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Characterization of Host-Specific Genes from Pine- and Grass-Associated Species of the Fusarium fujikuroi Species Complex. Pathogens 2022; 11:pathogens11080858. [PMID: 36014979 PMCID: PMC9415769 DOI: 10.3390/pathogens11080858] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
The Fusarium fujikuroi species complex (FFSC) includes socioeconomically important pathogens that cause disease for numerous crops and synthesize a variety of secondary metabolites that can contaminate feedstocks and food. Here, we used comparative genomics to elucidate processes underlying the ability of pine-associated and grass-associated FFSC species to colonize tissues of their respective plant hosts. We characterized the identity, possible functions, evolutionary origins, and chromosomal positions of the host-range-associated genes encoded by the two groups of fungi. The 72 and 47 genes identified as unique to the respective genome groups were potentially involved in diverse processes, ranging from transcription, regulation, and substrate transport through to virulence/pathogenicity. Most genes arose early during the evolution of Fusarium/FFSC and were only subsequently retained in some lineages, while some had origins outside Fusarium. Although differences in the densities of these genes were especially noticeable on the conditionally dispensable chromosome of F. temperatum (representing the grass-associates) and F. circinatum (representing the pine-associates), the host-range-associated genes tended to be located towards the subtelomeric regions of chromosomes. Taken together, these results demonstrate that multiple mechanisms drive the emergence of genes in the grass- and pine-associated FFSC taxa examined. It also highlighted the diversity of the molecular processes potentially underlying niche-specificity in these and other Fusarium species.
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Hill R, Buggs RJ, Vu DT, Gaya E. Lifestyle Transitions in Fusarioid Fungi are Frequent and Lack Clear Genomic Signatures. Mol Biol Evol 2022; 39:msac085. [PMID: 35484861 PMCID: PMC9051438 DOI: 10.1093/molbev/msac085] [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] [Indexed: 11/24/2022] Open
Abstract
The fungal genus Fusarium (Ascomycota) includes well-known plant pathogens that are implicated in diseases worldwide, and many of which have been genome sequenced. The genus also encompasses other diverse lifestyles, including species found ubiquitously as asymptomatic-plant inhabitants (endophytes). Here, we produced structurally annotated genome assemblies for five endophytic Fusarium strains, including the first whole-genome data for Fusarium chuoi. Phylogenomic reconstruction of Fusarium and closely related genera revealed multiple and frequent lifestyle transitions, the major exception being a monophyletic clade of mutualist insect symbionts. Differential codon usage bias and increased codon optimisation separated Fusarium sensu stricto from allied genera. We performed computational prediction of candidate secreted effector proteins (CSEPs) and carbohydrate-active enzymes (CAZymes)-both likely to be involved in the host-fungal interaction-and sought evidence that their frequencies could predict lifestyle. However, phylogenetic distance described gene variance better than lifestyle did. There was no significant difference in CSEP, CAZyme, or gene repertoires between phytopathogenic and endophytic strains, although we did find some evidence that gene copy number variation may be contributing to pathogenicity. Large numbers of accessory CSEPs (i.e., present in more than one taxon but not all) and a comparatively low number of strain-specific CSEPs suggested there is a limited specialisation among plant associated Fusarium species. We also found half of the core genes to be under positive selection and identified specific CSEPs and CAZymes predicted to be positively selected on certain lineages. Our results depict fusarioid fungi as prolific generalists and highlight the difficulty in predicting pathogenic potential in the group.
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Affiliation(s)
- Rowena Hill
- Comparative Fungal Biology, Royal Botanic Gardens Kew, Jodrell Laboratory, Richmond, United Kingdom
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Richard J.A. Buggs
- Comparative Fungal Biology, Royal Botanic Gardens Kew, Jodrell Laboratory, Richmond, United Kingdom
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Dang Toan Vu
- Research Planning and International Cooperation Department, Plant Resources Center, Hanoi, Vietnam
| | - Ester Gaya
- Comparative Fungal Biology, Royal Botanic Gardens Kew, Jodrell Laboratory, Richmond, United Kingdom
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Carter JW, Gordon TR. Tolerance of 2-Benzoxazolinone and Interactions with Grass and Pine Hosts in a Population of Fusarium circinatum. PLANT DISEASE 2021; 105:3880-3888. [PMID: 34232056 DOI: 10.1094/pdis-01-21-0203-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fusarium circinatum, the causal agent of pitch canker in pines and a cryptic endophyte of grasses, was examined for heritable variation in tolerance of the grass defense compound 2-benzoxazolinone (BOA). A diverse population of F. circinatum progeny was assayed for growth rate on potato dextrose agar amended with BOA. Matings were conducted to allow for selection of progeny with lower and higher tolerance of BOA. The results confirmed heritable variation in BOA tolerance in F. circinatum. A subset of differentially tolerant progeny was used for inoculations of growth chamber-grown Zea mays and greenhouse-grown Pinus radiata. No differences were detected in the rate of infection or extent of colonization of Z. mays inoculated with F. circinatum progeny differing in tolerance of BOA. Pitch canker symptoms in inoculated P. radiata trees showed that high BOA-tolerating isolates induced significantly longer lesion lengths than those induced by low BOA-tolerating isolates. Results from this study were consistent with the proposition that F. circinatum evolved from grass-colonizing ancestors and that pathogenicity to pine is a relatively recent evolutionary innovation.
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Affiliation(s)
- Jason W Carter
- Department of Plant Pathology, University of California, Davis, CA 95616
| | - Thomas R Gordon
- Department of Plant Pathology, University of California, Davis, CA 95616
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Global Geographic Distribution and Host Range of Fusarium circinatum, the Causal Agent of Pine Pitch Canker. FORESTS 2020. [DOI: 10.3390/f11070724] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen.
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Potential Interactions between Invasive Fusarium circinatum and Other Pine Pathogens in Europe. FORESTS 2019. [DOI: 10.3390/f11010007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pines are major components of native forests and plantations in Europe, where they have both economic significance and an important ecological role. Diseases of pines are mainly caused by fungal and oomycete pathogens, and can significantly reduce the survival, vigor, and yield of both individual trees and entire stands or plantations. Pine pitch canker (PPC), caused by Fusarium circinatum (Nirenberg and O’Donnell), is among the most devastating pine diseases in the world, and is an example of an emergent invasive disease in Europe. The effects of microbial interactions on plant health, as well as the possible roles plant microbiomes may have in disease expression, have been the focus of several recent studies. Here, we describe the possible effects of co-infection with pathogenic fungi and oomycetes with F. circinatum on the health of pine seedlings and mature plants, in an attempt to expand our understanding of the role that biotic interactions may play in the future of PPC disease in European nurseries and forests. The available information on pine pathogens that are able to co-occur with F. circinatum in Europe is here reviewed and interpreted to theoretically predict the effects of such co-occurrences on pine survival, growth, and yield. Beside the awareness that F. circinatum may co-occurr on pines with other pathogens, an additional outcome from this review is an updating of the literature, including the so-called grey literature, to document the geographical distribution of the relevant pathogens and to facilitate differential diagnoses, particularly in nurseries, where some of them may cause symptoms similar to those induced by F. circinatum. An early and accurate diagnosis of F. circinatum, a pathogen that has been recently introduced and that is currently regulated in Europe, is essential to prevent its introduction and spread in plantings and forests.
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Visser EA, Wegrzyn JL, Steenkamp ET, Myburg AA, Naidoo S. Dual RNA-Seq Analysis of the Pine- Fusarium circinatum Interaction in Resistant ( Pinus tecunumanii) and Susceptible ( Pinus patula) Hosts. Microorganisms 2019; 7:E315. [PMID: 31487786 PMCID: PMC6780516 DOI: 10.3390/microorganisms7090315] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/15/2019] [Accepted: 08/20/2019] [Indexed: 12/15/2022] Open
Abstract
Fusarium circinatum poses a serious threat to many pine species in both commercial and natural pine forests. Knowledge regarding the molecular basis of pine-F. circinatum host-pathogen interactions could assist efforts to produce more resistant planting stock. This study aimed to identify molecular responses underlying resistance against F. circinatum. A dual RNA-seq approach was used to investigate host and pathogen expression in F. circinatum challenged Pinus tecunumanii (resistant) and Pinus patula (susceptible), at three- and seven-days post inoculation. RNA-seq reads were mapped to combined host-pathogen references for both pine species to identify differentially expressed genes (DEGs). F. circinatum genes expressed during infection showed decreased ergosterol biosynthesis in P. tecunumanii relative to P. patula. For P. tecunumanii, enriched gene ontologies and DEGs indicated roles for auxin-, ethylene-, jasmonate- and salicylate-mediated phytohormone signalling. Correspondingly, key phytohormone signaling components were down-regulated in P. patula. Key F. circinatum ergosterol biosynthesis genes were expressed at lower levels during infection of the resistant relative to the susceptible host. This study further suggests that coordination of phytohormone signaling is required for F. circinatum resistance in P. tecunumanii, while a comparatively delayed response and impaired phytohormone signaling contributes to susceptibility in P. patula.
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Affiliation(s)
- Erik A Visser
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Centre for Bioinformatics and Computational Biology, University of Pretoria, Private Bag X20, Pretoria 0028, South Africa
| | - Jill L Wegrzyn
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Centre for Bioinformatics and Computational Biology, University of Pretoria, Private Bag X20, Pretoria 0028, South Africa
| | - Alexander A Myburg
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Centre for Bioinformatics and Computational Biology, University of Pretoria, Private Bag X20, Pretoria 0028, South Africa
| | - Sanushka Naidoo
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Centre for Bioinformatics and Computational Biology, University of Pretoria, Private Bag X20, Pretoria 0028, South Africa.
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Kernaghan G, Mayerhofer M, Griffin A. Fungal endophytes of wild and hybrid Vitis leaves and their potential for vineyard biocontrol. Can J Microbiol 2017; 63:583-595. [PMID: 28407475 DOI: 10.1139/cjm-2016-0740] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plants are colonized by diverse assemblages of fungal endophytes that have potential as biocontrol agents for a variety of crops, including grapevine. Although the diversity of symbionts can be very high in wild plants, the fungal endophytes of wild Vitis plants have not yet been investigated. We surveyed the fungal endophytes of 6 wild populations of Vitis riparia, as well as a cold-tolerant, hybrid grapevine in 5 vineyards (1 certified organic), using 454 pyrosequencing. We detected between 43 and 235 operational taxonomic units per sample, with the highest richness and diversity in the wild, the lowest in conventional vineyards, and intermediate levels in the organic vineyard. Wild plants supported a range of taxa not seen in the conventional vineyards, and vineyards were dominated by relatively few taxa. We also isolated fungi from the wild plants and tested them for their ability to inhibit pathogens of grapevine. Several wild isolates (e.g., Ramularia spp.) were strongly inhibitory to grapevine pathogens. We show that wild Vitis supports a distinct and highly diverse community of fungal endophytes and may represent a rich repository of potential vineyard biocontrol agents.
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Affiliation(s)
- Gavin Kernaghan
- Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada.,Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada
| | - Michael Mayerhofer
- Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada.,Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada
| | - Amanda Griffin
- Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada.,Biology Department, Mount St. Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada
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Wang Y, Lai Z, Li XX, Yan RM, Zhang ZB, Yang HL, Zhu D. Isolation, diversity and acetylcholinesterase inhibitory activity of the culturable endophytic fungi harboured in Huperzia serrata from Jinggang Mountain, China. World J Microbiol Biotechnol 2016; 32:20. [PMID: 26745980 DOI: 10.1007/s11274-015-1966-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/29/2015] [Indexed: 11/27/2022]
Abstract
Huperzia serrata has many important medicinal properties with proven pharmacological potential. Some of these properties may be mediated by its endophytic fungi. To test this hypothesis, in the present study, we provided a first insights into evaluating the species composition and acetylcholinesterase (AChE) inhibitory activity of the culturable endophytic fungi of H. serrata from the regional at Jinggang Mountain in southeastern China. A total number of 885 fungal isolates distributed across 44 genera and 118 putative species were obtained from 1422 fragments of fine H. serrata roots, stems and leaves base on ITS-rDNA sequences BLAST analysis. The endophytic fungi were phylogenetically diverse and species-rich, with high rate of colonization and isolation. The assemble of endophytic fungi consisted mainly of Ascomycota (97.15%), followed by Basidiomycota (1.92%) and unknown fungal species (0.90%). Colletotrichum (64.29%), Phyllosticta (3.39%), Hypoxylon (2.81%), Xylaria (2.25%) and Nigrospora (2.04%) were the most abundant genera, whereas the remaining genera were infrequent groups. Although, roots yielded low abundance strains, the diverse and species-rich were both higher than that of stems and leaves. In addition, out of the 247 endophytic fungi strains determinated, 221 fungal extracts showed AChE inhibition activities in vitro. Among them, 22 endophytic fungi strains achieved high inhibitory activity (≥50%) on AChE which belongs to 13 genera and five incertae sedis strains. Four endophytic fungi designated as JS4 (Colletotrichum spp.), FL14 (Ascomycota spp.), FL9 (Sarcosomataceae spp.) and FL7 (Dothideomycetes spp.) were displayed highly active (≥80%) against AChE, which the inhibition effects were even more intense than the positive control. Our findings highlight that H. serrata grown in Jinggang Mountain harbors a rich and fascinating endophytic fungus community with potential AChE inhibitory activity, which could further broaden the natural acetylcholinesterase inhibitors resources used for Alzheimer's disease treatment.
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Affiliation(s)
- Ya Wang
- Key Laboratory of Bioprocess Engineering of Jiangxi Province, College of life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
- Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, 336000, China
| | - Zheng Lai
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Xi-Xi Li
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
- Science and Technology College, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330025, China
| | - Ri-Ming Yan
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Zhi-Bin Zhang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Hui-Lin Yang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Du Zhu
- Key Laboratory of Bioprocess Engineering of Jiangxi Province, College of life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China.
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China.
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Swett CL, Kirkpatrick SC, Gordon TR. Evidence for a Hemibiotrophic Association of the Pitch Canker Pathogen Fusarium circinatum with Pinus radiata. PLANT DISEASE 2016; 100:79-84. [PMID: 30688583 DOI: 10.1094/pdis-03-15-0270-re] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Fusarium circinatum can be a cause of mortality in pine seedlings but it is also possible for infected seedlings to remain symptomless. The results of this study documented a biotrophic phase in symptomless Pinus radiata seedlings that can persist for at least 52 weeks. A strain of F. circinatum, transformed to express the green fluorescent protein, was observed to grow intercellularly in the root cortex, with no evidence of damage to surrounding cells. Under experimental conditions, shoot symptoms developed only following collar infection, and root deterioration was seen only in plants that first expressed aboveground symptoms. This sequence of events implies that damage to the root system was a secondary consequence of girdling. If so, root symptoms may not reliably detect seedlings infected by F. circinatum. Supplemental mineral nutrition increased the incidence of infection and symptom development in seedlings but some infected plants remained symptomless, precluding the use of this approach to detect infected seedlings. Overall, our findings suggest that the ecological activities of F. circinatum may not be limited to a necrotrophic association with pine trees. A more comprehensive understanding of the life history of this fungus may yield insights that contribute to more effective management of pitch canker.
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Affiliation(s)
- Cassandra L Swett
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park 20742
| | | | - Thomas R Gordon
- Department of Plant Pathology, University of California, Davis 95616
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Spatafora JW, Bushley KE. Phylogenomics and evolution of secondary metabolism in plant-associated fungi. CURRENT OPINION IN PLANT BIOLOGY 2015; 26:37-44. [PMID: 26116974 DOI: 10.1016/j.pbi.2015.05.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/20/2015] [Accepted: 05/25/2015] [Indexed: 06/04/2023]
Abstract
Fungi produce a myriad of secondary metabolites, compounds that are not required for basic cellular processes, but are thought to be central to ecological functions. Genomic sequencing of fungi has revealed a greater diversity of secondary metabolism than previously realized, including novel taxonomic distributions of known compounds and uncharacterized gene clusters in well-studied organisms. Here we provide an overview of the major groups of metabolites, their ecological functions, the genetic systems that produce them, and the patterns and processes associated with evolutionary diversification of secondary metabolism in plant-associated filamentous ascomycetes.
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Affiliation(s)
- Joseph W Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
| | - Kathryn E Bushley
- Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA
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