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Lin Y, Pan G, Qi Y, Wang B, Jin C, Fang W. A novel hypovirulence-associated Hadaka virus 1 (HadV1-LA6) in Fusarium oxysporum f. sp. cubense. mSphere 2024; 9:e0042824. [PMID: 39012104 PMCID: PMC11351034 DOI: 10.1128/msphere.00428-24] [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: 06/12/2024] [Accepted: 06/18/2024] [Indexed: 07/17/2024] Open
Abstract
Fusarium oxysporum f. sp. cubense (Foc) poses a significant threat to banana crops as a lethal fungal pathogen. The global spread of Foc underscores the formidable challenges associated with traditional management methods in combating this pathogen. This study delves into the hypovirulence-associated mycovirus in Foc. From Foc strain LA6, we isolated and characterized a novel member of the Hadakaviridae family, named Hadaka virus 1 strain LA6 (HadV1-LA6). HadV1-LA6 comprises 10 genomic RNA segments, with RNA1 to RNA7 sharing 80.9%-95.0% amino acid sequence identity with known HadV1-7n, while RNA8 to RNA10 display significantly lower identity. HadV1-LA6 demonstrates horizontal transmission capabilities in an all-or-none fashion between different Foc strains via coculturing. Phenotypic comparisons highlight that HadV1-LA6 significantly reduces the growth rates of its host fungus under cell wall stress and oxidative stress conditions. Importantly, HadV1-LA6 attenuates Foc's virulence in detached leaves and banana plants. This study represents the first introduction of a novel hypovirulence-associated Hadaka virus 1 in Foc.IMPORTANCEFusarium wilt of banana (FWB) is a severe fungal disease caused by soil-borne Fusarium oxysporum f. sp. cubense (Foc). Among various strategies, biocontrol emerges as a safe, ecologically friendly, and cost-effective approach to managing FWB. In this study, we focus on exploring the potential of a novel hypovirulent member of hadakavirid, HadV1-LA6. Previous reports suggest that HadV1 shows no apparent effect on the host. However, through phenotypic assessments, we demonstrate that HadV1-LA6 significantly impedes the growth rates of its host fungus under stress conditions. More importantly, HadV1-LA6 exhibits a remarkable capacity to attenuate Foc's virulence in detached leaves and banana plants. Furthermore, HadV1-LA6 could be horizontally transmitted between different Foc strains, presenting a promising resource for revealing the molecular mechanism of the interaction between Hadaka virus 1 and its host.
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Affiliation(s)
- Yinfu Lin
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Guangqun Pan
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
- College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Yanhua Qi
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Bin Wang
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Cheng Jin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wenxia Fang
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
- College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
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Battersby JL, Stevens DA, Coutts RHA, Havlíček V, Hsu JL, Sass G, Kotta-Loizou I. The Expanding Mycovirome of Aspergilli. J Fungi (Basel) 2024; 10:585. [PMID: 39194910 DOI: 10.3390/jof10080585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/08/2024] [Accepted: 08/14/2024] [Indexed: 08/29/2024] Open
Abstract
Mycoviruses are viruses that infect fungi and are widespread across all major fungal taxa, exhibiting great biological diversity. Since their discovery in the 1960s, researchers have observed a myriad of fungal phenotypes altered due to mycoviral infection. In this review, we examine the nuanced world of mycoviruses in the context of the medically and agriculturally important fungal genus, Aspergillus. The advent of RNA sequencing has revealed a previous underestimate of viral prevalence in fungi, in particular linear single-stranded RNA viruses, and here we outline the diverse viral families known to date that contain mycoviruses infecting Aspergillus. Furthermore, we describe these novel mycoviruses, highlighting those with peculiar genome structures, such as a split RNA dependent RNA polymerase gene. Next, we delineate notable mycovirus-mediated phenotypes in Aspergillus, in particular reporting on observations of mycoviruses that affect their fungal host's virulence and explore how this may relate to virus-mediated decreased stress tolerance. Furthermore, mycovirus effects on microbial competition and antifungal resistance are discussed. The factors that influence the manifestation of these phenotypes, such as temperature, fungal life stage, and infection with multiple viruses, among others, are also evaluated. In addition, we attempt to elucidate the molecular mechanisms that underpin these phenotypes, examining how mycoviruses can be targets, triggers, and even suppressors of RNA silencing and how this can affect fungal gene expression and phenotypes. Finally, we highlight the potential therapeutic applications of mycoviruses and how, in an approach analogous to bacteriophage therapy, their ability to produce hypovirulence in Aspergillus might be used to attenuate invasive aspergillosis infections in humans.
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Affiliation(s)
- Josephine L Battersby
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - David A Stevens
- California Institute for Medical Research, San Jose, CA 95128, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Robert H A Coutts
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 00 Prague, Czech Republic
- Department of Analytical Chemistry, Palacky University, 17. Listopadu 2, 779 00 Olomouc, Czech Republic
| | - Joe L Hsu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gabriele Sass
- California Institute for Medical Research, San Jose, CA 95128, USA
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Department of Clinical, Pharmaceutical and Biological Science, University of Hertfordshire, Hatfield AL10 9AB, UK
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3
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Ahmad F, Tomada S, Poonsiri T, Baric S. Molecular genetic variability of Cryphonectria hypovirus 1 associated with Cryphonectria parasitica in South Tyrol (northern Italy). Front Microbiol 2024; 15:1291542. [PMID: 38476955 PMCID: PMC10927965 DOI: 10.3389/fmicb.2024.1291542] [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: 09/09/2023] [Accepted: 01/25/2024] [Indexed: 03/14/2024] Open
Abstract
Cryphonectria hypovirus 1 (CHV-1) has been widely studied and used as a biocontrol agent because of its ability to infect the chestnut blight fungus, Cryphonectria parasitica, and to reduce its virulence. Knowledge about the hypovirus, its presence, and diversity is completely lacking in South Tyrol (northern Italy), which may obstruct biocontrol measures for chestnut blight based on CHV-1. This work aimed to study the occurrence of CHV-1 infecting C. parasitica in South Tyrol and to perform a genetic characterization of the hypovirus. In South Tyrol, CHV-1 was found to occur in 29.2% of the fungal isolates investigated, varying in frequency between different regions and chestnut stands. Twenty-three haplotypes based on partial cDNA (complementary DNA) sequences of open reading frame (ORF)-A and 30 haplotypes based on partial cDNA sequences of ORF-B were identified among 47 and 56 hypovirulent fungal isolates, respectively. Phylogenetic analysis showed that all the haplotypes belonged to the Italian subtype of CHV-1 and that they were closely related to the populations of Italy, Switzerland, Croatia and Slovenia. Evidence of recombination was not found in the sequences and point mutations were the main source of diversity. Overall, this study indicated that the prevalence of CHV-1 in South Tyrol is low compared to many other central and western European populations and determined a need to actively impose biocontrol measures. Using sequence analysis, we identified some variants of interest of CHV-1 that should be studied in detail for their potential use in biocontrol.
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Affiliation(s)
- Farooq Ahmad
- Laboratory for Phytopathology, Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Bolzano, Italy
| | - Selena Tomada
- Laboratory for Phytopathology, Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Bolzano, Italy
| | - Thanalai Poonsiri
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Sanja Baric
- Laboratory for Phytopathology, Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Bolzano, Italy
- Competence Centre for Plant Health, Free University of Bozen-Bolzano, Bolzano, Italy
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Sass G, Martinez M, Kotta-Loizou I, Stevens D. AfuPmV-1-Infected Aspergillus fumigatus Is More Susceptible to Stress Than Virus-Free Fungus. J Fungi (Basel) 2023; 9:750. [PMID: 37504738 PMCID: PMC10381315 DOI: 10.3390/jof9070750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 07/29/2023] Open
Abstract
Infection with Aspergillus fumigatus polymycovirus 1 (AfuPmV-1) affects Aspergillus fumigatus Af293's growth in vitro, iron metabolism, resistance in intermicrobial competition with Pseudomonas aeruginosa, resistance to osmotic stress, and resistance to the chitin synthase inhibitor nikkomycin Z. Here, we show that response to high temperature, Congo Red-induced stress, and hydrogen peroxide are also dependent on the viral infection status of A. fumigatus. AfuPmV-1- infected Af293 was more susceptible than virus-free Af293 to growth inhibition by high temperature, hydrogen peroxide, Congo Red exposure, and nutrient restriction. Increased resistance of virus-free fungus was observed when cultures were started from conidia but, in the case of high temperature and hydrogen peroxide, not when cultures were started from hyphae. This indicates that the virus impairs the stress response during the growth phase of germination of conidia and development into hyphae. In conclusion, our work indicates that AfuPmV-1 infection in A. fumigatus impairs host responses to stress, as shown by exposure to high temperature, oxidative stress such as hydrogen peroxide, and some cell wall stresses, as shown by exposure to Congo Red (in agreement with our previous observations using nikkomycin Z) and nutrient restriction.
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Affiliation(s)
- Gabriele Sass
- California Institute for Medical Research, San Jose, CA 95128, USA
| | - Marife Martinez
- California Institute for Medical Research, San Jose, CA 95128, USA
| | - Ioly Kotta-Loizou
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, South Kensington Campus, London SW72AZ, UK
- Department of Clinical, Pharmaceutical and Biological Science, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield AL109AB, UK
| | - David Stevens
- California Institute for Medical Research, San Jose, CA 95128, USA
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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Popović M, Nuskern L, Peranić K, Vuković R, Katanić Z, Krstin L, Ćurković-Perica M, Leigh DM, Poljak I, Idžojtić M, Rigling D, Ježić M. Physiological variations in hypovirus-infected wild and model long-term laboratory strains of Cryphonectria parasitica. Front Microbiol 2023; 14:1192996. [PMID: 37426020 PMCID: PMC10324583 DOI: 10.3389/fmicb.2023.1192996] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/25/2023] [Indexed: 07/11/2023] Open
Abstract
Introduction Forest ecosystems are highly threatened by the simultaneous effects of climate change and invasive pathogens. Chestnut blight, caused by the invasive phytopathogenic fungus Cryphonectria parasitica, has caused severe damage to European chestnut groves and catastrophic dieback of American chestnut in North America. Within Europe, the impacts of the fungus are widely mitigated through biological control that utilizes the RNA mycovirus: Cryphonectria hypovirus 1 (CHV1). Viral infections, similarly to abiotic factors, can cause oxidative stress in their hosts leading to physiological attrition through stimulating ROS (reactive oxygen species) and NOx production. Methods To fully understand the interactions leading to the biocontrol of chestnut blight, it is vital to determine oxidative stress damage arising during CHV1 infection, especially considering that other abiotic factors, like long-term cultivation of model fungal strains, can also impact oxidative stress. Our study compared CHV1-infected C. parasitica isolates from two Croatian wild populations with CHV1-infected model strains (EP713, Euro7 and CR23) that have experienced long-term laboratory cultivation. Results and Discussion We determined the level of oxidative stress in the samples by measuring stress enzymes' activity and oxidative stress biomarkers. Furthermore, for the wild populations, we studied the activity of fungal laccases, expression of the laccase gene lac1, and a possible effect of CHV1 intra-host diversity on the observed biochemical responses. Relative to the wild isolates, the long-term model strains had lower enzymatic activities of superoxide dismutase (SOD) and glutathione S-transferase (GST), and higher content of malondialdehyde (MDA) and total non-protein thiols. This indicated generally higher oxidative stress, likely arising from their decades-long history of subculturing and freeze-thaw cycles. When comparing the two wild populations, differences between them in stress resilience and levels of oxidative stress were also observed, as evident from the different MDA content. The intra-host genetic diversity of the CHV1 had no discernible effect on the stress levels of the virus-infected fungal cultures. Our research indicated that an important determinant modulating both lac1 expression and laccase enzyme activity is intrinsic to the fungus itself, possibly related to the vc type of the fungus, i.e., vegetative incompatibility genotype.
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Affiliation(s)
- Maja Popović
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Lucija Nuskern
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Karla Peranić
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Rosemary Vuković
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Zorana Katanić
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ljiljana Krstin
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | | | | | - Igor Poljak
- Faculty of Forestry and Wood Technology, University of Zagreb, Zagreb, Croatia
| | - Marilena Idžojtić
- Faculty of Forestry and Wood Technology, University of Zagreb, Zagreb, Croatia
| | - Daniel Rigling
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
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Škorić D, Černi S, Ćurković-Perica M, Ježić M, Krajačić M, Šeruga Musić M. Legacy of Plant Virology in Croatia-From Virus Identification to Molecular Epidemiology, Evolution, Genomics and Beyond. Viruses 2021; 13:2339. [PMID: 34960609 PMCID: PMC8707422 DOI: 10.3390/v13122339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022] Open
Abstract
This paper showcases the development of plant virology in Croatia at the University of Zagreb, Faculty of Science, from its beginning in the 1950s until today, more than 70 years later. The main achievements of the previous and current group members are highlighted according to various research topics and fields. Expectedly, some of those accomplishments remained within the field of plant virology, but others make part of a much-extended research spectrum exploring subviral pathogens, prokaryotic plant pathogens, fungi and their viruses, as well as their interactions within ecosystems. Thus, the legacy of plant virology in Croatia continues to contribute to the state of the art of microbiology far beyond virology. Research problems pertinent for directing the future research endeavors are also proposed in this review.
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Affiliation(s)
- Dijana Škorić
- Department of Biology, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia; (S.Č.); (M.Ć.-P.); (M.J.); (M.K.); (M.Š.M.)
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7
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Nuskern L, Tkalec M, Srezović B, Ježić M, Gačar M, Ćurković-Perica M. Laccase Activity in Fungus Cryphonectria parasitica Is Affected by Growth Conditions and Fungal-Viral Genotypic Interactions. J Fungi (Basel) 2021; 7:958. [PMID: 34829245 PMCID: PMC8620238 DOI: 10.3390/jof7110958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/06/2021] [Accepted: 11/08/2021] [Indexed: 11/16/2022] Open
Abstract
Laccase activity reduction in the chestnut blight fungus Cryphonectria parasitica usually accompanies the hypovirulence caused by the infection of fungus with Cryphonectria hypovirus 1 (CHV1). However, the different methods utilized for assessing this phenomenon has produced varied and often conflicting results. Furthermore, the majority of experimental setups included only one prototypic system, further confounding the results. Considering the diversity of fungal isolates, viral strains, and variability of their effects on the phytopathogenic process observed in nature, our goal was to ascertain if laccase activity variability is affected by (1) different C. parasitica isolates infected with several CHV1 strains, and (2) growth conditions. We have demonstrated that some CHV1 strains, contrary to previous assumptions, increase the activity of C. parasitica laccases. The specific fungal isolates used in the experiments and culture conditions also affected the results. Furthermore, we showed that two commonly used laccase substrates, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 2,4-dimethoxyphenol, cannot be used interchangeably in C. parasitica laccase activity measurements. Our results illustrate the importance of conducting this type of study in experimental systems and culture conditions that resemble natural conditions as much as possible to be able to infer the most relevant conclusions applicable to natural populations.
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Affiliation(s)
- Lucija Nuskern
- Department of Biology, Division of Microbiology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000 Zagreb, Croatia; (L.N.); (B.S.); (M.J.); (M.G.)
| | - Mirta Tkalec
- Department of Biology, Division of Botany, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia;
| | - Bruno Srezović
- Department of Biology, Division of Microbiology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000 Zagreb, Croatia; (L.N.); (B.S.); (M.J.); (M.G.)
| | - Marin Ježić
- Department of Biology, Division of Microbiology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000 Zagreb, Croatia; (L.N.); (B.S.); (M.J.); (M.G.)
| | - Martina Gačar
- Department of Biology, Division of Microbiology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000 Zagreb, Croatia; (L.N.); (B.S.); (M.J.); (M.G.)
| | - Mirna Ćurković-Perica
- Department of Biology, Division of Microbiology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000 Zagreb, Croatia; (L.N.); (B.S.); (M.J.); (M.G.)
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The Physiological and Biochemical Responses of European Chestnut ( Castanea sativa L.) to Blight Fungus ( Cryphonectria parasitica (Murill) Barr). PLANTS 2021; 10:plants10102136. [PMID: 34685944 PMCID: PMC8537955 DOI: 10.3390/plants10102136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/01/2021] [Accepted: 10/06/2021] [Indexed: 12/04/2022]
Abstract
The most important disease of European chestnut (Castanea sativa Mill.) is chestnut blight caused by the fungus Cryphonectria parasitica (Murrill) Barr which induces yield reduction in Europe and North America. This study aimed to investigate the impacts of C. parasitica infection on the physiological and biochemical characteristics of European chestnut at two different growth stages, 3 and 6 weeks after the infection. The amount of photosynthetic pigments (chlorophyll-a, chlorophyll-b, and carotenoids), the relative chlorophyll content, and the photochemical efficiency of the photosystem II (PSII) were measured in the leaves above and below the virulent and hypovirulent C. parasitica infections. The highest values were measured in the control leaves, the lowest values were in the leaves of the upper part of virulent necrosis. Antioxidant enzyme activities such as ascorbate peroxidase (APX), guaiacol peroxidase (POD), and superoxide dismutase (SOD), proline, and malondialdehyde concentrations were also investigated. In each of these measured values, the lowest level was measured in the control leaves, while the highest was in leaves infected with the virulent fungal strain. By measuring all of these stress indicator parameters the responses of chestnut to C. parasitica infection can be monitored and determined. The results of this study showed that the virulent strain caused more pronounced defense responses of chestnut’s defense system. The measured parameter above the infection was more exposed to the blight fungus disease relative to the leaves below the infection.
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Krstin L, Katanić Z, Repar J, Ježić M, Kobaš A, Ćurković-Perica M. Genetic Diversity of Cryphonectria hypovirus 1, a Biocontrol Agent of Chestnut Blight, in Croatia and Slovenia. MICROBIAL ECOLOGY 2020; 79:148-163. [PMID: 31053974 DOI: 10.1007/s00248-019-01377-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Transmissible hypovirulence associated with Cryphonectria hypovirus 1 (CHV1) has been used for biological control of chestnut blight, devastating disease of chestnut caused by the fungus Cryphonectria parasitica. The main aims of this study were to provide molecular characterization of CHV1 from Croatia and Slovenia and to reveal its genetic variability, phylogeny, and diversification of populations. Fifty-one CHV1 haplotypes were detected among 54 partially sequenced CHV1 isolates, all belonging to Italian subtype (I). Diversity was mainly generated by point mutations while evidence of recombination was not found. The level of conservation over analyzed parts of ORF-A proteins p29 and p40 varied, but functional sites were highly conserved. Phylogenetic analysis revealed close relatedness and intermixing of Croatian and Slovenian CHV1 populations. Our CHV1 isolates were also related to Swiss and Bosnian hypoviruses supporting previously suggested course of CHV1 invasion in Europe. Overall, this study indicates that phylogeny of CHV1 subtype I in Europe is complex and characterized with frequent point mutations resulting in many closely related variants of the virus. Possible association between variations within CHV1 ORF-A and growth of the hypovirulent fungal isolates is tested and presented.
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Affiliation(s)
- Ljiljana Krstin
- Department of Biology, Josip Juraj Strossmayer University of Osijek, HR-31000, Osijek, Croatia
| | - Zorana Katanić
- Department of Biology, Josip Juraj Strossmayer University of Osijek, HR-31000, Osijek, Croatia
| | - Jelena Repar
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, HR-10000, Zagreb, Croatia
| | - Ana Kobaš
- Department of Biology, Josip Juraj Strossmayer University of Osijek, HR-31000, Osijek, Croatia
| | - Mirna Ćurković-Perica
- Department of Biology, Faculty of Science, University of Zagreb, HR-10000, Zagreb, Croatia.
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Vuković R, Liber Z, Ježić M, Sotirovski K, Ćurković-Perica M. Link between epigenetic diversity and invasive status of south-eastern European populations of phytopathogenic fungus Cryphonectria parasitica. Environ Microbiol 2019; 21:4521-4536. [PMID: 31314941 DOI: 10.1111/1462-2920.14742] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/14/2022]
Abstract
Epigenetic modifications may play an important role in invasion and adaptation of clonal and invasive populations to different environments. The aim of this study was to analyse epigenetic diversity and structure within and among populations of invasive pathogenic fungus Cryphonectria parasitica from south-eastern Europe, where one haplotype S12 dominates. The highest level of epigenetic diversity was found in haplotype S1, followed by S2, while the lowest level of epigenetic diversity was found in haplotype S12. Similar pattern of epigenetic diversity was detected in the control, genetically diverse Croatian population where S1 haplotype dominates. In four south-eastern European populations, the highest level of epigenetic diversity was observed in the Italian population, the oldest population in the studied area, while the lowest diversity was found in most recently established Bulgarian population. This relationship between epigenetic diversity and population age implies the important role of epigenetic modifications on the process of invasion. Our data suggest that epigenetic differences might affect the success of expansion of certain haplotype into new regions. Understanding the role of epigenetic processes in expansion and (pre)adaptation of fungal plant pathogens, besides fundamental knowledge, can contribute to development of strategies for control of fungal spread and pathogenesis.
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Affiliation(s)
- Rosemary Vuković
- Department of Biology, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Zlatko Liber
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia.,Centre of Excellence for Biodiversity and Molecular Plant Breeding, Zagreb, Croatia
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Kiril Sotirovski
- Faculty of Forestry, Ss. Cyril and Methodius University of Skopje, Skopje, North Macedonia
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Nuskern L, Ježić M, Liber Z, Mlinarec J, Ćurković-Perica M. Cryphonectria hypovirus 1-Induced Epigenetic Changes in Infected Phytopathogenic Fungus Cryphonectria parasitica. MICROBIAL ECOLOGY 2018; 75:790-798. [PMID: 28865007 DOI: 10.1007/s00248-017-1064-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 08/24/2017] [Indexed: 06/07/2023]
Abstract
Biotic stress caused by virus infections induces epigenetic changes in infected plants and animals, but this is the first report on methylation pattern changes in a fungus after mycovirus infection. As a model pathosystem for mycovirus-host interactions, we used Cryphonectria hypovirus 1 (CHV1) and its host fungus Cryphonectria parasitica, in which deregulation of methylation cycle enzymes upon virus infection was observed previously. Six CHV1 strains of different subtypes were transferred into three different C. parasitica isolates in order to assess the effect of different CHV1 strains and/or subtypes on global cytosine methylation level in infected fungus, using methylation-sensitive amplification polymorphism (MSAP). Infection with CHV1 affected the methylation pattern of the C. parasitica genome; it increased the number and diversity of methylated, hemi-methylated, and total MSAP markers found in infected fungal isolates compared to virus-free controls. The increase in methylation levels correlated well with the CHV1-induced reduction of fungal growth in vitro, indicating that C. parasitica genome methylation upon CHV1 infection, rather than being the defensive mechanism of the fungus, is more likely to be the virulence determinant of the virus. Furthermore, the severity of CHV1 effect on methylation levels of infected C. parasitica isolates depended mostly on individual CHV1 strains and on the combination of host and virus genomes, rather than on the virus subtype. These novel findings broaden our knowledge about CHV1 strains which could potentially be used in human-aided biocontrol of chestnut blight, a disease caused by C. parasitica in chestnut forest ecosystems and orchards.
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Affiliation(s)
- Lucija Nuskern
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000, Zagreb, Croatia
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000, Zagreb, Croatia
| | - Zlatko Liber
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000, Zagreb, Croatia
| | - Jelena Mlinarec
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000, Zagreb, Croatia
| | - Mirna Ćurković-Perica
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000, Zagreb, Croatia.
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Mlinarec J, Nuskern L, Ježić M, Rigling D, Ćurković-Perica M. Molecular evolution and invasion pattern of Cryphonectria hypovirus 1 in Europe: Mutation rate, and selection pressure differ between genome domains. Virology 2018; 514:156-164. [PMID: 29179038 DOI: 10.1016/j.virol.2017.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/13/2017] [Accepted: 11/14/2017] [Indexed: 01/08/2023]
Abstract
Understanding virus evolution is a fundamental goal of virology, evolutionary biology, and disease epidemiology. We provide a detailed analysis of evolution and origin of Cryphonectria hypovirus 1 (CHV1) populations in Europe, based on the complete genome sequence of all European subtypes. Phylogenetic analyses divided European strains into two closely related clades. Strains of the subtype I belong to the first, while strains of the subtypes F1, D and E belong to the second clade suggesting that the subtypes F1, D and E are more closely related than previously thought. Strains of the subtype F2 appeared to be recombinant; subtypes F1/D/E contributed a larger fraction of sequence while subtype I contributed a smaller fraction. The p29 was the most variable domain, while the replication-associated large ORF B protein was the most conserved domain within the CHV1. Low sequence similarity, predominant negative selection and frequent recombination characterise the evolution of CHV1.
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Affiliation(s)
- Jelena Mlinarec
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000 Zagreb, Croatia
| | - Lucija Nuskern
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000 Zagreb, Croatia
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000 Zagreb, Croatia
| | - Daniel Rigling
- WSL Swiss Federal Research Institute, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - Mirna Ćurković-Perica
- Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, HR-10 000 Zagreb, Croatia.
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