1
|
Battersby JL, Stevens DA, Coutts RHA, Havlíček V, Hsu JL, Sass G, Kotta-Loizou I. The Expanding Mycovirome of Aspergilli. J Fungi (Basel) 2024; 10:585. [PMID: 39194910 DOI: 10.3390/jof10080585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/08/2024] [Accepted: 08/14/2024] [Indexed: 08/29/2024] Open
Abstract
Mycoviruses are viruses that infect fungi and are widespread across all major fungal taxa, exhibiting great biological diversity. Since their discovery in the 1960s, researchers have observed a myriad of fungal phenotypes altered due to mycoviral infection. In this review, we examine the nuanced world of mycoviruses in the context of the medically and agriculturally important fungal genus, Aspergillus. The advent of RNA sequencing has revealed a previous underestimate of viral prevalence in fungi, in particular linear single-stranded RNA viruses, and here we outline the diverse viral families known to date that contain mycoviruses infecting Aspergillus. Furthermore, we describe these novel mycoviruses, highlighting those with peculiar genome structures, such as a split RNA dependent RNA polymerase gene. Next, we delineate notable mycovirus-mediated phenotypes in Aspergillus, in particular reporting on observations of mycoviruses that affect their fungal host's virulence and explore how this may relate to virus-mediated decreased stress tolerance. Furthermore, mycovirus effects on microbial competition and antifungal resistance are discussed. The factors that influence the manifestation of these phenotypes, such as temperature, fungal life stage, and infection with multiple viruses, among others, are also evaluated. In addition, we attempt to elucidate the molecular mechanisms that underpin these phenotypes, examining how mycoviruses can be targets, triggers, and even suppressors of RNA silencing and how this can affect fungal gene expression and phenotypes. Finally, we highlight the potential therapeutic applications of mycoviruses and how, in an approach analogous to bacteriophage therapy, their ability to produce hypovirulence in Aspergillus might be used to attenuate invasive aspergillosis infections in humans.
Collapse
Affiliation(s)
- Josephine L Battersby
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - David A Stevens
- California Institute for Medical Research, San Jose, CA 95128, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Robert H A Coutts
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 00 Prague, Czech Republic
- Department of Analytical Chemistry, Palacky University, 17. Listopadu 2, 779 00 Olomouc, Czech Republic
| | - Joe L Hsu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gabriele Sass
- California Institute for Medical Research, San Jose, CA 95128, USA
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
| |
Collapse
|
2
|
Fan Y, Zhao W, Tang X, Yang M, Yang Y, Zhang Z, Cheng B, Zhou E, He Z. Co-infection of Four Novel Mycoviruses from Three Lineages Confers Hypovirulence on Phytopathogenic Fungus Ustilaginoidea virens. RICE (NEW YORK, N.Y.) 2024; 17:44. [PMID: 39014281 PMCID: PMC11252108 DOI: 10.1186/s12284-024-00721-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 06/21/2024] [Indexed: 07/18/2024]
Abstract
Rice false smut caused by Ustilaginoidea virens has become one of the most important diseases of rice. Mycoviruses are viruses that can infect fungi with the potential to control fungal diseases. However, little is known about the biocontrol role of hypoviruses in U. virens. In this study, we revealed that the hypovirulence-associated U. virens strain Uv325 was co-infected by four novel mycoviruses from three lineages, designated Ustilaginoidea virens RNA virus 16 (UvRV16), Ustilaginoidea virens botourmiavirus virus 8 (UvBV8), Ustilaginoidea virens botourmiavirus virus 9 (UvBV9), and Ustilaginoidea virens narnavirus virus 13 (UvNV13), respectively. The U. virens strain co-infected by four mycoviruses showed slower growth rates, reduced conidial yield, and attenuated pigmentation. We demonstrated that UvRV16 was not only the major factor responsible for the hypovirulent phenotype in U. vriens, but also able to prevent U. virens to accumulate more mycotoxin, thereby weakening the inhibitory effects on rice seed germination and seedling growth. Additionally, we indicated that UvRV16 can disrupt the antiviral response of U. virens by suppressing the transcriptional expression of multiple genes involved in autophagy and RNA silencing. In conclusion, our study provided new insights into the biological control of rice false smut.
Collapse
Affiliation(s)
- Yu Fan
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Wenhua Zhao
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Xiaolin Tang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Mei Yang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Yingqing Yang
- Institute of Plant Protection, Jiangxi Academy of Agricultural Sciences, Nanchang, 330200, China
| | - Zixuan Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Baoping Cheng
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences/Guangdong Provincial Key Laboratory of High Technology for Plant Protection/Key Laboratory of Green Prevention and Control On Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangdong, 510642, China.
| | - Erxun Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China.
| | - Zhenrui He
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China.
| |
Collapse
|
3
|
Spada M, Pugliesi C, Fambrini M, Pecchia S. Challenges and Opportunities Arising from Host- Botrytis cinerea Interactions to Outline Novel and Sustainable Control Strategies: The Key Role of RNA Interference. Int J Mol Sci 2024; 25:6798. [PMID: 38928507 PMCID: PMC11203536 DOI: 10.3390/ijms25126798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
The necrotrophic plant pathogenic fungus Botrytis cinerea (Pers., 1794), the causative agent of gray mold disease, causes significant losses in agricultural production. Control of this fungal pathogen is quite difficult due to its wide host range and environmental persistence. Currently, the management of the disease is still mainly based on chemicals, which can have harmful effects not only on the environment and on human health but also because they favor the development of strains resistant to fungicides. The flexibility and plasticity of B. cinerea in challenging plant defense mechanisms and its ability to evolve strategies to escape chemicals require the development of new control strategies for successful disease management. In this review, some aspects of the host-pathogen interactions from which novel and sustainable control strategies could be developed (e.g., signaling pathways, molecules involved in plant immune mechanisms, hormones, post-transcriptional gene silencing) were analyzed. New biotechnological tools based on the use of RNA interference (RNAi) are emerging in the crop protection scenario as versatile, sustainable, effective, and environmentally friendly alternatives to the use of chemicals. RNAi-based fungicides are expected to be approved soon, although they will face several challenges before reaching the market.
Collapse
Affiliation(s)
- Maria Spada
- Department of Agriculture Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Claudio Pugliesi
- Department of Agriculture Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Marco Fambrini
- Department of Agriculture Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Susanna Pecchia
- Department of Agriculture Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| |
Collapse
|
4
|
Sato Y, Kondo H, Suzuki N. Argonaute-independent, Dicer-dependent antiviral defense against RNA viruses. Proc Natl Acad Sci U S A 2024; 121:e2322765121. [PMID: 38865263 PMCID: PMC11194562 DOI: 10.1073/pnas.2322765121] [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: 12/24/2023] [Accepted: 05/07/2024] [Indexed: 06/14/2024] Open
Abstract
Antiviral RNA interference (RNAi) is conserved from yeasts to mammals. Dicer recognizes and cleaves virus-derived double-stranded RNA (dsRNA) and/or structured single-stranded RNA (ssRNA) into small-interfering RNAs, which guide effector Argonaute to homologous viral RNAs for digestion and inhibit virus replication. Thus, Argonaute is believed to be essential for antiviral RNAi. Here, we show Argonaute-independent, Dicer-dependent antiviral defense against dsRNA viruses using Cryphonectria parasitica (chestnut blight fungus), which is a model filamentous ascomycetous fungus and hosts a variety of viruses. The fungus has two dicer-like genes (dcl1 and dcl2) and four argonaute-like genes (agl1 to agl4). We prepared a suite of single to quadruple agl knockout mutants with or without dcl disruption. We tested these mutants for antiviral activities against diverse dsRNA viruses and ssRNA viruses. Although both DCL2 and AGL2 worked as antiviral players against some RNA viruses, DCL2 without argonaute was sufficient to block the replication of other RNA viruses. Overall, these results indicate the existence of a Dicer-alone defense and different degrees of susceptibility to it among RNA viruses. We discuss what determines the great difference in susceptibility to the Dicer-only defense.
Collapse
Affiliation(s)
- Yukiyo Sato
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama710-0046, Japan
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama710-0046, Japan
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama710-0046, Japan
| |
Collapse
|
5
|
Jiang Y, Liu X, Tian X, Zhou J, Wang Q, Wang B, Yu W, Jiang Y, Hsiang T, Qi X. RNA interference of Aspergillus flavus in response to Aspergillus flavus partitivirus 1 infection. Front Microbiol 2023; 14:1252294. [PMID: 38033556 PMCID: PMC10682719 DOI: 10.3389/fmicb.2023.1252294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/19/2023] [Indexed: 12/02/2023] Open
Abstract
RNA interference (RNAi) is one of the important defense responses against viral infection, but its mechanism and impact remain unclear in mycovirus infections. In our study, reverse genetics and virus-derived small RNA sequencing were used to show the antiviral responses of RNAi components in Aspergillus flavus infected with Aspergillus flavus partitivirus 1 (AfPV1). qRT-PCR revealed that AfPV1 infection induced the expression of the RNAi components in A. flavus compared with noninfected A. flavus. Knock mutants of each RNAi component were generated, but the mutants did not exhibit any obvious phenotypic changes compared with the A. flavus parental strain. However, after AfPV1 inoculation, production of AfPV1 was significantly less than in the parental strain. Furthermore, sporulation was greater in each AfPV1-infected mutant compared with the AfPV1-infected parental A. flavus. We also investigated the sensitivity of virus-free and AfPV1-infected RNAi mutants and the parental strain to cell wall stress, osmotic stress, genotoxic stress, and oxidative stress. The mutants of DCLs and AGOs infected by AfPV1 displayed more changes than RDRP mutants in response to the first three stresses. Small RNA sequencing analysis suggested that AfPV1 infection reduced the number of unique reads of sRNA in A. flavus, although there were many vsiRNA derived from the AfPV1 genome. GO term and KEGG pathway analyses revealed that the functions of sRNA affected by AfPV1 infection were closely related to vacuole production. These results provide a better understanding of the functional role of RNAi in the impact of AfPV1 on the hypovirulence of A. flavus.
Collapse
Affiliation(s)
- Yinhui Jiang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Xiang Liu
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Xun Tian
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Jianhong Zhou
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Qinrong Wang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Bi Wang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Wenfeng Yu
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| | - Yanping Jiang
- Department of Dermatology, The Affiliated Hospital, Guizhou Medical University, Guiyang, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Xiaolan Qi
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medical Molecular Biology of Guizhou Province, Guizhou Medical University, Guiyang, China
| |
Collapse
|
6
|
Zhang L, Wang S, Ruan S, Nzabanita C, Wang Y, Guo L. A Mycovirus VIGS Vector Confers Hypovirulence to a Plant Pathogenic Fungus to Control Wheat FHB. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302606. [PMID: 37587761 PMCID: PMC10582431 DOI: 10.1002/advs.202302606] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/01/2023] [Indexed: 08/18/2023]
Abstract
Mycovirus-mediated hypovirulence has the potential to control fungal diseases. However, the availability of hypovirulence-conferring mycoviruses for plant fungal disease control is limited as most fungal viruses are asymptomatic. In this study, the virus-induced gene silencing (VIGS) vector p26-D4 of Fusarium graminearum gemytripvirus 1 (FgGMTV1), a tripartite circular single-stranded DNA mycovirus, is successfully constructed to convert the causal fungus of cereal Fusarium head blight (FHB) into a hypovirulent strain. p26-D4, with an insert of a 75-150 bp fragment of the target reporter transgene transcript in both sense and antisense orientations, efficiently triggered gene silencing in Fusarium graminearum. Notably, the two hypovirulent strains, p26-D4-Tri101, and p26-D4-FgPP1, obtained by silencing the virulence-related genes Tri101 and FgPP1 with p26-D4, can be used as biocontrol agents to protect wheat from a fungal disease FHB and mycotoxin contamination at the field level. This study not only describes the first mycovirus-derived VIGS system but also proves that the VIGS vector can be used to establish multiple hypovirulent strains to control pathogenic fungi.
Collapse
Affiliation(s)
- Lihang Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Shuangchao Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Shaojian Ruan
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Clement Nzabanita
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Yanfei Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Lihua Guo
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| |
Collapse
|
7
|
Andika IB, Tian M, Bian R, Cao X, Luo M, Kondo H, Sun L. Cross-Kingdom Interactions Between Plant and Fungal Viruses. Annu Rev Virol 2023; 10:119-138. [PMID: 37406341 DOI: 10.1146/annurev-virology-111821-122539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
The large genetic and structural divergences between plants and fungi may hinder the transmission of viruses between these two kingdoms to some extent. However, recent accumulating evidence from virus phylogenetic analyses and the discovery of naturally occurring virus cross-infection suggest the occurrence of past and current transmissions of viruses between plants and plant-associated fungi. Moreover, artificial virus inoculation experiments showed that diverse plant viruses can multiply in fungi and vice versa. Thus, virus cross-infection between plants and fungi may play an important role in the spread, emergence, and evolution of both plant and fungal viruses and facilitate the interaction between them. In this review, we summarize current knowledge related to cross-kingdom virus infection in plants and fungi and further discuss the relevance of this new virological topic in the context of understanding virus spread and transmission in nature as well as developing control strategies for crop plant diseases.
Collapse
Affiliation(s)
- Ida Bagus Andika
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China;
| | - Mengyuan Tian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, China;
| | - Ruiling Bian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, China;
| | - Xinran Cao
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China;
| | - Ming Luo
- College of Agronomy, Xinjiang Agricultural University, Urumqi, China
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan;
| | - Liying Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, China;
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan;
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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: 18] [Impact Index Per Article: 18.0] [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.
Collapse
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.)
| | | |
Collapse
|
10
|
Ko Y, Chun J, Yang H, Kim D. Hypoviral-regulated HSP90 co-chaperone p23 (CpCop23) determines the colony morphology, virulence, and viral response of chestnut blight fungus Cryphonectria parasitica. MOLECULAR PLANT PATHOLOGY 2023; 24:413-424. [PMID: 36762926 PMCID: PMC10098053 DOI: 10.1111/mpp.13308] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/20/2023] [Accepted: 01/22/2023] [Indexed: 05/03/2023]
Abstract
We previously identified a protein spot that showed down-regulation in the presence of Cryphonectria hypovirus 1 (CHV1) and tannic acid supplementation as a Hsp90 co-chaperone p23 gene (CpCop23). The CpCop23-null mutant strain showed retarded growth with less aerial mycelia and intense pigmentation. Conidia of the CpCop23-null mutant were significantly decreased and their viability was dramatically diminished. The CpCop23-null mutant showed hypersensitivity to Hsp90 inhibitors. However, no differences in responsiveness were observed after exposure to other stressors such as temperature, reactive oxygen species, and high osmosis, the exception being cell wall-disturbing agents. A severe reduction in virulence was observed in the CpCop23-null mutant. Interestingly, viral transfer to the CpCop23-null mutant from CHV1-infected strain via anastomosis was more inefficient than a comparable transfer with the wild type as a result of decreased hyphal branching of the CpCop23-null mutant around the peripheral region, which resulted in less fusion of the hyphae. The CHV1-infected CpCop23-null mutant exhibited recovered mycelial growth with less pigmentation and sporulation. The CHV1-transfected CpCop23-null mutant demonstrated almost no virulence, that is, even less than that of the CHV1-infected wild type (UEP1), a further indication that reduced virulence of the mutant is not attributable exclusively to the retarded growth but rather is a function of the CpCop23 gene. Thus, this study indicates that CpCop23 plays a role in ensuring appropriate mycelial growth and development, spore viability, responses to antifungal drugs, and fungal virulence. Moreover, the CpCop23 gene acts as a host factor that affects CHV1-infected fungal growth and maintains viral symptom development.
Collapse
Affiliation(s)
- Yo‐Han Ko
- Department of Molecular Biology, Department of Bioactive Material Sciences, Institute for Molecular Biology and GeneticsJeonbuk National UniversityJeonjuSouth Korea
| | - Jeesun Chun
- Department of Molecular Biology, Department of Bioactive Material Sciences, Institute for Molecular Biology and GeneticsJeonbuk National UniversityJeonjuSouth Korea
| | - Han‐Eul Yang
- Department of Molecular Biology, Department of Bioactive Material Sciences, Institute for Molecular Biology and GeneticsJeonbuk National UniversityJeonjuSouth Korea
| | - Dae‐Hyuk Kim
- Department of Molecular Biology, Department of Bioactive Material Sciences, Institute for Molecular Biology and GeneticsJeonbuk National UniversityJeonjuSouth Korea
| |
Collapse
|
11
|
Kwon G, Yu J, Kim KH. Identifying transcription factors associated with Fusarium graminearum virus 2 accumulation in Fusarium graminearum by phenome-based investigation. Virus Res 2023; 326:199061. [PMID: 36738934 DOI: 10.1016/j.virusres.2023.199061] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/06/2023]
Abstract
Fusarium graminearum virus 2 (FgV2) infection induces phenotypic changes like reduction of growth rate and virulence with an alteration of the transcriptome, including various transcription factor (TFs) gene transcripts in Fusarium graminearum. Transcription factors are the primary regulator in many cellular processes and are significant in virus-host interactions. However, a detailed study about specific TFs to understand interactions between FgV2 and F. graminearum has yet to be conducted. We transferred FgV2 to a F. graminearum TF gene deletion mutant library to identify host TFs related to FgV2 infection. FgV2-infected TF mutants were classified into three groups depending on colony growth. The FgV2 accumulation level was generally higher in TF mutants showing more reduced growth. Among these FgV2-infected TF mutants, we found several possible TFs that might be involved in FgV2 accumulation, generation of defective interfering RNAs, and transcriptional regulation of FgDICER-2 and FgAGO-1 in response to virus infection. We also investigated the relation between FgV2 accumulation and production of reactive oxygen species (ROS) and DNA damage in fungal host cells by using DNA damage- or ROS-responsive TF deletion mutants. Our studies provide insights into the host factors related to FgV2 infection and bases for further investigation to understand interactions between FgV2 and F. graminearum.
Collapse
Affiliation(s)
- Gudam Kwon
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jisuk Yu
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, South Korea.
| | - Kook-Hyung Kim
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, South Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, South Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, South Korea.
| |
Collapse
|
12
|
Wang S, Ruan S, Zhang M, Nie J, Nzabanita C, Guo L. Interference of Small RNAs in Fusarium graminearum through FgGMTV1 Infection. J Fungi (Basel) 2022; 8:jof8121237. [PMID: 36547570 PMCID: PMC9781238 DOI: 10.3390/jof8121237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 11/24/2022] Open
Abstract
Small RNA (sRNA) plays a central role in RNA silencing in fungi. The genome of Fusarium graminearum gemytripvirus 1 (FgGMTV1) is comprised of three DNA segments: DNA-A, DNA-B, and DNA-C. DNA-A and DNA-B are associated with fungal growth and virulence reduction. To elucidate the role of RNA silencing during the interactions of fungi and viruses, the sRNA profiles of F. graminearum in association with FgGMTV1 were established, using an FgGMTV1-free library (S-S), a library for infection with the DNA-A and DNA-B segments (S-AB), and a library for infection with the DNA-A, DNA-B, and DNA-C segments (S-ABC). A large amount of virus-derived sRNA (vsiRNA) was detected in the S-AB and S-ABC libraries, accounting for 9.9% and 13.8% of the total sRNA, respectively, indicating that FgGMTV1 triggers host RNA silencing. The total numbers of sRNA reads differed among the three libraries, suggesting that FgGMTV1 infection interferes with host RNA silencing. In addition, the relative proportions of the different sRNA lengths were altered in the S-AB and S-ABC libraries. The genome distribution patterns of the mapping of vsiRNA to DNA-A and DNA-B in the S-AB and S-ABC libraries were also different. These results suggest the influence of DNA-C on host RNA silencing. Transcripts targeted by vsiRNAs were enriched in pathways that included flavin adenine dinucleotide binding, protein folding, and filamentous growth.
Collapse
Affiliation(s)
- Shuangchao Wang
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Shaojian Ruan
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Mingming Zhang
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
| | - Jianhua Nie
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Clement Nzabanita
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Lihua Guo
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
- Correspondence: ; Tel.: +86-01082105928
| |
Collapse
|
13
|
Similar Characteristics of siRNAs of Plant Viruses Which Replicate in Plant and Fungal Hosts. BIOLOGY 2022; 11:biology11111672. [PMID: 36421386 PMCID: PMC9687825 DOI: 10.3390/biology11111672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
Abstract
Simple Summary RNA silencing in fungi was shown to confer antiviral defense against plant viruses. In this study, using high-throughput sequencing and bioinformatic analyses, we showed that small interfering RNAs (siRNAs) of cucumber mosaic virus and tobacco mosaic virus (TMV) which replicated in phytopathogenic fungi Rhizoctonia solani and Fusarium graminearum had similarities with viral siRNAs produced in plant hosts in regard to the size distributions, proportion of plus and minus senses, and nucleotide preference for the 5′ termini. Additionally, our results also determined that both F. graminearum DCL1 and DCL2 were involved in the production of TMV siRNAs. Thus, the fungal RNA silencing machineries have adaptive capabilities to recognize and process the genome of invading plant viruses. Abstract RNA silencing is a host innate antiviral mechanism which acts via the synthesis of viral-derived small interfering RNAs (vsiRNAs). We have previously reported the infection of phytopathogenic fungi by plant viruses such as cucumber mosaic virus (CMV) and tobacco mosaic virus (TMV). Furthermore, fungal RNA silencing was shown to suppress plant virus accumulation, but the characteristics of plant vsiRNAs associated with the antiviral response in this nonconventional host remain unknown. Using high-throughput sequencing, we characterized vsiRNA profiles in two plant RNA virus–fungal host pathosystems: CMV infection in phytopathogenic fungus Rhizoctonia solani and TMV infection in phytopathogenic fungus Fusarium graminearum. The relative abundances of CMV and TMV siRNAs in the respective fungal hosts were much lower than those in the respective experimental plant hosts, Nicotiana benthamiana and Nicotiana tabacum. However, CMV and TMV siRNAs in fungi had similar characteristics to those in plants, particularly in their size distributions, proportion of plus and minus senses, and nucleotide preference for the 5′ termini of vsiRNAs. The abundance of TMV siRNAs largely decreased in F. graminearum mutants with a deletion in either dicer-like 1 (dcl1) or dcl2 genes which encode key proteins for the production of siRNAs and antiviral responses. However, deletion of both dcl1 and dcl2 restored TMV siRNA accumulation in F. graminearum, indicating the production of dcl-independent siRNAs with no antiviral function in the absence of the dcl1 and dcl2 genes. Our results suggest that fungal RNA silencing recognizes and processes the invading plant RNA virus genome in a similar way as in plants.
Collapse
|
14
|
Wang S, Zhang J, Nzabanita C, Zhang M, Nie J, Guo L. Fungal Virus, FgHV1-Encoded p20 Suppresses RNA Silencing through Single-Strand Small RNA Binding. J Fungi (Basel) 2022; 8:1171. [PMID: 36354938 PMCID: PMC9693516 DOI: 10.3390/jof8111171] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/03/2022] [Accepted: 11/03/2022] [Indexed: 10/14/2023] Open
Abstract
Fungal viruses are widespread in fungi infecting plants, insects and animals. High-throughput sequencing has rapidly led to the discovery of fungal viruses. However, the interactive exploration between fungi and viruses is relatively limited. RNA silencing is the fundamental antivirus pathway in fungi. Fusarium graminearum small RNA (sRNA) pattern was regulated by Fusarium graminearum hypovirus 1 (FgHV1) infection, indicating the activation of RNA silencing in virus defense. In this study, we focused on the function of an uncharacterized protein sized at 20 kD (p20) encoded by FgHV1. In the agro-infiltration assay, p20 was identified as a novel fungal RNA silencing suppressor. p20 can block systemic RNA silencing signals besides local RNA silencing suppression. We further elucidated the RNA silencing suppression mechanism of p20. The single-strand sRNA, instead of double-strand sRNA, can be incorporated by p20 in electrophoretic mobility shift assay. p20 binds sRNA originating from virus and non-virus sources in a non-sequence-specific manner. In addition, The F. graminearum 22 and 23-nt sRNA abundance and pathways related to RNA processing and redox regulation were regulated by p20. Our study revealed the first fungal virus-encoded RNA silencing suppressor with sRNA binding capability.
Collapse
Affiliation(s)
- Shuangchao Wang
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jingze Zhang
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Clement Nzabanita
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Mingming Zhang
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
| | - Jianhua Nie
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lihua Guo
- State Key Laboratory of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| |
Collapse
|
15
|
Hai D, Li J, Lan S, Wu T, Li Y, Cheng J, Fu Y, Lin Y, Jiang D, Wang M, Xie J. Discovery and Evolution of Six Positive-Sense RNA Viruses Co-infecting the Hypovirulent Strain SCH733 of Sclerotinia sclerotiorum. PHYTOPATHOLOGY 2022; 112:2449-2461. [PMID: 35793152 DOI: 10.1094/phyto-05-22-0148-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Sclerotinia sclerotiorum is a well-known phytopathogenic fungus with a wide host range. Identifying novel mycoviruses in phytopathogenic fungi is necessary to develop novel strategies for plant health protection and contribute to understanding the origin of viruses. Six new mycoviruses with positive single-stranded RNA genomes co-infecting the hypovirulent strain SCH733 of S. sclerotiorum were identified using a metatranscriptomic approach, and their complete genome sequences were molecularly determined. These mycoviruses belong to the following five families: Narnaviridae, Mitoviridae, Deltaflexviridae, Botourmiaviridae, and Ambiguiviridae. Three of these mycoviruses belong to existing International Committee on Taxonomy of Viruses (ICTV)-recognized species. Two of these newly identified mycoviruses have unique genomic features that are significantly different from those of all known mycoviruses. Phylogenetic analysis revealed that these six mycoviruses included close as well as distant relatives of known mycoviruses, thereby providing new insight into virus evolution and classification. Mycovirus horizontal transmission and elimination experiments revealed that Sclerotinia sclerotiorum narnavirus 5 is associated with hypovirulence of S. sclerotiorum, although we have not shown that it is independently responsible for the hypovirulence phenotype. This study broadens the diversity of known mycoviruses infecting S. sclerotiorum and provides a clue toward limiting hypovirulence in S. sclerotiorum.
Collapse
Affiliation(s)
- Du Hai
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Jincang Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Shangsong Lan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Tun Wu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Ying Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Jiasen Cheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yanping Fu
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yang Lin
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Minghong Wang
- Hubei Key Laboratory of Biological Resources Protection and Utilization, College of Forestry and Horticulture, Hubei Minzu University, Enshi, China
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
Paudel B, Pedersen C, Yen Y, Marzano SYL. Fusarium Graminearum Virus-1 Strain FgV1-SD4 Infection Eliminates Mycotoxin Deoxynivalenol Synthesis by Fusarium graminearum in FHB. Microorganisms 2022; 10:microorganisms10081484. [PMID: 35893542 PMCID: PMC9394287 DOI: 10.3390/microorganisms10081484] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/05/2022] [Accepted: 07/13/2022] [Indexed: 02/06/2023] Open
Abstract
Deoxynivalenol (DON) toxin production during the infection of F. graminearum in small grain crops is one of the most harmful virulence factors associated with economic losses. Metatranscriptome sequencing and RT-qPCR traced back that the only mycovirus infecting an F. graminearum isolate, designated as Fg-4-2, was a novel strain of Fusarium graminearum virus 1 (FgV1), designated as FgV1-SD4. The isolate Fg-4-2 showed significantly reduced virulence against wheat compared to the virus-free culture, designated as isolate Fg-4-1, which was obtained by deep freezing and single conidial germination. Notably, no DON accumulation was detected in the harvested wheat seeds infected by Fg-4-2, whereas ~18 ppm DON was detected in seeds infected by Fg-4-1. Comparison of the genome sequence of FgV1-SD4 with other identified strains of FgV1, i.e., FgV1-DK21 and FgV1-ch, indicates mutations on ORF-2 and the 3′-UTR in the genome that might be associated with hypovirulence. This mycovirus strain alone and specific genetic components of FgV1-SD4 can be further optimized to be developed as a biocontrol agent to reduce Fusarium head blight and to lower the DON accumulation levels in small grain crops due to this fungal disease.
Collapse
Affiliation(s)
- Bimal Paudel
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA; (B.P.); (C.P.)
| | - Connor Pedersen
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA; (B.P.); (C.P.)
- United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Toledo, OH 43606, USA
| | - Yang Yen
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA; (B.P.); (C.P.)
- Correspondence: (Y.Y.); (S.-Y.L.M.)
| | - Shin-Yi Lee Marzano
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA; (B.P.); (C.P.)
- United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Toledo, OH 43606, USA
- Correspondence: (Y.Y.); (S.-Y.L.M.)
| |
Collapse
|
18
|
Shimura H, Kim H, Matsuzawa A, Akino S, Masuta C. Coat protein of partitiviruses isolated from mycorrhizal fungi functions as an RNA silencing suppressor in plants and fungi. Sci Rep 2022; 12:7855. [PMID: 35551196 PMCID: PMC9098641 DOI: 10.1038/s41598-022-11403-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
Orchid seeds depend on colonization by orchid mycorrhizal (OM) fungi for their germination; therefore, the orchids and OM fungi have long maintained a close relationship (e.g., formation of the hyphal mass structure, peloton) during their evolution. In the present study, we isolated new partitiviruses from OM fungi; partitivirus were separately found in different subcultures from the same fungi. Partitiviruses have been believed to lack an RNA silencing suppressor (RSS), which is generally associated with viral pathogenicity, because most partitiviruses isolated so far are latent in both plants and fungi. However, we found that the coat protein (CP) of our partitiviruses indeed had RSS activity, which differed among the virus isolates from OM fungi; one CP showed RSS activity in both plants and fungi, while another CP showed no activity. The family Partitiviridae include viruses isolated from plants and fungi, and it has been suggested that these viruses may occasionally be transmitted between plant and fungal hosts. Given that there are several reports showing that viruses can adapt to nonhost using strong RSS, we here discussed the idea that partitiviruses may be better able to migrate between the orchid and fungus probably through the pelotons formed in the orchid cells, if host RNA silencing is suppressed by partitivirus RSS.
Collapse
Affiliation(s)
- Hanako Shimura
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Kita 9, Nishi 9, Sapporo, 060-8589, Japan.
| | - Hangil Kim
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Kita 9, Nishi 9, Sapporo, 060-8589, Japan
| | - Akihiko Matsuzawa
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Kita 9, Nishi 9, Sapporo, 060-8589, Japan
| | - Seishi Akino
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Kita 9, Nishi 9, Sapporo, 060-8589, Japan
| | - Chikara Masuta
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Kita 9, Nishi 9, Sapporo, 060-8589, Japan.
| |
Collapse
|
19
|
Li M, Xie L, Wang M, Lin Y, Zhong J, Zhang Y, Zeng J, Kong G, Xi P, Li H, Ma LJ, Jiang Z. FoQDE2-dependent milRNA promotes Fusarium oxysporum f. sp. cubense virulence by silencing a glycosyl hydrolase coding gene expression. PLoS Pathog 2022; 18:e1010157. [PMID: 35512028 PMCID: PMC9113603 DOI: 10.1371/journal.ppat.1010157] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/17/2022] [Accepted: 04/07/2022] [Indexed: 11/18/2022] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate protein-coding gene expression primarily found in plants and animals. Fungi produce microRNA-like RNAs (milRNAs) that are structurally similar to miRNAs and functionally important in various biological processes. The fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Banana Fusarium vascular wilt that threatens global banana production. It remains uncharacterized about the biosynthesis and functions of milRNAs in Foc. In this study, we investigated the biological function of milRNAs contributing to Foc pathogenesis. Within 24 hours post infecting the host, the Argonaute coding gene FoQDE2, and two Dicer coding genes FoDCL1 and FoDCL2, all of which are involved in milRNA biosynthesis, were significantly induced. FoQDE2 deletion mutant exhibited decreased virulence, suggesting the involvement of milRNA biosynthesis in the Foc pathogenesis. By small RNA sequencing, we identified 364 small RNA-producing loci in the Foc genome, 25 of which were significantly down-regulated in the FoQDE2 deletion mutant, from which milR-87 was verified as a FoQDE2-depedent milRNA based on qRT-PCR and Northern blot analysis. Compared to the wild-type, the deletion mutant of milR-87 was significantly reduced in virulence, while overexpression of milR-87 enhanced disease severity, confirming that milR-87 is crucial for Foc virulence in the infection process. We furthermore identified FOIG_15013 (a glycosyl hydrolase-coding gene) as the direct target of milR-87 based on the expression of FOIG_15013-GFP fusion protein. The FOIG_15013 deletion mutant displayed similar phenotypes as the overexpression of milR-87, with a dramatic increase in the growth, conidiation and virulence. Transient expression of FOIG_15013 in Nicotiana benthamiana leaves activates the host defense responses. Collectively, this study documents the involvement of milRNAs in the manifestation of the devastating fungal disease in banana, and demonstrates the importance of milRNAs in the pathogenesis and other biological processes. Further analyses of the biosynthesis and expression regulation of fungal milRNAs may offer a novel strategy to combat devastating fungal diseases. The fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Banana Fusarium vascular wilt that threatens global banana production. However, knowledge about pathogenesis of Foc is limited. In particular, pathogenic regulatory mechanism of the microRNA like small RNAs (milRNAs) found in Foc is unknown. Here, we found that FoQDE2, an Argonaute coding gene, and two Dicer coding genes FoDCL1 and FoDCL2, which are involved in milRNA biosynthesis, are significantly induced during the early infection stage of Foc. The results suggested that the milRNAs biosynthesis mediated by these genes may play an active role in the infection process of Foc. Based on this assumption, we subsequently found a FoQDE2-dependent milRNA (milR-87) and identified its target gene. Functional analysis showed that FoQDE2, milR-87 and its target gene were involved in the pathogenicity of Foc in different degree. The studies help us gain insight into the pathogenesis with FoQDE2, milR-87, and its target gene as central axis in Foc. The identified pathogenicity-involved milRNA provides an active target for developing novel and efficient biocontrol agents against Banana Fusarium wilt.
Collapse
Affiliation(s)
- Minhui Li
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
- * E-mail: (ML); (LJM); (ZJ)
| | - Lifei Xie
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Meng Wang
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Yilian Lin
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Jiaqi Zhong
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Yong Zhang
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
- Bioinformatics section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, United States of America
| | - Jing Zeng
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Guanghui Kong
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Pinggen Xi
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Huaping Li
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
| | - Li-Jun Ma
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
- * E-mail: (ML); (LJM); (ZJ)
| | - Zide Jiang
- Department of Plant Pathology / Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, PR China
- * E-mail: (ML); (LJM); (ZJ)
| |
Collapse
|
20
|
Non-detection of mycoviruses in amphibian chytrid fungus (Batrachochytrium dendrobatidis) from Australia. Fungal Biol 2021; 126:75-81. [PMID: 34930560 DOI: 10.1016/j.funbio.2021.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/04/2022]
Abstract
Mycoviruses may influence the pathogenicity of disease-causing fungi. Although mycoviruses have been found in some chytrid fungi, limited testing has not detected them in Batrachochytrium dendrobatidis (Bd), the cause of the devastating amphibian disease, chytridiomycosis. Here we conducted a survey for mycovirus presence in 38 Bd isolates from Australia (n = 31), Brazil (n = 5) and South Korea (n = 2) with a combination of modern high-throughput sequencing and conventional dsRNA cellulose chromatography. Mycoviruses were not detected in any isolates. This result was unexpected, given the long evolutionary history of Bd, as well as the high prevalence of mycoviruses in related fungal species. Given our widespread sampling in Australia and the limited number of Bd introductions, we suggest that mycoviruses are uncommon or absent from Australian Bd. Testing more isolates from regions where Bd originated, as well as regions with high diversity or low fungal virulence may identify mycoviruses that could aid in disease control.
Collapse
|
21
|
Kotta-Loizou I. Mycoviruses and their role in fungal pathogenesis. Curr Opin Microbiol 2021; 63:10-18. [PMID: 34102567 DOI: 10.1016/j.mib.2021.05.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/03/2021] [Accepted: 05/17/2021] [Indexed: 12/11/2022]
Abstract
Nowadays, the focus of mycovirology research has expanded from plant pathogenic fungi and mycovirus mediated hypovirulence to include insect and human pathogenic fungi together with a range of mycovirus mediated phenotypes, such as hypervirulence, control of endophytic traits, regulation of metabolite production and drug resistance. In fungus-mycovirus-environmental interactions, the environment and both abiotic and biotic factors play crucial roles in whether and how mycovirus mediated phenotypes are manifest. Mycovirus infections result in alterations in the host transcriptome profile, via protein-protein interactions and triggering of antiviral RNA silencing in the fungus. These alterations, in combination with the environmental factors, may result in desirable phenotypic traits for the host, for us and in some cases for both.
Collapse
Affiliation(s)
- Ioly Kotta-Loizou
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, South Kensington Campus, SW7 2AZ London, United Kingdom.
| |
Collapse
|
22
|
Yang S, Dai R, Salaipeth L, Huang L, Liu J, Andika IB, Sun L. Infection of Two Heterologous Mycoviruses Reduces the Virulence of Valsa mali, a Fungal Agent of Apple Valsa Canker Disease. Front Microbiol 2021; 12:659210. [PMID: 34113326 PMCID: PMC8186502 DOI: 10.3389/fmicb.2021.659210] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/13/2021] [Indexed: 11/29/2022] Open
Abstract
Mycovirus infection has been widely shown to attenuate the virulence of phytopathogenic fungi. Valsa mali is an agriculturally important fungus that causes Valsa canker disease in apple trees. In this study, two unrelated mycoviruses [Cryphonectria hypovirus 1 (CHV1, genus Hypovirus, and single-stranded RNA) and Mycoreovirus 1 (MyRV1, genus Mycoreovirus, double-stranded RNA)] that originated from Cryphonectria parasitica (chestnut blight fungus) were singly or doubly introduced into V. mali via protoplast fusion. CHV1 and MyRV1 stably infected V. mali and caused a reduction in fungal vegetative growth and virulence. Co-infection of both viruses further reduced the virulence of V. mali but compromised the stability of CHV1 infection and horizontal transmission through hyphal anastomosis. Infections of MyRV1 and, to a lesser extent, CHV1 up-regulated the transcript expression of RNA silencing-related genes in V. mali. The accumulation of CHV1 (but not MyRV1) was elevated by the knockdown of dcl2, a key gene of the RNA silencing pathway. Similarly, the accumulation of CHV1 and the efficiency of the horizontal transmission of CHV1 during co-infection was restored by the knockdown of dcl2. Thus, CHV1 and MyRV1 are potential biological control agents for apple Valsa canker disease, but co-infection of both viruses has a negative effect on CHV1 infection in V. mali due to the activation of antiviral RNA silencing by MyRV1 infection.
Collapse
Affiliation(s)
- Shian Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Ruoyin Dai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Lakha Salaipeth
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, China
| | - Jie Liu
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Ida Bagus Andika
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Liying Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, China
| |
Collapse
|
23
|
Yu J, Kim KH. A Phenome-Wide Association Study of the Effects of Fusarium graminearum Transcription Factors on Fusarium Graminearum Virus 1 Infection. Front Microbiol 2021; 12:622261. [PMID: 33643250 PMCID: PMC7904688 DOI: 10.3389/fmicb.2021.622261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
The Fusarium graminearum virus 1 (FgV1) causes noticeable phenotypic changes such as reduced mycelial growth, increase pigmentation, and reduced pathogenicity in its host fungi, Fusarium graminearum. Previous study showed that the numerous F. graminearum genes including regulatory factors were differentially expressed upon FgV1 infection, however, we have limited knowledge on the effect(s) of specific transcription factor (TF) during FgV1 infection in host fungus. Using gene-deletion mutant library of 657 putative TFs in F. graminearum, we transferred FgV1 by hyphal anastomosis to screen transcription factors that might be associated with viral replication or symptom induction. FgV1-infected TF deletion mutants were divided into three groups according to the mycelial growth phenotype compare to the FgV1-infected wild-type strain (WT-VI). The FgV1-infected TF deletion mutants in Group 1 exhibited slow or weak mycelial growth compare to that of WT-VI on complete medium at 5 dpi. In contrast, Group 3 consists of virus-infected TF deletion mutants showing faster mycelial growth and mild symptom compared to that of WT-VI. The hyphal growth of FgV1-infected TF deletion mutants in Group 2 was not significantly different from that of WT-VI. We speculated that differences of mycelial growth among the FgV1-infected TF deletion mutant groups might be related with the level of FgV1 RNA accumulations in infected host fungi. By conducting real-time quantitative reverse transcription polymerase chain reaction, we observed close association between FgV1 RNA accumulation and phenotypic differences of FgV1-infected TF deletion mutants in each group, i.e., increased and decreased dsRNA accumulation in Group 1 and Group 3, respectively. Taken together, our analysis provides an opportunity to identify host's regulator(s) of FgV1-triggered signaling and antiviral responses and helps to understand complex regulatory networks between FgV1 and F. graminearum interaction.
Collapse
Affiliation(s)
- Jisuk Yu
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
| | - Kook-Hyung Kim
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea.,Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul, South Korea.,Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| |
Collapse
|
24
|
In-Tree Behavior of Diverse Viruses Harbored in the Chestnut Blight Fungus, Cryphonectria parasitica. J Virol 2021; 95:JVI.01962-20. [PMID: 33361433 DOI: 10.1128/jvi.01962-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022] Open
Abstract
The ascomycete Cryphonectria parasitica causes destructive chestnut blight. Biological control of the fungus by virus infection (hypovirulence) has been shown to be an effective control strategy against chestnut blight in Europe. To provide biocontrol effects, viruses must be able to induce hypovirulence and spread efficiently in chestnut trees. Field studies using living trees to date have focused on a selected family of viruses called hypoviruses, especially prototypic hypovirus CHV1, but there are now known to be many other viruses that infect C. parasitica Here, we tested seven different viruses for their hypovirulence induction, biocontrol potential, and transmission properties between two vegetatively compatible but molecularly distinguishable fungal strains in trees. The test included cytosolically and mitochondrially replicating viruses with positive-sense single-stranded RNA or double-stranded RNA genomes. The seven viruses showed different in planta behaviors and were classified into four groups. Group I, including CHV1, had great biocontrol potential and could protect trees by efficiently spreading and converting virulent to hypovirulent cankers in the trees. Group II could induce high levels of hypovirulence but showed much smaller biocontrol potential, likely because of inefficient virus transmission. Group III showed poor performance in hypovirulence induction and biocontrol, while efficiently being transmitted in the infected trees. Group IV could induce hypovirulence and spread efficiently but showed poor biocontrol potential. Nuclear and mitochondrial genotyping of fungal isolates obtained from the treated cankers confirmed virus transmission between the two fungal strains in most isolates. These results are discussed in view of dynamic interactions in the tripartite pathosystem.IMPORTANCE The ascomycete Cryphonectria parasitica causes destructive chestnut blight, which is controllable by hypovirulence-conferring viruses infecting the fungus. The tripartite chestnut/C. parasitica/virus pathosystem involves the dynamic interactions of their genetic elements, i.e., virus transmission and lateral transfer of nuclear and mitochondrial genomes between fungal strains via anastomosis occurring in trees. Here, we tested diverse RNA viruses for their hypovirulence induction, biocontrol potential, and transmission properties between two vegetatively compatible but molecularly distinguishable fungal strains in live chestnut trees. The tested viruses, which are different in genome type (single-stranded or double-stranded RNA) and organization, replication site (cytosol or mitochondria), virus form (encapsidated or capsidless) and/or symptomatology, have been unexplored in the aforementioned aspects under controlled conditions. This study showed intriguing different in-tree behaviors of the seven viruses and suggested that to exert significant biocontrol effects, viruses must be able to induce hypovirulence and spread efficiently in the fungus infecting the chestnut trees.
Collapse
|
25
|
Feng H, Xu M, Gao Y, Liang J, Guo F, Guo Y, Huang L. Vm-milR37 contributes to pathogenicity by regulating glutathione peroxidase gene VmGP in Valsa mali. MOLECULAR PLANT PATHOLOGY 2021; 22:243-254. [PMID: 33278058 PMCID: PMC7814965 DOI: 10.1111/mpp.13023] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/18/2020] [Accepted: 11/05/2020] [Indexed: 05/22/2023]
Abstract
MicroRNAs play important roles in various biological processes by regulating their corresponding target genes. However, the function and regulatory mechanism of fungal microRNA-like RNAs (milRNAs) are still largely unknown. In this study, a milRNA (Vm-milR37) was isolated and identified from Valsa mali, which causes the most serious disease on the trunk of apple trees in China. Based on the results of deep sequencing and quantitative reverse transcription PCR, Vm-milR37 was found to be expressed in the mycelium, while it was not expressed during the V. mali infection process. Overexpression of Vm-milR37 did not affect vegetative growth, but significantly decreased pathogenicity. Based on degradome sequencing, the target of Vm-milR37 was identified as VmGP, a glutathione peroxidase. The expression of Vm-milR37 and VmGP showed a divergent trend in V. mali-apple interaction samples and Vm-milR37 overexpression transformants. The expression of VmGP could be suppressed significantly by Vm-milR37 when coexpressed in tobacco leaves. Deletion of VmGP showed significantly reduced pathogenicity compared with the wild type. VmGP deletion mutants showed more sensitivity to hydrogen peroxide. Apple leaves inoculated with Vm-milR37 overexpression transformants and VmGP deletion mutant displayed increased accumulation of reactive oxygen species compared with the wild type. Thus, Vm-milR37 plays a critical role in pathogenicity by regulating VmGP, which contributes to the oxidative stress response during V. mali infection. These results provide important evidence to define the roles of milRNAs and their corresponding target genes in pathogenicity.
Collapse
Affiliation(s)
- Hao Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Ming Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life SciencesNorthwest A&F UniversityYanglingChina
| | - Yuqi Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Jiahao Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Feiran Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Yan Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| |
Collapse
|
26
|
Identification of an RNA Silencing Suppressor Encoded by a Symptomless Fungal Hypovirus, Cryphonectria Hypovirus 4. BIOLOGY 2021; 10:biology10020100. [PMID: 33572564 PMCID: PMC7912522 DOI: 10.3390/biology10020100] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 01/28/2021] [Indexed: 12/14/2022]
Abstract
Simple Summary Host antiviral defense/viral counter-defense is an interesting topic in modern virology. RNA silencing is the primary antiviral mechanism in insects, plants, and fungi, while viruses encode and utilize RNA silencing suppressors against the host defense. Hypoviruses are positive-sense single-stranded RNA viruses with phylogenetic affinity to the picorna-like supergroup, including animal poliovirus and plant potyvirus. The prototype hypovirus Cryphonectria hypovirus 1, CHV1, is one of the best-studied fungal viruses. It is known to induce hypovirulence in the chestnut blight fungus, Cryphonectria parasitica, and encode an RNA silencing suppressor. CHV4 is another hypovirus asymptomatically that infects the same host fungus. This study shows that the N-terminal portion of the CHV4 polyprotein, termed p24, is a protease that autocatalytically cleaves itself from the rest of the viral polyprotein, and functions as an antiviral RNA silencing suppressor. Abstract Previously, we have reported the ability of a symptomless hypovirus Cryphonectria hypovirus 4 (CHV4) of the chestnut blight fungus to facilitate stable infection by a co-infecting mycoreovirus 2 (MyRV2)—likely through the inhibitory effect of CHV4 on RNA silencing (Aulia et al., Virology, 2019). In this study, the N-terminal portion of the CHV4 polyprotein, termed p24, is identified as an autocatalytic protease capable of suppressing host antiviral RNA silencing. Using a bacterial expression system, CHV4 p24 is shown to cleave autocatalytically at the di-glycine peptide (Gly214-Gly215) of the polyprotein through its protease activity. Transgenic expression of CHV4 p24 in Cryphonectria parasitica suppresses the induction of one of the key genes of the antiviral RNA silencing, dicer-like 2, and stabilizes the infection of RNA silencing-susceptible virus MyRV2. This study shows functional similarity between CHV4 p24 and its homolog p29, encoded by the symptomatic prototype hypovirus CHV1.
Collapse
|
27
|
Belov AA, Witte TE, Overy DP, Smith ML. Transcriptome analysis implicates secondary metabolite production, redox reactions, and programmed cell death during allorecognition in Cryphonectria parasitica. G3-GENES GENOMES GENETICS 2021; 11:6025178. [PMID: 33561228 PMCID: PMC7849911 DOI: 10.1093/g3journal/jkaa021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/16/2020] [Indexed: 02/04/2023]
Abstract
The underlying molecular mechanisms of programmed cell death associated with fungal allorecognition, a form of innate immunity, remain largely unknown. In this study, transcriptome analysis was used to infer mechanisms activated during barrage formation in vic3-incompatible strains of Cryphonectria parasitica, the chestnut blight fungus. Pronounced differential expression occurred in barraging strains of genes involved in mating pheromone (mf2-1, mf2-2), secondary metabolite production, detoxification (including oxidative stress), apoptosis-related, RNA interference, and HET-domain genes. Evidence for secondary metabolite production and reactive oxygen species (ROS) accumulation is supported through UPLC-HRMS analysis and cytological staining, respectively. Differential expression of mating-related genes and HET-domain genes was further examined by RT-qPCR of incompatible interactions involving each of the six vegetative incompatibility (vic) loci in C. parasitica and revealed distinct recognition process networks. We infer that vegetative incompatibility in C. parasitica activates defence reactions that involve secondary metabolism, resulting in increased toxicity of the extra- and intracellular environment. Accumulation of ROS (and other potential toxins) may result in detoxification failure and activation of apoptosis, sporulation, and the expression of associated pheromone genes. The incompatible reaction leaves abundant traces of a process-specific metabolome as conidiation is initiated.
Collapse
Affiliation(s)
- Anatoly A Belov
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Thomas E Witte
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - David P Overy
- Agriculture and Agri-Food Canada, Ottawa, ON, K1Y 4X2, Canada
| | - Myron L Smith
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| |
Collapse
|
28
|
Ho T, Panyim S, Udomkit A. Assessment of the function of gonad-specific PmAgo4 in viral replication and spermatogenesis in Penaeus monodon. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103824. [PMID: 32791174 DOI: 10.1016/j.dci.2020.103824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/30/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Argonaute family is phylogenetically subdivided into Ago and Piwi subfamilies that operate either transcriptional or post-transcriptional regulation in association with particular types of small RNAs. Among the four members of Ago subfamily (PmAgo1-4) found in black tiger shrimp Penaeus monodon, PmAgo4 exhibits gonad-restricted expression and takes part in transposon repression as the Piwi subfamily. While PmAgo1-3 participate in RNA interference (RNAi)-based mechanism, the role of PmAgo4 in RNAi is still mysterious, and was therefore investigated in this study. The results showed that knockdown of PmAgo4 in shrimp testis did not have a significant effect on the potency of PmRab7 silencing by dsPmRab7. In addition, replication of YHV as well as YHV-induced cumulative mortality in PmAgo4-knockdown shrimp are comparable to the control shrimp, suggesting the irrelevant association of PmAgo4 with RNAi-mediated gene silencing and antiviral immunity. Since PmAgo4 did not function in common with the Ago subfamily, its potential function in gametogenesis of male shrimp was further investigated. The reduction of PmAgo4 transcript levels in male shrimp revealed significant defect in testicular maturity as measured by Testicular Index (TI). Moreover, the numbers of mature sperm in spermatophore of PmAgo4-knockdown shrimp were significantly decreased comparing with the control shrimp. Our studies thus suggest a distinctive role of PmAgo4 that is not consistent with a dsRNA-mediate gene regulation and virus replication, but has a key function in controlling spermatogenesis in P. monodon.
Collapse
Affiliation(s)
- Teerapong Ho
- Institute of Molecular Biosciences, Mahidol University, Phutthamonthon 4 Road, Salaya, Nakhon Pathom, 73170, Thailand
| | - Sakol Panyim
- Institute of Molecular Biosciences, Mahidol University, Phutthamonthon 4 Road, Salaya, Nakhon Pathom, 73170, Thailand; Department of Biochemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Apinunt Udomkit
- Institute of Molecular Biosciences, Mahidol University, Phutthamonthon 4 Road, Salaya, Nakhon Pathom, 73170, Thailand.
| |
Collapse
|
29
|
Residual Effects Caused by a Past Mycovirus Infection in Fusarium circinatum. FORESTS 2020. [DOI: 10.3390/f12010011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mycoviruses are known to be difficult to cure in fungi but their spontaneous loss occurs commonly. The unexpected disappearance of mycoviruses can be explained by diverse reasons, from methodological procedures to biological events such as posttranscriptional silencing machinery. The long-term effects of a virus infection on the host organism have been well studied in the case of human viruses; however, the possible residual effect on a fungus after the degradation of a mycovirus is unknown. For that, this study analyses a possible residual effect on the transcriptome of the pathogenic fungus Fusarium circinatum after the loss of the mitovirus FcMV1. The mycovirus that previously infected the fungal isolate was not recovered after a 4-year storage period. Only 14 genes were determined as differentially expressed and were related to cell cycle regulation and amino acid metabolism. The results showed a slight acceleration in the metabolism of the host that had lost the mycovirus by the upregulation of the genes involved in essential functions for fungal development. The analysis also revealed a weak expression in the annotated genes of the RNA silencing machinery. To our knowledge, this is the first time that a potential residual effect on the host transcriptome caused by the past infection of a mycovirus is reported.
Collapse
|
30
|
Lax C, Tahiri G, Patiño-Medina JA, Cánovas-Márquez JT, Pérez-Ruiz JA, Osorio-Concepción M, Navarro E, Calo S. The Evolutionary Significance of RNAi in the Fungal Kingdom. Int J Mol Sci 2020; 21:E9348. [PMID: 33302447 PMCID: PMC7763443 DOI: 10.3390/ijms21249348] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/18/2022] Open
Abstract
RNA interference (RNAi) was discovered at the end of last millennium, changing the way scientists understood regulation of gene expression. Within the following two decades, a variety of different RNAi mechanisms were found in eukaryotes, reflecting the evolutive diversity that RNAi entails. The essential silencing mechanism consists of an RNase III enzyme called Dicer that cleaves double-stranded RNA (dsRNA) generating small interfering RNAs (siRNAs), a hallmark of RNAi. These siRNAs are loaded into the RNA-induced silencing complex (RISC) triggering the cleavage of complementary messenger RNAs by the Argonaute protein, the main component of the complex. Consequently, the expression of target genes is silenced. This mechanism has been thoroughly studied in fungi due to their proximity to the animal phylum and the conservation of the RNAi mechanism from lower to higher eukaryotes. However, the role and even the presence of RNAi differ across the fungal kingdom, as it has evolved adapting to the particularities and needs of each species. Fungi have exploited RNAi to regulate a variety of cell activities as different as defense against exogenous and potentially harmful DNA, genome integrity, development, drug tolerance, or virulence. This pathway has offered versatility to fungi through evolution, favoring the enormous diversity this kingdom comprises.
Collapse
Affiliation(s)
- Carlos Lax
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - Ghizlane Tahiri
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - José Alberto Patiño-Medina
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Michoacán CP 58030, Mexico;
| | - José T. Cánovas-Márquez
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - José A. Pérez-Ruiz
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - Macario Osorio-Concepción
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - Eusebio Navarro
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain; (C.L.); (G.T.); (J.T.C.-M.); (J.A.P.-R.); (M.O.-C.); (E.N.)
| | - Silvia Calo
- School of Natural and Exact Sciences, Pontificia Universidad Católica Madre y Maestra, 51033 Santiago de los Caballeros, Dominican Republic
| |
Collapse
|
31
|
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: 15] [Impact Index Per Article: 3.8] [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.
Collapse
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.
| |
Collapse
|
32
|
Honda S, Eusebio-Cope A, Miyashita S, Yokoyama A, Aulia A, Shahi S, Kondo H, Suzuki N. Establishment of Neurospora crassa as a model organism for fungal virology. Nat Commun 2020; 11:5627. [PMID: 33159072 PMCID: PMC7648066 DOI: 10.1038/s41467-020-19355-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/08/2020] [Indexed: 01/07/2023] Open
Abstract
The filamentous fungus Neurospora crassa is used as a model organism for genetics, developmental biology and molecular biology. Remarkably, it is not known to host or to be susceptible to infection with any viruses. Here, we identify diverse RNA viruses in N. crassa and other Neurospora species, and show that N. crassa supports the replication of these viruses as well as some viruses from other fungi. Several encapsidated double-stranded RNA viruses and capsid-less positive-sense single-stranded RNA viruses can be experimentally introduced into N. crassa protoplasts or spheroplasts. This allowed us to examine viral replication and RNAi-mediated antiviral responses in this organism. We show that viral infection upregulates the transcription of RNAi components, and that Dicer proteins (DCL-1, DCL-2) and an Argonaute (QDE-2) participate in suppression of viral replication. Our study thus establishes N. crassa as a model system for the study of host-virus interactions. The fungus Neurospora crassa is a model organism for the study of various biological processes, but it is not known to be infected by any viruses. Here, Honda et al. identify RNA viruses that infect N. crassa and examine viral replication and RNAi-mediated antiviral responses, thus establishing this fungus as a model for the study of host-virus interactions.
Collapse
Affiliation(s)
- Shinji Honda
- Faculty of Medical Sciences, University of Fukui, Fukui, 910-1193, Japan
| | - Ana Eusebio-Cope
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Shuhei Miyashita
- Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki-Aza- Aoba, Sendai, 980-0845, Japan
| | - Ayumi Yokoyama
- Faculty of Medical Sciences, University of Fukui, Fukui, 910-1193, Japan
| | - Annisa Aulia
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Sabitree Shahi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, 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.
| |
Collapse
|
33
|
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.
Collapse
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.
| |
Collapse
|
34
|
A Novel Mycovirus Evokes Transcriptional Rewiring in the Fungus Malassezia and Stimulates Beta Interferon Production in Macrophages. mBio 2020; 11:mBio.01534-20. [PMID: 32873760 PMCID: PMC7468202 DOI: 10.1128/mbio.01534-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Malassezia species represent the most common fungal inhabitant of the mammalian skin microbiome and are natural skin commensal flora. However, these fungi are also associated with a variety of clinical skin disorders. Recent studies have reported associations of Malassezia with Crohn’s disease and pancreatic cancer, further implicating this fungal genus in inflammatory and neoplastic disease states. Because M. sympodialis has lost genes involved in RNA interference (RNAi), we hypothesized Malassezia could harbor dsRNA mycoviruses. Indeed, we identified a novel mycovirus of the totivirus family in several Malassezia species and characterized the MsMV1 mycovirus of M. sympodialis. We found conditions that lead to curing of the virus and analyzed isogenic virus-infected/virus-cured strains to determine MsMV1 genetic and pathogenic impacts. MsMV1 induces a strong overexpression of transcription factors and ribosomal genes, while downregulating cellular metabolism. Moreover, MsMV1 induced a significantly higher level of beta interferon expression in cultured macrophages. This study sheds light on the mechanisms of pathogenicity of Malassezia, focusing on a previously unidentified novel mycovirus. Mycoviruses infect fungi, and while most persist asymptomatically, there are examples of mycoviruses having both beneficial and detrimental effects on their host. Virus-infected Saccharomyces and Ustilago strains exhibit a killer phenotype conferring a growth advantage over uninfected strains and other competing yeast species, whereas hypovirus-infected Cryphonectria parasitica displays defects in growth, sporulation, and virulence. In this study, we identify a double-stranded RNA (dsRNA) mycovirus in five Malassezia species. Sequence analysis reveals it to be a totivirus with two dsRNA segments: a larger 4.5-kb segment with genes encoding components for viral replication and maintenance, and a smaller 1.4-kb segment encoding a novel protein. Furthermore, transcriptome sequencing (RNA-seq) of virus-infected versus virus-cured Malassezia sympodialis revealed an upregulation of dozens of ribosomal components in the cell, suggesting the virus modifies the transcriptional and translational landscapes of the cell. Given that Malassezia is the most abundant fungus on human skin, we assessed the impact of the mycovirus in a murine epicutaneous infection model. Although infection with virus-infected strains was not associated with an increased inflammatory response, we did observe enhanced skin colonization in one of two virus-infected M. sympodialis strains. Noteworthy, beta interferon expression was significantly upregulated in bone marrow-derived macrophages when challenged with virus-infected, compared to virus-cured, M. sympodialis, suggesting that the presence of the virus can induce an immunological response. Although many recent studies have illuminated how widespread mycoviruses are, there are relatively few in-depth studies about their impact on disease caused by the host fungus. We describe here a novel mycovirus in Malassezia and its possible implications in pathogenicity.
Collapse
|
35
|
Xu M, Guo Y, Tian R, Gao C, Guo F, Voegele RT, Bao J, Li C, Jia C, Feng H, Huang L. Adaptive regulation of virulence genes by microRNA-like RNAs in Valsa mali. THE NEW PHYTOLOGIST 2020; 227:899-913. [PMID: 32222083 DOI: 10.1111/nph.16561] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
MicroRNAs play important roles in the regulation of gene expression in plants and animals. However, little information is known about the action mechanism and function of fungal microRNA-like RNAs (milRNAs). In this study, combining deep sequencing, molecular and histological assays, milRNAs and their targets in the phytopathogenic fungus Valsa mali were isolated and identified. A critical milRNA, Vm-milR16, was identified to adaptively regulate the expression of virulence genes. Fourteen isolated milRNAs showed high expression abundance. Based on the assessment of a pathogenicity function of these milRNAs, Vm-milR16 was found to be a critical milRNA in V. mali by regulating sucrose non-fermenting 1 (VmSNF1), 4,5-DOPA dioxygenase extradiol (VmDODA), and a hypothetical protein (VmHy1). During V. mali infection, Vm-milR16 is downregulated, while its targets are upregulated. Overexpression of Vm-milR16, but not mutated Vm-milR16, significantly reduces the expression of targets and virulence of V. mali. Furthermore, deletion of VmSNF1, VmDODA and VmHy1 significantly reduce virulence of V. mali. All three targets seem to be essential for oxidative stress response and VmSNF1 is required for expression of pectinase genes during V. mali-host interaction. Our results demonstrate Vm-milRNAs contributing to the infection of V. mali on apple trees by adaptively regulating virulence genes.
Collapse
Affiliation(s)
- Ming Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yan Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Runze Tian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chen Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Feiran Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ralf T Voegele
- Department of Phytopathology, Institute of Phytomedicine, Faculty of Agricultural Sciences, University of Hohenheim, 70599, Stuttgart, Germany
| | - Jiyuan Bao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chenjing Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Conghui Jia
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hao Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| |
Collapse
|
36
|
Chun J, Ko YH, Kim DH. Transcriptome Analysis of Cryphonectria parasitica Infected With Cryphonectria hypovirus 1 (CHV1) Reveals Distinct Genes Related to Fungal Metabolites, Virulence, Antiviral RNA-Silencing, and Their Regulation. Front Microbiol 2020; 11:1711. [PMID: 32765480 PMCID: PMC7379330 DOI: 10.3389/fmicb.2020.01711] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/30/2020] [Indexed: 01/07/2023] Open
Abstract
Comprehensive transcriptome analysis was conducted to elucidate the molecular basis of the interaction between chestnut blight fungus, Cryphonectria parasitica, and single-stranded RNA (ssRNA) mycovirus Cryphonectria hypovirus 1 (CHV1), using RNA-sequencing (RNA-seq). A total of 1,023 differentially expressed genes (DEGs) were affected by CHV1 infection, of which 753 DEGs were upregulated and 270 DEGs were downregulated. Significant correlations in qRT-PCR analysis of 20 randomly selected DEGs and agreement with previously characterized marker genes validated our RNA-seq analysis as representing global transcriptional profiling of virus-free and -infected isogenic strains of C. parasitica. Gene Ontology (GO) analysis of DEGs indicated that “cellular aromatic compound metabolic process” and “transport” were the two most enriched components in the “biological process.” In addition, “cytoplasm” was the most enriched term in the “cellular component” and “nucleotide binding” and “cation binding” were the two most enriched terms in the “molecular function” category. These results suggested that altered expression of genes encoding numerous intracellular proteins due to hypoviral infection resulted in changes in specific metabolic processes as well as transport processes. Kyoto Encyclopedia of Genes and Genomes function analysis demonstrated that pathways for “biosynthesis of other secondary metabolites,” “amino acid metabolism,” “carbohydrate metabolism,” and “translation” were enriched among the DEGs in C. parasitica. These results demonstrate that hypoviral infection resulted in massive but specific changes in primary and secondary metabolism, of which antiviral fungal metabolites were highly induced. The results of this study provide further insights into the mechanism of fungal gene regulation by CHV1 at the transcriptome level.
Collapse
Affiliation(s)
- Jeesun Chun
- Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju, South Korea
| | - Yo-Han Ko
- Department of Bioactive Material Sciences, Jeonbuk National University, Jeonju, South Korea
| | - Dae-Hyuk Kim
- Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju, South Korea.,Department of Bioactive Material Sciences, Jeonbuk National University, Jeonju, South Korea.,Department of Molecular Biology, Jeonbuk National University, Jeonju, South Korea
| |
Collapse
|
37
|
Telengech P, Hisano S, Mugambi C, Hyodo K, Arjona-López JM, López-Herrera CJ, Kanematsu S, Kondo H, Suzuki N. Diverse Partitiviruses From the Phytopathogenic Fungus, Rosellinia necatrix. Front Microbiol 2020; 11:1064. [PMID: 32670213 PMCID: PMC7332551 DOI: 10.3389/fmicb.2020.01064] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/29/2020] [Indexed: 01/18/2023] Open
Abstract
Partitiviruses (dsRNA viruses, family Partitiviridae) are ubiquitously detected in plants and fungi. Although previous surveys suggested their omnipresence in the white root rot fungus, Rosellinia necatrix, only a few of them have been molecularly and biologically characterized thus far. We report the characterization of a total of 20 partitiviruses from 16 R. necatrix strains belonging to 15 new species, for which “Rosellinia necatrix partitivirus 11–Rosellinia necatrix partitivirus 25” were proposed, and 5 previously reported species. The newly identified partitiviruses have been taxonomically placed in two genera, Alphapartitivirus, and Betapartitivirus. Some partitiviruses were transfected into reference strains of the natural host, R. necatrix, and an experimental host, Cryphonectria parasitica, using purified virions. A comparative analysis of resultant transfectants revealed interesting differences and similarities between the RNA accumulation and symptom induction patterns of R. necatrix and C. parasitica. Other interesting findings include the identification of a probable reassortment event and a quintuple partitivirus infection of a single fungal strain. These combined results provide a foundation for further studies aimed at elucidating mechanisms that underly the differences observed.
Collapse
Affiliation(s)
- Paul Telengech
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Sakae Hisano
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Cyrus Mugambi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Kiwamu Hyodo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Juan Manuel Arjona-López
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan.,Institute for Sustainable Agriculture, Spanish Research Council, Córdoba, Spain
| | | | - Satoko Kanematsu
- Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NARO), Morioka, Japan
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| |
Collapse
|
38
|
Sato Y, Shamsi W, Jamal A, Bhatti MF, Kondo H, Suzuki N. Hadaka Virus 1: a Capsidless Eleven-Segmented Positive-Sense Single-Stranded RNA Virus from a Phytopathogenic Fungus, Fusarium oxysporum. mBio 2020; 11:e00450-20. [PMID: 32457242 PMCID: PMC7251205 DOI: 10.1128/mbio.00450-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/28/2020] [Indexed: 12/16/2022] Open
Abstract
The search for viruses infecting fungi, or mycoviruses, has extended our knowledge about the diversity of RNA viruses, as exemplified by the discovery of polymycoviruses, a phylogenetic group of multisegmented RNA viruses with unusual forms. The genomic RNAs of known polymycoviruses, which show a phylogenetic affinity for animal positive-sense single-stranded RNA [(+)RNA] viruses such as caliciviruses, are comprised of four conserved segments with an additional zero to four segments. The double-stranded form of polymycovirus genomic RNA is assumed to be associated with a virally encoded protein (proline-alanine-serine-rich protein [PASrp]) in either of two manners: a capsidless colloidal form or a filamentous encapsidated form. Detailed molecular characterizations of polymycoviruses, however, have been conducted for only a few strains. Here, a novel polymyco-related virus named Hadaka virus 1 (HadV1), from the phytopathogenic fungus Fusarium oxysporum, was characterized. The genomic RNA of HadV1 consisted of an 11-segmented positive-sense RNA with highly conserved terminal nucleotide sequences. HadV1 shared the three conserved segments with known polymycoviruses but lacked the PASrp-encoding segment. Unlike the known polymycoviruses and encapsidated viruses, HadV1 was not pelleted by conventional ultracentrifugation, possibly due to the lack of PASrp. This result implied that HadV1 exists only as a soluble form with naked RNA. Nevertheless, the 11 genomic segments of HadV1 have been stably maintained through host subculturing and conidiation. Taken together, the results of this study revealed a virus with a potential novel virus lifestyle, carrying many genomic segments without typical capsids or PASrp-associated forms.IMPORTANCE Fungi collectively host various RNA viruses. Examples include encapsidated double-stranded RNA (dsRNA) viruses with diverse numbers of genomic segments (from 1 to 12) and capsidless viruses with nonsegmented (+)RNA genomes. Recently, viruses with unusual intermediate features of an infectious entity between encapsidated dsRNA viruses and capsidless (+)RNA viruses were found. They are called polymycoviruses, which typically have four to eight dsRNA genomic segments associated with one of the virus-encoded proteins and are phylogenetically distantly related to animal (+)RNA caliciviruses. Here, we identified a novel virus phylogenetically related to polymycoviruses, from the phytopathogenic fungus Fusarium oxysporum The virus, termed Hadaka virus 1 (HadV1), has 11 (+)RNA genomic segments, the largest number in known (+)RNA viruses. Nevertheless, HadV1 lacked a typical structural protein of polymycoviruses and was not pelleted by standard ultracentrifugation, implying an unusual capsidless nature of HadV1. This study reveals a potential novel lifestyle of multisegmented RNA viruses.
Collapse
Affiliation(s)
- Yukiyo Sato
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Wajeeha Shamsi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan
| | - Atif Jamal
- Crop Diseases Research Institute, National Agricultural Research Centre, Islamabad, Pakistan
| | - Muhammad Faraz Bhatti
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| |
Collapse
|
39
|
Differential Accumulation of Innate- and Adaptive-Immune-Response-Derived Transcripts during Antagonism between Papaya Ringspot Virus and Papaya Mosaic Virus. Viruses 2020; 12:v12020230. [PMID: 32092910 PMCID: PMC7077339 DOI: 10.3390/v12020230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/19/2020] [Accepted: 01/20/2020] [Indexed: 02/06/2023] Open
Abstract
Papaya ringspot virus (PRSV), a common potyvirus infecting papaya plants worldwide, can lead to either antagonism or synergism in mixed infections with Papaya mosaic virus (PapMV), a potexvirus. These two unrelated viruses produce antagonism or synergism depending on their order of infection in the plant. When PRSV is inoculated first or at the same time as PapMV, the viral interaction is synergistic. However, an antagonistic response is observed when PapMV is inoculated before PRSV. In the antagonistic condition, PRSV is deterred from the plant and its drastic effects are overcome. Here, we examine differences in gene expression by high-throughput RNA sequencing, focused on immune system pathways. We present the transcriptomic expression of single and mixed inoculations of PRSV and PapMV leading to synergism and antagonism. Upregulation of dominant and hormone-mediated resistance transcripts suggests that the innate immune system participates in synergism. In antagonism, in addition to innate immunity, upregulation of RNA interference-mediated resistance transcripts suggests that adaptive immunity is involved.
Collapse
|
40
|
Bian R, Andika IB, Pang T, Lian Z, Wei S, Niu E, Wu Y, Kondo H, Liu X, Sun L. Facilitative and synergistic interactions between fungal and plant viruses. Proc Natl Acad Sci U S A 2020; 117:3779-3788. [PMID: 32015104 PMCID: PMC7035501 DOI: 10.1073/pnas.1915996117] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Plants and fungi are closely associated through parasitic or symbiotic relationships in which bidirectional exchanges of cellular contents occur. Recently, a plant virus was shown to be transmitted from a plant to a fungus, but it is unknown whether fungal viruses can also cross host barriers and spread to plants. In this study, we investigated the infectivity of Cryphonectria hypovirus 1 (CHV1, family Hypoviridae), a capsidless, positive-sense (+), single-stranded RNA (ssRNA) fungal virus in a model plant, Nicotiana tabacum CHV1 replicated in mechanically inoculated leaves but did not spread systemically, but coinoculation with an unrelated plant (+)ssRNA virus, tobacco mosaic virus (TMV, family Virgaviridae), or other plant RNA viruses, enabled CHV1 to systemically infect the plant. Likewise, CHV1 systemically infected transgenic plants expressing the TMV movement protein, and coinfection with TMV further enhanced CHV1 accumulation in these plants. Conversely, CHV1 infection increased TMV accumulation when TMV was introduced into a plant pathogenic fungus, Fusarium graminearum In the in planta F. graminearum inoculation experiment, we demonstrated that TMV infection of either the plant or the fungus enabled the horizontal transfer of CHV1 from the fungus to the plant, whereas CHV1 infection enhanced fungal acquisition of TMV. Our results demonstrate two-way facilitative interactions between the plant and fungal viruses that promote cross-kingdom virus infections and suggest the presence of plant-fungal-mediated routes for dissemination of fungal and plant viruses in nature.
Collapse
Affiliation(s)
- Ruiling Bian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Ida Bagus Andika
- College of Plant Health and Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Tianxing Pang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Ziqian Lian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Shuang Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Erbo Niu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Yunfeng Wu
- Key Laboratory of Integrated Pest Management on Crops In Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, 712100 Yangling, China
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, 710-0046 Kurashiki, Japan
| | - Xili Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China
| | - Liying Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, 712100 Yangling, China;
- Key Laboratory of Integrated Pest Management on Crops In Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, 712100 Yangling, China
| |
Collapse
|
41
|
Yu J, Park JY, Heo J, Kim K. The ORF2 protein of Fusarium graminearum virus 1 suppresses the transcription of FgDICER2 and FgAGO1 to limit host antiviral defences. MOLECULAR PLANT PATHOLOGY 2020; 21:230-243. [PMID: 31815356 PMCID: PMC6988435 DOI: 10.1111/mpp.12895] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The filamentous fungus Fusarium graminearum possesses an RNA-interference (RNAi) pathway that acts as a defence response against virus infections and exogenous double-stranded (ds) RNA. Fusarium graminearum virus 1 (FgV1), which infects F. graminearum, confers hypovirulence-associated traits such as reduced mycelial growth, increased pigmentation and reduced pathogenicity. In this study, we found that FgV1 can suppress RNA silencing by interfering with the induction of FgDICER2 and FgAGO1, which are involved in RNAi antiviral defence and the hairpin RNA/RNAi pathway in F. graminearum. In an FgAGO1- or FgDICER2-promoter/GFP-reporter expression assay the green fluorescent protein (GFP) transcript levels were reduced in FgV1-infected transformed mutant strains. By comparing transcription levels of FgDICER2 and FgAGO1 in fungal transformed mutants expressing each open reading frame (ORF) of FgV1 with or without a hairpin RNA construct, we determined that reduction of FgDICER2 and FgAGO1 transcript levels requires only the FgV1 ORF2-encoded protein (pORF2). Moreover, we confirmed that the pORF2 binds to the upstream region of FgDICERs and FgAGOs in vitro. These combined results indicate that the pORF2 of FgV1 counteracts the RNAi defence response of F. graminearum by interfering with the induction of FgDICER2 and FgAGO1 in a promoter-dependent manner.
Collapse
Affiliation(s)
- Jisuk Yu
- Plant Genomics and Breeding InstituteSeoul National UniversitySeoulKorea
| | - Ju Yeon Park
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
| | - Jeong‐In Heo
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
| | - Kook‐Hyung Kim
- Plant Genomics and Breeding InstituteSeoul National UniversitySeoulKorea
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulKorea
| |
Collapse
|
42
|
Abstract
In this review, we discuss recent studies of the interaction between Fusarium graminearum viruses (FgVs) and the fungal host, Fusarium graminearum. Comprehensive transcriptome and proteome analyses have shown changes in the expression of host genes in response to infection by diverse FgVs. Using omics data and reverse genetics, researchers have determined the effects of some fungal host proteins (including FgHex1, FgHal2, FgSwi6, and vr1) on virus accumulation, virus transmission, and host symptom development. Recent reports have revealed the functions of the RNAi component in F. graminearum and the functional redundancy of FgDICERs and FgAGOs in the antiviral defense response against different FgV infections. Studies have also documented a unique mechanism used by FgV1 to overcome the antiviral response of the fungal host.
Collapse
|
43
|
Abstract
Protection against microbial infection in eukaryotes is provided by diverse cellular and molecular mechanisms. Here, we present a comparative view of the antiviral activity of virus-derived small interfering RNAs in fungi, plants, invertebrates and mammals, detailing the mechanisms for their production, amplification and activity. We also highlight the recent discovery of viral PIWI-interacting RNAs in animals and a new role for mobile host and pathogen small RNAs in plant defence against eukaryotic pathogens. In turn, viruses that infect plants, insects and mammals, as well as eukaryotic pathogens of plants, have evolved specific virulence proteins that suppress RNA interference (RNAi). Together, these advances suggest that an antimicrobial function of the RNAi pathway is conserved across eukaryotic kingdoms.
Collapse
|
44
|
García-Pedrajas MD, Cañizares MC, Sarmiento-Villamil JL, Jacquat AG, Dambolena JS. Mycoviruses in Biological Control: From Basic Research to Field Implementation. PHYTOPATHOLOGY 2019; 109:1828-1839. [PMID: 31398087 DOI: 10.1094/phyto-05-19-0166-rvw] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mycoviruses from plant pathogens can induce hypovirulence (reduced virulence) in their host fungi and have gained considerable attention as potential biocontrol tools. An increasing number of mycoviruses that induce fungal hypovirulence, from a wide variety of taxonomic groups, are currently being reported. Successful application of these viruses in disease management is greatly dependent on their ability to spread in the natural populations of the pathogen. Mycoviruses generally lack extracellular routes of transmission. Hyphal anastomosis is the main route of horizontal mycovirus transmission to other isolates, and conidia of vertical transmission to the progeny. Transmission efficiencies are influenced by both the fungal host and the infecting virus. Interestingly, artificial transfection methods have shown that potential biocontrol mycoviruses often have the ability to infect a variety of fungi. This expands their possible use to the control of pathogens others than those where they were identified. Mycovirus research is also focused on gaining insights into their complex molecular biology and the molecular bases of fungus-virus interactions. This knowledge could be exploited to manipulate the mycovirus and/or the host and generate combinations with enhanced properties in biological control. Finally, when exploring the use of mycoviruses in field conditions, the pathogen life style and the characteristics of the disease and crops affected will deeply impact the specific challenges to overcome, and the development of biocontrol formulations and delivery methods.
Collapse
Affiliation(s)
- M D García-Pedrajas
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora," 29750 Algarrobo-Costa, Málaga, Spain
| | - M C Cañizares
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora," 29750 Algarrobo-Costa, Málaga, Spain
| | - J L Sarmiento-Villamil
- Centre d'étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6, Canada
| | - A G Jacquat
- Instituto Multidisciplinario de Biología Vegetal (IMBiV-CONICET), Universidad Nacional de Córdoba, Avenida Vélez Sarsfield 1611, Córdoba, X5016GCA, Argentina
| | - J S Dambolena
- Instituto Multidisciplinario de Biología Vegetal (IMBiV-CONICET), Universidad Nacional de Córdoba, Avenida Vélez Sarsfield 1611, Córdoba, X5016GCA, Argentina
| |
Collapse
|
45
|
Muslin C, Mac Kain A, Bessaud M, Blondel B, Delpeyroux F. Recombination in Enteroviruses, a Multi-Step Modular Evolutionary Process. Viruses 2019; 11:E859. [PMID: 31540135 PMCID: PMC6784155 DOI: 10.3390/v11090859] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 01/15/2023] Open
Abstract
RNA recombination is a major driving force in the evolution and genetic architecture shaping of enteroviruses. In particular, intertypic recombination is implicated in the emergence of most pathogenic circulating vaccine-derived polioviruses, which have caused numerous outbreaks of paralytic poliomyelitis worldwide. Recent experimental studies that relied on recombination cellular systems mimicking natural genetic exchanges between enteroviruses provided new insights into the molecular mechanisms of enterovirus recombination and enabled to define a new model of genetic plasticity for enteroviruses. Homologous intertypic recombinant enteroviruses that were observed in nature would be the final products of a multi-step process, during which precursor nonhomologous recombinant genomes are generated through an initial inter-genomic RNA recombination event and can then evolve into a diversity of fitter homologous recombinant genomes over subsequent intra-genomic rearrangements. Moreover, these experimental studies demonstrated that the enterovirus genome could be defined as a combination of genomic modules that can be preferentially exchanged through recombination, and enabled defining the boundaries of these recombination modules. These results provided the first experimental evidence supporting the theoretical model of enterovirus modular evolution previously elaborated from phylogenetic studies of circulating enterovirus strains. This review summarizes our current knowledge regarding the mechanisms of recombination in enteroviruses and presents a new evolutionary process that may apply to other RNA viruses.
Collapse
Affiliation(s)
- Claire Muslin
- One Health Research Group, Faculty of Health Sciences, Universidad de las Américas, Quito EC170125, Pichincha, Ecuador.
| | - Alice Mac Kain
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Maël Bessaud
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Bruno Blondel
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
| | - Francis Delpeyroux
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
| |
Collapse
|
46
|
Neupane A, Feng C, Mochama PK, Saleem H, Lee Marzano SY. Roles of Argonautes and Dicers on Sclerotinia sclerotiorum Antiviral RNA Silencing. FRONTIERS IN PLANT SCIENCE 2019; 10:976. [PMID: 31440265 PMCID: PMC6694225 DOI: 10.3389/fpls.2019.00976] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/11/2019] [Indexed: 05/30/2023]
Abstract
RNA silencing or RNA interference (RNAi) is an essential mechanism in animals, fungi, and plants that functions in gene regulation and defense against foreign nucleic acids. In fungi, RNA silencing has been shown to function primarily in defense against invasive nucleic acids. We previously determined that mycoviruses are triggers and targets of RNA silencing in Sclerotinia sclerotiorum. However, recent progresses in RNAi or dsRNA-based pest control requires more detailed characterization of the RNA silencing pathways in S. sclerotiorum to investigate the utility of dsRNA-based strategy for white mold control. This study elucidates the roles of argonaute enzymes, agl-2 and agl-4, in small RNA metabolism in S. sclerotiorum. Gene disruption mutants of agl-2 and agl-4 were compared for changes in phenotype, virulence, viral susceptibility, and small RNA profiles. The Δagl-2 mutant but not the Δagl-4 mutant had significantly slower growth and virulence prior to virus infection. Similarly, the Δagl-2 mutant but not the Δagl-4 mutant, showed greater debilitation under virus infection compared to uninfected strains. The responses were confirmed in complementation studies and revealed the antiviral role of agl-2. Gene disruption mutants of agl-2, agl-4, Dicer-like (dcl)-1, and dcl-2 did not change the stability of the most abundant endogenous small RNAs, which suggests the existence of alternative enzymes/pathways for small RNA biogenesis in S. sclerotiorum. Furthermore, in vitro synthesized dsRNA targeting agl-2 showed a significantly reduced average lesion diameter (P < 0.05) on canola leaves with agl-2 down-regulated compared to controls. This is the first report describing the effectiveness of RNA pesticides targeting S. sclerotiorum RNA silencing pathway for the control of the economically important pathogen.
Collapse
Affiliation(s)
- Achal Neupane
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, United States
| | - Chenchen Feng
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, United States
| | - Pauline K. Mochama
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, United States
| | - Huma Saleem
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, United States
| | - Shin-Yi Lee Marzano
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, United States
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, United States
| |
Collapse
|
47
|
Jamal A, Sato Y, Shahi S, Shamsi W, Kondo H, Suzuki N. Novel Victorivirus from a Pakistani Isolate of Alternaria alternata Lacking a Typical Translational Stop/Restart Sequence Signature. Viruses 2019; 11:E577. [PMID: 31242660 PMCID: PMC6631646 DOI: 10.3390/v11060577] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 01/27/2023] Open
Abstract
The family Totiviridae currently contains five genera Totivirus, Victorivirus, Leishmavirus, Trichomonasvirus, and Giardiavirus. Members in this family generally have a set of two-open reading frame (ORF) elements in their genome with the 5'-proximal ORF (ORF1) encoding a capsid protein (CP) and the 3'-proximal one (ORF2) for RNA-dependent RNA polymerase (RdRp). How the downstream open reading frames (ORFs) are expressed is genus-specific. All victoriviruses characterized thus far appear to use the stop/restart translation mechanism, allowing for the expression of two separate protein products from bicitronic genome-sized viral mRNA, while the totiviruses use a -1 ribosomal frame-shifting that leads to a fusion product of CP and RdRp. We report the biological and molecular characterization of a novel victorivirus termed Alternaria alternata victorivirus 1 (AalVV1) isolated from Alternaria alternata in Pakistan. The phylogenetic and molecular analyses showed AalVV1 to be distinct from previously reported victoriviruses. AalVV1 appears to have a sequence signature required for the -1 frame-shifting at the ORF1/2 junction region, rather than a stop/restart key mediator. By contrast, SDS-polyacrylamide gel electrophoresis and peptide mass fingerprinting analyses of purified virion preparations suggested the expression of two protein products, not a CP-RdRp fusion product. How these proteins are expressed is discussed in this study. Possible effects of infection by this virus were tested in two fungal species: A. alternata and RNA silencing proficient and deficient strains of Cryphonectria parasitica, a model filamentous fungus. AalVV1 showed symptomless infection in all of these fungal strains, even in the RNA silencing deficient C. parasitica strain.
Collapse
Affiliation(s)
- Atif Jamal
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
- Crop Diseases Research Institute, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan.
| | - Yukiyo Sato
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| | - Sabitree Shahi
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| | - Wajeeha Shamsi
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| |
Collapse
|
48
|
Hu W, Luo H, Yang Y, Wang Q, Hong N, Wang G, Wang A, Wang L. Comprehensive analysis of full genome sequence and Bd-milRNA/target mRNAs to discover the mechanism of hypovirulence in Botryosphaeria dothidea strains on pear infection with BdCV1 and BdPV1. IMA Fungus 2019; 10:3. [PMID: 32647612 PMCID: PMC7325678 DOI: 10.1186/s43008-019-0008-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 11/23/2022] Open
Abstract
Pear ring rot disease, mainly caused by Botryosphaeria dothidea, is widespread in most pear and apple-growing regions. Mycoviruses are used for biocontrol, especially in fruit tree disease. BdCV1 (Botryosphaeria dothidea chrysovirus 1) and BdPV1 (Botryosphaeria dothidea partitivirus 1) influence the biological characteristics of B. dothidea strains. BdCV1 is a potential candidate for the control of fungal disease. Therefore, it is vital to explore interactions between B. dothidea and mycovirus to clarify the pathogenic mechanisms of B. dothidea and hypovirulence of B. dothidea in pear. A high-quality full-length genome sequence of the B. dothidea LW-Hubei isolate was obtained using Single Molecule Real-Time sequencing. It has high repeat sequence with 9.3% and DNA methylation existence in the genome. The 46.34 Mb genomes contained 14,091 predicted genes, which of 13,135 were annotated. B. dothidea was predicted to express 3833 secreted proteins. In bioinformatics analysis, 351 CAZy members, 552 transporters, 128 kinases, and 1096 proteins associated with plant-host interaction (PHI) were identified. RNA-silencing components including two endoribonuclease Dicer, four argonaute (Ago) and three RNA-dependent RNA polymerase (RdRp) molecules were identified and expressed in response to mycovirus infection. Horizontal transfer of the LW-C and LW-P strains indicated that BdCV1 induced host gene silencing in LW-C to suppress BdPV1 transmission. To investigate the role of RNA-silencing in B. dothidea defense, we constructed four small RNA libraries and sequenced B. dothidea micro-like RNAs (Bd-milRNAs) produced in response to BdCV1 and BdPV1 infection. Among these, 167 conserved and 68 candidate novel Bd-milRNAs were identified, of which 161 conserved and 20 novel Bd-milRNA were differentially expressed. WEGO analysis revealed involvement of the differentially expressed Bd-milRNA-targeted genes in metabolic process, catalytic activity, cell process and response to stress or stimulus. BdCV1 had a greater effect on the phenotype, virulence, conidiomata, vertical and horizontal transmission ability, and mycelia cellular structure biological characteristics of B. dothidea strains than BdPV1 and virus-free strains. The results obtained in this study indicate that mycovirus regulates biological processes in B. dothidea through the combined interaction of antiviral defense mediated by RNA-silencing and milRNA-mediated regulation of target gene mRNA expression.
Collapse
Affiliation(s)
- Wangcheng Hu
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Hui Luo
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Yuekun Yang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Qiong Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Ni Hong
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Guoping Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON N5V 4T3 Canada
| | - Liping Wang
- State Key Laboratory of Agricultural Microbiology, Wuhan, Hubei 430070 People's Republic of China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People's Republic of China.,Key Lab of Plant Pathology of Hubei Province, Wuhan, Hubei 430070 People's Republic of China
| |
Collapse
|
49
|
Aulia A, Andika IB, Kondo H, Hillman BI, Suzuki N. A symptomless hypovirus, CHV4, facilitates stable infection of the chestnut blight fungus by a coinfecting reovirus likely through suppression of antiviral RNA silencing. Virology 2019; 533:99-107. [PMID: 31146252 DOI: 10.1016/j.virol.2019.05.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 01/10/2023]
Abstract
Field-collected US strain C18 of Cryphonectria parasitica, the chestnut blight fungus, was earlier reported to be infected by a double-stranded RNA virus, mycoreovirus 2 (MyRV2). Next-generation sequencing has revealed co-infection of C18 by a positive-strand RNA virus, hypovirus 4 (CHV4). The current molecular and genetic analyses showed interesting commensal interactions between the two viruses. CHV4 facilitated the stable infection and enhanced vertical transmission of MyRV2, which was readily lost during subculturing and showed reduced vertical transmission in single infections. Deletion of a key antiviral RNA silencing gene, dcl2, in isolate C18 increased stability of MyRV2 in single infections. The ability of CHV4 to facilitate stable infection with MyRV2 appears to be associated with the inhibitory effect of CHV4 on RNA silencing via compromising the induction of transcriptional up-regulation of dcl2. These results suggest that natural infection of isolate C18 by MyRV2 in the field was facilitated by CHV4 co-infection.
Collapse
Affiliation(s)
- Annisa Aulia
- Institute of Plant Science and Resources (IPSR), Okayama University, Kurashiki, 710-0046, Japan; Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Ida Bagus Andika
- Institute of Plant Science and Resources (IPSR), Okayama University, Kurashiki, 710-0046, Japan
| | - Hideki Kondo
- Institute of Plant Science and Resources (IPSR), Okayama University, Kurashiki, 710-0046, Japan
| | - Bradley I Hillman
- Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources (IPSR), Okayama University, Kurashiki, 710-0046, Japan.
| |
Collapse
|
50
|
Ding F, Cheng J, Fu Y, Chen T, Li B, Jiang D, Xie J. Early Transcriptional Response to DNA Virus Infection in Sclerotinia sclerotiorum. Viruses 2019; 11:v11030278. [PMID: 30893849 PMCID: PMC6466436 DOI: 10.3390/v11030278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/13/2019] [Accepted: 03/15/2019] [Indexed: 01/02/2023] Open
Abstract
We previously determined that virions of Sclerotinia sclerotiorum hypovirulence associated DNA virus 1 (SsHADV-1) could directly infect hyphae of Sclerotinia sclerotiorum, resulting in hypovirulence of the fungal host. However, the molecular mechanisms of SsHADV-1 virions disruption of the fungal cell wall barrier and entrance into the host cell are still unclear. To investigate the early response of S. sclerotiorum to SsHADV-1 infection, S. sclerotiorum hyphae were inoculated with purified SsHADV-1 virions. The pre- and post-infection hyphae were collected at one–three hours post-inoculation for transcriptome analysis. Further, bioinformatic analysis showed that differentially expressed genes (DEGs) regulated by SsHADV-1 infection were identified in S. sclerotiorum. In total, 187 genes were differentially expressed, consisting of more up-regulated (114) than down-regulated (73) genes. The identified DEGs were involved in several important pathways. Metabolic processes, biosynthesis of antibiotics, and secondary metabolites were the most affected categories in S. sclerotiorum upon SsHADV-1 infection. Cell structure analysis suggested that 26% of the total DEGs were related to membrane tissues. Furthermore, 10 and 27 DEGs were predicted to be located in the cell membrane and mitochondria, respectively. Gene ontology enrichment analyses of the DEGs were performed, followed by functional annotation of the genes. Interestingly, one third of the annotated functional DEGs could be involved in the Ras-small G protein signal transduction pathway. These results revealed that SsHADV-1 virions may be able to bind host membrane proteins and influence signal transduction through Ras-small G protein-coupled receptors during early infection, providing new insight towards the molecular mechanisms of virions infection in S. sclerotiorum.
Collapse
Affiliation(s)
- Feng Ding
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Jiasen Cheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Yanping Fu
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Tao Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Bo Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
| |
Collapse
|