1
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Hua H, Zhang X, Liu L, Wu X. A Novel Strain of Fusarium oxysporum Alternavirus 1 Isolated from Fusarium oxysporum f. sp. melonis Strain T-BJ17 Confers Hypovirulence and Increases the Sensitivity of Its Host Fungus to Difenoconazole and Pydiflumetofen. Viruses 2024; 16:901. [PMID: 38932193 PMCID: PMC11209391 DOI: 10.3390/v16060901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
In the current study, a novel strain of Fusarium oxysporum alternavirus 1 (FoAV1) was identified from the Fusarium oxysporum f. sp. melonis (FOM) strain T-BJ17 and was designated as Fusarium oxysporum alternavirus 1-FOM (FoAV1-FOM). Its genome consists of four dsRNA segments of 3515 bp (dsRNA1), 2663 bp (dsRNA2), 2368 bp (dsRNA3), and 1776 bp (dsRNA4) in length. Open reading frame 1 (ORF1) in dsRNA1 was found to encode a putative RNA-dependent RNA polymerase (RdRp), whose amino acid sequence was 99.02% identical to that of its counterpart in FoAV1; while ORF2 in dsRNA2, ORF3 in dsRNA3, and ORF4 in dsRNA4 were all found to encode hypothetical proteins. Strain T-BJ17-VF, which was verified to FoAV1-FOM-free, was obtained using single-hyphal-tip culture combined with high-temperature treatment to eliminate FoAV1-FOM from strain T-BJ17. The colony growth rate, ability to produce spores, and virulence of strain T-BJ17 were significantly lower than those of T-BJ17-VF, while the dry weight of the mycelial biomass and the sensitivity to difenoconazole and pydiflumetofen of strain T-BJ17 were greater than those of T-BJ17-VF. FoAV1-FOM was capable of 100% vertical transmission via spores. To our knowledge, this is the first time that an alternavirus has infected FOM, and this is the first report of hypovirulence and increased sensitivity to difenoconazole and pydiflumetofen induced by FoAV1-FOM infection in FOM.
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Affiliation(s)
| | | | | | - Xuehong Wu
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, China (X.Z.); (L.L.)
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2
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Khan HA, Baig DI, Bhatti MF. An Overview of Mycoviral Curing Strategies Used in Evaluating Fungal Host Fitness. Mol Biotechnol 2023; 65:1547-1564. [PMID: 36841858 PMCID: PMC9963364 DOI: 10.1007/s12033-023-00695-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/11/2023] [Indexed: 02/27/2023]
Abstract
The number of novel mycoviruses is increasing at a high pace due to advancements in sequencing technologies. As a result, an uncountable number of mycoviral sequences are available in public sequence repositories. However, only genomic information is not sufficient to understand the impact of mycoviruses on their host biology. Biological characterization is required to determine the nature of mycoviruses (cryptic, hypervirulent, or hypovirulent) and to search for mycoviruses with biocontrol and therapeutic potential. Currently, no particular selective method is used as the gold standard against these mycoviral infections. Given the importance of curing, we present an overview of procedures used in preparation of isogenic lines, along with their benefits and drawbacks. We concluded that a combination of single-spore isolation and hyphal tipping is the best fit for preparation of isogenic lines. Furthermore, recent bioinformatic approaches should be introduced in the field of mycovirology to predict virus-specific antivirals to get robust results.
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Affiliation(s)
- Haris Ahmed Khan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
- Department of Biotechnology, University of Mianwali, Punjab, 42200 Pakistan
| | - Danish Ilyas Baig
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
| | - Muhammad Faraz Bhatti
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, 44000 Pakistan
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3
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Boulanouar F, Ranque S, Levasseur A. Tracking Mycoviruses in Public RNAseq Datasets of Malassezia: Three Original Totiviruses Revealed. Viruses 2023; 15:1368. [PMID: 37376667 DOI: 10.3390/v15061368] [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: 05/17/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Mycoviruses are viruses that selectively infect and multiply in fungal cells. Malassezia is the most abundant fungus on human skin and is associated with a variety of conditions, including atopic eczema, atopic dermatitis, dandruff, folliculitis, pityriasis versicolor, and seborrheic dermatitis. Here, we conducted mycovirome studies on 194 public transcriptomes of Malassezia (2,568,212,042 paired-end reads) screened against all available viral proteins. Transcriptomic data were assembled de novo resulting in 1,170,715 contigs and 2,995,306 open reading frames (ORFs) that were subsequently tracked for potential viral sequences. Eighty-eight virus-associated ORFs were detected in 68 contigs from 28 Sequence Read Archive (SRA) samples. Seventy-five and thirteen ORFs were retrieved from transcriptomes of Malassezia globosa and Malassezia restricta, respectively. Phylogenetic reconstructions revealed three new mycoviruses belonging to the Totivirus genus and named Malassezia globosa-associated-totivirus 1 (MgaTV1); Malassezia restricta-associated-totivirus 1 (MraTV1) and Malassezia restricta-associated-totivirus 2 (MraTV2). These viral candidates extend our understanding of the diversity and taxonomy of mycoviruses as well as their co-evolution with their fungal hosts. These results reflected the unexpected diversity of mycoviruses hidden in public databases. In conclusion, this study sheds light on the discovery of novel mycoviruses and opens the door to study their impact on disease caused by the host fungus Malassezia and globally, their implication in clinical skin disorders.
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Affiliation(s)
- Fatima Boulanouar
- Aix-Marseille Université (AMU), UMR VITROME, IRD, APHM, Faculté de Médecine, 13005 Marseille, France
- Aix-Marseille Université (AMU), UMR MEPHI, IRD, APHM, Faculté de Médecine, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Stéphane Ranque
- Aix-Marseille Université (AMU), UMR VITROME, IRD, APHM, Faculté de Médecine, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Anthony Levasseur
- Aix-Marseille Université (AMU), UMR VITROME, IRD, APHM, Faculté de Médecine, 13005 Marseille, France
- Aix-Marseille Université (AMU), UMR MEPHI, IRD, APHM, Faculté de Médecine, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Institut Universitaire de France, 75005 Paris, France
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Zhang Y, Guo H, Zhou S, Chen D, Xu G, Kang Z, Zheng L. A Novel Mitovirus PsMV2 Facilitates the Virulence of Wheat Stripe Rust Fungus. Viruses 2023; 15:1265. [PMID: 37376565 DOI: 10.3390/v15061265] [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: 04/02/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
Wheat stripe rust, caused by the obligate biotrophic fungus Puccinia striiformis f. sp. tritici (Pst), seriously affects wheat production. Here, we report the complete genome sequence and biological characterization of a new mitovirus from P. striiformis strain GS-1, which was designated as "Puccinia striiformis mitovirus 2" (PsMV2). Genome sequence analysis showed that PsMV2 is 2658 nt in length with an AU-rich of 52.3% and comprises a single ORF of 2348 nt encoding an RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that PsMV2 is a new member of the genus Unuamitovirus within the family Mitoviridae. In addition, PsMV2 multiplied highly during Pst infection and it suppresses programmed cell death (PCD) triggered by Bax. Silencing of PsMV2 in Pst by barley stripe mosaic virus (BSMV)-mediated Host Induced Gene Silencing (HIGS) reduced fungal growth and decreased pathogenicity of Pst. These results indicate PsMV2 promotes host pathogenicity in Pst. Interestingly, PsMV2 was detected among a wide range of field isolates of Pst and may have coevolved with Pst in earlier times. Taken together, our results characterized a novel mitovirus PsMV2 in wheat stripe rust fungus, which promotes the virulence of its fungal host and wide distribution in Pst which may offer new strategies for disease control.
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Affiliation(s)
- Yanhui Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, China
| | - Hualong Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, China
| | - Siyu Zhou
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China
| | - Daipeng Chen
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China
| | - Gang Xu
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, China
| | - Li Zheng
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China
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Hough B, Steenkamp E, Wingfield B, Read D. Fungal Viruses Unveiled: A Comprehensive Review of Mycoviruses. Viruses 2023; 15:1202. [PMID: 37243288 PMCID: PMC10224137 DOI: 10.3390/v15051202] [Citation(s) in RCA: 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.
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Affiliation(s)
| | | | - Brenda Wingfield
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria 0002, South Africa; (B.H.); (E.S.); (D.R.)
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6
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Zhao YJ, Shirouzu T, Chiba Y, Hosaka K, Moriyama H, Urayama SI, Hagiwara D. Identification of novel RNA mycoviruses from wild mushroom isolates in Japan. Virus Res 2023; 325:199045. [PMID: 36681193 DOI: 10.1016/j.virusres.2023.199045] [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: 11/07/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
The characterization of viruses from environmental samples could aid in our understanding of their ecological significance and potential for biotechnological exploitation. While there has been much focus on pathogenic fungi or commercially cultivated mushrooms, attention to viruses from wild Basidiomycota mushrooms is lacking. Therefore, in this study, we conducted viral screening of fungal mycelia isolated from wild basidiocarps using agarose gel electrophoresis (AGE) and fragmented and primer-ligated dsRNA sequencing (FLDS). Among the 51 isolates, seven isolates were detected with virus-like bands during the initial screening with AGE, but only five isolates were detected with viruses after long-term storage. Using the FLDS method, we obtained seven viral genome sequences, including five double-stranded RNA (dsRNA) viruses belonging to Partitiviridae and Curvulaviridae, one positive-sense single-stranded RNA (ssRNA) virus belonging to Endornaviridae and one negative-sense ssRNA virus belonging to Tulasviridae (Bunyavirales). All viruses characterized in this study are novel species. These findings greatly expanded our knowledge of the diversity of RNA viruses from environmental samples.
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Affiliation(s)
- Yan-Jie Zhao
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Takashi Shirouzu
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan
| | - Yuto Chiba
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Kentaro Hosaka
- Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Syun-Ichi Urayama
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan; Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
| | - Daisuke Hagiwara
- Laboratory of Fungal Interaction and Molecular Biology (donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan; Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
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7
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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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Zhang X, Li S, Ma Z, Cai Q, Zhou T, Wu X. Complete genome sequence of a novel mitovirus isolated from the fungus Fusarium equiseti causing potato dry rot. Arch Virol 2022; 167:2777-2781. [PMID: 36178543 DOI: 10.1007/s00705-022-05578-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/14/2022] [Indexed: 12/14/2022]
Abstract
In this study, a novel mitovirus was isolated from the fungus Fusarium equiseti causing potato dry rot and tentatively designated as "Fusarium equiseti mitovirus 1" (FeMV1). The full-length genome sequence of FeMV1 consists of 2,459 nucleotides with a predicted A + U content of 69.5%. Using the mold mitochondrial genetic code, an open reading frame (ORF) of 725 amino acids (aa) was predicted to encode an RNA-dependent RNA polymerase (RdRp). The RdRp protein contains six conserved motifs, with the highly conserved GDD in motif IV, and the 5'-untranslated region (UTR) and 3'-UTR of FeMV1 have the potential to fold into stem-loop secondary structures and a panhandle structure, both of which are typical characteristics of members of the family Mitoviridae. Results of a BLASTp search showed that the RdRp aa sequence of FeMV1 shared the highest sequence similarity with that of Fusarium poae mitovirus 2 (FpMV2) (76.84% identity, E-value = 0.0). Phylogenetic analysis based on the complete aa sequence of RdRp further suggested that FeMV1 is a new member of the family Mitoviridae. This is the first report of the complete genome sequence analysis of a mitovirus associated with F. equiseti.
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Affiliation(s)
- Xiaofang Zhang
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China
| | - Siwei Li
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China
| | - Zhihao Ma
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China
| | - Qingnian Cai
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China
| | - Tao Zhou
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China
| | - Xuehong Wu
- College of Plant Protection, China Agricultural University, Haidian District, 100193, Beijing, People's Republic of China.
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Rodriguez Coy L, Plummer KM, Khalifa ME, MacDiarmid RM. Mycovirus-encoded suppressors of RNA silencing: Possible allies or enemies in the use of RNAi to control fungal disease in crops. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:965781. [PMID: 37746227 PMCID: PMC10512228 DOI: 10.3389/ffunb.2022.965781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023]
Abstract
Plants, fungi, and many other eukaryotes have evolved an RNA interference (RNAi) mechanism that is key for regulating gene expression and the control of pathogens. RNAi inhibits gene expression, in a sequence-specific manner, by recognizing and deploying cognate double-stranded RNA (dsRNA) either from endogenous sources (e.g. pre-micro RNAs) or exogenous origin (e.g. viruses, dsRNA, or small interfering RNAs, siRNAs). Recent studies have demonstrated that fungal pathogens can transfer siRNAs into plant cells to suppress host immunity and aid infection, in a mechanism termed cross-kingdom RNAi. New technologies, based on RNAi are being developed for crop protection against insect pests, viruses, and more recently against fungal pathogens. One example, is host-induced gene silencing (HIGS), which is a mechanism whereby transgenic plants are modified to produce siRNAs or dsRNAs targeting key transcripts of plants, or their pathogens or pests. An alternative gene regulation strategy that also co-opts the silencing machinery is spray-induced gene silencing (SIGS), in which dsRNAs or single-stranded RNAs (ssRNAs) are applied to target genes within a pathogen or pest. Fungi also use their RNA silencing machinery against mycoviruses (fungal viruses) and mycoviruses can deploy virus-encoded suppressors of RNAi (myco-VSRs) as a counter-defence. We propose that myco-VSRs may impact new dsRNA-based management methods, resulting in unintended outcomes, including suppression of management by HIGS or SIGS. Despite a large diversity of mycoviruses being discovered using high throughput sequencing, their biology is poorly understood. In particular, the prevalence of mycoviruses and the cellular effect of their encoded VSRs are under-appreciated when considering the deployment of HIGS and SIGS strategies. This review focuses on mycoviruses, their VSR activities in fungi, and the implications for control of pathogenic fungi using RNAi.
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Affiliation(s)
- Lorena Rodriguez Coy
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Kim M. Plummer
- Australian Research Council Research Hub for Sustainable Crop Protection, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Mahmoud E. Khalifa
- Botany and Microbiology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Robin M. MacDiarmid
- BioProtection, The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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10
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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.
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Shafik K, Umer M, You H, Aboushedida H, Wang Z, Ni D, Xu W. Characterization of a Novel Mitovirus Infecting Melanconiella theae Isolated From Tea Plants. Front Microbiol 2021; 12:757556. [PMID: 34867881 PMCID: PMC8635788 DOI: 10.3389/fmicb.2021.757556] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
A dsRNA segment was identified in the fungus Melanconiella theae isolated from tea plants. The complete dsRNA sequence, determined by random cloning together with RACE protocol, is 2,461 bp in length with an AU-rich content (62.37%) and comprises a single ORF of 2,265-nucleotides encoding an RNA-dependent RNA-polymerase (RdRp, 754 amino acids in size). The terminus sequences can fold into predicted stable stem-loop structures. A BLASTX and phylogenetic analysis revealed the dsRNA genome shows similarities with the RdRp sequences of mitoviruses, with the highest identity of 48% with those of grapevine-associated mitovirus 20 and Colletotrichum fructicola mitovirus 1. Our results reveal a novel member, tentatively named Melanconiella theae mitovirus 1 (MtMV1), belongs to the family Mitoviridae. MtMV1 is capsidless as examined by transmission electron microscope, efficiently transmitted through conidia as 100 conidium-generated colonies were analyzed, and easily eliminated by hyphal tipping method combined with green-leaf tea powder. MtMV1 has a genomic sequence obviously divergent from those of most members in the family Mitoviridae and some unique characteristics unreported in known members. This is the first report of a mycovirus infecting Melanconiella fungi to date.
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Affiliation(s)
- Karim Shafik
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Department of Plant Pathology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Muhammad Umer
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Huafeng You
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hamdy Aboushedida
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Department of Plant Pathology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhenhua Wang
- Technology Center of Wuhan Customs District, Wuhan, China
| | - Dejiang Ni
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Wenxing Xu
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Key Lab of Plant Pathology of Hubei Province, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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