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Ding H, Wang Y, Li C, Shuai S, An H, Fang S, Zhang S, Deng Q. Molecular characterization of a single-negative-stranded RNA virus from the rice blast fungus Magnaporthe oryzae isolate NJ39. Arch Virol 2024; 169:128. [PMID: 38802709 DOI: 10.1007/s00705-024-06054-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 02/29/2024] [Indexed: 05/29/2024]
Abstract
A novel negative-sense single-stranded RNA mycovirus, designated as "Magnaporthe oryzae mymonavirus 1" (MoMNV1), was identified in the rice blast fungus Magnaporthe oryzae isolate NJ39. MoMNV1 has a single genomic RNA segment consisting of 10,515 nucleotides, which contains six open reading frames. The largest open reading frame contains 5837 bases and encodes an RNA replicase. The six open reading frames have no overlap and are arranged linearly on the genome, but the spacing of the genes is small, with a maximum of 315 bases and a minimum of 80 bases. Genome comparison and phylogenetic analysis indicated that MoMNV1 is a new member of the genus Penicillimonavirus of the family Mymonaviridae.
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Affiliation(s)
- Hang Ding
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Yao Wang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Cong Li
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Simin Shuai
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Hongliu An
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
- Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, China
| | - Shouguo Fang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
- Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, China
| | - Songbai Zhang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
- Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, China
| | - Qingchao Deng
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China.
- Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, China.
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Ye L, Shi X, He Y, Chen J, Xu Q, Shafik K, Fu L, Yin Y, Kotta-Loizou I, Xu W. A novel botybirnavirus with a unique satellite dsRNA causes latent infection in Didymella theifolia isolated from tea plants. Microbiol Spectr 2023; 11:e0003323. [PMID: 37962342 PMCID: PMC10714997 DOI: 10.1128/spectrum.00033-23] [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: 03/22/2023] [Accepted: 10/02/2023] [Indexed: 11/15/2023] Open
Abstract
IMPORTANCE A novel botybirnavirus, infecting the tea plant pathogen Didymella theifolia and tentatively named Didymella theifolia botybirnavirus 1 (DtBRV1), together with an additional double-stranded RNA (dsRNA), was characterized. DtBRV1 comprises two dsRNAs (1 and 2) encapsidated in isometric virions, while dsRNA3 is a satellite. The satellite represents a unique specimen since it contains a duplicated region and has high similarity to the two botybirnavirus dsRNAs, supporting the notion that it most likely originated from a deficient genomic component. The biological characteristics of DtBRV1 were further determined. With their unique molecular traits, DtBRV1 and its related dsRNA expand our understanding of virus diversity, taxonomy, and evolution.
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Affiliation(s)
- Liangchao Ye
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Xinyu Shi
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Yunqiang He
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Jiao Chen
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Qingeng Xu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Karim Shafik
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- Department of Plant Pathology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
| | - Lanning Fu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Yumeng Yin
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
- Department of Clinical, Pharmaceutical and Biological Science, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - Wenxing Xu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
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Zhang Z, Guo W, Lu Y, Kang Q, Sui L, Liu H, Zhao Y, Zou X, Li Q. Hypovirulence-associated mycovirus epidemics cause pathogenicity degeneration of Beauveria bassiana in the field. Virol J 2023; 20:255. [PMID: 37924080 PMCID: PMC10623766 DOI: 10.1186/s12985-023-02217-6] [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: 08/17/2023] [Accepted: 10/26/2023] [Indexed: 11/06/2023] Open
Abstract
BACKGROUND The entomogenous fungus Beauveria bassiana is used as a biological insecticide worldwide, wild B. bassiana strains with high pathogenicity in the field play an important role in controlling insect pests via not only screening of highly virulent strains but also natural infection, but the pathogenicity degeneration of wild strains severely affected aforementioned effects. Previous studies have showed that multiple factors contributed to this phenomenon. It has been extensively proved that the mycovirus infection caused hypovirulence of phytopathogenic fungi, which has been used for plant disease biocontrol. However, it remains unknown whether the mycovirus epidemics is a key factor causing hypovirulence of B. bassiana naturally in the field. METHODS Wild strains of B. bassiana were collected from different geographic locations in Jilin Province, China, to clarify the epidemic and diversity of the mycoviruses. A mycovirus Beauveria bassiana chrysovirus 2 (BbCV2) we have previously identified was employed to clarify its impact on the pathogenicity of host fungi B. bassiana against the larvae of insect pest Ostrinia furnacalis. The serological analysis was conducted by preparing polyclonal antibody against a BbCV2 coat protein, to determine whether it can dissociate outside the host fungal cells and subsequently infect new hosts. Transcriptome analysis was used to reveal the interactions between viruses and hosts. RESULTS We surprisingly found that the mycovirus BbCV2 was prevalent in the field as a core virus in wild B. bassiana strains, without obvious genetic differentiation, this virus possessed efficient and stable horizontal and vertical transmission capabilities. The serological results showed that the virus could not only replicate within but also dissociate outside the host cells, and the purified virions could infect B. bassiana by co-incubation. The virus infection causes B. bassiana hypovirulence. Transcriptome analysis revealed decreased expression of genes related to insect epidermis penetration, hypha growth and toxin metabolism in B. bassiana caused by mycovirus infection. CONCLUSION Beauveria bassiana infected by hypovirulence-associated mycovirus can spread the virus to new host strains after infecting insects, and cause the virus epidemics in the field. The findings confirmed that mycovirus infection may be an important factor affecting the pathogenicity degradation of B. bassiana in the field.
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Affiliation(s)
- Zhengkun Zhang
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
| | - Wenbo Guo
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, People's Republic of China
| | - Yang Lu
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, People's Republic of China
| | - Qin Kang
- Institute of Zoology, Chinese Academy of Sciences, Beijing, 101408, People's Republic of China
| | - Li Sui
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
| | - Hongyu Liu
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
| | - Yu Zhao
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
| | - Xiaowei Zou
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China
| | - Qiyun Li
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Jilin Key Laboratory of Agricultural Microbiology, Key Laboratory of Integrated Pest Management on Crops in Northeast China, Ministry of Agriculture and Rural Areas, Changchun, 130033, People's Republic of China.
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
- Jilin Agricultural Science and Technology University, Jilin, 132109, People's Republic of China.
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Khan HA, Baig DI, Bhatti MF. An Overview of Mycoviral Curing Strategies Used in Evaluating Fungal Host Fitness. Mol Biotechnol 2023; 65:1547-1564. [PMID: 36841858 PMCID: PMC9963364 DOI: 10.1007/s12033-023-00695-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/11/2023] [Indexed: 02/27/2023]
Abstract
The number of novel mycoviruses is increasing at a high pace due to advancements in sequencing technologies. As a result, an uncountable number of mycoviral sequences are available in public sequence repositories. However, only genomic information is not sufficient to understand the impact of mycoviruses on their host biology. Biological characterization is required to determine the nature of mycoviruses (cryptic, hypervirulent, or hypovirulent) and to search for mycoviruses with biocontrol and therapeutic potential. Currently, no particular selective method is used as the gold standard against these mycoviral infections. Given the importance of curing, we present an overview of procedures used in preparation of isogenic lines, along with their benefits and drawbacks. We concluded that a combination of single-spore isolation and hyphal tipping is the best fit for preparation of isogenic lines. Furthermore, recent bioinformatic approaches should be introduced in the field of mycovirology to predict virus-specific antivirals to get robust results.
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Affiliation(s)
- Haris Ahmed Khan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
- Department of Biotechnology, University of Mianwali, Punjab, 42200 Pakistan
| | - Danish Ilyas Baig
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
| | - Muhammad Faraz Bhatti
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
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Khan HA, Nerva L, Bhatti MF. The good, the bad and the cryptic: The multifaceted roles of mycoviruses and their potential applications for a sustainable agriculture. Virology 2023; 585:259-269. [PMID: 37453341 DOI: 10.1016/j.virol.2023.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
Mycoviruses are natural inhabitants of fungi and have been identified in almost all fungal taxonomic groups. Mycoviruses that infect phytopathogenic fungi are now becoming a hot research area due to their potential for the biocontrol of important plant pathogens. But, before considering a mycovirus for biocontrol, we should be fully aware of the effects it induces in a fungal host and its interactions with other viruses, fungal strains and even the host plants. Mycoviral infections are generally associated with different effects, ranging from hypovirulence to hypervirulence, but they can often be cryptic (latent infections). The cryptic lifestyle has been associated to many mycoviruses, but thanks to growing knowledge we are now aware that it is often associated to axenic conditions while the real effects can be observed only in nature. Other mycoviruses either promote (hypervirulence) or (hypovirulence) fungal pathogenicity by a strong impact on the fungal physiology or by blocking the production of toxins or effectors. Finally, indirect effects of mycoviral infections can also be provided to the plant that hosts the fungal isolate, highlighting not only their potential as direct biocontrol agents but also as priming agents for plant resilience to biotic and abiotic stresses. This review provides a broad overview of mycoviral interactions both with their hosts and with other mycoviruses, highlighting the most interesting examples. In contrast to what has been observed to date, we believe that the collective availability of these data will not only improve our understanding of mycoviruses, but also increase our confidence in considering them as alternative measures against fungal diseases to improve the sustainable production of food and feed commodities.
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Affiliation(s)
- Haris Ahmed Khan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, 44000, Islamabad, Pakistan; Department of Biotechnology, University of Mianwali, Punjab, 42200, Pakistan
| | - Luca Nerva
- Research Centre for Viticulture and Enology, Council for Agricultural Research and Economics (CREA-VE), Via XXVIII Aprile, 31015, Conegliano, (TV), Italy.
| | - Muhammad Faraz Bhatti
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, 44000, Islamabad, Pakistan
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Hough B, Steenkamp E, Wingfield B, Read D. Fungal Viruses Unveiled: A Comprehensive Review of Mycoviruses. Viruses 2023; 15:1202. [PMID: 37243288 PMCID: PMC10224137 DOI: 10.3390/v15051202] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/07/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Mycoviruses (viruses of fungi) are ubiquitous throughout the fungal kingdom and are currently classified into 23 viral families and the genus botybirnavirus by the International Committee on the Taxonomy of Viruses (ICTV). The primary focus of mycoviral research has been on mycoviruses that infect plant pathogenic fungi, due to the ability of some to reduce the virulence of their host and thus act as potential biocontrol against these fungi. However, mycoviruses lack extracellular transmission mechanisms and rely on intercellular transmission through the hyphal anastomosis, which impedes successful transmission between different fungal strains. This review provides a comprehensive overview of mycoviruses, including their origins, host range, taxonomic classification into families, effects on their fungal counterparts, and the techniques employed in their discovery. The application of mycoviruses as biocontrol agents of plant pathogenic fungi is also discussed.
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Affiliation(s)
| | | | - Brenda Wingfield
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria 0002, South Africa; (B.H.); (E.S.); (D.R.)
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Zheng Y, Yin S, Zhao Y, Li S, Lu Z, Li Z, Deng Q, Li Z, Zhang S, Fang S. Molecular and biological characteristics of a novel chrysovirus infecting the fungus phytopathogenic Setosphaeria turcica f.sp. sorghi. Virus Res 2023; 325:199037. [PMID: 36596382 DOI: 10.1016/j.virusres.2022.199037] [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: 10/09/2022] [Revised: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 01/01/2023]
Abstract
A new double-stranded RNA (dsRNA) virus has been identified in the filamentous fungus Setosphaeria turcica f.sp. sorghi, whose genome consists of four segments (dsRNA1-4). Each dsRNA carries single open reading frame (ORF) flanked by 5' and 3' untranslated regions (UTRs) containing strictly conserved termini. The putative protein encoded by dsRNA1 showed 80.50% identity to the RNA-dependent RNA polymerase (RdRp) of the most closely related virus, Alternaria alternata chrysovirus 1 (AaCV1), belonging to the Chrysoviridae. dsRNA2 encodes the putative coat protein, while dsRNA3 and dsRNA4 respectively encode the hypothetical proteins of unknown functions. Phylogenetic analysis based on the RdRp protein indicated the virus clustered with members of the genus Betachrysovirus in the family Chrysoviridae. Based on the dsRNA profile, amino acid sequence comparisons, and phylogenetic analyses, the mycovirus is thought to be a new member of the family Chrysoviridae and designated as Setosphaeria turcica chrysovirus 1 (StCV1). Moreover, obvious differences were observed in the colony, mycelial and spore morphology between StCV1-infected and virus-cured strains of S. turcica f.sp. sorghi. StCV1 infection strongly reduced colony growth rate, spore production ability and virulence on host fungus. To our knowledge, this is the first report about mycovirus infecting S. turcica f.sp. sorghi and also the first chrysovirus infecting S. turcica.
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Affiliation(s)
- Yun Zheng
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Shuangshuang Yin
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Yinxiao Zhao
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Siyu Li
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Zhou Lu
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Zikuo Li
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Qingchao Deng
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China
| | - Zhanbiao Li
- MARA Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Guangxi Academy of Agricultural Sciences, Nanning 530007, China
| | - Songbai Zhang
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China; MARA Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
| | - Shouguo Fang
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Engineering Research Center for Pest Forewarning and Management, Yangtze University, Jingzhou 434025, China.
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Rodriguez Coy L, Plummer KM, Khalifa ME, MacDiarmid RM. Mycovirus-encoded suppressors of RNA silencing: Possible allies or enemies in the use of RNAi to control fungal disease in crops. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:965781. [PMID: 37746227 PMCID: PMC10512228 DOI: 10.3389/ffunb.2022.965781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023]
Abstract
Plants, fungi, and many other eukaryotes have evolved an RNA interference (RNAi) mechanism that is key for regulating gene expression and the control of pathogens. RNAi inhibits gene expression, in a sequence-specific manner, by recognizing and deploying cognate double-stranded RNA (dsRNA) either from endogenous sources (e.g. pre-micro RNAs) or exogenous origin (e.g. viruses, dsRNA, or small interfering RNAs, siRNAs). Recent studies have demonstrated that fungal pathogens can transfer siRNAs into plant cells to suppress host immunity and aid infection, in a mechanism termed cross-kingdom RNAi. New technologies, based on RNAi are being developed for crop protection against insect pests, viruses, and more recently against fungal pathogens. One example, is host-induced gene silencing (HIGS), which is a mechanism whereby transgenic plants are modified to produce siRNAs or dsRNAs targeting key transcripts of plants, or their pathogens or pests. An alternative gene regulation strategy that also co-opts the silencing machinery is spray-induced gene silencing (SIGS), in which dsRNAs or single-stranded RNAs (ssRNAs) are applied to target genes within a pathogen or pest. Fungi also use their RNA silencing machinery against mycoviruses (fungal viruses) and mycoviruses can deploy virus-encoded suppressors of RNAi (myco-VSRs) as a counter-defence. We propose that myco-VSRs may impact new dsRNA-based management methods, resulting in unintended outcomes, including suppression of management by HIGS or SIGS. Despite a large diversity of mycoviruses being discovered using high throughput sequencing, their biology is poorly understood. In particular, the prevalence of mycoviruses and the cellular effect of their encoded VSRs are under-appreciated when considering the deployment of HIGS and SIGS strategies. This review focuses on mycoviruses, their VSR activities in fungi, and the implications for control of pathogenic fungi using RNAi.
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Affiliation(s)
- Lorena Rodriguez Coy
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Kim M. Plummer
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Mahmoud E. Khalifa
- Botany and Microbiology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Robin M. MacDiarmid
- BioProtection, The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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Metatranscriptomic Analysis Reveals Rich Mycoviral Diversity in Three Major Fungal Pathogens of Rice. Int J Mol Sci 2022; 23:ijms23169192. [PMID: 36012458 PMCID: PMC9409214 DOI: 10.3390/ijms23169192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/11/2022] [Accepted: 08/14/2022] [Indexed: 11/17/2022] Open
Abstract
In recent years, three major fungal diseases of rice, i.e., rice blast, rice false smut, and rice-sheath blight, have caused serious worldwide rice-yield reductions and are threatening global food security. Mycoviruses are ubiquitous in almost all major groups of filamentous fungi, oomycetes, and yeasts. To reveal the mycoviral diversity in three major fungal pathogens of rice, we performed a metatranscriptomic analysis of 343 strains, representing the three major fungal pathogens of rice, Pyricularia oryzae, Ustilaginoidea virens, and Rhizoctonia solani, sampled in southern China. The analysis identified 682 contigs representing the partial or complete genomes of 68 mycoviruses, with 42 described for the first time. These mycoviruses showed affinity with eight distinct lineages: Botourmiaviridae, Partitiviridae, Totiviridae, Chrysoviridae, Hypoviridae, Mitoviridae, Narnaviridae, and Polymycoviridae. More than half (36/68, 52.9%) of the viral sequences were predicted to be members of the families Narnaviridae and Botourmiaviridae. The members of the family Polymycoviridae were also identified for the first time in the three major fungal pathogens of rice. These findings are of great significance for understanding the diversity, origin, and evolution of, as well as the relationship between, genome structures and functions of mycoviruses in three major fungal pathogens of rice.
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Shuai S, Zheng H, Ding H, Wang Y, Li J, Liu F, Liu F, An H, Fang S, Zhang S, Deng Q. Molecular characterization of a novel botourmiavirus with inverted complementary termini from the rice blast fungus Magnaporthe oryzae isolate HF04. Arch Virol 2022; 167:1899-1903. [PMID: 35716263 DOI: 10.1007/s00705-022-05506-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/09/2022] [Indexed: 11/29/2022]
Abstract
A novel positive-sense single-stranded RNA mycovirus, designated as "Magnaporthe oryzae botourmiavirus 10" (MoBV10), was identified in the rice blast fungus Magnaporthe oryzae isolate HF04. MoBV10 has a single genomic RNA segment consisting of 2,448 nucleotides, which contains a single open reading frame encoding an RNA-dependent RNA polymerase. Genome comparison and phylogenetic analysis indicated that MoBV10 is a new member of the genus Betascleroulivirus in the family Botourmiaviridae. The 5'- and 3'-terminal sequences of the genomic RNA of MoBV10 have inverted complementarity and potentially form a panhandle structure, which is very rare in RNA viruses.
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Affiliation(s)
- Simnin Shuai
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Hong Zheng
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Hang Ding
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Yao Wang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Jinzhe Li
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Fuyu Liu
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Fengying Liu
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Hongliu An
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Shouguo Fang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Songbai Zhang
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China
| | - Qingchao Deng
- College of Agriculture, Yangtze University, Jingzhou, 434005, Hubei, China. .,Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, China.
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11
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Xu G, Zhang X, Liang X, Chen D, Xie C, Kang Z, Zheng L. A novel hexa-segmented dsRNA mycovirus confers hypovirulence in the phytopathogenic fungus Diaporthe pseudophoenicicola. Environ Microbiol 2022; 24:4274-4284. [PMID: 35315558 DOI: 10.1111/1462-2920.15963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 03/02/2022] [Indexed: 11/28/2022]
Abstract
A novel hexa-segmented double-stranded RNA (dsRNA) mycovirus was isolated and characterized from the filamentous phytopathogenic fungus Diaporthe pseudophoenicicola, and was named Diaporthe pseudophoenicicola chrysovirus 1 (DpCV1). The full-length cDNAs of dsRNA1-6 were 3335, 3030, 3039, 2980, 963, and 780 bp, respectively. Sequence analysis indicated the presence of nine open reading frames (ORFs) in the DpCV1 genome. ORF1 in dsRNA1 putatively encoded the RNA-dependent RNA polymerase (RdRp), and ORF3 in dsRNA2 encoded a capsid protein (CP). The seven remaining ORFs, ORF2 in dsRNA2, ORF4 in dsRNA3, ORF6, 7 in dsRNA4, ORF8 in dsRNA5, and ORF9 in dsRNA6, encoded proteins with unknown functions. Phylogenetic analysis revealed that DpCV1 is closely related to members of the cluster I group within the family Chrysoviridae but formed a separate clade. Importantly, all the six segments of DpCV1 were cured successfully through single spore isolation to obtain the isogenic virus-free strains. DpCV1 can confer hypovirulence to the fungal host of Diaporthe pseudophoenicicola. Compared with the virus-free strain, WC02 harboring the DpCV1 is more sensitive to fungicide prochloraz. Furthermore, the cell wall of DpCV1 infected strain was loose and enlarged. This is the first report of a hexa-segmented tentative chrysovirus in D. pseudophoenicicola. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Gang Xu
- Key Laboratory of Green Prevention and Control of Tropical Plant Disease and Pests, Ministry of Education and School of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Xinchun Zhang
- Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan, 571101, China
| | - Xiaofei Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Daipeng Chen
- Key Laboratory of Green Prevention and Control of Tropical Plant Disease and Pests, Ministry of Education and School of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Changping Xie
- Key Laboratory of Green Prevention and Control of Tropical Plant Disease and Pests, Ministry of Education and School of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Li Zheng
- Key Laboratory of Green Prevention and Control of Tropical Plant Disease and Pests, Ministry of Education and School of Plant Protection, Hainan University, Haikou, Hainan, 570228, China
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12
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Complete nucleotide sequence of a novel botourmiavirus from the rice blast fungus Magnaporthe oryzae isolate SH05. Arch Virol 2021; 166:1783-1787. [PMID: 33779811 DOI: 10.1007/s00705-021-05044-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/04/2021] [Indexed: 10/21/2022]
Abstract
A novel mycovirus with the proposed name "Magnaporthe oryzae botourmiavirus 9" (MoBV9) was found in the rice blast fungus Magnaporthe oryzae isolate SH05. The virus has a positive single-stranded RNA genome of 2,812 nucleotides and contains a single open reading frame predicted to encode an RNA-dependent RNA polymerase that is closely related to those of some unclassified viruses of the family Botourmiaviridae, including Plasmopara viticola lesion associated ourmia-like virus 44, Plasmopara viticola lesion associated ourmia-like virus 47, and Cladosporium uredinicola ourmiavirus 1. Genome sequence comparisons and phylogenetic analysis supported the notion that MoBV9 is a new member of the family Botourmiaviridae.
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13
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Chiba Y, Oiki S, Yaguchi T, Urayama SI, Hagiwara D. Discovery of divided RdRp sequences and a hitherto unknown genomic complexity in fungal viruses. Virus Evol 2020; 7:veaa101. [PMID: 33505709 PMCID: PMC7816673 DOI: 10.1093/ve/veaa101] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
By identifying variations in viral RNA genomes, cutting-edge metagenome
technology has potential to reshape current concepts about the evolution of RNA
viruses. This technology, however, cannot process low-homology genomic regions
properly, leaving the true diversity of RNA viruses unappreciated. To overcome
this technological limitation, we applied an advanced method, Fragmented and
Primer-Ligated Double-stranded (ds) RNA Sequencing (FLDS), to screen RNA viruses
from 155 fungal isolates, which allowed us to obtain complete viral genomes in a
homology-independent manner. We created a high-quality catalog of 19 RNA viruses
(12 viral species) that infect Aspergillus isolates. Among
them, nine viruses were not detectable by the conventional methodology involving
agarose gel electrophoresis of dsRNA, a hallmark of RNA virus infections.
Segmented genome structures were determined in 42 per cent of the viruses. Some
RNA viruses had novel genome architectures; one contained a dual
methyltransferase domain and another had a separated RNA-dependent RNA
polymerase (RdRp) gene. A virus from a different fungal taxon
(Pyricularia) had an RdRp sequence that was separated on
different segments, suggesting that a divided RdRp is widely present among
fungal viruses, despite the belief that all RNA viruses encode RdRp as a single
gene. These findings illustrate the previously hidden diversity and evolution of
RNA viruses, and prompt reconsideration of the structural plasticity of
RdRp.
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Affiliation(s)
- Yuto Chiba
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Sayoko Oiki
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Takashi Yaguchi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Syun-Ichi Urayama
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Daisuke Hagiwara
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
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14
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Liu Y, Zhang L, Esmael A, Duan J, Bian X, Jia J, Xie J, Cheng J, Fu Y, Jiang D, Lin Y. Four Novel Botourmiaviruses Co-Infecting an Isolate of the Rice Blast Fungus Magnaporthe oryzae. Viruses 2020; 12:E1383. [PMID: 33287110 PMCID: PMC7761653 DOI: 10.3390/v12121383] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 11/16/2022] Open
Abstract
Via virome sequencing, six viruses were detected from Magnaporthe oryzae strains YC81-2, including one virus in the family Tombusviridae, one virus in the family Narnaviridae and four viruses in the family Botourmiaviridae. Since the RNA-dependent RNA polymerase (RdRp) of one botourmiavirus show the highest identity (79%) with Magnaporthe oryzae ourmia-like virus 1 (MOLV1), the virus that was grouped into the genus Magoulivirus was designated as Magnaporthe oryzae botourmiavirus 2 (MOBV2). The three other novel botourmiaviruses were selected for further study. The complete nucleotide sequences of the three botourmiaviruses were determined. Sequence analysis showed that virus 1, virus 2, and virus 3 were 2598, 2385, and 2326 nts in length, respectively. The variable 3' untranslated region (3'-UTR) and 5'-UTR of each virus could be folded into a stable stem-loop secondary structure. Each virus consisted of a unique ORF encoding a putative RdRp. The putative proteins with a conserved GDD motif of RdRp showed the highest sequence similarity to RdRps of viruses in the family Botourmiaviridae. Phylogenetic analysis demonstrated that these viruses were three distinct novel botourmiaviruses, clustered into the Botourmiaviridae family but not belonging to any known genera of this family. Thus, virus 1, virus 2, and virus 3 were designated as Magnaporthe oryzae botourmiavirus 5, 6, and 7 (MOBV5, MOBV6, and MOBV7), respectively. Our results suggest that four distinct botourmiaviruses, MOBV2, MOBV5, MOBV6, and MOBV7, co-infect a single strain of Magnaporthe oryzae, and MOBV5, MOBV6, and MOBV7 are members of three unclassified genera in the family Botourmiaviridae.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (Y.L.); (A.E.); (J.J.); (J.X.); (D.J.)
| | - Liyan Zhang
- Institute of Biotechnology, Heilongjiang Academy of Agricultural Sciences, Harbin 150001, China;
| | - Ahmed Esmael
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (Y.L.); (A.E.); (J.J.); (J.X.); (D.J.)
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
- Botany and Microbiology Department, Faculty of Science, Benha University, Qalubiya Governorate, Benha 13511, Egypt
| | - Jie Duan
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Xuefeng Bian
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Jichun Jia
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (Y.L.); (A.E.); (J.J.); (J.X.); (D.J.)
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (Y.L.); (A.E.); (J.J.); (J.X.); (D.J.)
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Jiasen Cheng
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Yanping Fu
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (Y.L.); (A.E.); (J.J.); (J.X.); (D.J.)
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
| | - Yang Lin
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (J.D.); (X.B.); (J.C.); (Y.F.)
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15
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Shahi S, Chiba S, Kondo H, Suzuki N. Cryphonectria nitschkei chrysovirus 1 with unique molecular features and a very narrow host range. Virology 2020; 554:55-65. [PMID: 33383414 DOI: 10.1016/j.virol.2020.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/21/2020] [Accepted: 11/23/2020] [Indexed: 12/20/2022]
Abstract
Cryphonectria nitschkei chrysovirus 1 (CnCV1), was described earlier from an ascomycetous fungus, Cryphonectria nitschkei strain OB5/11, collected in Japan; its partial sequence was reported a decade ago. Complete sequencing of the four genomic dsRNA segments revealed molecular features similar to but distinct from previously reported members of the family Chrysoviridae. Unique features include the presence of a mini-cistron preceding the major large open reading frame in each genomic segment. Common features include the presence of CAA repeats in the 5'-untranslated regions and conserved terminal sequences. CnCV1-OB5/11 could be laterally transferred to C. nitschkei and its relatives C. radicalis and C. naterciae via coculturing, virion transfection and protoplast fusion, but not to fungal species other than the three species mentioned above, even within the genus Cryphonectria, suggesting a very narrow host range. Phenotypic comparison of a few sets of CnCV1-infected and -free isogenic strains showed symptomless infection in new hosts.
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Affiliation(s)
- Sabitree Shahi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Sotaro Chiba
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan.
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16
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Owashi Y, Aihara M, Moriyama H, Arie T, Teraoka T, Komatsu K. Population Structure of Double-Stranded RNA Mycoviruses That Infect the Rice Blast Fungus Magnaporthe oryzae in Japan. Front Microbiol 2020; 11:593784. [PMID: 33193269 PMCID: PMC7664462 DOI: 10.3389/fmicb.2020.593784] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/28/2020] [Indexed: 11/28/2022] Open
Abstract
Various viruses infect Magnaporthe oryzae (syn. Pyricularia oryzae), which is a well-studied fungus that causes rice blast disease. Most research has focused on the discovery of new viruses and the hypovirulence-associated traits conferred by them. Therefore, the diversity and prevalence of viruses in wild fungal populations have not been explored. We conducted a comprehensive screening of M. oryzae mycoviruses from various regions in Japan using double-stranded RNA (dsRNA) electrophoresis and RT-PCR assays. We detected three mycoviruses, Magnaporthe oryzae virus 2 (MoV2), Magnaporthe oryzae chrysovirus 1 (MoCV1), and Magnaporthe oryzae partitivirus 1 (MoPV1), among 127 of the 194 M. oryzae strains screened. The most prevalent virus was MoPV1 (58.8%), which often co-infected in a single fungal strain together with MoV2 or MoCV1. MoV2 and MoCV1 were found in 22.7 and 10.8% of strains, respectively, and they were usually distributed in different regions so that mixed-infection with these two mycoviruses was extremely rare. The predominance of MoPV1 in M. oryzae is supported by significant negative values from neutrality tests, which indicate that the population size of MoPV1 tends to increase. Population genetic analyses revealed high nucleotide diversity and the presence of phylogenetically diverse subpopulations among the MoV2 isolates. This was not the case for MoPV1. Furthermore, studies of a virus-cured M. oryzae strain revealed that MoV2 does not cause any abnormalities or symptoms in its host. However, a leaf sheath inoculation assay showed that its presence slightly increased the speed of mycelial growth, compared with virus-free mycelia. These results demonstrate that M. oryzae in Japan harbors diverse dsRNA mycovirus communities with wide variations in their population structures among different viruses.
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Affiliation(s)
- Yuta Owashi
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan.,Western Region Agricultural Research Center, National Agriculture and Food Research Organization, Fukuyama, Japan
| | - Mitsuhiro Aihara
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan
| | - Hiromitsu Moriyama
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan
| | - Tohru Teraoka
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Japan
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17
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Olivé M, Campo S. The dsRNA mycovirus ChNRV1 causes mild hypervirulence in the fungal phytopathogen Colletotrichum higginsianum. Arch Microbiol 2020; 203:241-249. [PMID: 32914229 DOI: 10.1007/s00203-020-02030-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/21/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022]
Abstract
The genus Colletotrichum comprises a large number of filamentous fungi responsible for anthracnose diseases in many tropical and subtropical fruits and vegetables. In particular, Colletotrichum higginsianum infects Brassicaceae species, including Arabidopsis. The C. higginsianum strain IMI349063A is naturally infected with a dsRNA virus, named Colletorichum higginsianum non-segmented virus (ChNRV1). Here, we investigated the biological effect of ChNRV1 in C. higginsianum by comparing strains with and without the virus. ChNRV1 does not have an effect on C. higginsianum growth under salt and cell-wall stress conditions. However, thermal stress reduced C. higginsianum growth rate, this effect being more evident in the wild-type C. higginsianum strain containing the virus. Although ChNRV1 had no effect in conidiation, conidia were narrower when the virus is present. More importantly, ChNRV1 causes a mild increase in C. higginsianum virulence (hypervirulence) when infecting Arabidopsis plants. These findings indicated that, whereas the ChNRV1 mycovirus does not impair growth and conidiation of C. higginsianum, it confers hypervirulence to the fungal host. These findings will help in future research on the effect of mycoviral infection on pathogenic fungi in plant species of agronomical relevance.
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Affiliation(s)
- Marta Olivé
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus Universitat Autònoma de Barcelona (UAB), Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
| | - Sonia Campo
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus Universitat Autònoma de Barcelona (UAB), Bellaterra (Cerdanyola del Vallés), Barcelona, Spain.
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18
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Lin Y, Zhou J, Zhou X, Shuai S, Zhou R, An H, Fang S, Zhang S, Deng Q. A novel narnavirus from the plant-pathogenic fungus Magnaporthe oryzae. Arch Virol 2020; 165:1235-1240. [PMID: 32157391 DOI: 10.1007/s00705-020-04586-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/08/2020] [Indexed: 10/24/2022]
Abstract
A novel mycovirus with the proposed name "Magnaporthe oryzae narnavirus virus 1" (MoNV1), was described in the rice blast fungus Magnaporthe oryzae. The virus has a single-stranded (+ss) RNA genome of 2452 nucleotides, contains a single open reading frame (ORF) predicted to encode an RNA-dependent RNA polymerase (RDRP), and is closely related to some viruses of the genus Narnavirus, family Narnaviridae, including Aspergillus fumigatus narnavirus 1 (AfNV1), Neofusicoccum parvum narnavirus 2 (NpNV2) and Alternaria tenuissima narnavirus 1 (AtNV2). Genome sequence comparisons and phylogenetic analysis suggested that MoNV1 is a new member of the genus Narnavirus. The RDRPs of MoNV1 and some closely related narnaviruses do not contain a typical metal-binding "GDD" motif and catalytic site. Further studies are needed to investigate the replication mechanism of these viruses.
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Affiliation(s)
- Yuan Lin
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Jia Zhou
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China.,College of Plant Protection, Hainan University, Haikou, 570228, Hainan, China
| | - Xuan Zhou
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Simin Shuai
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Rendi Zhou
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Hongliu An
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China.,Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, 434025, Hubei, China
| | - Shouguo Fang
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China.,Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, 434025, Hubei, China
| | - Songbai Zhang
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China. .,Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, 434025, Hubei, China.
| | - Qingchao Deng
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China. .,Hubei Engineering Research Center for Pest Forewarning and Management, Jingzhou, 434025, Hubei, China.
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19
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The PoV mycovirus affects extracellular enzyme expression and fruiting body yield in the oyster mushroom, Pleurotus ostreatus. Sci Rep 2020; 10:1094. [PMID: 31974404 PMCID: PMC6978373 DOI: 10.1038/s41598-020-58016-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/09/2020] [Indexed: 12/23/2022] Open
Abstract
Isogenic virus-cured and virus-infected fungal strains were previously obtained and compared to investigate mycoviral diseases and, specifically, the influence of viral infection on the vegetative growth of Pleurotus ostreatus. The present study demonstrated that infection with mycovirus PoV-ASI2792 (PoV) caused phenotypic and physiological changes in fungal cells and mycelia. The microscopically determined growth rate of the virus-infected strain was lower than that of the virus-cured strain, due to the conglomerate phenomenon during the mycelial growth process. An exploration of the viral effects of PoV on fruiting bodies yield showed significantly lower than that on virus-cured P. ostreatus. A colorimetric assay of polyphenol oxidase activity in the strains showed very weak activity in the virus-infected strain. To estimate the activity levels of enzymes related to the growth and fruiting body formation, the relative expression levels of genes encoding various extracellular enzymes such as Carbohydrate-Active Enzymes (CAZymes) were measured by quantitative RT-PCR. The expression levels of the assayed genes were significantly lower in virus-infected than in virus-cured P. ostreatus. Together, these results indicate that PoV infection affects the spawn growth and fruiting body formation of P. ostreatus via decreased expression and activity of some extracellular enzymes including lignocellulolytic enzymes.
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20
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Takahashi-Nakaguchi A, Shishido E, Yahara M, Urayama SI, Sakai K, Chibana H, Kamei K, Moriyama H, Gonoi T. Analysis of an Intrinsic Mycovirus Associated With Reduced Virulence of the Human Pathogenic Fungus Aspergillus fumigatus. Front Microbiol 2020; 10:3045. [PMID: 32010101 PMCID: PMC6978690 DOI: 10.3389/fmicb.2019.03045] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/17/2019] [Indexed: 11/21/2022] Open
Abstract
Aspergillus fumigatus is an airborne fungal pathogen that causes severe infections with invasive growth in immunocompromised patients. Several mycoviruses have recently been isolated from A. fumigatus strains, but there are presently no reports of mycoviral-mediated reduction or elimination of fungal pathogenicity in vertebrate models. Here, we report the biological features of a novel mycovirus, A. fumigatus chrysovirus 41362 (AfuCV41362), isolated from the hypovirulent A. fumigatus strain IFM 41362. The AfuCV41362 genome is comprised of four dsRNAs, each of which contains a single ORF (ORF1-4). ORF1 encodes a protein with sequence similarity to RNA-dependent RNA polymerases of viruses in the family Chrysoviridae, while ORF3 encodes a putative capsid protein. Viral RNAs are expressed primarily during the germination stage, and RNA-seq analysis of virus-infected A. fumigatus at the germination stage suggested that the virus suppressed expression of several pathogenicity-associated host genes, including hypoxia adaptation and nitric oxide detoxification genes. In vitro functional analysis revealed that the virus-infected strain had reduced tolerance to environmental stressors. Virus-infected A. fumigatus strain IFM 41362 had reduced virulence in vivo compared to the virus-free strain in a mouse infection model. Furthermore, introduction of the mycovirus to a natively virus-free KU A. fumigatus strain induced virus-infected phenotypes. To identify mycovirus genes responsible for the reduced virulence of A. fumigatus, each viral ORF was ectopically expressed in the virus-free KU strain. Ectopic expression of the individual ORFs only nominally reduced virulence of the host fungus in a mouse infection model. However, we found that ORF3 and ORF4 reduced tolerance to environmental stresses in in vitro analysis. Based on these results, we suggest that the AfuCV41362 mycovirus ORF3 and ORF4 reduce fungal virulence by suppressing stress tolerance together with other viral genes, rather than alone.
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Affiliation(s)
| | - Erika Shishido
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Misa Yahara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | | | - Kanae Sakai
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Katsuhiko Kamei
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | | | - Tohru Gonoi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
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21
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Petrzik K, Koloniuk I, Sehadová H, Sarkisova T. Chrysoviruses Inhabited Symbiotic Fungi of Lichens. Viruses 2019; 11:v11121120. [PMID: 31817044 PMCID: PMC6949994 DOI: 10.3390/v11121120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/26/2019] [Accepted: 11/30/2019] [Indexed: 12/28/2022] Open
Abstract
A lichen body is formed most often from green alga cells trapped in a net of ascomycetous fungi and accompanied by endolichenic or parasitic fungi, other algae, and symbiotic or free-living bacteria. The lichen’s microcosmos is inhabited by mites, insects, and other animals for which the lichen is a source of food or a place to live. Novel, four-segmented dsRNA viruses were detected in saxicolous Chrysothrixchlorina and Lepraria incana lichens. Comparison of encoded genome proteins revealed classification of the viruses to the genus Alphachrysovirus and a relationship to chrysoviruses from filamentous ascomycetous fungi. We propose the names Chrysothrix chrysovirus 1 (CcCV1) and Lepraria chrysovirus 1 (LiCV1) as acronyms for these viruses. Surprisingly, observation of Chrysothrix chlorina hybridization with fluorescent-labelled virus probe by confocal microscope revealed that the CcCV1 virus is not present in the lichen body-forming fungus but in accompanying endolichenic Penicilliumcitreosulfuratum fungus. These are the first descriptions of mycoviruses from a lichen environment.
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Affiliation(s)
- Karel Petrzik
- Department of Plant Virology, Institute of Plant Molecular Biology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; (I.K.); (T.S.)
- Correspondence: ; Tel.: +420-387-775-549
| | - Igor Koloniuk
- Department of Plant Virology, Institute of Plant Molecular Biology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; (I.K.); (T.S.)
| | - Hana Sehadová
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic;
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Tatiana Sarkisova
- Department of Plant Virology, Institute of Plant Molecular Biology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; (I.K.); (T.S.)
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22
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Higashiura T, Katoh Y, Urayama SI, Hayashi O, Aihara M, Fukuhara T, Fuji SI, Kobayashi T, Hase S, Arie T, Teraoka T, Komatsu K, Moriyama H. Magnaporthe oryzae chrysovirus 1 strain D confers growth inhibition to the host fungus and exhibits multiform viral structural proteins. Virology 2019; 535:241-254. [DOI: 10.1016/j.virol.2019.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 07/11/2019] [Accepted: 07/14/2019] [Indexed: 10/26/2022]
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23
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Three ourmia-like viruses and their associated RNAs in Pyricularia oryzae. Virology 2019; 534:25-35. [DOI: 10.1016/j.virol.2019.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 11/18/2022]
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24
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Wang S, Yang Z, Zhang T, Li N, Cao Q, Li G, Yuan Y, Liu D. Molecular Characterization of a Chrysovirus Isolated From the Citrus Pathogen Penicillium crustosum and Related Fungicide Resistance Analysis. Front Cell Infect Microbiol 2019; 9:156. [PMID: 31157173 PMCID: PMC6529537 DOI: 10.3389/fcimb.2019.00156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 04/26/2019] [Indexed: 12/30/2022] Open
Abstract
Penicillium sp. are damaging to a range of foods and fruits including citrus. To date, double-stranded (ds)RNA viruses have been reported in most Penicillium species but not in citrus pathogen P. crustosum. Here we report a novel dsRNA virus, designated as Penicillium crustosum chrysovirus 1 (PcCV1) and isolated from P. crustosum strain HS-CQ15. PcCV1 genome comprises four dsRNA segments, referred to as dsRNA1, dsRNA2, dsRNA3, and dsRNA4, which are 3600, 3177, 3078, and 2808 bp in length, respectively. Sequence analysis revealed the presence of four open reading frames (ORFs) in the PcCV1 genome. ORF1 in dsRNA1 encodes a putative RNA-dependent RNA polymerase (RdRp) and ORF2 in dsRNA2 encodes a putative coat protein (CP). The two remaining ORFs, ORF3 in dsRNA3 and ORF4 in dsRNA4, encode proteins of unknown function. Phylogenetic analysis based on RdRp sequences showed that PcCV1 clusters with other members of the genus Chrysovirus, family Chrysoviridae. Transmission electron microscope (TEM) analysis revealed that the PcCV1 visions are approximately 40 nm in diameter. Regarding biological effects of PcCV1, HS-CQ15 harboring the chrysovirus exhibited no obvious difference in colony morphology under fungicide-free conditions but decreased resistance to demethylation inhibitor (DMI)-fungicide prochloraz, as compared to PcCV1-cured strain. Here we provide the first evidence of a virus present in citrus pathogenic fungus P. crustosum and the chrysovirus-induced change in fungicide-resistance of its host fungus.
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Affiliation(s)
- Shengqiang Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Zhu Yang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Tingfu Zhang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Na Li
- College of Life Science and Technology, Honghe University, Mengzi, China
| | - Qianwen Cao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Guoqi Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Yongze Yuan
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Deli Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
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Li CX, Zhu JZ, Gao BD, Zhu HJ, Zhou Q, Zhong J. Characterization of a Novel Ourmia-Like Mycovirus Infecting Magnaporthe oryzae and Implications for Viral Diversity and Evolution. Viruses 2019; 11:v11030223. [PMID: 30841545 PMCID: PMC6465991 DOI: 10.3390/v11030223] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 01/06/2023] Open
Abstract
Here, the molecular characterization of a novel mycovirus that was isolated from a phytopathogenic fungus Magnaporthe oryzae and designed as Magnaporthe oryzae ourmia-like virus 4 (MOLV4) is reported. MOLV4 has a genome that is 2497 bp long and possesses a single open reading frame (ORF), which encodes the product RNA-dependent RNA polymerase (RdRp). Sequence similarities were found between the MOLV4 encoded RdRp and the counterparts of a few previously reported ourmia-like mycoviruses. Virus-curing and biological comparison indicate that the virus has no or mild effects on the morphology and mycelium growth rate of the host fungus. Phylogenetic analysis using the RdRp aa sequences was performed. The results show that MOLV4 is clustered with the ourmia-like mycoviruses, forming a clade closely related to ourmiaviruses but distinct from narnaviruses. In addition, database searches revealed that several MOLV4-related sequences are present in the transcriptome shotgun assembly (TSA) library, expressed sequence tag database (ESTdb), whole-genome shotgun (WGS) library, and genomic survey sequences (GSS) libraries of a few other species of eukaryote organisms. Our results show that MOLV4, together with other similar ourmia-like mycoviruses, might represent a virus clade that links the plant ourmiaviruses and fungal narnaviruses and has a wide range of hosts.
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Affiliation(s)
- Chang Xin Li
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
| | - Jun Zi Zhu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
| | - Bi Da Gao
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
| | - Hong Jian Zhu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
| | - Qian Zhou
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
| | - Jie Zhong
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
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26
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Ejmal MA, Holland DJ, MacDiarmid RM, Pearson MN. A novel chrysovirus from a clinical isolate of Aspergillus thermomutatus affects sporulation. PLoS One 2018; 13:e0209443. [PMID: 30571748 PMCID: PMC6301774 DOI: 10.1371/journal.pone.0209443] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 12/05/2018] [Indexed: 12/15/2022] Open
Abstract
A clinical isolate of Aspergillus thermomutatus (Teleomorph: Neosartorya pseudofischeri) was found to contain ~35 nm isometric virus-like particles associated with four double-stranded (ds) RNA segments, each of which coded for a single open reading frame. The longest dsRNA element (3589 nt) encodes a putative RNA-dependent RNA polymerase (1114 aa), the second longest dsRNA element (2772 nt) encodes a coat protein (825 aa), and the other two dsRNAs (2676 nt, 2514 nt) encode hypothetical proteins of 768 aa and 711 aa, respectively. Phylogenetic analysis of the amino acid sequences showed 41-60% similarity to the proteins coded by the dsRNAs of the most closely related virus, Penicillium janczewskii chrysovirus 2, indicating that it is a new species based on the International Committee on Taxonomy of Viruses criteria for the genus Chrysovirus. This is the first virus reported from A. thermomutatus and was tentatively named Aspergillus thermomutatus chrysovirus 1. A virus free line of the fungal isolate, cured by cycloheximide treatment, produced large numbers of conidia but no ascospores at both 20°C and 37°C, whereas the virus infected line produced ten-fold fewer conidia at 20°C and a large number of ascospores at both temperatures. The effects of the virus on fungal sporulation have interesting implications for the spread of the fungus and possible use of the virus as a biological control agent.
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Affiliation(s)
- Mahjoub A. Ejmal
- School of Biological Sciences, the University of Auckland, Auckland, New Zealand
| | - David J. Holland
- Infectious Diseases Unit, Division of Medicine, Staff Centre, Middlemore Hospital, Auckland, New Zealand
| | - Robin M. MacDiarmid
- School of Biological Sciences, the University of Auckland, Auckland, New Zealand
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Michael N. Pearson
- School of Biological Sciences, the University of Auckland, Auckland, New Zealand
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27
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Chrysoviruses in Magnaporthe oryzae. Viruses 2018; 10:v10120697. [PMID: 30544784 PMCID: PMC6315753 DOI: 10.3390/v10120697] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 01/07/2023] Open
Abstract
Magnaporthe oryzae, the fungus that causes rice blast, is the most destructive pathogen of rice worldwide. A number of M. oryzae mycoviruses have been identified. These include Magnaporthe oryzae. viruses 1, 2, and 3 (MoV1, MoV2, and MoV3) belonging to the genus, Victorivirus, in the family, Totiviridae; Magnaporthe oryzae. partitivirus 1 (MoPV1) in the family, Partitiviridae; Magnaporthe oryzae. chrysovirus 1 strains A and B (MoCV1-A and MoCV1-B) belonging to cluster II of the family, Chrysoviridae; a mycovirus related to plant viruses of the family, Tombusviridae (Magnaporthe oryzae. virus A); and a (+)ssRNA mycovirus closely related to the ourmia-like viruses (Magnaporthe oryzae. ourmia-like virus 1). Among these, MoCV1-A and MoCV1-B were the first reported mycoviruses that cause hypovirulence traits in their host fungus, such as impaired growth, altered colony morphology, and reduced pigmentation. Recently we reported that, although MoCV1-A infection generally confers hypovirulence to fungi, it is also a driving force behind the development of physiological diversity, including pathogenic races. Another example of modulated pathogenicity caused by mycovirus infection is that of Alternaria alternata chrysovirus 1 (AaCV1), which is closely related to MoCV1-A. AaCV1 exhibits two contrasting effects: Impaired growth of the host fungus while rendering the host hypervirulent to the plant, through increased production of the host-specific AK-toxin. It is inferred that these mycoviruses might be epigenetic factors that cause changes in the pathogenicity of phytopathogenic fungi.
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28
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Ejmal MA, Holland DJ, MacDiarmid RM, Pearson MN. The Effect of Aspergillus Thermomutatus Chrysovirus 1 on the Biology of Three Aspergillus Species. Viruses 2018; 10:E539. [PMID: 30279352 PMCID: PMC6213286 DOI: 10.3390/v10100539] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 12/16/2022] Open
Abstract
This study determined the effects of Aspergillus thermomutatus chrysovirus 1 (AthCV1), isolated from Aspergillus thermomutatus, on A. fumigatus, A. nidulans and A. niger. Protoplasts of virus-free isolates of A. fumigatus, A. nidulans and A. niger were transfected with purified AthCV1 particles and the phenotype, growth and sporulation of the isogenic AthCV1-free and AthCV1-infected lines assessed at 20 °C and 37 °C and gene expression data collected at 37 °C. AthCV1-free and AthCV1-infected A. fumigatus produced only conidia at both temperatures but more than ten-fold reduced compared to the AthCV1-infected line. Conidiation was also significantly reduced in infected lines of A. nidulans and A. niger at 37 °C. AthCV1-infected lines of A. thermomutatus and A. nidulans produced large numbers of ascospores at both temperatures, whereas the AthCV1-free line of the former did not produce ascospores. AthCV1-infected lines of all species developed sectoring phenotypes with sclerotia produced in aconidial sectors of A. niger at 37 °C. AthCV1 was detected in 18% of sclerotia produced by AthCV1-infected A. niger and 31% of ascospores from AthCV1-infected A. nidulans. Transcriptome analysis of the naturally AthCV1-infected A. thermomutatus and the three AthCV1-transfected Aspergillus species showed altered gene expression as a result of AthCV1-infection. The results demonstrate that AthCV1 can infect a range of Aspergillus species resulting in reduced sporulation, a potentially useful attribute for a biological control agent.
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Affiliation(s)
- Mahjoub A Ejmal
- School of Biological Sciences, the University of Auckland, Auckland 1142 New Zealand.
| | - David J Holland
- Infectious Diseases Unit, Division of Medicine, Middlemore Hospital, Auckland 1640, New Zealand.
| | - Robin M MacDiarmid
- School of Biological Sciences, the University of Auckland, Auckland 1142 New Zealand.
- Plant and Food Research, Auckland 1142, New Zealand.
| | - Michael N Pearson
- School of Biological Sciences, the University of Auckland, Auckland 1142 New Zealand.
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29
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Zhai L, Zhang M, Hong N, Xiao F, Fu M, Xiang J, Wang G. Identification and Characterization of a Novel Hepta-Segmented dsRNA Virus From the Phytopathogenic Fungus Colletotrichum fructicola. Front Microbiol 2018; 9:754. [PMID: 29725323 PMCID: PMC5917037 DOI: 10.3389/fmicb.2018.00754] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 04/04/2018] [Indexed: 11/19/2022] Open
Abstract
A novel hepta-segmented double-stranded RNA (dsRNA) virus was isolated and characterized from the strain FJ-4 of the phytopathogenic fungus Colletotrichum fructicola, and was named Colletotrichum fructicola chrysovirus 1 (CfCV1). The full-length cDNAs of dsRNA1–7 were 3620, 2801, 2687, 2437, 1750, 1536, and 1211 bp, respectively. The 5′- and 3′-untranslated regions of the seven dsRNAs share highly similar internal sequence and contain conserved sequence stretches, indicating that they have a common virus origin. The 5′-and 3′-UTRs of the seven dsRNAs were predicted to fold into stable stem-loop structures. CfCV1 contains spherical virions that are 35 nm in diameter consisting of seven segments. The largest dsRNA of CfCV1 encodes an RNA-dependent RNA polymerase (RdRp), and the second dsRNA encodes a viral capsid protein (CP). The dsRNA5 encodes a C2H2-type zinc finger protein containing an R-rich region and a G-rich region. The smallest dsRNA is a satellite-like RNA. The functions of the other proteins encoded by dsRNA3, dsRNA4, dsRNA6 are unknown. Phylogenetic analysis, based on RdRp and CP, indicated that CfCV1 is phylogenetically related to Botryosphaeria dothidea chrysovirus 1 (BdCV1), and Penicillium janczewskii chrysovirus 2 (PjCV2), a cluster of an independent cluster II group in the family Chrysoviridae. Importantly, all the seven segments of CfCV1 were transmitted successfully to other virus-free strains with an all-or-none fashion. CfCV1 exerts minor influence on the growth of C. fructicola but can confer hypovirulence to the fungal host. To our knowledge, this is the first report of a hepta-segmented tentative chrysovirus in C. fructicola.
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Affiliation(s)
- Lifeng Zhai
- College of Life Science and Technology, Yangtze Normal University, Chongqing, China.,National Key Laboratory of Agromicrobiology, Huazhong Agricultural University, Wuhan, China
| | - Meixin Zhang
- College of Life Science and Technology, Yangtze Normal University, Chongqing, China.,National Key Laboratory of Agromicrobiology, Huazhong Agricultural University, Wuhan, China
| | - Ni Hong
- National Key Laboratory of Agromicrobiology, Huazhong Agricultural University, Wuhan, China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Feng Xiao
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Min Fu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jun Xiang
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Guoping Wang
- National Key Laboratory of Agromicrobiology, Huazhong Agricultural University, Wuhan, China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
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30
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Okada R, Ichinose S, Takeshita K, Urayama SI, Fukuhara T, Komatsu K, Arie T, Ishihara A, Egusa M, Kodama M, Moriyama H. Molecular characterization of a novel mycovirus in Alternaria alternata manifesting two-sided effects: Down-regulation of host growth and up-regulation of host plant pathogenicity. Virology 2018; 519:23-32. [PMID: 29631173 DOI: 10.1016/j.virol.2018.03.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/11/2018] [Accepted: 03/30/2018] [Indexed: 11/28/2022]
Abstract
A double-stranded RNA (dsRNA) mycovirus was detected in a strain of Alternaria alternata showing impaired growth phenotypes. The A. alternata strain is the Japanese pear pathotype, which produces a host-specific AK-toxin. Sequence analysis of the viral genome dsRNAs revealed that this mycovirus consists of five dsRNAs and is evolutionarily related to members of the family Chrysoviridae; the virus was named Alternaria alternata chrysovirus 1 (AaCV1). AaCV1-ORF2 protein accumulated in dsRNA-high-titer sub-isolates with severely impaired phenotypes; heterologous AaCV1-ORF2 overexpression in Saccharomyces cerevisiae caused growth inhibition. In contrast to this yeast growth inhibition phenomenon, the dsRNA-high-titer isolates displayed enhanced pathogenicity against Japanese pear plants, in accordance with a 13-fold increase in AK-toxin level in one such isolate. These findings indicated that AaCV1 is a novel mycovirus that exhibits two contrasting effects, impairing growth of the host fungus while rendering the host 'hypervirulent' to the plant.
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Affiliation(s)
- Ryo Okada
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Shun Ichinose
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Kana Takeshita
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Syun-Ichi Urayama
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Toshiyuki Fukuhara
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Atsushi Ishihara
- Laboratory of Natural Product, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, Tottori 680-8553, Japan
| | - Mayumi Egusa
- Laboratory of Plant Pathology, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, Tottori 680-8553, Japan
| | - Motoichiro Kodama
- Laboratory of Plant Pathology, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, Tottori 680-8553, Japan; Laboratory of Plant Pathology, The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori, Tottori 680-8553, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
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31
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Picarelli MASC, Gobatto D, Patrício F, Rivas EB, Colariccio A. Vírus que infectam fungos fitopatogênicos. ARQUIVOS DO INSTITUTO BIOLÓGICO 2018. [DOI: 10.1590/1808-1657000162016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RESUMO: Micovírus são vírus que infectam todos os taxa de fungos. São geralmente crípticos (latentes), mas podem causar pequenas ou imperceptíveis alterações no hospedeiro. Nos fungos fitopatogênicos, os vírus podem interferir com os sintomas e, em alguns casos, reduzir a virulência de seu hospedeiro; por esta razão, são objeto de estudo, por serem um potencial agente de biocontrole e por serem ferramentas importantes para o conhecimento sobre os mecanismos de patogênese de fungos. A presente revisão teve o objetivo de reunir os dados de literatura relacionados aos aspectos gerais da biologia e do comportamento dos micovírus presentes em alguns fungos fitopatogênicos.
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Identification of double-stranded RNA viruses in Brazilian strains of Metarhizium anisopliae and their effects on fungal biology and virulence. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.plgene.2017.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Abstract
Viruses with double-stranded RNA genomes form isometric particles or are capsidless. Here we report a double-stranded RNA virus, Colletotrichum camelliae filamentous virus 1 (CcFV-1) isolated from a fungal pathogen, that forms filamentous particles. CcFV-1 has eight genomic double-stranded RNAs, ranging from 990 to 2444 bp, encoding 10 putative open reading frames, of which open reading frame 1 encodes an RNA-dependent RNA polymerase and open reading frame 4 a capsid protein. When inoculated, the naked CcFV-1 double-stranded RNAs are infectious and induce the accumulation of the filamentous particles in vivo. CcFV-1 is phylogenetically related to Aspergillus fumigatus tetramycovirus-1 and Beauveria bassiana polymycovirus-1, but differs in morphology and in the number of genomic components. CcFV-1 might be an intermediate virus related to truly capsidated viruses, or might represent a distinct encapsidating strategy. In terms of genome and particle architecture, our findings are a significant addition to the knowledge of the virosphere diversity. Viruses with double-stranded RNA (dsRNA) genomes form typically isometric particles or are capsid-less. Here, the authors identify a mycovirus with an eight-segmented dsRNA genome that forms exceptionally long filamentous particles and could represent an evolutionary link between ssRNA and dsRNA viruses.
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Ding Z, Zhou T, Guo LY. Characterization of a novel strain of Botryosphaeria dothidea chrysovirus 1 from the apple white rot pathogen Botryosphaeria dothidea. Arch Virol 2017; 162:2097-2102. [DOI: 10.1007/s00705-017-3320-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/25/2017] [Indexed: 12/24/2022]
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The complete genome sequence of a double-stranded RNA mycovirus from Fusarium graminearum strain HN1. Arch Virol 2017; 162:2119-2124. [DOI: 10.1007/s00705-017-3317-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 02/23/2017] [Indexed: 10/20/2022]
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36
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Zhang J, Zhao Z, Hu R, Guo L, Zheng L, Du Z, Wu Z, Fang S, Zhang S, Liu Y. The genome sequence of Brassica campestris chrysovirus 1, a novel putative plant-infecting tripartite chrysovirus. Arch Virol 2016; 162:1107-1111. [PMID: 28004250 DOI: 10.1007/s00705-016-3196-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 12/07/2016] [Indexed: 11/25/2022]
Abstract
A putative chrysovirus recovered from Brassica campestris var. purpurea and provisionally named "Brassica campestris chrysovirus 1" (BrcCV1) was sequenced. The genome of the putative BrcCV1 consists of three double-stranded RNAs (dsRNAs) comprising 3,639 (dsRNA 1), 3,567 (dsRNA 2) and 3,337 (dsRNA 3) base pairs, respectively, each containing a single open reading frame (ORF 1-3). The putative proteins encoded by ORF 1-3 show homologies to RdRp, CP and chryso-P3 of approved or tentative chrysoviruses. In addition, the three dsRNAs of BrcCV1 contain highly conserved 5' and 3' untranslated regions (UTRs) in a way similar to known chrysoviruses. In a phylogenetic tree based on the conserved amino acid sequences of the RdRps of chrysoviruses, totiviruses and partitiviruses, the putative BrcCV1 formed a separate clade with Raphanus sativus chrysovirus 1 (RasCV1), a putative trisegmented, plant-infecting chrysovirus, in the family Chrysoviridae.
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Affiliation(s)
- Jun Zhang
- Engineering Research Centre of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, Hubei, China
- Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Zhonghao Zhao
- Engineering Research Centre of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, Hubei, China
- Hunan Plant Protection Institute, Changsha, 410125, Hunan, China
| | - Rong Hu
- Engineering Research Centre of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Lingfang Guo
- College of Chemistry and environmental Engineering, Yangtze University, Jingzhou, 434023, Hubei, China
| | - Limin Zheng
- Hunan Plant Protection Institute, Changsha, 410125, Hunan, China
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Zhenguo Du
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Zujian Wu
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Shouguo Fang
- Engineering Research Centre of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, Hubei, China
- Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Songbai Zhang
- Engineering Research Centre of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, Hubei, China.
- Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou, 434025, Hubei, China.
| | - Yong Liu
- Hunan Plant Protection Institute, Changsha, 410125, Hunan, China.
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Molecular characterization of a novel ssRNA ourmia-like virus from the rice blast fungus Magnaporthe oryzae. Arch Virol 2016; 162:891-895. [PMID: 27858291 DOI: 10.1007/s00705-016-3144-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/30/2016] [Indexed: 10/20/2022]
Abstract
In this study we characterize a novel positive and single stranded RNA (ssRNA) mycovirus isolated from the rice field isolate of Magnaporthe oryzae Guy11. The ssRNA contains a single open reading frame (ORF) of 2,373 nucleotides in length and encodes an RNA-dependent RNA polymerase (RdRp) closely related to ourmiaviruses (plant viruses) and ourmia-like mycoviruses. Accordingly, we name this virus Magnaporthe oryzae ourmia-like virus 1 (MOLV1). Although phylogenetic analysis suggests that MOLV1 is closely related to ourmia and ourmia-like viruses, it has some features never reported before within the Ourmiavirus genus. 3' RLM-RACE (RNA ligase-mediated rapid amplification of cDNA ends) and extension poly(A) tests (ePAT) suggest that the MOLV1 genome contains a poly(A) tail whereas the three cytosine and the three guanine residues present in 5' and 3' untranslated regions (UTRs) of ourmia viruses are not observed in the MOLV1 sequence. The discovery of this novel viral genome supports the hypothesis that plant pathogenic fungi may have acquired this type of viruses from their host plants.
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Deep Sequencing Analysis Reveals the Mycoviral Diversity of the Virome of an Avirulent Isolate of Rhizoctonia solani AG-2-2 IV. PLoS One 2016; 11:e0165965. [PMID: 27814394 PMCID: PMC5096721 DOI: 10.1371/journal.pone.0165965] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/20/2016] [Indexed: 02/06/2023] Open
Abstract
Rhizoctonia solani represents an important plant pathogenic Basidiomycota species complex and the host of many different mycoviruses, as indicated by frequent detection of dsRNA elements in natural populations of the fungus. To date, eight different mycoviruses have been characterized in Rhizoctonia and some of them have been reported to modulate its virulence. DsRNA extracts of the avirulent R. solani isolate DC17 (AG2-2-IV) displayed a diverse pattern, indicating multiple infections with mycoviruses. Deep sequencing analysis of the dsRNA extract, converted to cDNA, revealed that this isolate harbors at least 17 different mycovirus species. Based on the alignment of the conserved RNA-dependent RNA-polymerase (RdRp) domain, this viral community included putative members of the families Narnaviridae, Endornaviridae, Partitiviridae and Megabirnaviridae as well as of the order Tymovirales. Furthermore, viruses, which could not be assigned to any existing family or order, but showed similarities to so far unassigned species like Sclerotinia sclerotiorum RNA virus L, Rhizoctonia solani dsRNA virus 1, Aspergillus foetidus slow virus 2 or Rhizoctonia fumigata virus 1, were identified. This is the first report of a fungal isolate infected by 17 different viral species and a valuable study case to explore the diversity of mycoviruses infecting R. solani.
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Molecular Characterization of a Trisegmented Mycovirus from the Plant Pathogenic Fungus Colletotrichum gloeosporioides. Viruses 2016; 8:v8100268. [PMID: 27690081 PMCID: PMC5086604 DOI: 10.3390/v8100268] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 09/15/2016] [Accepted: 09/19/2016] [Indexed: 01/26/2023] Open
Abstract
A novel double-stranded RNA (dsRNA) mycovirus, consisting of three dsRNA genome segments and possibly belonging to the family Chrysoviridae, was isolated from the filamentous phytopathogenic fungus Colletotrichum gloeosporioides and designated as Colletotrichum gloeosprioides chrysovirus 1 (CgCV1). The three dsRNAs of the CgCV1 genome with lengths of 3397, 2869, and 2630 bp (dsRNAs1–3) were found to contain a single open reading frame (ORF) putatively encoding the RNA-dependent RNA polymerase (RdRp), a capsid protein, and a protease, respectively, all of which exhibited some degree of sequence similarity to the comparable putative proteins encoded by the genus Chrysovirus. The 5′- and 3′-untranslated regions in each dsRNA segment contained similar sequences that were strictly conserved at the termini. Moreover, isometric virus-like particles (VLPs) with a diameter of approximately 40 nm were extracted from fungal mycelia. Phylogenetic analysis based on the conserved dsRNA1-encoded RdRp showed that CgCV1 is a new virus belonging to the Chrysoviridae family. BLAST analysis revealed the presence of CgCV1-like sequences in the chromosomes of Medicago truncatula and Solanum tuberosum. Moreover, some sequences in the transcriptome shotgun assembly (TSA) library and expressed sequence tag database (ESTdb) of other eudicot and monocot plants were also found to be related to CgCV1.
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40
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Urayama SI, Kimura Y, Katoh Y, Ohta T, Onozuka N, Fukuhara T, Arie T, Teraoka T, Komatsu K, Moriyama H. Suppressive effects of mycoviral proteins encoded by Magnaporthe oryzae chrysovirus 1 strain A on conidial germination of the rice blast fungus. Virus Res 2016; 223:10-9. [DOI: 10.1016/j.virusres.2016.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/16/2016] [Accepted: 06/16/2016] [Indexed: 01/08/2023]
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41
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Complete nucleotide sequence of Magnaporthe oryzae partitivirus 1. Arch Virol 2016; 161:3295-8. [DOI: 10.1007/s00705-016-3025-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 08/20/2016] [Indexed: 11/25/2022]
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42
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Urayama SI, Takaki Y, Nunoura T. FLDS: A Comprehensive dsRNA Sequencing Method for Intracellular RNA Virus Surveillance. Microbes Environ 2016; 31:33-40. [PMID: 26877136 PMCID: PMC4791113 DOI: 10.1264/jsme2.me15171] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Knowledge of the distribution and diversity of RNA viruses is still limited in spite of their possible environmental and epidemiological impacts because RNA virus-specific metagenomic methods have not yet been developed. We herein constructed an effective metagenomic method for RNA viruses by targeting long double-stranded (ds)RNA in cellular organisms, which is a hallmark of infection, or the replication of dsRNA and single-stranded (ss)RNA viruses, except for retroviruses. This novel dsRNA targeting metagenomic method is characterized by an extremely high recovery rate of viral RNA sequences, the retrieval of terminal sequences, and uniform read coverage, which has not previously been reported in other metagenomic methods targeting RNA viruses. This method revealed a previously unidentified viral RNA diversity of more than 20 complete RNA viral genomes including dsRNA and ssRNA viruses associated with an environmental diatom colony. Our approach will be a powerful tool for cataloging RNA viruses associated with organisms of interest.
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Affiliation(s)
- Syun-Ichi Urayama
- Research and Development Center for Marine Biosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
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43
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Ai YP, Zhong J, Chen CY, Zhu HJ, Gao BD. A novel single-stranded RNA virus isolated from the rice-pathogenic fungus Magnaporthe oryzae with similarity to members of the family Tombusviridae. Arch Virol 2015; 161:725-9. [PMID: 26650038 DOI: 10.1007/s00705-015-2683-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 11/10/2015] [Indexed: 12/22/2022]
Abstract
Here, we report a novel virus isolated from rice blast fungus, Magnaporthe oryzae, an important plant pathogen. This virus has an RNA genome of 3246 nucleotides. Its genome possesses two in-frame open reading frames (ORFs). The smaller ORF1 encodes a protein with significant similarity to a protein encoded by the ssRNA mycovirus Diaporthe ambigua RNA virus 1 (DaRV1). The larger ORF2 encodes a protein with similarity to RNA-dependent RNA polymerases (RdRp) of DaRV1 and other plant viruses of the family Tombusviridae. In silico analysis and comparisons with DaRV1 genome expression suggest that ORF2 is translated via a readthrough mechanism together with ORF1. Based upon results of this study, this virus, for which the provisional name Magnaporthe oryzae virus A (MoVA) is proposed, belongs to a new virus species. Furthermore, MoVA along with DaRV1 belong to a new taxon of mycoviruses that are evolutionarily related to plant viruses belonging to the family Tombusviridae.
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Affiliation(s)
- Ye-Ping Ai
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China
| | - Jie Zhong
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China
| | - Chuan-Yuan Chen
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China
| | - Hong-Jian Zhu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China.
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China.
| | - Bi-Da Gao
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha, 410128, Hunan, People's Republic of China.
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Komatsu K, Urayama SI, Katoh Y, Fuji SI, Hase S, Fukuhara T, Arie T, Teraoka T, Moriyama H. Detection of Magnaporthe oryzae chrysovirus 1 in Japan and establishment of a rapid, sensitive and direct diagnostic method based on reverse transcription loop-mediated isothermal amplification. Arch Virol 2015; 161:317-26. [PMID: 26547578 DOI: 10.1007/s00705-015-2666-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
Magnaporthe oryzae chrysovirus 1 (MoCV1) is a mycovirus with a dsRNA genome that infects the rice blast fungus Magnaporthe oryzae and impairs its growth. To date, MoCV1 has only been found in Vietnamese isolates of M. oryzae, and the distribution of this virus in M. oryzae isolates from other parts of the world remains unknown. In this study, using a one-step reverse transcription PCR (RT-PCR) assay, we detected a MoCV1-related virus in M. oryzae in Japan (named MoCV1-AK) whose sequence shares considerable similarity with that of the MoCV1 Vietnamese isolate. To establish a system for a comprehensive survey of MoCV1 infection in the field, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for direct detection of the virus. The sensitivity of the RT-LAMP assay was at least as high as that of the one-step RT-PCR assay. In addition, we detected MoCV1-AK in M. oryzae-infected oatmeal agar plates and lesions on rice leaves using the RT-LAMP assay without dsRNA extraction, by simple sampling with a toothpick. Preliminary screening of MoCV1 in Japanese M. oryzae isolates indicated that MoCV1 is currently distributed in rice fields in Japan. Our results provide a first example of the application of RT-LAMP for the detection of mycoviruses, which will accelerate surveys for mycovirus infection.
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Affiliation(s)
- Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Syun-Ichi Urayama
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Yu Katoh
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Shin-Ichi Fuji
- Laboratory of Plant Protection, Faculty of Bioresorce Sciences, Akita Prefectural University, Akita, Japan
| | - Shu Hase
- Laboratory of Plant Pathology, Faculty of Agriculture, Yamagata University, Yamagata, Japan
| | - Toshiyuki Fukuhara
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Tohru Teraoka
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
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Genomic organization of a novel victorivirus from the rice blast fungus Magnaporthe oryzae. Arch Virol 2015; 160:2907-10. [DOI: 10.1007/s00705-015-2562-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 08/02/2015] [Indexed: 10/23/2022]
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46
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Complete genome sequence of a novel dsRNA mycovirus isolated from the phytopathogenic fungus Fusarium oxysporum f. sp. dianthi. Arch Virol 2015; 160:2375-9. [PMID: 26138558 DOI: 10.1007/s00705-015-2509-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/21/2015] [Indexed: 10/23/2022]
Abstract
A novel double-stranded RNA (dsRNA) mycovirus, designated Fusarium oxysporum f. sp. dianthi mycovirus 1 (FodV1), was isolated from a strain of the phytopathogenic fungus F. oxysporum f. sp. dianthi. The FodV1 genome had four dsRNA segments, designated, from the largest to the smallest one, dsRNA 1, 2 3, and 4. Each one of these segments contained a single open reading frame (ORF). dsRNA 1 (3555 bp) and dsRNA 3 (2794 bp) encoded a putative RNA-dependent RNA polymerase (RdRp) and a putative coat protein (CP), respectively. dsRNA 2 (2809 bp) and dsRNA 4 (2646 bp) contained ORFs encoding hypothetical proteins (named P2 and P4, respectively) with unknown functions. Analysis of its genomic structure, homology searches of the deduced amino acid sequences, and phylogenetic analysis all indicated that FodV1 is a new member of the family Chrysoviridae. This is the first report of the complete genomic characterization of a mycovirus identified in the plant pathogen Fusarium oxysporum.
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47
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Liu L, Wang Q, Cheng J, Fu Y, Jiang D, Xie J. Molecular characterization of a bipartite double-stranded RNA virus and its satellite-like RNA co-infecting the phytopathogenic fungus Sclerotinia sclerotiorum. Front Microbiol 2015; 6:406. [PMID: 25999933 PMCID: PMC4422086 DOI: 10.3389/fmicb.2015.00406] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 04/19/2015] [Indexed: 11/13/2022] Open
Abstract
A variety of mycoviruses have been found in Sclerotinia sclerotiorum. In this study, we report a novel mycovirus S. sclerotiorum botybirnavirus 1 (SsBRV1) that was originally isolated from the hypovirulent strain SCH941 of S. sclerotiorum. SsBRV1 has rigid spherical virions that are ∼38 nm in diameter, and three double-stranded RNA (dsRNA) segments (dsRNA1, 2, and 3 with lengths of 6.4, 6.0, and 1.7 kbp, respectively) were packaged in the virions. dsRNA1 encodes a cap-pol fusion protein, and dsRNA2 encodes a polyprotein with unknown functions but contributes to the formation of virus particles. The dsRNA3 is dispensable and may be a satellite-like RNA of SsBRV1. Although phylogenetic analysis of the RdRp domain demonstrated that SsBRV1 is related to Botrytis porri RNA virus 1 (BpRV1) and Ustilago maydis dsRNA virus-H1, the structure proteins of SsBRV1 do not have any significant sequence similarities with other known viral proteins with the exception of those of BpRV1. SsBRV1 carrying dsRNA3 seems to have no obvious effects on the colony morphology, but can significantly reduce the growth rate and virulence of S. sclerotiorum. These findings provide new insights into the virus taxonomy, virus evolution and the interactions between SsBRV1 and the fungal hosts.
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Affiliation(s)
- Lijiang Liu
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Qihua Wang
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Jiasen Cheng
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Yanping Fu
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology and The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China
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48
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Ghabrial SA, Castón JR, Jiang D, Nibert ML, Suzuki N. 50-plus years of fungal viruses. Virology 2015; 479-480:356-68. [PMID: 25771805 DOI: 10.1016/j.virol.2015.02.034] [Citation(s) in RCA: 445] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 01/31/2015] [Accepted: 02/19/2015] [Indexed: 10/23/2022]
Abstract
Mycoviruses are widespread in all major taxa of fungi. They are transmitted intracellularly during cell division, sporogenesis, and/or cell-to-cell fusion (hyphal anastomosis), and thus their life cycles generally lack an extracellular phase. Their natural host ranges are limited to individuals within the same or closely related vegetative compatibility groups, although recent advances have established expanded experimental host ranges for some mycoviruses. Most known mycoviruses have dsRNA genomes packaged in isometric particles, but an increasing number of positive- or negative-strand ssRNA and ssDNA viruses have been isolated and characterized. Although many mycoviruses do not have marked effects on their hosts, those that reduce the virulence of their phytopathogenic fungal hosts are of considerable interest for development of novel biocontrol strategies. Mycoviruses that infect endophytic fungi and those that encode killer toxins are also of special interest. Structural analyses of mycoviruses have promoted better understanding of virus assembly, function, and evolution.
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Affiliation(s)
- Said A Ghabrial
- Plant Pathology Department, University of Kentucky, Lexington, KY, USA.
| | - José R Castón
- Department of Structure of Macromolecules, Centro Nacional Biotecnologıa/CSIC, Campus de Cantoblanco, Madrid, Spain
| | - Daohong Jiang
- State Key Lab of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Max L Nibert
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, Japan
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Zhang R, Liu S, Chiba S, Kondo H, Kanematsu S, Suzuki N. A novel single-stranded RNA virus isolated from a phytopathogenic filamentous fungus, Rosellinia necatrix, with similarity to hypo-like viruses. Front Microbiol 2014; 5:360. [PMID: 25101066 PMCID: PMC4103508 DOI: 10.3389/fmicb.2014.00360] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/26/2014] [Indexed: 01/03/2023] Open
Abstract
Here we report a biological and molecular characterization of a novel positive-sense RNA virus isolated from a field isolate (NW10) of a filamentous phytopathogenic fungus, the white root rot fungus that is designated as Rosellinia necatrix fusarivirus 1 (RnFV1). A recently developed technology using zinc ions allowed us to transfer RnFV1 to two mycelially incompatible Rosellinia necatrix strains. A biological comparison of the virus-free and -recipient isogenic fungal strains suggested that RnFV1 infects latently and thus has no potential as a virocontrol agent. The virus has an undivided positive-sense RNA genome of 6286 nucleotides excluding a poly (A) tail. The genome possesses two non-overlapping open reading frames (ORFs): a large ORF1 that encodes polypeptides with RNA replication functions and a smaller ORF2 that encodes polypeptides of unknown function. A lack of coat protein genes was suggested by the failure of virus particles from infected mycelia. No evidence was obtained by Northern analysis or classical 5′-RACE for the presence of subgenomic RNA for the downstream ORF. Sequence similarities were found in amino-acid sequence between RnFV1 putative proteins and counterparts of a previously reported mycovirus, Fusarium graminearum virus 1 (FgV1). Interestingly, several related sequences were detected by BLAST searches of independent transcriptome assembly databases one of which probably represents an entire virus genome. Phylogenetic analysis based on the conserved RNA-dependent RNA polymerase showed that RnFV1, FgV1, and these similar sequences are grouped in a cluster distinct from distantly related hypoviruses. It is proposed that a new taxonomic family termed Fusariviridae be created to include RnFV1 and FgV1.
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Affiliation(s)
- Rui Zhang
- Group of Plant/Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kurashiki, Okayama, Japan
| | - Shengxue Liu
- Group of Plant/Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kurashiki, Okayama, Japan
| | - Sotaro Chiba
- Group of Plant/Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kurashiki, Okayama, Japan
| | - Hideki Kondo
- Group of Plant/Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kurashiki, Okayama, Japan
| | - Satoko Kanematsu
- Apple Research Division, National Institute of Fruit Tree Science, National Agricultural Research Organization (NARO) Morioka, Iwate, Japan
| | - Nobuhiro Suzuki
- Group of Plant/Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kurashiki, Okayama, Japan
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Wang L, Jiang J, Wang Y, Hong N, Zhang F, Xu W, Wang G. Hypovirulence of the phytopathogenic fungus Botryosphaeria dothidea: association with a coinfecting chrysovirus and a partitivirus. J Virol 2014; 88:7517-27. [PMID: 24760881 PMCID: PMC4054428 DOI: 10.1128/jvi.00538-14] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/08/2014] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Botryosphaeria dothidea is an important pathogenic fungus causing fruit rot, leaf and stem ring spots and dieback, stem canker, stem death or stool mortality, and decline of pear trees. Seven double-stranded RNAs (dsRNAs; dsRNAs 1 to 7 with sizes of 3,654, 2,773, 2,597, 2,574, 1,823, 1,623, and 511 bp, respectively) were identified in an isolate of B. dothidea exhibiting attenuated growth and virulence and a sectoring phenotype. Characterization of the dsRNAs revealed that they belong to two dsRNA mycoviruses. The four largest dsRNAs (dsRNAs 1 to 4) are the genomic components of a novel member of the family Chrysoviridae (tentatively designated Botryosphaeria dothidea chrysovirus 1 [BdCV1]), a view supported by the morphology of the virions and phylogenetic analysis of the putative RNA-dependent RNA polymerases (RdRps). Two other dsRNAs (dsRNAs 5 and 6) are the genomic components of a novel member of the family Partitiviridae (tentatively designated Botryosphaeria dothidea partitivirus 1 [BdPV1]), which is placed in a clade distinct from other established partitivirus genera on the basis of the phylogenetic analysis of its RdRp. The smallest dsRNA, dsRNA7, seems to be a noncoding satellite RNA of BdPV1 on the basis of the conservation of its terminal sequences in BdPV1 genomic segments and its cosegregation with BdPV1 after horizontal transmission. This is the first report of a chrysovirus and a partitivirus infecting B. dothidea and of a chrysovirus associated with the hypovirulence of a phytopathogenic fungus. IMPORTANCE Our studies identified and characterized two novel mycoviruses, Botryosphaeria dothidea chrysovirus 1 (BdCV1) and Botryosphaeria dothidea partitivirus 1 (BdPV1), associated with the hypovirulence of an important fungus pathogenic to fruit trees. This is the first report of a chrysovirus and a partitivirus infecting B. dothidea and of a chrysovirus associated with the hypovirulence of a phytopathogenic fungus. BdCV1 appears to be a good candidate for the biological control of the serious disease induced by B. dothidea. Additionally, BdPV1 is placed in a clade distinct from the established genera. The BdCV1 capsid has two major structural proteins, and the capsid is distinct from that made up by a single polypeptide of the typical chrysoviruses. BdPV1 is the second partitivirus in which the putative capsid protein shares no significant identity with any mycovirus protein. A small accompanying dsRNA that is presumed to be a noncoding satellite RNA of BdPV1 is the first of its kind reported for a partitivirus.
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Affiliation(s)
- LiPing Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - JingJing Jiang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - YanFen Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Ni Hong
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Fangpeng Zhang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - WenXing Xu
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - GuoPing Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei, People's Republic of China College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China National Indoor Conservation Center of Virus-Free Germplasms of Fruit Crops, Wuhan, Hubei, People's Republic of China Lab of Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei, People's Republic of China
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