1
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Higuchi A, Tojo M, Mochizuki T. Sensitivity of Globisporangium ultimum to the fungicide metalaxyl is enhanced by the infection with a toti-like mycovirus. Microbiol Res 2024; 285:127742. [PMID: 38723390 DOI: 10.1016/j.micres.2024.127742] [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: 02/23/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 06/15/2024]
Abstract
In recent years, numerous oomycete mycoviruses have been discovered; however, very few studies have focused on their effects on the host oomycete phenotype. In this study, we investigated the impact of toti-like Pythium ultimum RNA virus 2 (PuRV2) infection on the phytopathogenic soil-borne oomycete Globisporangium ultimum, which serves as a model species for Globisporangium and Pythium, specifically the UOP226 isolate in Japan. We generated a PuRV2-free isogenic line through hyphal tip isolation using high-temperature culture and subsequently compared the phenotypic characteristics and gene expression profiles of UOP226 and the PuRV2-free isogenic line. Our findings revealed that the metalaxyl sensitivity of UOP226 was greater than that of the PuRV2-free isogenic line, whereas the mycelial growth rate and colony morphology remained unchanged in the absence of the fungicide. Furthermore, transcriptome analyses using RNA-seq revealed significant downregulation of ABC-type transporter genes, which are involved in fungicide sensitivity, in UOP226. Our results suggest that PuRV2 infection influences the ecology of G. ultimum in agricultural ecosystems where metalaxyl is applied.
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Affiliation(s)
- Aika Higuchi
- Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 599-8531, Japan
| | - Motoaki Tojo
- Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 599-8531, Japan
| | - Tomofumi Mochizuki
- Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 599-8531, Japan; Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Sakai, Osaka 599-8531, Japan.
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2
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Queiroz VF, Tatara JM, Botelho BB, Rodrigues RAL, Almeida GMDF, Abrahao JS. The consequences of viral infection on protists. Commun Biol 2024; 7:306. [PMID: 38462656 PMCID: PMC10925606 DOI: 10.1038/s42003-024-06001-2] [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: 10/28/2023] [Accepted: 02/29/2024] [Indexed: 03/12/2024] Open
Abstract
Protists encompass a vast widely distributed group of organisms, surpassing the diversity observed in metazoans. Their diverse ecological niches and life forms are intriguing characteristics that render them valuable subjects for in-depth cell biology studies. Throughout history, viruses have played a pivotal role in elucidating complex cellular processes, particularly in the context of cellular responses to viral infections. In this comprehensive review, we provide an overview of the cellular alterations that are triggered in specific hosts following different viral infections and explore intricate biological interactions observed in experimental conditions using different host-pathogen groups.
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Affiliation(s)
- Victoria Fulgencio Queiroz
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana Miranda Tatara
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Bruna Barbosa Botelho
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Rodrigo Araújo Lima Rodrigues
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Gabriel Magno de Freitas Almeida
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway.
| | - Jonatas Santos Abrahao
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
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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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Poimala A, Vainio E. Discovery and Identification of Viruses Infecting Oomycetes. Methods Mol Biol 2024; 2732:45-65. [PMID: 38060117 DOI: 10.1007/978-1-0716-3515-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
This chapter describes protocols suitable for the detection and identification of RNA viruses infecting oomycetes (so-called water molds of Kingdom Heterokonta, Stramenopila), focusing on species of Phytophthora and exemplified by P. fragariae. The protocol includes laboratory procedures for oomycete cultivation and total RNA extraction from harvested mycelia, followed by instructions on suitable parameters given for sequencing companies on ribosomal RNA depletion, cDNA library preparation, and total RNA-sequencing (RNA-Seq). We also describe the bioinformatics steps needed for de novo assembly of raw reads into contigs, removal of host-associated contigs, and virus identification by database searches, as well as host validation by RT-PCR. All steps are described using an exemplar RNA-Seq library containing a yet undescribed fusagravirus hosted by a P. fragariae isolate.
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Affiliation(s)
- Anna Poimala
- Natural Resources Institute Finland (Luke), Helsinki, Finland.
| | - Eeva Vainio
- Natural Resources Institute Finland (Luke), Helsinki, Finland
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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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Sabnam N, Hussain A, Saha P. The secret password: Cell death-inducing proteins in filamentous phytopathogens - As versatile tools to develop disease-resistant crops. Microb Pathog 2023; 183:106276. [PMID: 37541554 DOI: 10.1016/j.micpath.2023.106276] [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: 05/05/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/06/2023]
Abstract
Cell death-inducing proteins (CDIPs) are some of the secreted effector proteins manifested by filamentous oomycetes and fungal pathogens to invade the plant tissue and facilitate infection. Along with their involvement in different developmental processes and virulence, CDIPs play a crucial role in plant-pathogen interactions. As the name implies, CDIPs cause necrosis and trigger localised cell death in the infected host tissues by the accumulation of higher concentrations of hydrogen peroxide (H2O2), oxidative burst, accumulation of nitric oxide (NO), and electrolyte leakage. They also stimulate the biosynthesis of defense-related phytohormones such as salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), and ethylene (ET), as well as the expression of pathogenesis-related (PR) genes that are important in disease resistance. Altogether, the interactions result in the hypersensitive response (HR) in the host plant, which might confer systemic acquired resistance (SAR) in some cases against a vast array of related and unrelated pathogens. The CDIPs, due to their capability of inducing host resistance, are thus unique among the array of proteins secreted by filamentous plant pathogens. More interestingly, a few transgenic plant lines have also been developed expressing the CDIPs with added resistance. Thus, CDIPs have opened an interesting hot area of research. The present study critically reviews the current knowledge of major types of CDIPs identified across filamentous phytopathogens and their modes of action in the last couple of years. This review also highlights the recent breakthrough technologies in studying plant-pathogen interactions as well as crop improvement by enhancing disease resistance through CDIPs.
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Affiliation(s)
- Nazmiara Sabnam
- Department of Life Sciences, Presidency University, Kolkata, India.
| | - Afzal Hussain
- Department of Bioinformatics, Maulana Azad National Institute of Technology, Bhopal, India
| | - Pallabi Saha
- Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, 55108, United States; Department of Biotechnology, National Institute of Technology, Durgapur, India
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Sakuta K, Uchida K, Fukuhara T, Komatsu K, Okada R, Moriyama H. Successful full-length genomic cloning and characterization of site-specific nick structures of Phytophthora endornaviruses 2 and 3 in yeast, Saccharomyces cerevisiae. Front Microbiol 2023; 14:1243068. [PMID: 37771702 PMCID: PMC10523305 DOI: 10.3389/fmicb.2023.1243068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/29/2023] [Indexed: 09/30/2023] Open
Abstract
Two endornaviruses, Phytophthora endornavirus 2 (PEV2) and Phytophthora endornavirus 3 (PEV3), have been discovered in pathogens targeting asparagus. In this study, we analyzed the nick structure in the RNA genomes of PEV2 and PEV3 in the host oomycetes. Northern blot hybridization using positive and negative strand-specific RNA probes targeting the 5' and 3' regions of PEV2 and PEV3 RNA genomes revealed approximately 1.0 kilobase (kb) RNA fragments located in the 5' regions of the two genomes. 3' RACE analysis determined that the size of the RNA fragments were 958 nucleotides (nt) for PEV2 and 968 nt for PEV3. We have successfully constructed full-length cDNA clones of the entire RNA genomes of PEV2 and PEV3 using a homologous recombination system in the yeast, Saccharomyces cerevisiae. These full-length cDNA sequences were ligated downstream of a constitutive expression promoter (TDH3) or a galactose-inducing promoter (GAL1) in the shuttle vector to enable the production of the full-length RNA transcripts of PEV2 and PEV3 in yeast cells. Interestingly, a 1.0 kb RNA fragment from the PEV3 positive-strand transcript was also detected with a 5'-region RNA probe, indicating that site-specific cleavage also occurred in yeast cells. Further, when PEV2 or PEV3 mRNA was overexpressed under the GAL1 promoter, yeast cell growth was suppressed. A fusion protein combining EGFP to the N-terminus of the full-length PEV2 ORF or C-terminus of the full-length PEV3 ORF was expressed, and allowed PEV2 and PEV3 ORFs to be successfully visualized in yeast cells. Expression of the fusion protein also revealed presence of heterogeneous bodies in the cells.
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Affiliation(s)
- Kohei Sakuta
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Keiko Uchida
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Toshiyuki Fukuhara
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Ryo Okada
- Horticultural Research Institute, Agricultural Center, Kasama, Ibaraki, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
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8
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Matsiakh I, Menkis A. An Overview of Phytophthora Species on Woody Plants in Sweden and Other Nordic Countries. Microorganisms 2023; 11:1309. [PMID: 37317283 DOI: 10.3390/microorganisms11051309] [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: 04/28/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
The genus Phytophthora, with 326 species in 12 phylogenetic clades currently known, includes many economically important pathogens of woody plants. Different Phytophthora species often possess a hemibiotrophic or necrotrophic lifestyle, have either a broad or narrow host range, can cause a variety of disease symptoms (root rot, damping-off, bleeding stem cankers, or blight of foliage), and occur in different growing environments (nurseries, urban and agricultural areas, or forests). Here, we summarize the available knowledge on the occurrence, host range, symptoms of damage, and aggressiveness of different Phytophthora species associated with woody plants in Nordic countries with a special emphasis on Sweden. We evaluate the potential risks of Phytophthora species to different woody plants in this geographical area and emphasize the increasing threats associated with continued introduction of invasive Phytophthora species.
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Affiliation(s)
- Iryna Matsiakh
- Southern Swedish Forest Research Centre, SLU Forest Damage Centre, Swedish University of Agricultural Sciences, Sundsvägen 3, 23422 Alnarp, Sweden
- Institute of Forestry and Park Gardening, Ukrainian National Forestry University, Pryrodna 19, 79057 Lviv, Ukraine
| | - Audrius Menkis
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, SLU Forest Damage Centre, Swedish University of Agricultural Sciences, P.O. Box 7026, 75007 Uppsala, Sweden
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Raco M, Jung T, Horta Jung M, Chi NM, Botella L, Suzuki N. Sequence and phylogenetic analysis of a novel alphaendornavirus, the first virus described from the oomycete plant pathogen Phytophthora heveae. Arch Virol 2023; 168:158. [PMID: 37166518 PMCID: PMC10175314 DOI: 10.1007/s00705-023-05786-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
Here, we report the discovery and complete genome sequence of a novel virus, designated as "Phytophthora heveae alphaendornavirus 1" (PhAEV1), from a single isolate of the plant pathogenic oomycete Phytophthora heveae (kingdom Stramenipila) isolated from a tropical evergreen lowland rainforest in northern Vietnam. PhAEV1 was detected by both cellulose affinity chromatography of dsRNA and high-throughput sequencing of total RNA, and its presence and sequence were confirmed by RT-PCR and Sanger sequencing. The PhAEV1 genome, 12,820 nucleotides (nt) in length, was predicted to encode a single large polyprotein with the catalytic core domain of viral (superfamily 1) RNA helicase (HEL, amino acid [aa] positions 1,287-1,531), glycosyltransferase (GT, aa positions ca. 2,800-3,125), and RNA-directed RNA polymerase (RdRp, aa positions 3,875-4,112). PhAEV1 is the most similar to Phytophthora cactorum alphaendornavirus 3, sharing 39.4% and 39.1% nt and aa sequence identity, respectively. In addition to the first 5'-terminal AUG codon, three additional in-frame methionine codons were found in close proximity (nt 14-16, 96-98, and 176-178), suggesting potential additional translation initiation sites. Conserved RdRp motifs (A-E) similar to those detected in related endornaviruses were identified in PhAEV1, as well as in several previously described alphaendornaviruses from other Phytophthora species in which these motifs had not been identified previously. Phylogenetic analysis showed that PhAEV1 clusters with members of the genus Alphaendornavirus in the family Endornaviridae and is basal to two other alphaendornaviruses described from another oomycete, Phytophthora cactorum. PhAEV1 is the first virus reported in P. heveae.
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Grants
- CZ.02.1.01/0.0/0.0/15_003/0000453 European Regional Development Fund, project Phytophthora Research Centre
- LDF_VP_2021047 Specific University Research Fund of the Faculty of Forestry and Wood Technology, Mendel University in Brno
- KAKENHI 21H05035 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 21K18222 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16H06436 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16H06429 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
- 16K21723 Grants in Aid for the Scientific Research (S), Research on the Innovative Areas, and Grants in Aid for JSPS, from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
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Affiliation(s)
- Milica Raco
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00.
| | - Thomas Jung
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Marilia Horta Jung
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Nguyen Minh Chi
- Forest Protection Research Centre, Vietnamese Academy of Forest Sciences, Hanoi, 10000, Vietnam
| | - Leticia Botella
- Phytophthora Research Centre, Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic, Zemědělská 3, 613 00
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 7100046, Japan, Chuo 2-20-1
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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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