, Wang W, Sun J, Yang Q, Zhang Y, Yang S, Wang Q. Verticillium dahliae VdTHI20, Involved in Pyrimidine Biosynthesis, Is Required for DNA Repair Functions and Pathogenicity. Int J Mol Sci 2020; 21:E1378. [PMID: 32085660 PMCID: PMC7073022 DOI: 10.3390/ijms21041378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/11/2020] [Accepted: 02/15/2020] [Indexed: 11/25/2022] Open
Abstract
Verticillium dahliae (V. dahliae) infects roots and colonizes the vascular vessels of host plants, significantly reducing the economic yield of cotton and other crops. In this study, the protein VdTHI20, which is involved in the thiamine biosynthesis pathway, was characterized by knocking out the corresponding VdTHI20 gene in V. dahliae via Agrobacterium tumefaciens-mediated transformation (ATMT). The deletion of VdTHI20 resulted in several phenotypic defects in vegetative growth and conidiation and in impaired virulence in tobacco seedlings. We show that VdTHI20 increases the tolerance of V. dahliae to UV damage. The impaired vegetative growth of ΔVdTHI20 mutant strains was restored by complementation with a functional copy of the VdTHI20 gene or by supplementation with additional thiamine. Furthermore, the root infection and colonization of the ΔVdTHI20 mutant strains were suppressed, as indicated by green fluorescent protein (GFP)-labelling under microscope observation. When the RNAi constructs of VdTHI20 were used to transform Nicotiana benthamiana, the transgenic lines expressing dsVdTHI20 showed elevated resistance to V. dahliae. Together, these results suggest that VdTHI20 plays a significant role in the pathogenicity of V. dahliae. In addition, the pathogenesis-related gene VdTHI20 exhibits potential for controlling V. dahliae in important crops.
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Affiliation(s)
- Tengfei Qin
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Wei Hao
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong 999077, China;
| | - Runrun Sun
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Yuqing Li
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Yuanyuan Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Chunyan Wei
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Tao Dong
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Bingjie Wu
- College of Agriculture, Liaocheng University, Liaocheng 252059, China;
| | - Na Dong
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Weipeng Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Jialiang Sun
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Qiuyue Yang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Yaxin Zhang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Song Yang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
| | - Qinglian Wang
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Sciences and Technology, Xinxiang 453003, China; (T.Q.); (R.S.); (Y.L.); (Y.W.); (C.W.); (N.D.); (W.W.); (J.S.); (Y.Z.); (S.Y.)
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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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20
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Vurro M, Miguel-Rojas C, Pérez-de-Luque A. Safe nanotechnologies for increasing the effectiveness of environmentally friendly natural agrochemicals. PEST MANAGEMENT SCIENCE 2019; 75:2403-2412. [PMID: 30672106 DOI: 10.1002/ps.5348] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 05/05/2023]
Abstract
Natural compounds and living organisms continue to play a limited role in crop protection, and few of them have reached the market, despite their attractiveness and the efforts made in research. Very often these products have negative characteristics compared to synthetic compounds, e.g., higher costs of production, lower effectiveness, lack of persistence, and inability to reach and penetrate the target plant. Conversely, nanotechnologies are having an enormous impact on all human activities, including agriculture, even if the production of some nanomaterials is not environmentally friendly or could have adverse effects on agriculture and the environment. Thus, certain nanomaterials could facilitate the development of formulated natural pesticides, making them more effective and more environmentally friendly. Nanoformulations can improve efficacy, reduce effective doses, and increase shelf-life and persistence. Such controlled-release products can improve delivery to the target pest. This review considers certain available nanomaterials and nanotechnologies for use in agriculture, discussing their properties and the feasibility of their use in sustainable crop protection, in particular, in improving the effectiveness of natural bio-based agrochemicals. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Maurizio Vurro
- Institute of Sciences of Food Production, National Research Council (CNR), Bari, Italy
| | - Cristina Miguel-Rojas
- Department of Science and High Technology, University of Insubria and Total Scattering Laboratory, Como, Italy
| | - Alejandro Pérez-de-Luque
- Genomic and Biotechnology, Centre Alameda del Obispo, Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Cordoba, Spain
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21
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Catch Me If You Can! RNA Silencing-Based Improvement of Antiviral Plant Immunity. Viruses 2019; 11:v11070673. [PMID: 31340474 PMCID: PMC6669615 DOI: 10.3390/v11070673] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/11/2019] [Accepted: 07/17/2019] [Indexed: 12/27/2022] Open
Abstract
Viruses are obligate parasites which cause a range of severe plant diseases that affect farm productivity around the world, resulting in immense annual losses of yield. Therefore, control of viral pathogens continues to be an agronomic and scientific challenge requiring innovative and ground-breaking strategies to meet the demands of a growing world population. Over the last decade, RNA silencing has been employed to develop plants with an improved resistance to biotic stresses based on their function to provide protection from invasion by foreign nucleic acids, such as viruses. This natural phenomenon can be exploited to control agronomically relevant plant diseases. Recent evidence argues that this biotechnological method, called host-induced gene silencing, is effective against sucking insects, nematodes, and pathogenic fungi, as well as bacteria and viruses on their plant hosts. Here, we review recent studies which reveal the enormous potential that RNA-silencing strategies hold for providing an environmentally friendly mechanism to protect crop plants from viral diseases.
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22
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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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Kryovrysanaki N, Alexiadis A, Grigoriadou AM, Katsarou K, Kalantidis K. SERRATE, a miRNA biogenesis factor, affects viroid infection in Nicotiana benthamiana and Nicotiana tabacum. Virology 2019; 528:164-175. [PMID: 30599275 DOI: 10.1016/j.virol.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/14/2018] [Accepted: 12/15/2018] [Indexed: 12/14/2022]
Abstract
Viroids are plant infecting, non - coding RNA molecules of economic importance. Potato spindle tuber viroid (PSTVd), the type species of Pospiviroidae family, has been shown to be affected by specific RNA silencing pathways. Dicer like 1 (DCL1), a key player in micro RNA (miRNA) pathway has been previously linked with PSTVd infectivity. In this report we aim to further dissect the interaction between the miRNA pathway and Pospiviroid virulence. We mainly focused on the Zinc-finger protein SERRATE (SE) a co-factor of DCL1 and core component of miRNA pathway. We generated Nicotiana tabacum and Nicotiana benthamiana SE knock-down plants exhibiting considerable miRNA reduction and strong phenotypic abnormalities. PSTVd infection of SE suppressed plants resulted in a significant viroid reduction, especially at the initial infection stages. This positive correlation between SE levels and viroid infectivity underlines its role in PSTVd life cycle and reveals the importance of the miRNA pathway upon viroid infection.
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Affiliation(s)
- Nikoleta Kryovrysanaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, GR-7110 Heraklion, Crete, Greece; Department of Biology, University of Crete, Vassilika Vouton, GR-71409 Heraklion, Crete, Greece.
| | - Anastasios Alexiadis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, GR-7110 Heraklion, Crete, Greece; Department of Biology, University of Crete, Vassilika Vouton, GR-71409 Heraklion, Crete, Greece
| | - Alexandra M Grigoriadou
- Department of Biology, University of Crete, Vassilika Vouton, GR-71409 Heraklion, Crete, Greece
| | - Konstantina Katsarou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, GR-7110 Heraklion, Crete, Greece
| | - Kriton Kalantidis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, GR-7110 Heraklion, Crete, Greece; Department of Biology, University of Crete, Vassilika Vouton, GR-71409 Heraklion, Crete, Greece.
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24
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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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Adkar-Purushothama CR, Perreault JP. Alterations of the viroid regions that interact with the host defense genes attenuate viroid infection in host plant. RNA Biol 2018; 15:955-966. [PMID: 29683389 DOI: 10.1080/15476286.2018.1462653] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
Understanding in intimate details how the viroid interaction with host's defense genes is a cornerstone for developing viroid resistant plants. In this present study, small RNAs (sRNA) derived from Potato spindle tuber viroid (PSTVd) were studied in silico in order to detect any interactions with the serine threonine kinase receptor, a transmembrane protein that plays a role in disease resistance in plants. Using molecular biology techniques, it was determined that PSTVd infection negatively affects at least three serine threonine kinase receptors as well as with three other genes that are known to be involved in the overall development of the tomato plants. The transient expression of these putative PSTVd-sRNAs, using the microRNA sequence as a backbone, in tomato plants induced phenotypes similar to viroid infection. Mutants created by altering the sequence of PSTVd in these regions failed to infect the tomato plant. The data presented here illustrates the importance of these regions in viroid survival, and suggests a possible avenue of exploration for the development of viroid resistant plants.
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Affiliation(s)
- Charith Raj Adkar-Purushothama
- a RNA Group/Groupe ARN, Département de Biochimie, Faculté de médecine des sciences de la santé, Pavillon de Recherche Appliquée au Cancer , Université de Sherbrooke , 3201 rue Jean-Mignault, Sherbrooke , Québec , Canada
| | - Jean-Pierre Perreault
- a RNA Group/Groupe ARN, Département de Biochimie, Faculté de médecine des sciences de la santé, Pavillon de Recherche Appliquée au Cancer , Université de Sherbrooke , 3201 rue Jean-Mignault, Sherbrooke , Québec , Canada
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26
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Cai Q, He B, Kogel KH, Jin H. Cross-kingdom RNA trafficking and environmental RNAi-nature's blueprint for modern crop protection strategies. Curr Opin Microbiol 2018; 46:58-64. [PMID: 29549797 PMCID: PMC6499079 DOI: 10.1016/j.mib.2018.02.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 01/29/2018] [Accepted: 02/02/2018] [Indexed: 10/17/2022]
Abstract
In plants, small RNA (sRNA)-mediated RNA interference (RNAi) is critical for regulating host immunity against bacteria, fungi, oomycetes, viruses, and pests. Similarly, sRNAs from pathogens and pests also play an important role in modulating their virulence. Strikingly, recent evidence supports that some sRNAs can travel between interacting organisms and induce gene silencing in the counter party, a mechanism termed cross-kingdom RNAi. Exploiting this new knowledge, host-induced gene silencing (HIGS) by transgenic expression of pathogen gene-targeting double-stranded (ds)RNA has the potential to become an important disease-control method. To circumvent transgenic approaches, direct application of dsRNAs or sRNAs (environmental RNAi) onto host plants or post-harvest products leads to silencing of the target microbe/pest gene (referred to spray-induced gene silencing, SIGS) and confers efficient disease control. This review summarizes the current understanding of cross-kingdom RNA trafficking and environmental RNAi and how these findings can be developed into novel effective strategies to fight diseases caused by microbial pathogens and pests.
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Affiliation(s)
- Qiang Cai
- Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Baoye He
- Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Karl-Heinz Kogel
- Department of Phytopathology, Interdisciplinary Research Center for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Germany
| | - Hailing Jin
- Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA.
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27
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Adkar-Purushothama CR, Iyer PS, Perreault JP. Potato spindle tuber viroid infection triggers degradation of chloride channel protein CLC-b-like and Ribosomal protein S3a-like mRNAs in tomato plants. Sci Rep 2017; 7:8341. [PMID: 28827569 PMCID: PMC5566334 DOI: 10.1038/s41598-017-08823-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/14/2017] [Indexed: 11/29/2022] Open
Abstract
It is well established that viroid derived small RNA (vd-sRNA) induces RNA silencing of endogenous mRNA. However, it remains not clear how exactly viroid infections can lead to severe symptom induction given the fact that fewer vd-sRNAs binding the specific target mRNAs were recovered from the infected plants. To answer this question, the two least expressed (+) and (−) strand vd-sRNAs of potato spindle tuber viroid (PSTVd) binding to both the 3′ UTR and the coding region of tomato mRNAs were analyzed by infecting tomato plants with two variants of PSTVd. As products of these putative target mRNAs are involved in plant phenotype, the effect of this viroid on these genes were analyzed by infecting tomato plants with two variants of PSTVd. The direct interaction between the vd-sRNAs and putative mRNAs was validated by artificial microRNA experiments in a transient expression system and by RNA ligase-mediated rapid amplification of cDNA ends. Parallel analysis of RNA ends of viroid infected plants revealed the widespread cleavage of the target mRNAs in locations other than the vd-sRNA binding site during the viroid infection implying the viroid-infection induced vd-sRNA independent degradation of endogenous mRNAs during viroid infection.
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Affiliation(s)
- Charith Raj Adkar-Purushothama
- Département de Biochimie, RNA Group/Groupe ARN, Faculté de médecine des sciences de la santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, 3201 rue Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada.
| | - Pavithran Sridharan Iyer
- Département de Physique, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Québec, J1K 2R1, Canada
| | - Jean-Pierre Perreault
- Département de Biochimie, RNA Group/Groupe ARN, Faculté de médecine des sciences de la santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, 3201 rue Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada.
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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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29
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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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30
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Abstract
Biological processes such as defense mechanisms and microbial offense strategies are regulated through RNA induced interference in eukaryotes. Genetic mutations are modulated through biogenesis of small RNAs which directly impacts upon host development. Plant defense mechanisms are regulated and supported by a diversified group of small RNAs which are involved in streamlining several RNA interference pathways leading toward the initiation of pathogen gene silencing mechanisms. In the similar context, pathogens also utilize the support of small RNAs to launch their offensive attacks. Also there are strong evidences about the active involvement of these RNAs in symbiotic associations. Interestingly, small RNAs are not limited to the individuals in whom they are produced; they also show cross kingdom influences through variable interactions with other species thus leading toward the inter-organismic gene silencing. The phenomenon is understandable in the microbes which utilize these mechanisms to overcome host defense line. Understanding the mechanism of triggering host defense strategies can be a valuable step toward the generation of disease resistant host plants. We think that the cross kingdom trafficking of small RNA is an interesting insight that is needed to be explored for its vitality.
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Affiliation(s)
- Waqar Islam
- a College of Plant Protection , Fujian Agriculture and Forestry University , Fuzhou , Fujian , China
| | - Saif Ul Islam
- a College of Plant Protection , Fujian Agriculture and Forestry University , Fuzhou , Fujian , China
| | - Muhammad Qasim
- a College of Plant Protection , Fujian Agriculture and Forestry University , Fuzhou , Fujian , China
| | - Liande Wang
- a College of Plant Protection , Fujian Agriculture and Forestry University , Fuzhou , Fujian , China
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31
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Su X, Rehman L, Guo H, Li X, Zhang R, Cheng H. AAC as a Potential Target Gene to Control Verticillium dahliae. Genes (Basel) 2017; 8:genes8010025. [PMID: 28075391 PMCID: PMC5295020 DOI: 10.3390/genes8010025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/28/2016] [Accepted: 01/05/2017] [Indexed: 12/31/2022] Open
Abstract
Verticillium dahliae invades the roots of host plants and causes vascular wilt, which seriously diminishes the yield of cotton and other important crops. The protein AAC (ADP, ATP carrier) is responsible for transferring ATP from the mitochondria into the cytoplasm. When V. dahliae protoplasts were transformed with short interfering RNAs (siRNAs) targeting the VdAAC gene, fungal growth and sporulation were significantly inhibited. To further confirm a role for VdAAC in fungal development, we generated knockout mutants (ΔVdACC). Compared with wild-type V. dahliae (Vd wt), ΔVdAAC was impaired in germination and virulence; these impairments were rescued in the complementary strains (ΔVdAAC-C). Moreover, when an RNAi construct of VdAAC under the control of the 35S promoter was used to transform Nicotiana benthamiana, the expression of VdAAC was downregulated in the transgenic seedlings, and they had elevated resistance against V. dahliae. The results of this study suggest that VdAAC contributes to fungal development, virulence and is a promising candidate gene to control V. dahliae. In addition, RNAi is a highly efficient way to silence fungal genes and provides a novel strategy to improve disease resistance in plants.
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Affiliation(s)
- Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Latifur Rehman
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Huiming Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xiaokang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Rui Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Hongmei Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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32
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Guo Q, Liu Q, Smith NA, Liang G, Wang MB. RNA Silencing in Plants: Mechanisms, Technologies and Applications in Horticultural Crops. Curr Genomics 2016; 17:476-489. [PMID: 28217004 PMCID: PMC5108043 DOI: 10.2174/1389202917666160520103117] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 12/20/2022] Open
Abstract
Understanding the fundamental nature of a molecular process or a biological pathway is often a catalyst for the development of new technologies in biology. Indeed, studies from late 1990s to early 2000s have uncovered multiple overlapping but functionally distinct RNA silencing pathways in plants, including the posttranscriptional microRNA and small interfering RNA pathways and the transcriptional RNA-directed DNA methylation pathway. These findings have in turn been exploited for developing artificial RNA silencing technologies such as hairpin RNA, artificial microRNA, intrinsic direct repeat, 3' UTR inverted repeat, artificial trans-acting siRNA, and virus-induced gene silencing technologies. Some of these RNA silencing technologies, such as the hairpin RNA technology, have already been widely used for genetic improvement of crop plants in agriculture. For horticultural plants, RNA silencing technologies have been used to increase disease and pest resistance, alter plant architecture and flowering time, improve commercial traits of fruits and flowers, enhance nutritional values, remove toxic compounds and allergens, and develop high-value industrial products. In this article we aim to provide an overview of the RNA silencing pathways in plants, summarize the existing RNA silencing technologies, and review the current progress in applying these technologies for the improvement of agricultural crops particularly horticultural crops.
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Affiliation(s)
- Qigao Guo
- College of Horticulture & Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Qing Liu
- Commonwealth Scientific and Industrial Research Organisation Agriculture (CSIRO), ACT 2601, Australia
| | - Neil A Smith
- Commonwealth Scientific and Industrial Research Organisation Agriculture (CSIRO), ACT 2601, Australia
| | - Guolu Liang
- College of Horticulture & Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Ming-Bo Wang
- Commonwealth Scientific and Industrial Research Organisation Agriculture (CSIRO), ACT 2601, Australia
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33
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Katsarou K, Mavrothalassiti E, Dermauw W, Van Leeuwen T, Kalantidis K. Combined Activity of DCL2 and DCL3 Is Crucial in the Defense against Potato Spindle Tuber Viroid. PLoS Pathog 2016; 12:e1005936. [PMID: 27732664 PMCID: PMC5061435 DOI: 10.1371/journal.ppat.1005936] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 09/14/2016] [Indexed: 12/22/2022] Open
Abstract
Viroids are self replicating non-coding RNAs capable of infecting a wide range of plant hosts. They do not encode any proteins, thus the mechanism by which they escape plant defenses remains unclear. RNAi silencing is a major defense mechanism against virus infections, with the four DCL proteins being principal components of the pathway. We have used Nicotiana benthamiana as a model to study Potato spindle tuber viroid infection. This viroid is a member of the Pospiviroidae family and replicates in the nucleus via an asymmetric rolling circle mechanism. We have created knock-down plants for all four DCL genes and their combinations. Previously, we showed that DCL4 has a positive effect on PSTVd infectivity since viroid levels drop when DCL4 is suppressed. Here, we show that PSTVd levels remain decreased throughout infection in DCL4 knockdown plants, and that simultaneous knockdown of DCL1, DCL2 or DCL3 together with DCL4 cannot reverse this effect. Through infection of plants suppressed for multiple DCLs we further show that a combined suppression of DCL2 and DCL3 has a major effect in succumbing plant antiviral defense. Based on our results, we further suggest that Pospoviroids may have evolved to be primarily processed by DCL4 as it seems to be a DCL protein with less detrimental effects on viroid infectivity. These findings pave the way to delineate the complexity of the relationship between viroids and plant RNA silencing response.
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Affiliation(s)
- Konstantina Katsarou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | | | - Wannes Dermauw
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Belgium
| | - Thomas Van Leeuwen
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Belgium
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, The Netherlands
| | - Kriton Kalantidis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
- Department of Biology, University of Crete, Heraklion, Greece
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34
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Palma-Martínez I, Guerrero-Mandujano A, Ruiz-Ruiz MJ, Hernández-Cortez C, Molina-López J, Bocanegra-García V, Castro-Escarpulli G. Active Shiga-Like Toxin Produced by Some Aeromonas spp., Isolated in Mexico City. Front Microbiol 2016; 7:1552. [PMID: 27757103 PMCID: PMC5048074 DOI: 10.3389/fmicb.2016.01552] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/16/2016] [Indexed: 12/29/2022] Open
Abstract
RNA silencing is a conserved mechanism that utilizes small RNAs (sRNAs) to direct the regulation of gene expression at the transcriptional or post-transcriptional level. Plants utilizing RNA silencing machinery to defend pathogen infection was first identified in plant–virus interaction and later was observed in distinct plant–pathogen interactions. RNA silencing is not only responsible for suppressing RNA accumulation and movement of virus and viroid, but also facilitates plant immune responses against bacterial, oomycete, and fungal infection. Interestingly, even the same plant sRNA can perform different roles when encounters with different pathogens. On the other side, pathogens counteract by generating sRNAs that directly regulate pathogen gene expression to increase virulence or target host genes to facilitate pathogen infection. Here, we summarize the current knowledge of the characterization and biogenesis of host- and pathogen-derived sRNAs, as well as the different RNA silencing machineries that plants utilize to defend against different pathogens. The functions of these sRNAs in defense and counter-defense and their mechanisms for regulation during different plant–pathogen interactions are also discussed.
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Affiliation(s)
- Ingrid Palma-Martínez
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
| | - Andrea Guerrero-Mandujano
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
| | - Manuel J Ruiz-Ruiz
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio Central de Análisis Clínicos Unidad Médica de Alta Especialidad Hospital de Pediatría "Silvestre Frenk Freund," Centro Médico Nacional Siglo XXIMexico City, Mexico
| | - Cecilia Hernández-Cortez
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio de Bioquímica Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico
| | - José Molina-López
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| | | | - Graciela Castro-Escarpulli
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico
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35
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RNAi mediated inhibition of viroid infection in transgenic plants expressing viroid-specific small RNAs derived from various functional domains. Sci Rep 2015; 5:17949. [PMID: 26656294 PMCID: PMC4677296 DOI: 10.1038/srep17949] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 11/09/2015] [Indexed: 12/25/2022] Open
Abstract
Previous attempts to develop RNAi-mediated viroid-resistant transgenic plants using nearly full-length Potato spindle tuber viroid (PSTVd) hairpin RNA (hpRNA) were successful; however unusual phenotypes resembling viroid infection occurred. Therefore, in the present work, transgenic Nicotiana benthamiana lines expressing both partial and truncated versions of PSTVd hpRNA were developed. Specifically, seven partial or truncated versions of PSTVd sequences were selected according to the hotspots of both PSTVd-sRNAs and functional domains of the PSTVd. A total of 21 transgenic lines Nicotiana benthamiana were developed under the control of either the CaMV-35S or the CoYMV promoters. All of the transgenic lines established here were monitored for the induction of phenotypic changes, for PSTVd-sRNA expression and for the resistance against PSTVd infection. Additionally, this study demonstrates the use of inverted repeat construct sequences as short as 26- to -49 nucleotides for both the efficient expression of the PSTVd-sRNA and the inhibition of PSTVd infection.
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36
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Gago-Zachert S. Viroids, infectious long non-coding RNAs with autonomous replication. Virus Res 2015; 212:12-24. [PMID: 26319312 DOI: 10.1016/j.virusres.2015.08.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/20/2015] [Accepted: 08/22/2015] [Indexed: 10/23/2022]
Abstract
Transcriptome deep-sequencing studies performed during the last years confirmed that the vast majority of the RNAs transcribed in higher organisms correspond to several types of non-coding RNAs including long non-coding RNAs (lncRNAs). The study of lncRNAs and the identification of their functions, is still an emerging field in plants but the characterization of some of them indicate that they play an important role in crucial regulatory processes like flowering regulation, and responses to abiotic stress and plant hormones. A second group of lncRNAs present in plants is formed by viroids, exogenous infectious subviral plant pathogens well known since many years. Viroids are composed of circular RNA genomes without protein-coding capacity and subvert enzymatic activities of their hosts to complete its own biological cycle. Different aspects of viroid biology and viroid-host interactions have been elucidated in the last years and some of them are the main topic of this review together with the analysis of the state-of-the-art about the growing field of endogenous lncRNAs in plants.
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Affiliation(s)
- Selma Gago-Zachert
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
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37
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Itaya A, Lucas WJ, Qi Y, Qu F, Wang Y, Zhong X, Liu CM. In memory of Professor Biao Ding (1960-2015). JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:730-731. [PMID: 26182880 DOI: 10.1111/jipb.12381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Asuka Itaya
- Agriculture and Agri-Food Canada, Ottawa, Canada
| | - William J Lucas
- Department of Plant Biology, University of California, Davis, USA
| | - Yijun Qi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Feng Qu
- Department of Plant Pathology, Ohio State University, Columbus, USA
| | - Ying Wang
- Department of Molecular Genetics, Ohio State University, Columbus, USA
| | - Xuehua Zhong
- Wisconsin Institute for Discovery & Laboratory of Genetics, University of Wisconsin, Madison, USA
| | - Chun-Ming Liu
- Institute of Botany, Chinese Academy of Sciences, Beijing, China
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38
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Abstract
Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such.
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Affiliation(s)
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Seoul, Republic of Korea.
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Sangha JS, Kandasamy S, Khan W, Bahia NS, Singh RP, Critchley AT, Prithiviraj B. λ-Carrageenan Suppresses Tomato Chlorotic Dwarf Viroid (TCDVd) Replication and Symptom Expression in Tomatoes. Mar Drugs 2015; 13:2875-89. [PMID: 26006710 PMCID: PMC4446610 DOI: 10.3390/md13052875] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/18/2015] [Accepted: 04/27/2015] [Indexed: 11/25/2022] Open
Abstract
The effect of carrageenans on tomato chlorotic dwarf viroid (TCDVd) replication and symptom expression was studied. Three-week-old tomato plants were spray-treated with iota(ɩ)-, lambda(λ)-, and kappa(κ)-carrageenan at 1 g·L-1 and inoculated with TCDVd after 48 h. The λ-carrageenan significantly suppressed viroid symptom expression after eight weeks of inoculation, only 28% plants showed distinctive bunchy-top symptoms as compared to the 82% in the control group. Viroid concentration was reduced in the infected shoot cuttings incubated in λ-carrageenan amended growth medium. Proteome analysis revealed that 16 tomato proteins were differentially expressed in the λ-carrageenan treated plants. Jasmonic acid related genes, allene oxide synthase (AOS) and lipoxygenase (LOX), were up-regulated in λ-carrageenan treatment during viroid infection. Taken together, our results suggest that λ-carrageenan induced tomato defense against TCDVd, which was partly jasmonic acid (JA) dependent, and that it could be explored in plant protection against viroid infection.
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Affiliation(s)
- Jatinder S Sangha
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, NS B2N 5E3, Canada.
| | - Saveetha Kandasamy
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, NS B2N 5E3, Canada.
| | - Wajahatullah Khan
- Basic Sciences Department, King Saud Bin Abdul Aziz University for Health Sciences, P.O. Box 22490, Riyadh 11426, Saudi Arabia.
| | - Navratan Singh Bahia
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, NS B2N 5E3, Canada.
| | - Rudra P Singh
- Agriculture and Agri-Food Canada, 850 Lincoln Rd., Fredericton, NB E3B 4Z7, Canada.
| | - Alan T Critchley
- Acadian Seaplants Limited, 30 Brown Avenue, Dartmouth, NS B3B 1X8, Canada.
| | - Balakrishnan Prithiviraj
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, NS B2N 5E3, Canada.
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40
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Kamthan A, Chaudhuri A, Kamthan M, Datta A. Small RNAs in plants: recent development and application for crop improvement. FRONTIERS IN PLANT SCIENCE 2015; 6:208. [PMID: 25883599 PMCID: PMC4382981 DOI: 10.3389/fpls.2015.00208] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/16/2015] [Indexed: 05/19/2023]
Abstract
The phenomenon of RNA interference (RNAi) which involves sequence-specific gene regulation by small non-coding RNAs, i.e., small interfering RNA (siRNA) and microRNA (miRNA) has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RNAi has been used for enhancing the crop yield and productivity by manipulating the gene involved in biomass, grain yield and enhanced shelf life of fruits and vegetables. It has also been applied for developing resistance against various biotic (bacteria, fungi, viruses, nematodes, insects) and abiotic stresses (drought, salinity, cold, etc.). Nutritional improvements of crops have also been achieved by enriching the crops with essential amino acids, fatty acids, antioxidants and other nutrients beneficial for human health or by reducing allergens or anti-nutrients. microRNAs are key regulators of important plant processes like growth, development, and response to various stresses. In spite of similarity in size (20-24 nt), miRNA differ from siRNA in precursor structures, pathway of biogenesis, and modes of action. This review also highlights the miRNA based genetic modification technology where various miRNAs/artificial miRNAs and their targets can be utilized for improving several desirable plant traits. microRNA based strategies are much efficient than siRNA-based RNAi strategies due to its specificity and less undesirable off target effects. As per the FDA guidelines, small RNA (sRNA) based transgenics are much safer for consumption than those over-expressing proteins. This review thereby summarizes the emerging advances and achievement in the field of sRNAs and its application for crop improvement.
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Affiliation(s)
- Ayushi Kamthan
- National Institute of Plant Genome ResearchNew Delhi, India
| | | | - Mohan Kamthan
- Indian Institute of Toxicology ResearchLucknow, India
| | - Asis Datta
- National Institute of Plant Genome ResearchNew Delhi, India
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41
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Viroids, the simplest RNA replicons: How they manipulate their hosts for being propagated and how their hosts react for containing the infection. Virus Res 2015; 209:136-45. [PMID: 25738582 DOI: 10.1016/j.virusres.2015.02.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 12/31/2022]
Abstract
The discovery of viroids about 45 years ago heralded a revolution in Biology: small RNAs comprising around 350 nt were found to be able to replicate autonomously-and to incite diseases in certain plants-without encoding proteins, fundamental properties discriminating these infectious agents from viruses. The initial focus on the pathological effects usually accompanying infection by viroids soon shifted to their molecular features-they are circular molecules that fold upon themselves adopting compact secondary conformations-and then to how they manipulate their hosts to be propagated. Replication of viroids-in the nucleus or chloroplasts through a rolling-circle mechanism involving polymerization, cleavage and circularization of RNA strands-dealt three surprises: (i) certain RNA polymerases are redirected to accept RNA instead of their DNA templates, (ii) cleavage in chloroplastic viroids is not mediated by host enzymes but by hammerhead ribozymes, and (iii) circularization in nuclear viroids is catalyzed by a DNA ligase redirected to act upon RNA substrates. These enzymes (and ribozymes) are most probably assisted by host proteins, including transcription factors and RNA chaperones. Movement of viroids, first intracellularly and then to adjacent cells and distal plant parts, has turned out to be a tightly regulated process in which specific RNA structural motifs play a crucial role. More recently, the advent of RNA silencing has brought new views on how viroids may cause disease and on how their hosts react to contain the infection; additionally, viroid infection may be restricted by other mechanisms. Representing the lowest step on the biological size scale, viroids have also attracted considerable interest to get a tentative picture of the essential characteristics of the primitive replicons that populated the postulated RNA world.
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Dalakouras A, Dadami E, Wassenegger M. Engineering viroid resistance. Viruses 2015; 7:634-46. [PMID: 25674769 PMCID: PMC4353907 DOI: 10.3390/v7020634] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 01/30/2015] [Indexed: 12/31/2022] Open
Abstract
Viroids are non-encapsidated, non-coding, circular, single-stranded RNAs (ssRNAs). They are classified into the families Pospiviroidae and Avsunviroidae, whose members replicate in the nucleus and chloroplast of plant cells, respectively. Viroids have a wide host range, including crop and ornamental plants, and can cause devastating diseases with significant economic losses. Thus, several viroids are world-wide, classified as quarantine pathogens and, hence, there is an urgent need for the development of robust antiviroid strategies. RNA silencing-based technologies seem to be a promising tool in this direction. Here, we review the recent advances concerning the complex interaction of viroids with the host's RNA silencing machinery, evaluate past and present antiviroid approaches, and finally suggest alternative strategies that could potentially be employed in the future in order to achieve transgenic and non-transgenic viroid-free plants.
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Affiliation(s)
- Athanasios Dalakouras
- RLP AgroScience GmbH, AIPlanta-Institute for Plant Research, Neustadt, 67435, Germany.
| | - Elena Dadami
- RLP AgroScience GmbH, AIPlanta-Institute for Plant Research, Neustadt, 67435, Germany.
| | - Michael Wassenegger
- RLP AgroScience GmbH, AIPlanta-Institute for Plant Research, Neustadt, Germany and Centre for Organisational Studies (COS) Heidelberg, University of Heidelberg, Heidelberg, 69120, Germany.
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Dalakouras A, Dadami E, Bassler A, Zwiebel M, Krczal G, Wassenegger M. Replicating Potato spindle tuber viroid mediates de novo methylation of an intronic viroid sequence but no cleavage of the corresponding pre-mRNA. RNA Biol 2015; 12:268-75. [PMID: 25826660 PMCID: PMC4615544 DOI: 10.1080/15476286.2015.1017216] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 10/23/2022] Open
Abstract
In plants, Potato spindle tuber viroid (PSTVd) replication triggers post-transcriptional gene silencing (PTGS) and RNA-directed DNA methylation (RdDM) of homologous RNA and DNA sequences, respectively. PTGS predominantly occurs in the cytoplasm, but nuclear PTGS has been also reported. In this study, we investigated whether the nuclear replicating PSTVd is able to trigger nuclear PTGS. Transgenic tobacco plants carrying cytoplasmic and nuclear PTGS sensor constructs were PSTVd-infected resulting in the generation of abundant PSTVd-derived small interfering RNAs (vd-siRNAs). Northern blot analysis revealed that, in contrast to the cytoplasmic sensor, the nuclear sensor transcript was not targeted for RNA degradation. Bisulfite sequencing analysis showed that the nuclear PTGS sensor transgene was efficiently targeted for RdDM. Our data suggest that PSTVd fails to trigger nuclear PTGS, and that RdDM and nuclear PTGS are not necessarily coupled.
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Affiliation(s)
| | - Elena Dadami
- RLP AgroScience GmbH; AlPlanta-Institute for Plant Research; Neustadt, Germany
| | - Alexandra Bassler
- RLP AgroScience GmbH; AlPlanta-Institute for Plant Research; Neustadt, Germany
| | - Michele Zwiebel
- RLP AgroScience GmbH; AlPlanta-Institute for Plant Research; Neustadt, Germany
| | - Gabi Krczal
- RLP AgroScience GmbH; AlPlanta-Institute for Plant Research; Neustadt, Germany
| | - Michael Wassenegger
- RLP AgroScience GmbH; AlPlanta-Institute for Plant Research; Neustadt, Germany
- Centre for Organismal Studies (COS) Heidelberg; University of Heidelberg; Heidelberg, Germany
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Abstract
RNA interference (RNAi) has emerged as a leading technology in designing genetically modified crops engineered to resist viral infection. The last decades have seen the development of a large number of crops whose inherent posttranscriptional gene silencing mechanism has been exploited to target essential viral genes through the production of dsRNA that triggers an endogenous RNA-induced silencing complex (RISC), leading to gene silencing in susceptible viruses conferring them with resistance even before the onset of infection. Selection and breeding events have allowed for establishing this highly important agronomic trait in diverse crops. With improved techniques and the availability of new data on genetic diversity among several viruses, significant progress is being made in engineering plants using RNAi with the release of a number of commercially available crops. Biosafety concerns with respect to consumption of RNAi crops, while relevant, have been addressed, given the fact that experimental evidence using miRNAs associated with the crops shows that they do not pose any health risk to humans and animals.
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Affiliation(s)
- Abdulrazak B Ibrahim
- Embrapa Recursos Genéticos e Biotecnologia, LEG, PqEB W5 Norte, 70770-917, Brasília, DF, Brazil
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Kovalskaya N, Hammond RW. Molecular biology of viroid-host interactions and disease control strategies. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 228:48-60. [PMID: 25438785 DOI: 10.1016/j.plantsci.2014.05.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/26/2014] [Accepted: 05/14/2014] [Indexed: 06/04/2023]
Abstract
Viroids are single-stranded, covalently closed, circular, highly structured noncoding RNAs that cause disease in several economically important crop plants. They replicate autonomously and move systemically in host plants with the aid of the host machinery. In addition to symptomatic infections, viroids also cause latent infections where there is no visual evidence of infection in the host; however, transfer to a susceptible host can result in devastating disease. While there are non-hosts for viroids, no naturally occurring durable resistance has been observed in most host species. Current effective control methods for viroid diseases include detection and eradication, and cultural controls. In addition, heat or cold therapy combined with meristem tip culture has been shown to be effective for elimination of viroids for some viroid-host combinations. An understanding of viroid-host interactions, host susceptibility, and non-host resistance could provide guidance for the design of viroid-resistant plants. Efforts to engineer viroid resistance into host species have been underway for several years, and include the use of antisense RNA, antisense RNA plus ribozymes, a dsRNase, and siRNAs, among others. The results of those efforts and the challenges associated with creating viroid resistant plants are summarized in this review.
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Affiliation(s)
- Natalia Kovalskaya
- USDA ARS BARC Molecular Plant Pathology Laboratory, Beltsville, MD 20705, USA
| | - Rosemarie W Hammond
- USDA ARS BARC Molecular Plant Pathology Laboratory, Beltsville, MD 20705, USA.
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Minoia S, Carbonell A, Di Serio F, Gisel A, Carrington JC, Navarro B, Flores R. Specific argonautes selectively bind small RNAs derived from potato spindle tuber viroid and attenuate viroid accumulation in vivo. J Virol 2014; 88:11933-45. [PMID: 25100851 PMCID: PMC4178711 DOI: 10.1128/jvi.01404-14] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/31/2014] [Indexed: 12/21/2022] Open
Abstract
The identification of viroid-derived small RNAs (vd-sRNAs) of 21 to 24 nucleotides (nt) in plants infected by viroids (infectious non-protein-coding RNAs of just 250 to 400 nt) supports their targeting by Dicer-like enzymes, the first host RNA-silencing barrier. However, whether viroids, like RNA viruses, are also targeted by the RNA-induced silencing complex (RISC) remains controversial. At the RISC core is one Argonaute (AGO) protein that, guided by endogenous or viral sRNAs, targets complementary RNAs. To examine whether AGO proteins also load vd-sRNAs, leaves of Nicotiana benthamiana infected by potato spindle tuber viroid (PSTVd) were agroinfiltrated with plasmids expressing epitope-tagged versions of AGO1, AGO2, AGO3, AGO4, AGO5, AGO6, AGO7, AGO9, and AGO10 from Arabidopsis thaliana. Immunoprecipitation analyses of the agroinfiltrated halos revealed that all AGOs except AGO6, AGO7, and AGO10 associated with vd-sRNAs: AGO1, AGO2, and AGO3 preferentially with those of 21 and 22 nt, while AGO4, AGO5, and AGO9 additionally bound those of 24 nt. Deep-sequencing analyses showed that sorting of vd-sRNAs into AGO1, AGO2, AGO4, and AGO5 depended essentially on their 5'-terminal nucleotides, with the profiles of the corresponding AGO-loaded vd-sRNAs adopting specific hot spot distributions along the viroid genome. Furthermore, agroexpression of AGO1, AGO2, AGO4, and AGO5 on PSTVd-infected tissue attenuated the level of the genomic RNAs, suggesting that they, or their precursors, are RISC targeted. In contrast to RNA viruses, PSTVd infection of N. benthamiana did not affect miR168-mediated regulation of the endogenous AGO1, which loaded vd-sRNAs with specificity similar to that of its A. thaliana counterpart. Importance: To contain invaders, particularly RNA viruses, plants have evolved an RNA-silencing mechanism relying on the generation by Dicer-like (DCL) enzymes of virus-derived small RNAs of 21 to 24 nucleotides (nt) that load and guide Argonaute (AGO) proteins to target and repress viral RNA. Viroids, despite their minimal genomes (non-protein-coding RNAs of only 250 to 400 nt), infect and incite disease in plants. The accumulation in these plants of 21- to 24-nt viroid-derived small RNAs (vd-sRNAs) supports the notion that DCLs also target viroids but does not clarify whether vd-sRNAs activate one or more AGOs. Here, we show that in leaves of Nicotiana benthamiana infected by potato spindle tuber viroid, the endogenous AGO1 and distinct AGOs from Arabidopsis thaliana that were overexpressed were associated with vd-sRNAs displaying the same properties (5'-terminal nucleotide and size) previously established for endogenous and viral small RNAs. Overexpression of AGO1, AGO2, AGO4, and AGO5 attenuated viroid accumulation, supporting their role in antiviroid defense.
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Affiliation(s)
- Sofia Minoia
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | | | - Francesco Di Serio
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Andreas Gisel
- Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Bari, Italy
| | | | - Beatriz Navarro
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Ricardo Flores
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Valencia, Spain
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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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Saurabh S, Vidyarthi AS, Prasad D. RNA interference: concept to reality in crop improvement. PLANTA 2014; 239:543-64. [PMID: 24402564 DOI: 10.1007/s00425-013-2019-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 12/21/2013] [Indexed: 05/18/2023]
Abstract
The phenomenon of RNA interference (RNAi) is involved in sequence-specific gene regulation driven by the introduction of dsRNA resulting in inhibition of translation or transcriptional repression. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in opening a new vista for crop improvement. RNAi technology is precise, efficient, stable and better than antisense technology. It has been employed successfully to alter the gene expression in plants for better quality traits. The impact of RNAi to improve the crop plants has proved to be a novel approach in combating the biotic and abiotic stresses and the nutritional improvement in terms of bio-fortification and bio-elimination. It has been employed successfully to bring about modifications of several desired traits in different plants. These modifications include nutritional improvements, reduced content of food allergens and toxic compounds, enhanced defence against biotic and abiotic stresses, alteration in morphology, crafting male sterility, enhanced secondary metabolite synthesis and seedless plant varieties. However, crop plants developed by RNAi strategy may create biosafety risks. So, there is a need for risk assessment of GM crops in order to make RNAi a better tool to develop crops with biosafety measures. This article is an attempt to review the RNAi, its biochemistry, and the achievements attributed to the application of RNAi in crop improvement.
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Affiliation(s)
- Satyajit Saurabh
- Department of Biotechnology, Birla Institute of Technology, Mesra, Ranchi, 835125, India
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Serra P, Bani Hashemian SM, Fagoaga C, Romero J, Ruiz-Ruiz S, Gorris MT, Bertolini E, Duran-Vila N. Virus-viroid interactions: Citrus Tristeza Virus enhances the accumulation of Citrus Dwarfing Viroid in Mexican lime via virus-encoded silencing suppressors. J Virol 2014; 88:1394-7. [PMID: 24227850 PMCID: PMC3911637 DOI: 10.1128/jvi.02619-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 11/08/2013] [Indexed: 11/20/2022] Open
Abstract
An assay to identify interactions between Citrus Dwarfing Viroid (CDVd) and Citrus Tristeza Virus (CTV) showed that viroid titer was enhanced by the coinfecting CTV in Mexican lime but not in etrog citron. Since CTV encodes three RNA silencing suppressors (RSSs), p23, p20 and p25, an assay using transgenic Mexican limes expressing each RSS revealed that p23 and, to a lesser extent, p25 recapitulated the effect observed with coinfections of CTV and CDVd.
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Affiliation(s)
- Pedro Serra
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
- Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Valencia, Spain
| | - Seyed M. Bani Hashemian
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
- Iran Citrus Research Institute, Ramsar, Iran
| | - Carmen Fagoaga
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Juan Romero
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Susana Ruiz-Ruiz
- Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Valencia, Spain
| | - Maria T. Gorris
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Edson Bertolini
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
| | - Núria Duran-Vila
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain
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50
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Kasai A, Sano T, Harada T. Scion on a stock producing siRNAs of potato spindle tuber viroid (PSTVd) attenuates accumulation of the viroid. PLoS One 2013; 8:e57736. [PMID: 23469061 PMCID: PMC3585205 DOI: 10.1371/journal.pone.0057736] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/24/2013] [Indexed: 02/02/2023] Open
Abstract
Plants can attenuate the replication of plant viruses and viroids by RNA silencing induced by virus and viroid infection. In higher plants, silencing signals such as small interfering RNAs (siRNAs) produced by RNA silencing can be transported systemically through phloem, so it is anticipated that antiviral siRNA signals produced in a stock would have the potential to attenuate propagation of viruses or viroids in the scion. To test whether this is indeed the case, we prepared transgenic tobacco (Nicotiana benthamiana) expressing a hairpin RNA (hpRNA) of Potato spindle tuber viroid (PSTVd) in companion cells by using a strong companion cell-specific promoter. A grafting experiment of the wild type tobacco scion on the top of the transgenic tobacco stock revealed that accumulation of PSTVd challenge-inoculated into the scion was apparently attenuated compared to the control grafted plants. These results indicate that genetically modified rootstock expressing viroid-specific siRNAs can attenuate viroid accumulation in a non-genetically modified scion grafted on the stock.
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Affiliation(s)
- Atsushi Kasai
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Teruo Sano
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Takeo Harada
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
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