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Wang X, Kotta-Loizou I, Coutts RHA, Deng H, Han Z, Hong N, Shafik K, Wang L, Guo Y, Yang M, Xu W, Wang G. A circular single-stranded DNA mycovirus infects plants and confers broad-spectrum fungal resistance. MOLECULAR PLANT 2024; 17:955-971. [PMID: 38745413 DOI: 10.1016/j.molp.2024.05.003] [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: 01/25/2024] [Revised: 04/15/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Circular single-stranded DNA (ssDNA) viruses have been rarely found in fungi, and the evolutionary and ecological relationships among ssDNA viruses infecting fungi and other organisms remain unclear. In this study, a novel circular ssDNA virus, tentatively named Diaporthe sojae circular DNA virus 1 (DsCDV1), was identified in the phytopathogenic fungus Diaporthe sojae isolated from pear trees. DsCDV1 has a monopartite genome (3185 nt in size) encapsidated in isometric virions (21-26 nm in diameter). The genome comprises seven putative open reading frames encoding a discrete replicase (Rep) split by an intergenic region, a putative capsid protein (CP), several proteins of unknown function (P1-P4), and a long intergenic region. Notably, the two split parts of DsCDV1 Rep share high identities with the Reps of Geminiviridae and Genomoviridae, respectively, indicating an evolutionary linkage with both families. Phylogenetic analysis based on Rep or CP sequences placed DsCDV1 in a unique cluster, supporting the establishment of a new family, tentatively named Gegemycoviridae, intermediate to both families. DsCDV1 significantly attenuates fungal growth and nearly erases fungal virulence when transfected into the host fungus. Remarkably, DsCDV1 can systematically infect tobacco and pear seedlings, providing broad-spectrum resistance to fungal diseases. Subcellular localization analysis revealed that DsCDV1 P3 is systematically localized in the plasmodesmata, while its expression in trans-complementation experiments could restore systematic infection of a movement-deficient plant virus, suggesting that P3 is a movement protein. DsCDV1 exhibits unique molecular and biological traits not observed in other ssDNA viruses, serving as a link between fungal and plant ssDNA viruses and presenting an evolutionary connection between ssDNA viruses and fungi. These findings contribute to expanding our understanding of ssDNA virus diversity and evolution, offering potential biocontrol applications for managing crucial plant diseases.
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Affiliation(s)
- Xianhong Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK; Department of Clinical, Pharmaceutical and Biological Science, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - Robert H A Coutts
- Department of Clinical, Pharmaceutical and Biological Science, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - Huifang Deng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Zhenhao Han
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Ni Hong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Karim Shafik
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China; Department of Plant Pathology, Faculty of Agriculture, Alexandria University, Alexandria 21526, Egypt
| | - Liping Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Yashuang Guo
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Mengmeng Yang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China
| | - Wenxing Xu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China.
| | - Guoping Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Lab of Plant Pathology of Hubei Province, Wuhan 430070, China.
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Forgia M, Daghino S, Chiapello M, Ciuffo M, Turina M. New clades of viruses infecting the obligatory biotroph Bremia lactucae representing distinct evolutionary trajectory for viruses infecting oomycetes. Virus Evol 2024; 10:veae003. [PMID: 38361818 PMCID: PMC10868552 DOI: 10.1093/ve/veae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 02/17/2024] Open
Abstract
Recent advances in high throughput sequencing (HTS) approaches allowed a broad exploration of viromes from different fungal hosts, unveiling a great diversity of mycoviruses with interesting evolutionary features. The word mycovirus historically applies also to viruses infecting oomycetes but most studies are on viruses infecting fungi, with less mycoviruses found and characterized in oomycetes, particularly in the obligatory biotrophs. We, here, describe the first virome associated to Bremia lactucae, the causal agent of lettuce downy mildew, which is an important biotrophic pathogen for lettuce production and a model system for the molecular aspects of the plant-oomycetes interactions. Among the identified viruses, we could detect (1) two new negative sense ssRNA viruses related to the yueviruses, (2) the first example of permuted RdRp in a virus infecting fungi/oomycetes, (3) a new group of bipartite dsRNA viruses showing evidence of recent bi-segmentation and concomitantly, a possible duplication event bringing a bipartite genome to tripartite, (4) a first representative of a clade of viruses with evidence of recombination between distantly related viruses, (5) a new open reading frame (ORF)an virus encoding for an RdRp with low homology to known RNA viruses, and (6) a new virus, belonging to riboviria but not conserved enough to provide a conclusive phylogenetic placement that shows evidence of a recombination event between a kitrinoviricota-like and a pisuviricota-like sequence. The results obtained show a great diversity of viruses and evolutionary mechanisms previously unreported for oomycetes-infecting viruses, supporting the existence of a large diversity of oomycetes-specific viral clades ancestral of many fungal and insect virus clades.
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Affiliation(s)
| | - Stefania Daghino
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada Delle Cacce 73, Torino 10135, Italy
| | - Marco Chiapello
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada Delle Cacce 73, Torino 10135, Italy
| | - Marina Ciuffo
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada Delle Cacce 73, Torino 10135, Italy
| | - Massimo Turina
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada Delle Cacce 73, Torino 10135, Italy
- Institute for Sustainable Plant Protection, National Research Council of Italy, Via Branze 39, Brescia 25123, Italy
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Poimala A, Vainio E. Discovery and Identification of Viruses Infecting Oomycetes. Methods Mol Biol 2024; 2732:45-65. [PMID: 38060117 DOI: 10.1007/978-1-0716-3515-5_4] [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: 12/08/2023]
Abstract
This chapter describes protocols suitable for the detection and identification of RNA viruses infecting oomycetes (so-called water molds of Kingdom Heterokonta, Stramenopila), focusing on species of Phytophthora and exemplified by P. fragariae. The protocol includes laboratory procedures for oomycete cultivation and total RNA extraction from harvested mycelia, followed by instructions on suitable parameters given for sequencing companies on ribosomal RNA depletion, cDNA library preparation, and total RNA-sequencing (RNA-Seq). We also describe the bioinformatics steps needed for de novo assembly of raw reads into contigs, removal of host-associated contigs, and virus identification by database searches, as well as host validation by RT-PCR. All steps are described using an exemplar RNA-Seq library containing a yet undescribed fusagravirus hosted by a P. fragariae isolate.
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Affiliation(s)
- Anna Poimala
- Natural Resources Institute Finland (Luke), Helsinki, Finland.
| | - Eeva Vainio
- Natural Resources Institute Finland (Luke), Helsinki, Finland
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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.
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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
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Sakuta K, Uchida K, Fukuhara T, Komatsu K, Okada R, Moriyama H. Successful full-length genomic cloning and characterization of site-specific nick structures of Phytophthora endornaviruses 2 and 3 in yeast, Saccharomyces cerevisiae. Front Microbiol 2023; 14:1243068. [PMID: 37771702 PMCID: PMC10523305 DOI: 10.3389/fmicb.2023.1243068] [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: 06/20/2023] [Accepted: 08/29/2023] [Indexed: 09/30/2023] Open
Abstract
Two endornaviruses, Phytophthora endornavirus 2 (PEV2) and Phytophthora endornavirus 3 (PEV3), have been discovered in pathogens targeting asparagus. In this study, we analyzed the nick structure in the RNA genomes of PEV2 and PEV3 in the host oomycetes. Northern blot hybridization using positive and negative strand-specific RNA probes targeting the 5' and 3' regions of PEV2 and PEV3 RNA genomes revealed approximately 1.0 kilobase (kb) RNA fragments located in the 5' regions of the two genomes. 3' RACE analysis determined that the size of the RNA fragments were 958 nucleotides (nt) for PEV2 and 968 nt for PEV3. We have successfully constructed full-length cDNA clones of the entire RNA genomes of PEV2 and PEV3 using a homologous recombination system in the yeast, Saccharomyces cerevisiae. These full-length cDNA sequences were ligated downstream of a constitutive expression promoter (TDH3) or a galactose-inducing promoter (GAL1) in the shuttle vector to enable the production of the full-length RNA transcripts of PEV2 and PEV3 in yeast cells. Interestingly, a 1.0 kb RNA fragment from the PEV3 positive-strand transcript was also detected with a 5'-region RNA probe, indicating that site-specific cleavage also occurred in yeast cells. Further, when PEV2 or PEV3 mRNA was overexpressed under the GAL1 promoter, yeast cell growth was suppressed. A fusion protein combining EGFP to the N-terminus of the full-length PEV2 ORF or C-terminus of the full-length PEV3 ORF was expressed, and allowed PEV2 and PEV3 ORFs to be successfully visualized in yeast cells. Expression of the fusion protein also revealed presence of heterogeneous bodies in the cells.
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Affiliation(s)
- Kohei Sakuta
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Keiko Uchida
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Toshiyuki Fukuhara
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Ryo Okada
- Horticultural Research Institute, Agricultural Center, Kasama, Ibaraki, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
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Raco M, Jung T, Horta Jung M, Chi NM, Botella L, Suzuki N. Sequence and phylogenetic analysis of a novel alphaendornavirus, the first virus described from the oomycete plant pathogen Phytophthora heveae. Arch Virol 2023; 168:158. [PMID: 37166518 PMCID: PMC10175314 DOI: 10.1007/s00705-023-05786-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
Here, we report the discovery and complete genome sequence of a novel virus, designated as "Phytophthora heveae alphaendornavirus 1" (PhAEV1), from a single isolate of the plant pathogenic oomycete Phytophthora heveae (kingdom Stramenipila) isolated from a tropical evergreen lowland rainforest in northern Vietnam. PhAEV1 was detected by both cellulose affinity chromatography of dsRNA and high-throughput sequencing of total RNA, and its presence and sequence were confirmed by RT-PCR and Sanger sequencing. The PhAEV1 genome, 12,820 nucleotides (nt) in length, was predicted to encode a single large polyprotein with the catalytic core domain of viral (superfamily 1) RNA helicase (HEL, amino acid [aa] positions 1,287-1,531), glycosyltransferase (GT, aa positions ca. 2,800-3,125), and RNA-directed RNA polymerase (RdRp, aa positions 3,875-4,112). PhAEV1 is the most similar to Phytophthora cactorum alphaendornavirus 3, sharing 39.4% and 39.1% nt and aa sequence identity, respectively. In addition to the first 5'-terminal AUG codon, three additional in-frame methionine codons were found in close proximity (nt 14-16, 96-98, and 176-178), suggesting potential additional translation initiation sites. Conserved RdRp motifs (A-E) similar to those detected in related endornaviruses were identified in PhAEV1, as well as in several previously described alphaendornaviruses from other Phytophthora species in which these motifs had not been identified previously. Phylogenetic analysis showed that PhAEV1 clusters with members of the genus Alphaendornavirus in the family Endornaviridae and is basal to two other alphaendornaviruses described from another oomycete, Phytophthora cactorum. PhAEV1 is the first virus reported in P. heveae.
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Grants
- CZ.02.1.01/0.0/0.0/15_003/0000453 European Regional Development Fund, project Phytophthora Research Centre
- LDF_VP_2021047 Specific University Research Fund of the Faculty of Forestry and Wood Technology, Mendel University in Brno
- KAKENHI 21H05035 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 21K18222 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16H06436 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16H06429 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16K21723 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
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Affiliation(s)
- Milica Raco
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00.
| | - Thomas Jung
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Marilia Horta Jung
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Nguyen Minh Chi
- Forest Protection Research Centre, Vietnamese Academy of Forest Sciences, Hanoi, 10000, Vietnam
| | - Leticia Botella
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 7100046, Japan, Chuo 2-20-1
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Li J, Wu X, Liu H, Wang X, Yi S, Zhong X, Wang Y, Wang Z. Identification and Molecular Characterization of a Novel Carlavirus Infecting Chrysanthemum morifolium in China. Viruses 2023; 15:v15041029. [PMID: 37113009 PMCID: PMC10141686 DOI: 10.3390/v15041029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 04/29/2023] Open
Abstract
Chrysanthemum (Chrysanthemum morifolium) is an important ornamental and medicinal plant suffering from many viruses and viroids worldwide. In this study, a new carlavirus, tentatively named Chinese isolate of Carya illinoinensis carlavirus 1 (CiCV1-CN), was identified from chrysanthemum plants in Zhejiang Province, China. The genome sequence of CiCV1-CN was 8795 nucleotides (nt) in length, with a 68-nt 5'-untranslated region (UTR) and a 76-nt 3'-UTR, which contained six predicted open reading frames (ORFs) that encode six corresponding proteins of various sizes. Phylogenetic analyses based on full-length genome and coat protein sequences revealed that CiCV1-CN is in an evolutionary branch with chrysanthemum virus R (CVR) in the Carlavirus genus. Pairwise sequence identity analysis showed that, except for CiCV1, CiCV1-CN has the highest whole-genome sequence identity of 71.3% to CVR-X6. At the amino acid level, the highest identities of predicted proteins encoded by the ORF1, ORF2, ORF3, ORF4, ORF5, and ORF6 of CiCV1-CN were 77.1% in the CVR-X21 ORF1, 80.3% in the CVR-X13 ORF2, 74.8% in the CVR-X21 ORF3, 60.9% in the CVR-BJ ORF4, 90.2% in the CVR-X6 and CVR-TX ORF5s, and 79.4% in the CVR-X21 ORF6. Furthermore, we also found a transient expression of the cysteine-rich protein (CRP) encoded by the ORF6 of CiCV1-CN in Nicotiana benthamiana plants using a potato virus X-based vector, which can result in a downward leaf curl and hypersensitive cell death over the time course. These results demonstrated that CiCV1-CN is a pathogenic virus and C. morifolium is a natural host of CiCV1.
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Affiliation(s)
- Jiapeng Li
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Xiaoyin Wu
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Hui Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Xiaomei Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Shaokui Yi
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Xueting Zhong
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Zhanqi Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
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Huang H, Hua X, Pang X, Zhang Z, Ren J, Cheng J, Fu Y, Xiao X, Lin Y, Chen T, Li B, Liu H, Jiang D, Xie J. Discovery and Characterization of Putative Glycoprotein-Encoding Mycoviruses in the Bunyavirales. J Virol 2023; 97:e0138122. [PMID: 36625579 PMCID: PMC9888262 DOI: 10.1128/jvi.01381-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/16/2022] [Indexed: 01/11/2023] Open
Abstract
Although segmented negative-sense RNA viruses (SNSRVs) have been frequently discovered in various fungi, most SNSRVs reported only the large segments. In this study, we investigated the diversity of the mycoviruses in the phytopathogenic fungus Fusarium asiaticum using the metatranscriptomic technique. We identified 17 fungal single-stranded RNA (ssRNA) viruses including nine viruses within Mitoviridae, one each in Narnaviridae, Botourmiaviridae, Hypoviridae, Fusariviridae, and Narliviridae, two in Mymonaviridae, and one trisegmented virus temporarily named Fusarium asiaticum mycobunyavirus 1 (FaMBV1). The FaMBV1 genome comprises three RNA segments, large (L), medium (M), and small (S) with 6,468, 2,639, and 1,420 nucleotides, respectively. These L, M, and S segments putatively encode the L protein, glycoprotein, and nucleocapsid, respectively. Phylogenetic analysis based on the L protein showed that FaMBV1 is phylogenetically clustered with Alternaria tenuissima negative-stranded RNA virus 2 (AtNSRV2) and Sclerotinia sclerotiorum negative-stranded RNA virus 5 (SsNSRV5) but distantly related to the members of the family Phenuiviridae. FaMBV1 could be vertically transmitted by asexual spores with lower efficiency (16.7%, 2/42). Comparison between FaMBV1-free and -infected fungal strains revealed that FaMBV1 has little effect on hyphal growth, pathogenicity, and conidium production, and its M segment is dispensable for viral replication and lost during subculture and asexual conidiation. The M and S segments of AtNSRV2 and SsNSRV5 were found using bioinformatics methods, indicating that the two fungal NSRVs harbor trisegmented genomes. Our results provide a new example of the existence and evolution of the segmented negative-sense RNA viruses in fungi. IMPORTANCE Fungal segmented negative-sense RNA viruses (SNSRVs) have been frequently found. Only the large segment encoding RNA-dependent RNA polymerase (RdRp) has been reported in most fungal SNSRVs, except for a few fungal SNSRVs reported to encode nucleocapsids, nonstructural proteins, or movement proteins. Virome analysis of the Fusarium spp. that cause Fusarium head blight discovered a novel virus, Fusarium asiaticum mycobunyavirus 1 (FaMBV1), representing a novel lineage of the family Phenuiviridae. FaMBV1 harbors a trisegmented genome that putatively encodes RdRp, glycoproteins, and nucleocapsids. The putative glycoprotein was first described in fungal SNSRVs and shared homology with glycoprotein of animal phenuivirus but was dispensable for its replication in F. asiaticum. Two other trisegmented fungal SNSRVs that also encode glycoproteins were discovered, implying that three-segment bunyavirus infections may be common in fungi. These findings provide new insights into the ecology and evolution of SNSRVs, particularly those infecting fungi.
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Affiliation(s)
- Huang Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Xiangmin Hua
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Xidan Pang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Zhongmei Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Jingyi Ren
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi, China
| | - Jiasen Cheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yanping Fu
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xueqiong Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yang Lin
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Tao Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Bo Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi, China
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
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9
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Ayllón MA, Vainio EJ. Mycoviruses as a part of the global virome: Diversity, evolutionary links and lifestyle. Adv Virus Res 2023; 115:1-86. [PMID: 37173063 DOI: 10.1016/bs.aivir.2023.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Knowledge of mycovirus diversity, evolution, horizontal gene transfer and shared ancestry with viruses infecting distantly related hosts, such as plants and arthropods, has increased vastly during the last few years due to advances in the high throughput sequencing methodologies. This also has enabled the discovery of novel mycoviruses with previously unknown genome types, mainly new positive and negative single-stranded RNA mycoviruses ((+) ssRNA and (-) ssRNA) and single-stranded DNA mycoviruses (ssDNA), and has increased our knowledge of double-stranded RNA mycoviruses (dsRNA), which in the past were thought to be the most common viruses infecting fungi. Fungi and oomycetes (Stramenopila) share similar lifestyles and also have similar viromes. Hypothesis about the origin and cross-kingdom transmission events of viruses have been raised and are supported by phylogenetic analysis and by the discovery of natural exchange of viruses between different hosts during virus-fungus coinfection in planta. In this review we make a compilation of the current information on the genome organization, diversity and taxonomy of mycoviruses, discussing their possible origins. Our focus is in recent findings suggesting the expansion of the host range of many viral taxa previously considered to be exclusively fungal, but we also address factors affecting virus transmissibility and coexistence in single fungal or oomycete isolates, as well as the development of synthetic mycoviruses and their use in investigating mycovirus replication cycles and pathogenicity.
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Affiliation(s)
- María A Ayllón
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain; Departamento Biotecnología-Biología Vegetal, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), Madrid, Spain.
| | - Eeva J Vainio
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Helsinki, Finland
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10
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Poimala A, Raco M, Haikonen T, Černý M, Parikka P, Hantula J, Vainio EJ. Bunyaviruses Affect Growth, Sporulation, and Elicitin Production in Phytophthora cactorum. Viruses 2022; 14:v14122596. [PMID: 36560602 PMCID: PMC9788385 DOI: 10.3390/v14122596] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/02/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
Phytophthora cactorum is an important oomycetous plant pathogen with numerous host plant species, including garden strawberry (Fragaria × ananassa) and silver birch (Betula pendula). P. cactorum also hosts mycoviruses, but their phenotypic effects on the host oomycete have not been studied earlier. In the present study, we tested polyethylene glycol (PEG)-induced water stress for virus curing and created an isogenic virus-free isolate for testing viral effects in pair with the original isolate. Phytophthora cactorum bunya-like viruses 1 and 2 (PcBV1 & 2) significantly reduced hyphal growth of the P. cactorum host isolate, as well as sporangia production and size. Transcriptomic and proteomic analyses revealed an increase in the production of elicitins due to bunyavirus infection. However, the presence of bunyaviruses did not seem to alter the pathogenicity of P. cactorum. Virus transmission through anastomosis was unsuccessful in vitro.
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Affiliation(s)
- Anna Poimala
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
- Correspondence: ; Tel.: +358-29-5322173
| | - Milica Raco
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic
| | - Tuuli Haikonen
- Natural Resources Institute Finland, Toivonlinnantie 518, FI-21500 Piikkiö, Finland
| | - Martin Černý
- Phytophthora Research Centre, Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic
| | - Päivi Parikka
- Natural Resources Institute Finland, Humppilantie 18, FI-31600 Jokioinen, Finland
| | - Jarkko Hantula
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Eeva J. Vainio
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
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11
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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: 0] [Impact Index Per Article: 0] [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.
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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
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12
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Natural Populations from the Phytophthora palustris Complex Show a High Diversity and Abundance of ssRNA and dsRNA Viruses. J Fungi (Basel) 2022; 8:jof8111118. [PMID: 36354885 PMCID: PMC9698713 DOI: 10.3390/jof8111118] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 12/02/2022] Open
Abstract
We explored the virome of the “Phytophthora palustris complex”, a group of aquatic specialists geographically limited to Southeast and East Asia, the native origin of many destructive invasive forest Phytophthora spp. Based on high-throughput sequencing (RNAseq) of 112 isolates of “P. palustris” collected from rivers, mangroves, and ponds, and natural forests in subtropical and tropical areas in Indonesia, Taiwan, and Japan, 52 putative viruses were identified, which, to varying degrees, were phylogenetically related to the families Botybirnaviridae, Narnaviridae, Tombusviridae, and Totiviridae, and the order Bunyavirales. The prevalence of all viruses in their hosts was investigated and confirmed by RT-PCR. The rich virus composition, high abundance, and distribution discovered in our study indicate that viruses are naturally infecting taxa from the “P. palustris complex” in their natural niche, and that they are predominant members of the host cellular environment. Certain Indonesian localities are the viruses’ hotspots and particular “P. palustris” isolates show complex multiviral infections. This study defines the first bi-segmented bunya-like virus together with the first tombus-like and botybirna-like viruses in the genus Phytophthora and provides insights into the spread and evolution of RNA viruses in the natural populations of an oomycete species.
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13
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Rodriguez Coy L, Plummer KM, Khalifa ME, MacDiarmid RM. Mycovirus-encoded suppressors of RNA silencing: Possible allies or enemies in the use of RNAi to control fungal disease in crops. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:965781. [PMID: 37746227 PMCID: PMC10512228 DOI: 10.3389/ffunb.2022.965781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023]
Abstract
Plants, fungi, and many other eukaryotes have evolved an RNA interference (RNAi) mechanism that is key for regulating gene expression and the control of pathogens. RNAi inhibits gene expression, in a sequence-specific manner, by recognizing and deploying cognate double-stranded RNA (dsRNA) either from endogenous sources (e.g. pre-micro RNAs) or exogenous origin (e.g. viruses, dsRNA, or small interfering RNAs, siRNAs). Recent studies have demonstrated that fungal pathogens can transfer siRNAs into plant cells to suppress host immunity and aid infection, in a mechanism termed cross-kingdom RNAi. New technologies, based on RNAi are being developed for crop protection against insect pests, viruses, and more recently against fungal pathogens. One example, is host-induced gene silencing (HIGS), which is a mechanism whereby transgenic plants are modified to produce siRNAs or dsRNAs targeting key transcripts of plants, or their pathogens or pests. An alternative gene regulation strategy that also co-opts the silencing machinery is spray-induced gene silencing (SIGS), in which dsRNAs or single-stranded RNAs (ssRNAs) are applied to target genes within a pathogen or pest. Fungi also use their RNA silencing machinery against mycoviruses (fungal viruses) and mycoviruses can deploy virus-encoded suppressors of RNAi (myco-VSRs) as a counter-defence. We propose that myco-VSRs may impact new dsRNA-based management methods, resulting in unintended outcomes, including suppression of management by HIGS or SIGS. Despite a large diversity of mycoviruses being discovered using high throughput sequencing, their biology is poorly understood. In particular, the prevalence of mycoviruses and the cellular effect of their encoded VSRs are under-appreciated when considering the deployment of HIGS and SIGS strategies. This review focuses on mycoviruses, their VSR activities in fungi, and the implications for control of pathogenic fungi using RNAi.
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Affiliation(s)
- Lorena Rodriguez Coy
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Kim M. Plummer
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Mahmoud E. Khalifa
- Botany and Microbiology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Robin M. MacDiarmid
- BioProtection, The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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