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Umer M, Mubeen M, Shakeel Q, Ali S, Iftikhar Y, Bajwa RT, Anwar N, Rao MJ, He Y. Mycoviruses: Antagonistic Potential, Fungal Pathogenesis, and Their Interaction with Rhizoctonia solani. Microorganisms 2023; 11:2515. [PMID: 37894173 PMCID: PMC10609472 DOI: 10.3390/microorganisms11102515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/14/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
Mycoviruses, or fungal viruses, are prevalent in all significant fungal kingdoms and genera. These low-virulence viruses can be used as biocontrol agents to manage fungal diseases. These viruses are divided into 19 officially recognized families and 1 unclassified genus. Mycoviruses alter sexual reproduction, pigmentation, and development. Spores and fungal hypha spread mycoviruses. Isometric particles mostly encapsulate dsRNA mycoviruses. The widespread plant-pathogenic fungus Rhizoctonia solani, which has caused a rice sheath blight, has hosted many viruses with different morphologies. It causes significant crop diseases that adversely affect agriculture and the economy. Rice sheath blight threatens the 40% of the global population that relies on rice for food and nutrition. This article reviews mycovirology research on Rhizoctonia solani to demonstrate scientific advances. Mycoviruses control rice sheath blight. Hypovirulence-associated mycoviruses are needed to control R. solani since no cultivars are resistant. Mycoviruses are usually cryptic, but they can benefit the host fungus. Phytopathologists may use hypovirulent viruses as biological control agents. New tools are being developed based on host genome studies to overcome the intellectual challenge of comprehending the interactions between viruses and fungi and the practical challenge of influencing these interactions to develop biocontrol agents against significant plant pathogens.
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Affiliation(s)
- Muhammad Umer
- Forestry College, Research Centre of Forest Ecology, Guizhou University, Guiyang 550025, China;
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang 550025, China
| | - Mustansar Mubeen
- Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan; (M.M.); (Y.I.)
| | - Qaiser Shakeel
- Cholistan Institute of Desert Studies, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan; (Q.S.); (R.T.B.)
| | - Sajjad Ali
- Department of Entomology, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan;
| | - Yasir Iftikhar
- Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan; (M.M.); (Y.I.)
| | - Rabia Tahir Bajwa
- Cholistan Institute of Desert Studies, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan; (Q.S.); (R.T.B.)
| | - Naureen Anwar
- Department of Biology, Virtual University of Pakistan, Lahore 54000, Pakistan;
| | - Muhammad Junaid Rao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China
| | - Yuejun He
- Forestry College, Research Centre of Forest Ecology, Guizhou University, Guiyang 550025, China;
- Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang 550025, China
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Kolchenko M, Kapytina A, Kerimbek N, Pozharskiy A, Nizamdinova G, Khusnitdinova M, Taskuzhina A, Gritsenko D. Genetic Characterization of Raspberry Bushy Dwarf Virus Isolated from Red Raspberry in Kazakhstan. Viruses 2023; 15:v15040975. [PMID: 37112955 PMCID: PMC10143182 DOI: 10.3390/v15040975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Raspberry bushy dwarf virus (RBDV) is an economically significant pathogen of raspberry and grapevine, and it has also been found in cherry. Most of the currently available RBDV sequences are from European raspberry isolates. This study aimed to sequence genomic RNA2 of both cultivated and wild raspberry in Kazakhstan and compare them to investigate their genetic diversity and phylogenetic relationships, as well as to predict their protein structure. Phylogenetic and population diversity analyses were performed on all available RBDV RNA2, MP and CP sequences. Nine of the isolates investigated in this study formed a new, well-supported clade, while the wild isolates clustered with the European isolates. Predicted protein structure analysis revealed two regions that differed between α- and β-structures among the isolates. For the first time, the genetic composition of Kazakhstani raspberry viruses has been characterized.
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Affiliation(s)
- Mariya Kolchenko
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Anastasiya Kapytina
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Nazym Kerimbek
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Alexandr Pozharskiy
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
- Department of Molecular Biology and Genetics, Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Gulnaz Nizamdinova
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Marina Khusnitdinova
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Aisha Taskuzhina
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
| | - Dilyara Gritsenko
- Laboratory of Molecular Biology, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
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Abstract
Protoplasts are the naked plant cells lacking the rigid cell wall and have been broadly utilized as an excellent tool to study the molecular virus-plant interactions, particularly at the early stages of the infection process, such as virion disassembly, viral genome translation, intracellular trafficking, and virus replication. Compared to the use of whole plants, the protoplast system has several major advantages in plant virology research, including homogeneous cell populations, high percentage of infected cells, synchronous infection, effects free from other cells/tissues, and ease of extraction of the viral RNA. This chapter describes a simple, streamlined, and efficient protocol for isolation and purification of mesophyll protoplasts from the model plants Arabidopsis thaliana and Nicotiana benthamiana, and subsequent transfection of the isolated protoplasts with a potyvirus infectious clone.
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Affiliation(s)
- Zhaoji Dai
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.
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Hajeri S, Ng J, Grosser J, Vidalakis G. Isolation and Transfection of Citrus Protoplasts with Citrus Exocortis Viroid. Methods Mol Biol 2022; 2316:39-54. [PMID: 34845683 DOI: 10.1007/978-1-0716-1464-8_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Viroids are RNA-based infectious agents that are single-stranded, covalently closed circular, non-coding, and naked. Unlike RNA viruses, which at least encode proteins for replication, encapsidation, and movement, lack of protein-coding capacity of viroids makes them completely reliant on host for replication and movement. The high genetic diversity in viroids is believed to be due to the absence of proof-reading activity of the host RNA polymerases, the large population size, and the rapid rate of replication. Protoplasts are viable plant cells that are prepared by enzymatic removal of cell walls. Plant protoplasts provide a synchronous single-cell system for studying early events of viroid infection such as replication and genetic diversity at the cellular level. A simple and efficient method to isolate and transfect citrus protoplasts with transcript RNA of citrus exocortis viroid is described in this chapter.
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Affiliation(s)
- Subhas Hajeri
- Citrus Pest Detection Program, Central California Tristeza Eradication Agency, Tulare, CA, USA.
| | - James Ng
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, USA
| | - Jude Grosser
- Horticultural Sciences Department, University of Florida-IFAS, Citrus Research and Education Center (CREC), Lake Alfred, FL, USA
| | - Georgios Vidalakis
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, USA
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He G, Zhang Z, Sathanantham P, Diaz A, Wang X. Brome Mosaic Virus (Bromoviridae). ENCYCLOPEDIA OF VIROLOGY 2021. [PMCID: PMC7173524 DOI: 10.1016/b978-0-12-809633-8.21294-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Brome mosaic virus (BMV) is an isometric, non-enveloped, positive-strand RNA virus and a well-studied, representative member of the alphavirus-like super-family of human, animal, and plant viruses. BMV has been extensively studied as a model to examine some of the common features shared by all positive-strand RNA viruses. This article provides insights into virion assembly, encapsidation, gene expression, recombination, RNA replication, and virus-host interactions. These studies have not only advanced understanding of BMV, but have also revealed insights and principles extending to many other viruses and to general cellular biology.
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Viruses Infecting the Plant Pathogenic Fungus Rhizoctonia solani. Viruses 2019; 11:v11121113. [PMID: 31801308 PMCID: PMC6950361 DOI: 10.3390/v11121113] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/18/2019] [Accepted: 11/26/2019] [Indexed: 12/15/2022] Open
Abstract
The cosmopolitan fungus Rhizoctonia solani has a wide host range and is the causal agent of numerous crop diseases, leading to significant economic losses. To date, no cultivars showing complete resistance to R. solani have been identified and it is imperative to develop a strategy to control the spread of the disease. Fungal viruses, or mycoviruses, are widespread in all major groups of fungi and next-generation sequencing (NGS) is currently the most efficient approach for their identification. An increasing number of novel mycoviruses are being reported, including double-stranded (ds) RNA, circular single-stranded (ss) DNA, negative sense (−)ssRNA, and positive sense (+)ssRNA viruses. The majority of mycovirus infections are cryptic with no obvious symptoms on the hosts; however, some mycoviruses may alter fungal host pathogenicity resulting in hypervirulence or hypovirulence and are therefore potential biological control agents that could be used to combat fungal diseases. R. solani harbors a range of dsRNA and ssRNA viruses, either belonging to established families, such as Endornaviridae, Tymoviridae, Partitiviridae, and Narnaviridae, or unclassified, and some of them have been associated with hypervirulence or hypovirulence. Here we discuss in depth the molecular features of known viruses infecting R. solani and their potential as biological control agents.
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Kozieł E, Otulak-Kozieł K, Bujarski JJ. Ultrastructural Analysis of Prune DwarfVirus Intercellular Transport and Pathogenesis. Int J Mol Sci 2018; 19:E2570. [PMID: 30158483 PMCID: PMC6163902 DOI: 10.3390/ijms19092570] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 08/17/2018] [Accepted: 08/28/2018] [Indexed: 12/25/2022] Open
Abstract
Prune dwarf virus (PDV) is an important viral pathogen of plum, sweet cherry, peach, and many herbaceous test plants. Although PDV has been intensively investigated, mainly in the context of phylogenetic relationship of its genes and proteins, many gaps exist in our knowledge about the mechanism of intercellular transport of this virus. The aim of this work was to investigate alterations in cellular organelles and the cell-to-cell transport of PDV in Cucumis sativus cv. Polan at ultrastructural level. To analyze the role of viral proteins in local transport, double-immunogold assays were applied to localize PDV coat protein (CP) and movement protein (MP). We observe structural changes in chloroplasts, mitochondria, and cellular membranes. We prove that PDV is transported as viral particles via MP-generated tubular structures through plasmodesmata. Moreover, the computer-run 3D modeling reveals structural resemblances between MPs of PDV and of Alfalfa mosaic virus (AMV), implying similarities of transport mechanisms for both viruses.
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Affiliation(s)
- Edmund Kozieł
- Faculty of Agriculture and Biology, Department of Botany, Warsaw University of Life Sciences-SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland.
| | - Katarzyna Otulak-Kozieł
- Faculty of Agriculture and Biology, Department of Botany, Warsaw University of Life Sciences-SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland.
| | - Józef J Bujarski
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA.
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
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Kozieł E, Bujarski JJ, Otulak K. Molecular Biology of Prune Dwarf Virus-A Lesser Known Member of the Bromoviridae but a Vital Component in the Dynamic Virus-Host Cell Interaction Network. Int J Mol Sci 2017; 18:E2733. [PMID: 29258199 PMCID: PMC5751334 DOI: 10.3390/ijms18122733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/21/2017] [Accepted: 12/13/2017] [Indexed: 12/29/2022] Open
Abstract
Prune dwarf virus (PDV) is one of the members of Bromoviridae family, genus Ilarvirus. Host components that participate in the regulation of viral replication or cell-to-cell movement via plasmodesmata are still unknown. In contrast, viral infections caused by some other Bromoviridae members are well characterized. Bromoviridae can be distinguished based on localization of their replication process in infected cells, cell-to-cell movement mechanisms, and plant-specific response reactions. Depending upon the genus, "genome activation" and viral replication are linked to various membranous structures ranging from endoplasmic reticulum, to tonoplast. In the case of PDV, there is still no evidence of natural resistance sources in the host plants susceptible to virus infection. Apparently, PDV has a great ability to overcome the natural defense responses in a wide spectrum of plant hosts. The first manifestations of PDV infection are specific cell membrane alterations, and the formation of replicase complexes that support PDV RNA replication inside the spherules. During each stage of its life cycle, the virus uses cell components to replicate and to spread in whole plants, within the largely suppressed cellular immunity environment. This work presents the above stages of the PDV life cycle in the context of current knowledge about other Bromoviridae members.
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Affiliation(s)
- Edmund Kozieł
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences-SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland.
| | - Józef J Bujarski
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA.
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
| | - Katarzyna Otulak
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences-SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland.
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9
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Kolondam B, Rao P, Sztuba-Solinska J, Weber PH, Dzianott A, Johns MA, Bujarski JJ. Co-infection with two strains of Brome mosaic bromovirus reveals common RNA recombination sites in different hosts. Virus Evol 2015; 1:vev021. [PMID: 27774290 PMCID: PMC5014487 DOI: 10.1093/ve/vev021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have previously reported intra-segmental crossovers in Brome mosaic virus (BMV) RNAs. In this work, we studied the homologous recombination of BMV RNA in three different hosts: barley (Hordeum vulgare), Chenopodium quinoa, and Nicotiana benthamiana that were co-infected with two strains of BMV: Russian (R) and Fescue (F). Our work aimed at (1) establishing the frequency of recombination, (2) mapping the recombination hot spots, and (3) addressing host effects. The F and R nucleotide sequences differ from each other at many translationally silent nucleotide substitutions. We exploited this natural variability to track the crossover sites. Sequencing of a large number of cDNA clones revealed multiple homologous crossovers in each BMV RNA segment, in both the whole plants and protoplasts. Some recombination hot spots mapped at similar locations in different hosts, suggesting a role for viral factors, but other sites depended on the host. Our results demonstrate the chimeric ('mosaic') nature of the BMV RNA genome.
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Affiliation(s)
- Beivy Kolondam
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Parth Rao
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Joanna Sztuba-Solinska
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Philipp H Weber
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Aleksandra Dzianott
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Mitrick A Johns
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and
| | - Jozef J Bujarski
- Department of Biological Sciences and Plant Molecular Biology Center, Northern Illinois University, DeKalb, IL 60115, USA and; Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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Prosser SW, Xiao H, Li C, Nelson RS, Meng B. Subcellular localization and membrane association of the replicase protein of grapevine rupestris stem pitting-associated virus, family Betaflexiviridae. J Gen Virol 2015; 96:921-932. [PMID: 25502653 DOI: 10.1099/jgv.0.000019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
As a member of the newly established Betaflexiviridae family, grapevine rupestris stem pitting-associated virus (GRSPaV) has an RNA genome containing five ORFs. ORF1 encodes a putative replicase polyprotein typical of the alphavirus superfamily of positive-strand ssRNA viruses. Several viruses of this superfamily have been demonstrated to replicate in structures designated viral replication complexes associated with intracellular membranes. However, structure and cellular localization of the replicase complex have not been studied for members of Betaflexiviridae, a family of mostly woody plant viruses. As a first step towards the elucidation of the replication complex of GRSPaV, we investigated the subcellular localization of full-length and truncated versions of its replicase polyprotein via fluorescent tagging, followed by fluorescence microscopy. We found that the replicase polyprotein formed distinctive punctate bodies in both Nicotiana benthamiana leaf cells and tobacco protoplasts. We further mapped a region of 76 amino acids in the methyl-transferase domain responsible for the formation of these punctate structures. The punctate structures are distributed in close proximity to the endoplasmic reticulum network. Membrane flotation and biochemical analyses demonstrate that the N-terminal region responsible for punctate structure formation associated with cellular membrane is likely through an amphipathic α helix serving as an in-plane anchor. The identity of this membrane is yet to be determined. This is, to our knowledge, the first report on the localization and membrane association of the replicase proteins of a member of the family Betaflexiviridae.
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Affiliation(s)
- Sean W Prosser
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada N1G2W1
| | - Huogen Xiao
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada N1G2W1
| | - Caihong Li
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada N1G2W1
| | - Richard S Nelson
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73410, USA
| | - Baozhong Meng
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada N1G2W1
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11
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Hull R. Replication of Plant Viruses. PLANT VIROLOGY 2014. [PMCID: PMC7184227 DOI: 10.1016/b978-0-12-384871-0.00007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Viruses replicate using both their own genetic information and host cell components and machinery. The different genome types have different replication pathways which contain controls on linking the process with translation and movement around the cell as well as not compromising the infected cell. This chapter discusses the replication mechanisms, faults in replication and replication of viruses co-infecting cells. Viruses replicate using both their own genetic information and host cell components and machinery. The different genome types have different replication pathways which contain controls on linking the process with translation and movement around the cell as well as not compromising the infected cell. This chapter discusses the replication mechanisms, faults in replication and replication of viruses coinfecting cells.
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12
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Sztuba-Solińska J, Stollar V, Bujarski JJ. Subgenomic messenger RNAs: mastering regulation of (+)-strand RNA virus life cycle. Virology 2011; 412:245-55. [PMID: 21377709 PMCID: PMC7111999 DOI: 10.1016/j.virol.2011.02.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/14/2010] [Accepted: 02/04/2011] [Indexed: 12/12/2022]
Abstract
Many (+)-strand RNA viruses use subgenomic (SG) RNAs as messengers for protein expression, or to regulate their viral life cycle. Three different mechanisms have been described for the synthesis of SG RNAs. The first mechanism involves internal initiation on a (−)-strand RNA template and requires an internal SGP promoter. The second mechanism makes a prematurely terminated (−)-strand RNA which is used as template to make the SG RNA. The third mechanism uses discontinuous RNA synthesis while making the (−)-strand RNA templates. Most SG RNAs are translated into structural proteins or proteins related to pathogenesis: however other SG RNAs regulate the transition between translation and replication, function as riboregulators of replication or translation, or support RNA–RNA recombination. In this review we discuss these functions of SG RNAs and how they influence viral replication, translation and recombination.
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Affiliation(s)
- Joanna Sztuba-Solińska
- Plant Molecular Biology Center and the Department of Biological Sciences, Northern Illinois University, De Kalb, IL 60115, USA
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13
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Recombination of 5' subgenomic RNA3a with genomic RNA3 of Brome mosaic bromovirus in vitro and in vivo. Virology 2010; 410:129-41. [PMID: 21111438 PMCID: PMC7111948 DOI: 10.1016/j.virol.2010.10.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 08/28/2010] [Accepted: 10/29/2010] [Indexed: 01/03/2023]
Abstract
RNA-RNA recombination salvages viral RNAs and contributes to their genomic variability. A recombinationally-active subgenomic promoter (sgp) has been mapped in Brome mosaic bromovirus (BMV) RNA3 (Wierzchoslawski et al., 2004. J. Virol.78, 8552-8864) and mRNA-like 5' sgRNA3a was characterized (Wierzchoslawski et al., 2006. J. Virol. 80, 12357-12366). In this paper we describe sgRNA3a-mediated recombination in both in vitro and in vivo experiments. BMV replicase-directed co-copying of (-) RNA3 with wt sgRNA3a generated RNA3 recombinants in vitro, but it failed to when 3'-truncated sgRNA3a was substituted, demonstrating a role for the 3' polyA tail. Barley protoplast co-transfections revealed that (i) wt sgRNA3a recombines at the 3' and the internal sites; (ii) 3'-truncated sgRNA3as recombine more upstream; and (iii) 5'-truncated sgRNA3 recombine at a low rate. In planta co-inoculations confirmed the RNA3-sgRNA3a crossovers. In summary, the non-replicating sgRNA3a recombines with replicating RNA3, most likely via primer extension and/or internal template switching.
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14
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Abstract
Bioimaging contributes significantly to our understanding of plant virus infections. In the present review, we describe technical advances that enable imaging of the infection process at previously unobtainable levels. We highlight how such new advances in subcellular imaging are contributing to a detailed dissection of all stages of the viral infection process. Specifically, we focus on: (i) the increasingly detailed localizations of viral proteins enabled by a diversifying palette of cellular markers; (ii) approaches using fluorescence microscopy for the functional analysis of proteins in vivo; (iii) the imaging of viral RNAs; (iv) methods that bridge the gap between optical and electron microscopy; and (v) methods that are blurring the distinction between imaging and structural biology. We describe the advantages and disadvantages of such techniques and place them in the broader perspective of their utility in analysing plant virus infection.
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Salem NM, Chen AYS, Tzanetakis IE, Mongkolsiriwattana C, Ng JCK. Further complexity of the genus Crinivirus revealed by the complete genome sequence of Lettuce chlorosis virus (LCV) and the similar temporal accumulation of LCV genomic RNAs 1 and 2. Virology 2009; 390:45-55. [PMID: 19481773 DOI: 10.1016/j.virol.2009.04.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 04/05/2009] [Accepted: 04/28/2009] [Indexed: 11/19/2022]
Abstract
The sequence of Lettuce chlorosis virus (LCV) (genus Crinivirus) was determined and found to contain unique open reading frames (ORFs) and ORFs similar to those of other criniviruses, as well as 3' non-coding regions that shared a high degree of identity. Northern blot analysis of RNA extracted from LCV-infected plants identified subgenomic RNAs corresponding to six prominent internal ORFs and detected several novel LCV-single stranded RNA species. Virus replication in tobacco protoplasts was investigated and results indicated that LCV replication proceeded with novel crinivirus RNA accumulation kinetics, wherein viral genomic RNAs exhibited a temporally similar expression pattern early in the infection. This was noticeably distinct from the asynchronous RNA accumulation pattern previously observed for Lettuce infectious yellows virus (LIYV), the type member of the genus, suggesting that replication of the two viruses likely operate via dissimilar mechanisms.
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Affiliation(s)
- Nida' M Salem
- Microbiology, and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
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