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Kokkoris V, Banchini C, Paré L, Abdellatif L, Séguin S, Hubbard K, Findlay W, Dalpé Y, Dettman J, Corradi N, Stefani F. Rhizophagus irregularis, the model fungus in arbuscular mycorrhiza research, forms dimorphic spores. THE NEW PHYTOLOGIST 2024; 242:1771-1784. [PMID: 37434339 DOI: 10.1111/nph.19121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/10/2023] [Indexed: 07/13/2023]
Abstract
Rhizophagus irregularis is the model species for arbuscular mycorrhizal fungi (AMF) research and the most widely propagated species for commercial plant biostimulants. Using asymbiotic and symbiotic cultivation systems initiated from single spores, advanced microscopy, Sanger sequencing of the glomalin gene, and PacBio sequencing of the partial 45S rRNA gene, we show that four strains of R. irregularis produce spores of two distinct morphotypes, one corresponding to the morphotype described in the R. irregularis protologue and the other having the phenotype of R. fasciculatus. The two spore morphs are easily distinguished by spore colour, thickness of the subtending hypha, thickness of the second wall layer, lamination of the innermost layer, and the dextrinoid reaction of the two outer spore wall layers to Melzer's reagent. The glomalin gene of the two spore morphs is identical and that of the PacBio sequences of the partial SSU-ITS-LSU region (2780 bp) obtained from single spores of the R. cf fasciculatus morphotype has a median pairwise similarity of 99.8% (SD = 0.005%) to the rDNA ribotypes of R. irregularis DAOM 197198. Based on these results, we conclude that the model AMF species R. irregularis is dimorphic, which has caused taxonomic confusion in culture collections and possibly in AMF research.
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Affiliation(s)
- Vasilis Kokkoris
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
- Amsterdam Institute for Life and Environment (A-LIFE), Faculty of Science, Section Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands
| | - Claudia Banchini
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Louis Paré
- Université Laval, Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), 1030 Ave de la Médecine, Québec, QC, G1V 0A6, Canada
| | - Lobna Abdellatif
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Sylvie Séguin
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Keith Hubbard
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Wendy Findlay
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Yolande Dalpé
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Jeremy Dettman
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Franck Stefani
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A 0C6, Canada
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2
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Shi R, Mo X, Chen Z, Chen W, Yu S, Liu H, Li Y, Dai L, Li Y. Molecular characterization of a novel mycovirus from binucleate Rhizoctonia AG-A strain A46. Arch Virol 2024; 169:31. [PMID: 38233611 DOI: 10.1007/s00705-024-05963-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/20/2023] [Indexed: 01/19/2024]
Abstract
The complete genome sequence of a positive-sense single-stranded RNA (+ ssRNA) virus, Rhizoctonia beny-like virus 1 (RBLV1), isolated from binucleate Rhizoctonia AG-A strain A46, was determined. The RBLV1 genome is 10,280 nt in length and contains a short stretch of adenines at the 3' terminus. It contains a single open reading frame (ORF) encoding a 376.30-kDa protein with viral helicase and RNA-dependent RNA polymerase (RdRp) motifs. The encoded protein exhibited the highest sequence similarity to Rhizoctonia cerealis beny-like virus 0928-1 (RcBeLV 0928-1, 45.25%), with a sequence coverage of 63%. Phylogenetic analysis based on ORF protein sequences revealed that RBLV1 is a novel unclassified mycovirus.
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Affiliation(s)
- Rui Shi
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
- Yunnan Academy of Tobacco Agricultural Sciences, Kunming, Yunnan, 650021, China
| | - Xiaohan Mo
- Yunnan Academy of Tobacco Agricultural Sciences, Kunming, Yunnan, 650021, China
| | - Zebin Chen
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - Wurong Chen
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - Shuhui Yu
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - He Liu
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - Yuchuan Li
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - Lili Dai
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China
| | - Yanqiong Li
- College of Agriculture and Life Sciences, Kunming University, Kunming, Yunnan, 650214, China.
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3
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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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4
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Lanfranco L, Bonfante P. Lessons from arbuscular mycorrhizal fungal genomes. Curr Opin Microbiol 2023; 75:102357. [PMID: 37419003 DOI: 10.1016/j.mib.2023.102357] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/15/2023] [Accepted: 06/15/2023] [Indexed: 07/09/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) have accompanied the majority of land plants since their evolution in the Devonian period with a symbiotic alliance centered on nutrient exchanges. The exploration of AMF genomes is providing clues to explain major questions about their biology, evolution, and ecology. The dynamics of nuclei across the fungal life cycle, the abundance of transposable elements, and the epigenome landscape are emerging as sources of intraspecific variability, which can be especially important in organisms with no or rare sexual reproduction such as AMF. These features have been hypothesized to support AMF adaptability to a wide host range and to environmental changes. New insights on plant-fungus communication and on the iconic function of phosphate transport were also recently obtained that overall contribute to a better understanding of this ancient and fascinating symbiosis.
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Affiliation(s)
- Luisa Lanfranco
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy.
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy
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Ezawa T, Silvestri A, Maruyama H, Tawaraya K, Suzuki M, Duan Y, Turina M, Lanfranco L. Structurally distinct mitoviruses: are they an ancestral lineage of the Mitoviridae exclusive to arbuscular mycorrhizal fungi (Glomeromycotina)? mBio 2023; 14:e0024023. [PMID: 37162347 PMCID: PMC10470734 DOI: 10.1128/mbio.00240-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/10/2023] [Indexed: 05/11/2023] Open
Abstract
Mitoviruses in the family Mitoviridae are the mitochondria-replicating "naked RNA viruses" with genomes encoding only the replicase RNA-dependent RNA polymerase (RdRp) and prevalent across fungi, plants, and invertebrates. Arbuscular mycorrhizal fungi in the subphylum Glomeromycotina are obligate plant symbionts that deliver water and nutrients to the host. We discovered distinct mitoviruses in glomeromycotinian fungi, namely "large duamitovirus," encoding unusually large RdRp with a unique N-terminal motif that is endogenized in some host genomes. More than 400 viral sequences similar to the large duamitoviruses are present in metatranscriptome databases. They are globally distributed in soil ecosystems, consistent with the cosmopolitan distribution of glomeromycotinian fungi, and formed the most basal clade of the Mitoviridae in phylogenetic analysis. Given that glomeromycotinian fungi are the only confirmed hosts of these viruses, we propose the hypothesis that large duamitoviruses are the most ancestral lineage of the Mitoviridae that have been maintained exclusively in glomeromycotinian fungi.
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Affiliation(s)
- Tatsuhiro Ezawa
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Alessandro Silvestri
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Hayato Maruyama
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | | | - Mei Suzuki
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Yu Duan
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Massimo Turina
- Institute for Sustainable Plant Protection–CNR Torino, Torino, Italy
| | - Luisa Lanfranco
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
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Kelliher JM, Robinson AJ, Longley R, Johnson LYD, Hanson BT, Morales DP, Cailleau G, Junier P, Bonito G, Chain PSG. The endohyphal microbiome: current progress and challenges for scaling down integrative multi-omic microbiome research. MICROBIOME 2023; 11:192. [PMID: 37626434 PMCID: PMC10463477 DOI: 10.1186/s40168-023-01634-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 07/29/2023] [Indexed: 08/27/2023]
Abstract
As microbiome research has progressed, it has become clear that most, if not all, eukaryotic organisms are hosts to microbiomes composed of prokaryotes, other eukaryotes, and viruses. Fungi have only recently been considered holobionts with their own microbiomes, as filamentous fungi have been found to harbor bacteria (including cyanobacteria), mycoviruses, other fungi, and whole algal cells within their hyphae. Constituents of this complex endohyphal microbiome have been interrogated using multi-omic approaches. However, a lack of tools, techniques, and standardization for integrative multi-omics for small-scale microbiomes (e.g., intracellular microbiomes) has limited progress towards investigating and understanding the total diversity of the endohyphal microbiome and its functional impacts on fungal hosts. Understanding microbiome impacts on fungal hosts will advance explorations of how "microbiomes within microbiomes" affect broader microbial community dynamics and ecological functions. Progress to date as well as ongoing challenges of performing integrative multi-omics on the endohyphal microbiome is discussed herein. Addressing the challenges associated with the sample extraction, sample preparation, multi-omic data generation, and multi-omic data analysis and integration will help advance current knowledge of the endohyphal microbiome and provide a road map for shrinking microbiome investigations to smaller scales. Video Abstract.
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Affiliation(s)
| | | | - Reid Longley
- Los Alamos National Laboratory, Los Alamos, NM, USA
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7
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Liu H, Zhang Y, Liu Y, Xiao J, Huang Z, Li Y, Li H, Li P. Virome analysis of an ectomycorrhizal fungus Suillus luteus revealing potential evolutionary implications. Front Cell Infect Microbiol 2023; 13:1229859. [PMID: 37662006 PMCID: PMC10470027 DOI: 10.3389/fcimb.2023.1229859] [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: 05/27/2023] [Accepted: 07/31/2023] [Indexed: 09/05/2023] Open
Abstract
Suillus luteus is a widespread edible ectomycorrhizal fungus that holds significant importance in both ecological and economic value. Mycoviruses are ubiquitous infectious agents hosted in different fungi, with some known to exert beneficial or detrimental effects on their hosts. However, mycoviruses hosted in ectomycorrhizal fungi remain poorly studied. To address this gap in knowledge, we employed next-generation sequencing (NGS) to investigate the virome of S. luteus. Using BLASTp analysis and phylogenetic tree construction, we identified 33 mycovirus species, with over half of them belonging to the phylum Lenarviricota, and 29 of these viruses were novel. These mycoviruses were further grouped into 11 lineages, with the discovery of a new negative-sense single-stranded RNA viral family in the order Bunyavirales. In addition, our findings suggest the occurrence of cross-species transmission (CST) between the fungus and ticks, shedding light on potential evolutionary events that have shaped the viral community in different hosts. This study is not only the first study to characterize mycoviruses in S. luteus but highlights the enormous diversity of mycoviruses and their implications for virus evolution.
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Affiliation(s)
| | | | | | | | | | | | - Huaping Li
- Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Pengfei Li
- Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
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8
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Hough B, Steenkamp E, Wingfield B, Read D. Fungal Viruses Unveiled: A Comprehensive Review of Mycoviruses. Viruses 2023; 15:1202. [PMID: 37243288 PMCID: PMC10224137 DOI: 10.3390/v15051202] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/07/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Mycoviruses (viruses of fungi) are ubiquitous throughout the fungal kingdom and are currently classified into 23 viral families and the genus botybirnavirus by the International Committee on the Taxonomy of Viruses (ICTV). The primary focus of mycoviral research has been on mycoviruses that infect plant pathogenic fungi, due to the ability of some to reduce the virulence of their host and thus act as potential biocontrol against these fungi. However, mycoviruses lack extracellular transmission mechanisms and rely on intercellular transmission through the hyphal anastomosis, which impedes successful transmission between different fungal strains. This review provides a comprehensive overview of mycoviruses, including their origins, host range, taxonomic classification into families, effects on their fungal counterparts, and the techniques employed in their discovery. The application of mycoviruses as biocontrol agents of plant pathogenic fungi is also discussed.
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Affiliation(s)
| | | | - Brenda Wingfield
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria 0002, South Africa; (B.H.); (E.S.); (D.R.)
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9
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Putative Mitoviruses without In-Frame UGA(W) Codons: Evolutionary Implications. Viruses 2023; 15:v15020340. [PMID: 36851553 PMCID: PMC9965874 DOI: 10.3390/v15020340] [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: 10/25/2022] [Revised: 01/22/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023] Open
Abstract
Mitoviruses are small vertically transmitted RNA viruses found in fungi, plants and animals. Taxonomically, a total of 105 species and 4 genera have been formally recognized by ICTV, and recently, 18 new putative species have been included in a new proposed genus. Transcriptomic and metatranscriptomic studies are a major source of countless new virus-like sequences that are continually being added to open databases and these may be good sources for identifying new putative mitoviruses. The search for mitovirus-like sequences in the NCBI databases resulted in the discovery of more than one hundred new putative mitoviruses, with important implications for taxonomy and also for the evolutionary scenario. Here, we propose the inclusion of four new putative members to the genus Kvaramitovirus, and the existence of a new large basally divergent lineage composed of 144 members that lack internal UGA codons (subfamily "Arkeomitovirinae"), a feature not shared by the vast majority of mitoviruses. Finally, a taxonomic categorization proposal and a detailed description of the evolutionary history of mitoviruses were carried out. This in silico study supports the hypothesis of the existence of a basally divergent lineage that could have had an impact on the early evolutionary history of mitoviruses.
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10
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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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11
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Jacquat AG, Ulla SB, Debat HJ, Muñoz-Adalia EJ, Theumer MG, Pedrajas MDG, Dambolena JS. An in silico analysis revealed a novel evolutionary lineage of putative mitoviruses. Environ Microbiol 2022; 24:6463-6475. [PMID: 36085554 DOI: 10.1111/1462-2920.16202] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/07/2022] [Indexed: 01/12/2023]
Abstract
Mitoviruses (family Mitoviridae) are small capsid-less RNA viruses that replicate in the mitochondria of fungi and plants. However, to date, the only authentic animal mitovirus infecting an insect was identified as Lutzomyia longipalpis mitovirus 1 (LulMV1). Public databases of transcriptomic studies from several animals may be a good source for identifying the often missed mitoviruses. Consequently, a search of mitovirus-like transcripts at the NCBI transcriptome shotgun assembly (TSA) library, and a search for the mitoviruses previously recorded at the NCBI non-redundant (nr) protein sequences library, were performed in order to identify new mitovirus-like sequences associated with animals. In total, 10 new putative mitoviruses were identified in the TSA database and 8 putative mitoviruses in the nr protein database. To our knowledge, these results represent the first evidence of putative mitoviruses associated with poriferan, cnidarians, echinoderms, crustaceans, myriapods and arachnids. According to different phylogenetic inferences using the maximum likelihood method, these 18 putative mitoviruses form a robust monophyletic lineage with LulMV1, the only known animal-infecting mitovirus. These findings based on in silico procedures provide strong evidence for the existence of a clade of putative mitoviruses associated with animals, which has been provisionally named 'kvinmitovirus'.
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Affiliation(s)
- Andrés Gustavo Jacquat
- Universidad Nacional de Córdoba (UNC), Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN), Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal, IMBIV, Córdoba, Argentina
| | - Sofía Belén Ulla
- Universidad Nacional de Córdoba (UNC), Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN), Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal, IMBIV, Córdoba, Argentina
| | - Humberto Julio Debat
- Instituto Nacional de Tecnología Agropecuaria (INTA), Centro de Investigaciones Agropecuarias (CIAP), Instituto de Patología Vegetal (IPAVE), Córdoba, Argentina
| | - Emigdio Jordán Muñoz-Adalia
- Forest Sciences Center of Catalonia, CTFC, Solsona, Spain.,Department of Crop and Forest Science, University of Lleida, Lleida, Spain
| | - Martín Gustavo Theumer
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba (UNC), Facultad de Ciencias Químicas (FCQ), Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Córdoba, Argentina
| | - María Dolores García Pedrajas
- Universidad de Málaga - Consejo Superior de Investigaciones Científicas (UMA-CSIC), Instituto de Hortofruticultura Subtropical y Mediterránea (IHSM), "La Mayora", Algarrobo-Costa (Málaga), Spain
| | - José Sebastián Dambolena
- Universidad Nacional de Córdoba (UNC), Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN), Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal, IMBIV, Córdoba, Argentina
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12
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Sun A, Sun Y, Luo L, Zhao L, Li C, Yang G, Dong W. Molecular characterization of a novel mitovirus from Rhizoctonia solani AG-4 HGIII strain XMC-IF. Arch Virol 2022; 167:2821-2825. [PMID: 36261748 DOI: 10.1007/s00705-022-05599-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/30/2022] [Indexed: 12/14/2022]
Abstract
The nucleotide sequence of a viral double-stranded RNA (dsRNA) from Rhizoctonia solani AG-4 HGIII strain XMC-IF (designated as "Rhizoctonia solani mitovirus 106", RsMV-106) was determined. The complete sequence was 2794 bp in length with a 57.50% A + U content and contained a large open reading frame (ORF) when the fungal mitochondrial genetic code was used. The ORF potentially encodes a 95.76-kDa protein containing a conserved domain of an RNA-dependent RNA polymerase (RdRp). BLASTp analysis revealed that the RdRp domain of RsMV-106 shared 47.52-73.24% sequence identity with those of viruses of the genus Duamitovirus and was most similar (73.24% identity) to that of Alternaria alternata mitovirus 1 (AaMV1). Phylogenetic analysis showed that RsMV-106 is a novel member of the genus Duamitovirus, family Mitoviridae. This is the first report of the full genome sequence of a mitovirus associated with R. solani AG-4 HGIII.
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Affiliation(s)
- Aili Sun
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China
| | - Yang Sun
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China
| | - Li Luo
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China
| | - Lianjing Zhao
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China
| | - Chengyun Li
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China
| | - Genhua Yang
- State Key Laboratory for Protection and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, 650201, Kunming, Yunnan, China.
| | - Wenhan Dong
- Technology Department, Yunnan Agricultural University, 650201, Kunming, Yunnan, China.
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13
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Kondo H, Botella L, Suzuki N. Mycovirus Diversity and Evolution Revealed/Inferred from Recent Studies. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:307-336. [PMID: 35609970 DOI: 10.1146/annurev-phyto-021621-122122] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
High-throughput virome analyses with various fungi, from cultured or uncultured sources, have led to the discovery of diverse viruses with unique genome structures and even neo-lifestyles. Examples in the former category include splipalmiviruses and ambiviruses. Splipalmiviruses, related to yeast narnaviruses, have multiple positive-sense (+) single-stranded (ss) RNA genomic segments that separately encode the RNA-dependent RNA polymerase motifs, the hallmark of RNA viruses (members of the kingdom Orthornavirae). Ambiviruses appear to have an undivided ssRNA genome of 3∼5 kb with two large open reading frames (ORFs) separated by intergenic regions. Another narna-like virus group has two fully overlapping ORFs on both strands of a genomic segment that span more than 90% of the genome size. New virus lifestyles exhibited by mycoviruses include the yado-kari/yado-nushi nature characterized by the partnership between the (+)ssRNA yadokarivirus and an unrelated dsRNA virus (donor of the capsid for the former) and the hadaka nature of capsidless 10-11 segmented (+)ssRNA accessible by RNase in infected mycelial homogenates. Furthermore, dsRNA polymycoviruses with phylogenetic affinity to (+)ssRNA animal caliciviruses have been shown to be infectious as dsRNA-protein complexes or deproteinized naked dsRNA. Many previous phylogenetic gaps have been filled by recently discovered fungal and other viruses, which haveprovided interesting evolutionary insights. Phylogenetic analyses and the discovery of natural and experimental cross-kingdom infections suggest that horizontal virus transfer may have occurred and continue to occur between fungi and other kingdoms.
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Affiliation(s)
- Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan;
| | - Leticia Botella
- Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University, Brno, Czech Republic
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan;
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14
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Bonfante P. Microbe Profile: Gigaspora margarita, a multifaceted arbuscular mycorrhizal fungus. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35737726 DOI: 10.1099/mic.0.001202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Gigaspora margarita is a cosmopolitan arbuscular mycorrhizal fungus, which - as an obligate symbiont- requires being associated to a host plant to accomplish its life cycle. It is characterized by huge white spores, the development of extraradical auxiliary cells, and the lack of intraradical vesicles. Its genome is dominated by transposable elements and is one of the largest fungal genomes so far sequenced. G. margarita has the peculiar feature to host taxonomically different endobacteria in its cytoplasm. The development of a cured line has allowed us to demonstrate how the endobacteria have a positive impact on the fungal physiology and -with a cascade effect- on the mycorrhizal plant.
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Affiliation(s)
- Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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15
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Complexity and local specificity of the virome associated with tospovirus-transmitting thrips species. J Virol 2021; 95:e0059721. [PMID: 34232724 PMCID: PMC8513489 DOI: 10.1128/jvi.00597-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Frankliniella occidentalis (western flower thrips=WFT) and Thrips tabaci (onion thrips=OT) are insect species that greatly impact horticultural crops through direct damage and their efficient vectoring of tomato spotted wilt virus and iris yellow spot virus. In this study we collected thrips of these species from 12 field populations in various regions in Italy. We also included one field population of Neohydatothrips variabilis (soybean thrips=ST) from the U.S.A. Total RNAseq from high-throughput sequencing (HTS) was used to assemble the virome and then we assigned putative viral contigs to each thrips sample by qRT-PCR. Excluding plant and fungal viruses, we were able to identify 61 viral segments, corresponding to 41 viruses: 14 were assigned to WFT, 17 to OT, one from ST and 9 viruses could not be assigned to any species based on our stringent criteria. All these viruses are putative representative of new species (with only the exception of a sobemo-like virus that is 100% identical to a virus recently characterized in ST) and some belong to new higher-ranking taxa. These additions to the viral phylogeny suggest previously undescribed evolutionary niches. Most of the Baltimore's classes of RNA viruses were present (positive- and minus- strand and dsRNA viruses), but only one DNA virus was identified in our collection. Repeated sampling in a subset of locations in 2019 and 2020 and further virus characterization in a subset of four thrips populations maintained in laboratory allowed us to provide evidence of a locally persistent thrips core virome that characterizes each population. IMPORTANCE Harnessing the insect microbiome can result in new approaches to contain their populations or the damage they cause vectoring viruses of medical, veterinary, or agricultural importance. Persistent insect viruses are a neglected component of their microbiota. Here for the first time, we characterize the virome associated with the two model systems for tospovirus-transmitting thrips species, of utmost importance for the direct and indirect damage they cause to a number of different crops. The thrips virome here characterized includes several novel viruses, that in some cases reveal previously undescribed clades. More importantly, some of the viruses we describe are part of a core virome that is specific and consistently present in distinct geographical locations monitored over the years, hinting at a possible mutualistic symbiotic relationship with their host.
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16
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Espino-Vázquez AN, Bermúdez-Barrientos JR, Cabrera-Rangel JF, Córdova-López G, Cardoso-Martínez F, Martínez-Vázquez A, Camarena-Pozos DA, Mondo SJ, Pawlowska TE, Abreu-Goodger C, Partida-Martínez LP. Narnaviruses: novel players in fungal-bacterial symbioses. ISME JOURNAL 2020; 14:1743-1754. [PMID: 32269378 DOI: 10.1038/s41396-020-0638-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 03/11/2020] [Accepted: 03/17/2020] [Indexed: 12/31/2022]
Abstract
Rhizopus microsporus is an early-diverging fungal species with importance in ecology, agriculture, food production, and public health. Pathogenic strains of R. microsporus harbor an intracellular bacterial symbiont, Mycetohabitans (formerly named Burkholderia). This vertically transmitted bacterial symbiont is responsible for the production of toxins crucial to the pathogenicity of Rhizopus and remarkably also for fungal reproduction. Here we show that R. microsporus can live not only in symbiosis with bacteria but also with two viral members of the genus Narnavirus. Our experiments revealed that both viruses replicated similarly in the growth conditions we tested. Viral copies were affected by the developmental stage of the fungus, the substrate, and the presence or absence of Mycetohabitans. Absolute quantification of narnaviruses in isolated asexual sporangiospores and sexual zygospores indicates their vertical transmission. By curing R. microsporus of its viral and bacterial symbionts and reinfecting bacteria to reestablish symbiosis, we demonstrate that these viruses affect fungal biology. Narnaviruses decrease asexual reproduction, but together with Mycetohabitans, are required for sexual reproductive success. This fungal-bacterial-viral system represents an outstanding model to investigate three-way microbial symbioses and their evolution.
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Affiliation(s)
- Astrid N Espino-Vázquez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - J Roberto Bermúdez-Barrientos
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico.,Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - J Francisco Cabrera-Rangel
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - Gonzalo Córdova-López
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico.,Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - Faviola Cardoso-Martínez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - Azul Martínez-Vázquez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - David A Camarena-Pozos
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - Stephen J Mondo
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA.,Bioagricultural Science and Pest Management Department, Colorado State University, Fort Collins, CO, 80521, USA
| | - Teresa E Pawlowska
- School of Integrative Plant Science, Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Cei Abreu-Goodger
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico
| | - Laila P Partida-Martínez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados, Irapuato, 36824, Mexico.
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17
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Silvestri A, Turina M, Fiorilli V, Miozzi L, Venice F, Bonfante P, Lanfranco L. Different Genetic Sources Contribute to the Small RNA Population in the Arbuscular Mycorrhizal Fungus Gigaspora margarita. Front Microbiol 2020; 11:395. [PMID: 32231650 PMCID: PMC7082362 DOI: 10.3389/fmicb.2020.00395] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/26/2020] [Indexed: 01/01/2023] Open
Abstract
RNA interference (RNAi) is a key regulatory pathway of gene expression in almost all eukaryotes. This mechanism relies on short non-coding RNA molecules (sRNAs) to recognize in a sequence-specific manner DNA or RNA targets leading to transcriptional or post-transcriptional gene silencing. To date, the fundamental role of sRNAs in the regulation of development, stress responses, defense against viruses and mobile elements, and cross-kingdom interactions has been extensively studied in a number of biological systems. However, the knowledge of the “RNAi world” in arbuscular mycorrhizal fungi (AMF) is still limited. AMF are obligate mutualistic endosymbionts of plants, able to provide several benefits to their partners, from improved mineral nutrition to stress tolerance. Here we described the RNAi-related genes of the AMF Gigaspora margarita and characterized, through sRNA sequencing, its complex small RNAome, considering the possible genetic sources and targets of the sRNAs. G. margarita indeed is a mosaic of different genomes since it hosts endobacteria, RNA viruses, and non-integrated DNA fragments corresponding to mitovirus sequences. Our findings show that G. margarita is equipped with a complete set of RNAi-related genes characterized by the expansion of the Argonaute-like (AGO-like) gene family that seems a common trait of AMF. With regards to sRNAs, we detected populations of sRNA reads mapping to nuclear, mitochondrial, and viral genomes that share similar features (25-nt long and 5′-end uracil read enrichments), and that clearly differ from sRNAs of endobacterial origin. Furthermore, the annotation of nuclear loci producing sRNAs suggests the occurrence of different sRNA-generating processes. In silico analyses indicate that the most abundant G. margarita sRNAs, including those of viral origin, could target transcripts in the host plant, through a hypothetical cross-kingdom RNAi.
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Affiliation(s)
- Alessandro Silvestri
- Department of Life Sciences and Systems Biology, School of Nature Sciences, University of Turin, Turin, Italy
| | - Massimo Turina
- Institute for Sustainable Plant Protection, Italian National Research Council, Turin, Italy
| | - Valentina Fiorilli
- Department of Life Sciences and Systems Biology, School of Nature Sciences, University of Turin, Turin, Italy
| | - Laura Miozzi
- Institute for Sustainable Plant Protection, Italian National Research Council, Turin, Italy
| | - Francesco Venice
- Department of Life Sciences and Systems Biology, School of Nature Sciences, University of Turin, Turin, Italy
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, School of Nature Sciences, University of Turin, Turin, Italy
| | - Luisa Lanfranco
- Department of Life Sciences and Systems Biology, School of Nature Sciences, University of Turin, Turin, Italy
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18
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Viruses Infecting the Plant Pathogenic Fungus Rhizoctonia solani. Viruses 2019; 11:v11121113. [PMID: 31801308 PMCID: PMC6950361 DOI: 10.3390/v11121113] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/18/2019] [Accepted: 11/26/2019] [Indexed: 12/15/2022] Open
Abstract
The cosmopolitan fungus Rhizoctonia solani has a wide host range and is the causal agent of numerous crop diseases, leading to significant economic losses. To date, no cultivars showing complete resistance to R. solani have been identified and it is imperative to develop a strategy to control the spread of the disease. Fungal viruses, or mycoviruses, are widespread in all major groups of fungi and next-generation sequencing (NGS) is currently the most efficient approach for their identification. An increasing number of novel mycoviruses are being reported, including double-stranded (ds) RNA, circular single-stranded (ss) DNA, negative sense (−)ssRNA, and positive sense (+)ssRNA viruses. The majority of mycovirus infections are cryptic with no obvious symptoms on the hosts; however, some mycoviruses may alter fungal host pathogenicity resulting in hypervirulence or hypovirulence and are therefore potential biological control agents that could be used to combat fungal diseases. R. solani harbors a range of dsRNA and ssRNA viruses, either belonging to established families, such as Endornaviridae, Tymoviridae, Partitiviridae, and Narnaviridae, or unclassified, and some of them have been associated with hypervirulence or hypovirulence. Here we discuss in depth the molecular features of known viruses infecting R. solani and their potential as biological control agents.
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19
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Venice F, Ghignone S, Salvioli di Fossalunga A, Amselem J, Novero M, Xianan X, Sędzielewska Toro K, Morin E, Lipzen A, Grigoriev IV, Henrissat B, Martin FM, Bonfante P. At the nexus of three kingdoms: the genome of the mycorrhizal fungus Gigaspora margarita provides insights into plant, endobacterial and fungal interactions. Environ Microbiol 2019; 22:122-141. [PMID: 31621176 DOI: 10.1111/1462-2920.14827] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 01/04/2023]
Abstract
As members of the plant microbiota, arbuscular mycorrhizal fungi (AMF, Glomeromycotina) symbiotically colonize plant roots. AMF also possess their own microbiota, hosting some uncultivable endobacteria. Ongoing research has revealed the genetics underlying plant responses to colonization by AMF, but the fungal side of the relationship remains in the dark. Here, we sequenced the genome of Gigaspora margarita, a member of the Gigasporaceae in an early diverging group of the Glomeromycotina. In contrast to other AMF, G. margarita may host distinct endobacterial populations and possesses the largest fungal genome so far annotated (773.104 Mbp), with more than 64% transposable elements. Other unique traits of the G. margarita genome include the expansion of genes for inorganic phosphate metabolism, the presence of genes for production of secondary metabolites and a considerable number of potential horizontal gene transfer events. The sequencing of G. margarita genome reveals the importance of its immune system, shedding light on the evolutionary pathways that allowed early diverging fungi to interact with both plants and bacteria.
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Affiliation(s)
- Francesco Venice
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Stefano Ghignone
- Institute for Sustainable Plant Protection-CNR, Turin Unit, Turin, Italy
| | | | | | - Mara Novero
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Xie Xianan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory of Innovation and Utilization of Forest Plant Germplasm in Guangdong Province, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Kinga Sędzielewska Toro
- Genetics, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Emmanuelle Morin
- Institut National de la Recherche Agronomique (INRA), Laboratory of Excellence Advanced Research on the Biology of Tree and Forest Ecosystems (ARBRE), UMR, 1136, Champenoux, France
| | - Anna Lipzen
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Igor V Grigoriev
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, 13288, France.,Institut National de la Recherche Agronomique, USC1408 Architecture et Fonction des Macromolécules Biologiques, Marseille, F-13288, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Francis M Martin
- Institut National de la Recherche Agronomique (INRA), Laboratory of Excellence Advanced Research on the Biology of Tree and Forest Ecosystems (ARBRE), UMR, 1136, Champenoux, France
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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20
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Nerva L, Forgia M, Ciuffo M, Chitarra W, Chiapello M, Vallino M, Varese GC, Turina M. The mycovirome of a fungal collection from the sea cucumber Holothuria polii. Virus Res 2019; 273:197737. [PMID: 31479695 DOI: 10.1016/j.virusres.2019.197737] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/26/2019] [Accepted: 08/30/2019] [Indexed: 01/11/2023]
Abstract
Holothuria polii is a marine animal with an important ecological and economic impact. In the present study we analysed the presence of mycoviruses associated to fungi that were isolated from different H. polii tissues. Among the 48 fungal isolates analysed we identified 10 viruses in 8 strains belonging to 7 fungal species. Five out of nine viruses have a dsRNA genome: three of them belong to the Partitiviridae family, one belongs to a still undefined clade of bipartite viruses and the last one belongs to the Chrysoviridae family. We also identified two viruses belonging to a recently proposed new mycovirus taxon named polymycovirus. Two viruses belong to the positive single stranded RNA clade: one falls into the new Botourmiaviridae family, specifically in the Magoulivirus genus, and the other one falls into a still undefined clade phylogenetically related to tombusviruses. Finally, we also identified a virus with a negative stranded RNA genome showing similarity to a group of viruses recently proposed as a new family of mycoviruses in the order Bunyavirales. A bioinformatics approach comparing two datasets of contigs containing two closely related mycobunyaviruses allowed us to identify putative nucleocapsids (Nc) and non-structural (Ns) associated proteins. The GenBank/eMBL/DDBJ accession numbers of the sequences reported in this paper are: PRJNA432529, MG913290, MG913291, MG887747, MG887748, MG887749, MG887750, MG887751, MG887752, MG887753, MG887754, MG887755, MG887756, MG887757, MG887758, MG887759, MG887760, MG887761, MG887762, MG887763, MG887764, MG887765, MG887766, MG887767, MH271211, MN163273, MN163274.
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Affiliation(s)
- L Nerva
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy; Research Centre for Viticulture and Enology, CREA, Via XXVIII Aprile 26, 31015 Conegliano, Italy
| | - M Forgia
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy; Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Torino, Italy
| | - M Ciuffo
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - W Chitarra
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy; Research Centre for Viticulture and Enology, CREA, Via XXVIII Aprile 26, 31015 Conegliano, Italy
| | - M Chiapello
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - M Vallino
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - G C Varese
- Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Torino, Italy
| | - M Turina
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy.
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21
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Sutela S, Poimala A, Vainio EJ. Viruses of fungi and oomycetes in the soil environment. FEMS Microbiol Ecol 2019; 95:5542194. [DOI: 10.1093/femsec/fiz119] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022] Open
Abstract
ABSTRACTSoils support a myriad of organisms hosting highly diverse viromes. In this minireview, we focus on viruses hosted by true fungi and oomycetes (members of Stamenopila, Chromalveolata) inhabiting bulk soil, rhizosphere and litter layer, and representing different ecological guilds, including fungal saprotrophs, mycorrhizal fungi, mutualistic endophytes and pathogens. Viruses infecting fungi and oomycetes are characterized by persistent intracellular nonlytic lifestyles and transmission via spores and/or hyphal contacts. Almost all fungal and oomycete viruses have genomes composed of single-stranded or double-stranded RNA, and recent studies have revealed numerous novel viruses representing yet unclassified family-level groups. Depending on the virus–host combination, infections can be asymptomatic, beneficial or detrimental to the host. Thus, mycovirus infections may contribute to the multiplex interactions of hosts, therefore likely affecting the dynamics of fungal communities required for the functioning of soil ecosystems. However, the effects of fungal and oomycete viruses on soil ecological processes are still mostly unknown. Interestingly, new metagenomics data suggest an extensive level of horizontal virus transfer between plants, fungi and insects.
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Affiliation(s)
- Suvi Sutela
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Anna Poimala
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Eeva J Vainio
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
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22
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Picarelli MASC, Forgia M, Rivas EB, Nerva L, Chiapello M, Turina M, Colariccio A. Extreme Diversity of Mycoviruses Present in Isolates of Rhizoctonia solani AG2-2 LP From Zoysia japonica From Brazil. Front Cell Infect Microbiol 2019; 9:244. [PMID: 31355150 PMCID: PMC6640214 DOI: 10.3389/fcimb.2019.00244] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/21/2019] [Indexed: 11/16/2022] Open
Abstract
Zoysia japonica, in Brazil, is commonly infected by Rhizoctonia solani (R. solani) in humid and cool weather conditions. Eight isolates of R. solani, previously identified as belonging to the AG2-2 LP anastomosis group, isolated from samples from large path symptoms, were collected from three counties in São Paulo state (Brazil) and investigated for the presence of mycoviruses. After detection of double-strand RNA (dsRNA) in all samples, RNA_Seq analysis of ribosomal RNA-depleted total RNA from in vitro cultivated mycelia was performed. Forty-seven partial or complete viral unique RNA dependent-RNA polymerase (RdRp) sequences were obtained with a high prevalence of positive sense ssRNA viruses. Sequences were sufficiently different from the first match in BLAST searches suggesting that they all qualify as possible new viral species, except for one sequence showing an almost complete match with Rhizoctonia solani dsRNA virus 2, an alphapartitivirus. Surprisingly four large contigs of putative viral RNA could not be assigned to any existing clade of viruses present in the databases, but no DNA was detected corresponding to these fragments confirming their viral replicative nature. This is the first report on the occurrence of mycoviruses in R. solani AG2-2 LP in South America.
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Affiliation(s)
| | - Marco Forgia
- Department of Life Science and System Biology, University of Turin, Turin, Italy.,Institute for Sustainable Plant Protection, CNR, Turin, Italy
| | - Eliana B Rivas
- Phytopathological Diagnostic Laboratory, Instituto Biológico, São Paulo, Brazil
| | - Luca Nerva
- Institute for Sustainable Plant Protection, CNR, Turin, Italy.,Council for Agricultural Research and Economics-Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
| | - Marco Chiapello
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
| | - Massimo Turina
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
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23
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Nerva L, Turina M, Zanzotto A, Gardiman M, Gaiotti F, Gambino G, Chitarra W. Isolation, molecular characterization and virome analysis of culturable wood fungal endophytes in esca symptomatic and asymptomatic grapevine plants. Environ Microbiol 2019; 21:2886-2904. [DOI: 10.1111/1462-2920.14651] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Luca Nerva
- Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology CREA‐VE Via XXVIII Aprile 26, 31015 Conegliano (TV) Italy
- Institute for Sustainable Plant Protection CNR, Strada delle Cacce 73, 10135 Torino Italy
| | - Massimo Turina
- Institute for Sustainable Plant Protection CNR, Strada delle Cacce 73, 10135 Torino Italy
| | - Alessandro Zanzotto
- Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology CREA‐VE Via XXVIII Aprile 26, 31015 Conegliano (TV) Italy
| | - Massimo Gardiman
- Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology CREA‐VE Via XXVIII Aprile 26, 31015 Conegliano (TV) Italy
| | - Federica Gaiotti
- Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology CREA‐VE Via XXVIII Aprile 26, 31015 Conegliano (TV) Italy
| | - Giorgio Gambino
- Institute for Sustainable Plant Protection CNR, Strada delle Cacce 73, 10135 Torino Italy
| | - Walter Chitarra
- Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology CREA‐VE Via XXVIII Aprile 26, 31015 Conegliano (TV) Italy
- Institute for Sustainable Plant Protection CNR, Strada delle Cacce 73, 10135 Torino Italy
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Miozzi L, Vaira AM, Catoni M, Fiorilli V, Accotto GP, Lanfranco L. Arbuscular Mycorrhizal Symbiosis: Plant Friend or Foe in the Fight Against Viruses? Front Microbiol 2019; 10:1238. [PMID: 31231333 PMCID: PMC6558290 DOI: 10.3389/fmicb.2019.01238] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/17/2019] [Indexed: 11/13/2022] Open
Abstract
Plant roots establish interactions with several beneficial soil microorganisms including arbuscular mycorrhizal fungi (AMF). In addition to promoting plant nutrition and growth, AMF colonization can prime systemic plant defense and enhance tolerance to a wide range of environmental stresses and below-ground pathogens. A protective effect of the AMF against above-ground pathogens has also been described in different plant species, but it seems to largely rely on the type of attacker. Viruses are obligate biotrophic pathogens able to infect a large number of plant species, causing massive losses in crop yield worldwide. Despite their economic importance, information on the effect of the AM symbiosis on viral infection is limited and not conclusive. However, several experimental evidences, obtained under controlled conditions, show that AMF colonization may enhance viral infection, affecting susceptibility, symptomatology and viral replication, possibly related to the improved nutritional status and to the delayed induction of pathogenesis-related proteins in the mycorrhizal plants. In this review, we give an overview of the impact of the AMF colonization on plant infection by pathogenic viruses and summarize the current knowledge of the underlying mechanisms. For the cases where AMF colonization increases the susceptibility of plants to viruses, the term "mycorrhiza-induced susceptibility" (MIS) is proposed.
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Affiliation(s)
- Laura Miozzi
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin, Italy
| | - Anna Maria Vaira
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin, Italy
| | - Marco Catoni
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Valentina Fiorilli
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Gian Paolo Accotto
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin, Italy
| | - Luisa Lanfranco
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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Nibert ML, Debat HJ, Manny AR, Grigoriev IV, De Fine Licht HH. Mitovirus and Mitochondrial Coding Sequences from Basal Fungus Entomophthora muscae. Viruses 2019; 11:E351. [PMID: 30999558 PMCID: PMC6520771 DOI: 10.3390/v11040351] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/11/2019] [Accepted: 04/15/2019] [Indexed: 02/07/2023] Open
Abstract
Fungi constituting the Entomophthora muscae species complex (members of subphylum Entomophthoromycotina, phylum Zoopagamycota) commonly kill their insect hosts and manipulate host behaviors in the process. In this study, we made use of public transcriptome data to identify and characterize eight new species of mitoviruses associated with several different E. muscae isolates. Mitoviruses are simple RNA viruses that replicate in host mitochondria and are frequently found in more phylogenetically apical fungi (members of subphylum Glomeromyoctina, phylum Mucoromycota, phylum Basidiomycota and phylum Ascomycota) as well as in plants. E. muscae is the first fungus from phylum Zoopagomycota, and thereby the most phylogenetically basal fungus, found to harbor mitoviruses to date. Multiple UGA (Trp) codons are found not only in each of the new mitovirus sequences from E. muscae but also in mitochondrial core-gene coding sequences newly assembled from E. muscae transcriptome data, suggesting that UGA (Trp) is not a rarely used codon in the mitochondria of this fungus. The presence of mitoviruses in these basal fungi has possible implications for the evolution of these viruses.
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Affiliation(s)
- Max L Nibert
- Department of Microbiology and Program in Virology, Harvard Medical School, Boston, MA 02115, USA.
| | - Humberto J Debat
- Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-CIAP-INTA), Córdoba X5020ICA, Argentina.
| | - Austin R Manny
- Department of Microbiology and Program in Virology, Harvard Medical School, Boston, MA 02115, USA.
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Henrik H De Fine Licht
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark.
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Yang M, Zhai L, Xiao F, Guo Y, Fu M, Hong N, Wang G. Characterization of a novel victorivirus isolated from the phytopathogenic fungus Botryosphaeria dothidea. Arch Virol 2019; 164:1609-1617. [DOI: 10.1007/s00705-019-04234-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 02/21/2019] [Indexed: 02/02/2023]
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Nerva L, Vigani G, Di Silvestre D, Ciuffo M, Forgia M, Chitarra W, Turina M. Biological and Molecular Characterization of Chenopodium quinoa Mitovirus 1 Reveals a Distinct Small RNA Response Compared to Those of Cytoplasmic RNA Viruses. J Virol 2019; 93:e01998-18. [PMID: 30651361 PMCID: PMC6430534 DOI: 10.1128/jvi.01998-18] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 01/08/2019] [Indexed: 02/07/2023] Open
Abstract
Indirect evidence of mitochondrial viruses in plants comes from discovery of genomic fragments integrated into the nuclear and mitochondrial DNA of a number of plant species. Here, we report the existence of replicating mitochondrial virus in plants: from transcriptome sequencing (RNA-seq) data of infected Chenopodium quinoa, a plant species commonly used as a test plant in virus host range experiments, among other virus contigs, we could assemble a 2.7-kb contig that had highest similarity to mitoviruses found in plant genomes. Northern blot analyses confirmed the existence of plus- and minus-strand RNA corresponding to the mitovirus genome. No DNA corresponding to the genomic RNA was detected, excluding the endogenization of such virus. We have tested a number of C. quinoa accessions, and the virus was present in a number of commercial varieties but absent from a large collection of Bolivian and Peruvian accessions. The virus could not be transmitted mechanically or by grafting, but it is transmitted vertically through seeds at a 100% rate. Small RNA analysis of a C. quinoa line carrying the mitovirus and infected by alfalfa mosaic virus showed that the typical antiviral silencing response active against cytoplasmic viruses (21- to 22-nucleotide [nt] vsRNA peaks) is not active against CqMV1, since in this specific case the longest accumulating vsRNA length is 16 nt, which is the same as that corresponding to RNA from mitochondrial genes. This is evidence of a distinct viral RNA degradation mechanism active inside mitochondria that also may have an antiviral effect.IMPORTANCE This paper reports the first biological characterization of a bona fide plant mitovirus in an important crop, Chenopodium quinoa, providing data supporting that mitoviruses have the typical features of cryptic (persistent) plant viruses. We, for the first time, demonstrate that plant mitoviruses are associated with mitochondria in plants. In contrast to fungal mitoviruses, plant mitoviruses are not substantially affected by the antiviral silencing pathway, and the most abundant mitovirus small RNA length is 16 nt.
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Affiliation(s)
- L Nerva
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
- Council for Agricultural Research and Economics-Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
| | - G Vigani
- Plant Physiology Unit, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - D Di Silvestre
- Institute for Biomedical Technology, CNR, Segrate, Milan, Italy
| | - M Ciuffo
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
| | - M Forgia
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - W Chitarra
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
- Council for Agricultural Research and Economics-Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
| | - M Turina
- Institute for Sustainable Plant Protection, CNR, Turin, Italy
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28
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Deja-Sikora E, Mercy L, Baum C, Hrynkiewicz K. The Contribution of Endomycorrhiza to the Performance of Potato Virus Y-Infected Solanaceous Plants: Disease Alleviation or Exacerbation? Front Microbiol 2019; 10:516. [PMID: 30984121 PMCID: PMC6449694 DOI: 10.3389/fmicb.2019.00516] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/28/2019] [Indexed: 11/13/2022] Open
Abstract
Solanaceae, comprising meaningful crops (as potato, tomato, pepper, eggplant, and tobacco), can benefit from a symbiosis with arbuscular mycorrhizal fungi (AMF), which improve plant fitness and support plant defense against pathogens. Currently, those crops are likely the most impacted by Potato virus Y (PVY). Unfortunately, the effects of AM symbiosis on the severity of disease induced by PVY in solanaceous crops remain uncertain, partly because the interplay between AMF and PVY is poorly characterized. To shed some light on this issue, available studies on interactions in tripartite association between the host plant, its fungal colonizer, and viral pathogen were analyzed and discussed. Although the best-documented PVY transmission pathway is aphid-dependent, PVY infections are also observed in the absence of insect vector. We hypothesize the existence of an additional pathway for virus transmission involving AMF, in which the common mycorrhizal network (CMN) may act as a potential bridge. Therefore, we reviewed (1) the significance of AM colonization for the course of disease, (2) the potential of AMF networks to act as vectors for PVY, and (3) the consequences for crop breeding and production of AM biofertilizers.
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Affiliation(s)
- Edyta Deja-Sikora
- Department of Microbiology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Torun, Poland
| | | | - Christel Baum
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
| | - Katarzyna Hrynkiewicz
- Department of Microbiology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Torun, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Torun, Poland
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29
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Investigation of Host Range of and Host Defense against a Mitochondrially Replicating Mitovirus. J Virol 2019; 93:JVI.01503-18. [PMID: 30626664 DOI: 10.1128/jvi.01503-18] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/18/2018] [Indexed: 01/19/2023] Open
Abstract
Mitoviruses (genus Mitovirus, family Narnaviridae) are mitochondrially replicating viruses that have the simplest positive-sense RNA genomes of 2.2 to 4.4 kb with a single open reading frame (ORF) encoding an RNA-dependent RNA polymerase. Cryphonectria parasitica mitovirus 1 (CpMV1) from U.S. strain NB631 of the chestnut blight fungus, Cryphonectria parasitica, was the first virus identified as a mitochondrially replicating virus. Despite subsequent discovery of many other mitoviruses from diverse fungi, no great advances in understanding mitovirus biology have emerged, partly because of the lack of inoculation methods. Here we developed a protoplast fusion-based protocol for horizontal transmission of CpMV1 that entailed fusion of recipient and donor protoplasts, hyphal anastomosis, and single-conidium isolation. This method allowed expansion of the host range to many other C. parasitica strains. Species within and outside the family Cryphonectriaceae, Cryphonectria radicalis and Valsa ceratosperma, also supported the replication of CpMV1 at a level comparable to that in the natural host. No stable maintenance of CpMV1 was observed in Helminthosporium victoriae PCR-based haplotyping of virus-infected fungal strains confirmed the recipient mitochondrial genetic background. Phenotypic comparison between CpMV1-free and -infected isogenic strains revealed no overt effects of the virus. Taking advantage of the infectivity to the standard strain C. parasitica EP155, accumulation levels were compared among antiviral RNA silencing-proficient and -deficient strains in the EP155 background. Comparable accumulation levels were observed among these strains, suggesting the avoidance of antiviral RNA silencing by CpMV1, which is consistent with its mitochondrial replication. Collectively, the results of study provide a foundation to further explore the biology of mitoviruses.IMPORTANCE Capsidless mitoviruses, which are ubiquitously detected in filamentous fungi, have the simplest RNA genomes of 2.2 to 4.4 kb, encoding only RNA-dependent RNA polymerase. Despite their simple genomes, detailed biological characterization of mitoviruses has been hampered by their mitochondrial location within the cell, posing challenges to their experimental introduction and study. Here we developed a protoplast fusion-based protocol for horizontal transfer of the prototype mitovirus, Cryphonectria parasitica mitovirus 1 (CpMV1), which was isolated from strain NB631 of the chestnut blight fungus (Cryphonectria parasitica), a model filamentous fungus for studying virus-host interactions. The host range of CpMV1 has been expanded to many different strains of C. parasitica and different fungal species within and outside the Cryphonectriaceae. Comparison of CpMV1 accumulation among various RNA silencing-deficient and -competent strains showed clearly that the virus was unaffected by RNA silencing. This study provides a solid foundation for further exploration of mitovirus-host interactions.
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30
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Neupane A, Feng C, Feng J, Kafle A, Bücking H, Lee Marzano SY. Metatranscriptomic Analysis and In Silico Approach Identified Mycoviruses in the Arbuscular Mycorrhizal Fungus Rhizophagus spp. Viruses 2018; 10:E707. [PMID: 30545059 PMCID: PMC6316171 DOI: 10.3390/v10120707] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 12/06/2018] [Accepted: 12/07/2018] [Indexed: 12/27/2022] Open
Abstract
Arbuscular mycorrhizal fungi (AMF), including Rhizophagus spp., can play important roles in nutrient cycling of the rhizosphere. However, the effect of virus infection on AMF's role in nutrient cycling cannot be determined without first knowing the diversity of the mycoviruses in AMF. Therefore, in this study, we sequenced the R. irregularis isolate-09 due to its previously demonstrated high efficiency in increasing the N/P uptake of the plant. We identified one novel mitovirus contig of 3685 bp, further confirmed by reverse transcription-PCR. Also, publicly available Rhizophagus spp. RNA-Seq data were analyzed to recover five partial virus sequences from family Narnaviridae, among which four were from R. diaphanum MUCL-43196 and one was from R. irregularis strain-C2 that was similar to members of the Mitovirus genus. These contigs coded genomes larger than the regular mitoviruses infecting pathogenic fungi and can be translated by either a mitochondrial translation code or a cytoplasmic translation code, which was also reported in previously found mitoviruses infecting mycorrhizae. The five newly identified virus sequences are comprised of functionally conserved RdRp motifs and formed two separate subclades with mitoviruses infecting Gigasporamargarita and Rhizophagusclarus, further supporting virus-host co-evolution theory. This study expands our understanding of virus diversity. Even though AMF is notably hard to investigate due to its biotrophic nature, this study demonstrates the utility of whole root metatranscriptome.
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Affiliation(s)
- Achal Neupane
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
| | - Chenchen Feng
- Department of Agronomy, Horticulture, and Plant Sciences, South Dakota State University, Brookings, SD 57007, USA.
| | - Jiuhuan Feng
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
- Department of Agronomy, Horticulture, and Plant Sciences, South Dakota State University, Brookings, SD 57007, USA.
| | - Arjun Kafle
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
| | - Heike Bücking
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
| | - Shin-Yi Lee Marzano
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
- Department of Agronomy, Horticulture, and Plant Sciences, South Dakota State University, Brookings, SD 57007, USA.
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31
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Lanfranco L, Fiorilli V, Gutjahr C. Partner communication and role of nutrients in the arbuscular mycorrhizal symbiosis. THE NEW PHYTOLOGIST 2018; 220:1031-1046. [PMID: 29806959 DOI: 10.1111/nph.15230] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/11/2018] [Indexed: 05/20/2023]
Abstract
Contents Summary 1031 I. Introduction 1031 II. Interkingdom communication enabling symbiosis 1032 III. Nutritional and regulatory roles for key metabolites in the AM symbiosis 1035 IV. The plant-fungus genotype combination determines the outcome of the symbiosis 1039 V. Perspectives 1039 Acknowledgements 1041 References 1041 SUMMARY: The evolutionary and ecological success of the arbuscular mycorrhizal (AM) symbiosis relies on an efficient and multifactorial communication system for partner recognition, and on a fine-tuned and reciprocal metabolic regulation of each symbiont to reach an optimal functional integration. Besides strigolactones, N-acetylglucosamine-derivatives released by the plant were recently suggested to trigger fungal reprogramming at the pre-contact stage. Remarkably, N-acetylglucosamine-based diffusible molecules also are symbiotic signals produced by AM fungi (AMF) and clues on the mechanisms of their perception by the plant are emerging. AMF genomes and transcriptomes contain a battery of putative effector genes that may have conserved and AMF- or host plant-specific functions. Nutrient exchange is the key feature of AM symbiosis. A mechanism of phosphate transport inside fungal hyphae has been suggested, and first insights into the regulatory mechanisms of root colonization in accordance with nutrient transfer and status were obtained. The recent discovery of the dependency of AMF on fatty acid transfer from the host has offered a convincing explanation for their obligate biotrophism. Novel studies highlighted the importance of plant and fungal genotypes for the outcome of the symbiosis. These findings open new perspectives for fundamental research and application of AMF in agriculture.
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Affiliation(s)
- Luisa Lanfranco
- Department of Life Sciences and Systems Biology, University of Torino, Viale P.A. Mattioli 25, 10125, Torino, Italy
| | - Valentina Fiorilli
- Department of Life Sciences and Systems Biology, University of Torino, Viale P.A. Mattioli 25, 10125, Torino, Italy
| | - Caroline Gutjahr
- Plant Genetics, School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Emil Ramann Str. 4, D-85354, Freising, Germany
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