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Netherway T, Bahram M. Melanized root-associated fungi: key players in plant-soil systems. Trends Microbiol 2024:S0966-842X(24)00169-0. [PMID: 38987052 DOI: 10.1016/j.tim.2024.06.006] [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: 04/30/2024] [Revised: 06/03/2024] [Accepted: 06/21/2024] [Indexed: 07/12/2024]
Abstract
Melanized root-associated fungi are a group of fungi that produce melanized structures and form root associations, including different mycorrhizal and endophytic symbioses with plants. They are pervasive across terrestrial ecosystems and play an important role in the prevailing soil carbon (C) and nutrient cycling syndromes through direct and indirect mechanisms, where they may strongly modulate plant-microbe interactions and structure root and soil microbiomes. Furthermore, melanized root-associated fungi can confer on plants an enhanced ability to tolerate abiotic and biotic stressors such as drought, extreme temperatures, heavy metals, and pathogen attacks. We propose that melanized root-associated fungi are a cohesive and ecologically relevant grouping that can be an indicator of plant-soil system functioning, and considering them will advance research on plant-soil interactions.
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Affiliation(s)
- Tarquin Netherway
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51 Uppsala, Sweden.
| | - Mohammad Bahram
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51 Uppsala, Sweden; Department of Agroecology, Aarhus University, Slagelse, Denmark; Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
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Rojas-Sánchez B, Castelán-Sánchez H, Garfias-Zamora EY, Santoyo G. Diversity of the Maize Root Endosphere and Rhizosphere Microbiomes Modulated by the Inoculation with Pseudomonas fluorescens UM270 in a Milpa System. PLANTS (BASEL, SWITZERLAND) 2024; 13:954. [PMID: 38611483 PMCID: PMC11013257 DOI: 10.3390/plants13070954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024]
Abstract
Milpa is an agroecological production system based on the polyculture of plant species, with corn featuring as a central component. Traditionally, the milpa system does not require the application of chemicals, and so pest attacks and poor growth in poor soils can have adverse effects on its production. Therefore, the application of bioinoculants could be a strategy for improving crop growth and health; however, the effect of external inoculant agents on the endemic microbiota associated with corn has not been extensively studied. Here, the objective of this work was to fertilize a maize crop under a milpa agrosystem with the PGPR Pseudomonas fluorescens UM270, evaluating its impact on the diversity of the rhizosphere (rhizobiome) and root endophytic (root endobiome) microbiomes of maize plants. The endobiome of maize roots was evaluated by 16S rRNA and internal transcribed spacer region (ITS) sequencing, and the rhizobiome was assessed by metagenomic sequencing upon inoculation with the strain UM270. The results showed that UM270 inoculation of the rhizosphere of P. fluorescens UM270 did not increase alpha diversity in either the monoculture or milpa, but it did alter the endophytic microbiome of maize plant roots by stimulating the presence of bacterial operational taxonomic units (OTUs) of the genera Burkholderia and Pseudomonas (in a monoculture), whereas, in the milpa system, the PGPR stimulated greater endophytic diversity and the presence of genera such as Burkholderia, Variovorax, and N-fixing rhizobia genera, including Rhizobium, Mesorhizobium, and Bradyrhizobium. No clear association was found between fungal diversity and the presence of strain UM270, but beneficial fungi, such as Rizophagus irregularis and Exophiala pisciphila, were detected in the Milpa system. In addition, network analysis revealed unique interactions with species such as Stenotrophomonas sp., Burkholderia xenovorans, and Sphingobium yanoikuyae, which could potentially play beneficial roles in the plant. Finally, the UM270 strain does not seem to have a strong impact on the microbial diversity of the rhizosphere, but it does have a strong impact on some functions, such as trehalose synthesis, ammonium assimilation, and polyamine metabolism. The inoculation of UM270 biofertilizer in maize plants modifies the rhizo- and endophytic microbiomes with a high potential for stimulating plant growth and health in agroecological crop models.
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Affiliation(s)
- Blanca Rojas-Sánchez
- Genomic Diversity Lab, Institute of Chemical and Biological Research, Universidad Michoacana de San Nicolas de Hidalgo, Morelia 58030, Mexico; (B.R.-S.); (E.Y.G.-Z.)
| | - Hugo Castelán-Sánchez
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada;
| | - Esmeralda Y. Garfias-Zamora
- Genomic Diversity Lab, Institute of Chemical and Biological Research, Universidad Michoacana de San Nicolas de Hidalgo, Morelia 58030, Mexico; (B.R.-S.); (E.Y.G.-Z.)
| | - Gustavo Santoyo
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada;
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Müller M, Kües U, Budde KB, Gailing O. Applying molecular and genetic methods to trees and their fungal communities. Appl Microbiol Biotechnol 2023; 107:2783-2830. [PMID: 36988668 PMCID: PMC10106355 DOI: 10.1007/s00253-023-12480-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/30/2023]
Abstract
Forests provide invaluable economic, ecological, and social services. At the same time, they are exposed to several threats, such as fragmentation, changing climatic conditions, or increasingly destructive pests and pathogens. Trees, the inherent species of forests, cannot be viewed as isolated organisms. Manifold (micro)organisms are associated with trees playing a pivotal role in forest ecosystems. Of these organisms, fungi may have the greatest impact on the life of trees. A multitude of molecular and genetic methods are now available to investigate tree species and their associated organisms. Due to their smaller genome sizes compared to tree species, whole genomes of different fungi are routinely compared. Such studies have only recently started in forest tree species. Here, we summarize the application of molecular and genetic methods in forest conservation genetics, tree breeding, and association genetics as well as for the investigation of fungal communities and their interrelated ecological functions. These techniques provide valuable insights into the molecular basis of adaptive traits, the impacts of forest management, and changing environmental conditions on tree species and fungal communities and can enhance tree-breeding cycles due to reduced time for field testing. It becomes clear that there are multifaceted interactions among microbial species as well as between these organisms and trees. We demonstrate the versatility of the different approaches based on case studies on trees and fungi. KEY POINTS: • Current knowledge of genetic methods applied to forest trees and associated fungi. • Genomic methods are essential in conservation, breeding, management, and research. • Important role of phytobiomes for trees and their ecosystems.
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Affiliation(s)
- Markus Müller
- Forest Genetics and Forest Tree Breeding, Faculty for Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 2, 37077, Göttingen, Germany.
- Center for Integrated Breeding Research (CiBreed), University of Goettingen, 37073, Göttingen, Germany.
| | - Ursula Kües
- Molecular Wood Biotechnology and Technical Mycology, Faculty for Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 2, 37077, Göttingen, Germany
- Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077, Göttingen, Germany
- Center of Sustainable Land Use (CBL), Georg-August-University Göttingen, 37077, Göttingen, Germany
| | - Katharina B Budde
- Forest Genetics and Forest Tree Breeding, Faculty for Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 2, 37077, Göttingen, Germany
- Center of Sustainable Land Use (CBL), Georg-August-University Göttingen, 37077, Göttingen, Germany
| | - Oliver Gailing
- Forest Genetics and Forest Tree Breeding, Faculty for Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 2, 37077, Göttingen, Germany
- Center for Integrated Breeding Research (CiBreed), University of Goettingen, 37073, Göttingen, Germany
- Center of Sustainable Land Use (CBL), Georg-August-University Göttingen, 37077, Göttingen, Germany
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Different Geographic Strains of Dinoflagellate Karlodinium veneficum Host Highly Diverse Fungal Community and Potentially Serve as Possible Niche for Colonization of Fungal Endophytes. Int J Mol Sci 2023; 24:ijms24021672. [PMID: 36675187 PMCID: PMC9865425 DOI: 10.3390/ijms24021672] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/03/2023] [Accepted: 01/08/2023] [Indexed: 01/18/2023] Open
Abstract
In numerous studies, researchers have explored the interactions between fungi and their hosting biota in terrestrial systems, while much less attention has been paid to the counterpart interactions in aquatic, and particularly marine, ecosystems. Despite the growing recognition of the potential functions of fungi in structuring phytoplankton communities, the current insights were mostly derived from phytoplankton hosts, such as diatoms, green microalgae, and cyanobacteria. Dinoflagellates are the second most abundant group of phytoplankton in coastal marine ecosystems, and they are notorious for causing harmful algal blooms (HABs). In this study, we used high-throughput amplicon sequencing to capture global snapshots of specific fungal assemblages associated with laboratory-cultured marine dinoflagellate. We investigated a total of 13 clonal cultures of the dinoflagellate Karlodinium veneficum that were previously isolated from 5 geographic origins and have been maintained in our laboratory from several months to more than 14 years. The total recovered fungal microbiome, which consisted of 349 ASVs (amplicon sequencing variants, sequences clustered at a 100% sequence identity), could be assigned to 4 phyla, 18 classes, 37 orders, 65 families, 97 genera, and 131 species. The fungal consortium displayed high diversity and was dominated by filamentous fungi and ascomycetous and basidiomycetous yeasts. A core set of three genera among all the detected fungi was constitutively present in the K. veneficum strains isolated from geographically distant regions, with the top two most abundant genera, Thyridium and Pseudeurotium, capable of using hydrocarbons as the sole or major source of carbon and energy. In addition, fungal taxa previously documented as endophytes in other hosts were also found in all tested strains of K. veneficum. Because host-endophyte interactions are highly variable and strongly case-dependent, these fungal taxa were not necessarily genuine endosymbionts of K. veneficum; instead, it raised the possibility that dinoflagellates could potentially serve as an alternative ecological niche for the colonization of fungal endophytes. Our findings lay the foundation for further investigations into the potential roles or functions of fungi in the regulation of the growth dynamics and HABs of marine dinoflagellates in the field.
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Wang K, Wen Z, Asiegbu FO. The dark septate endophyte Phialocephala sphaeroides suppresses conifer pathogen transcripts and promotes root growth of Norway spruce. TREE PHYSIOLOGY 2022; 42:2627-2639. [PMID: 35878416 PMCID: PMC9743008 DOI: 10.1093/treephys/tpac089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Plant-associated microbes including dark septate endophytes (DSEs) of forest trees play diverse functional roles in host fitness including growth promotion and increased defence. However, little is known about the impact on the fungal transcriptome and metabolites during tripartite interaction involving plant host, endophyte and pathogen. To understand the transcriptional regulation of endophyte and pathogen during co-infection, Norway spruce (Picea abies) seedlings were infected with DSE Phialocephala sphaeroides, or conifer root-rot pathogen Heterobasidion parviporum, or both. Phialocephala sphaeroides showed low but stable transcripts abundance (a decrease of 40%) during interaction with Norway spruce and conifer pathogen. By contrast, H. parviporum transcripts were significantly reduced (92%) during co-infection. With RNA sequencing analysis, P. sphaeroides experienced a shift from cell growth to anti-stress and antagonistic responses, while it repressed the ability of H. parviporum to access carbohydrate nutrients by suppressing its carbohydrate/polysaccharide-degrading enzyme machinery. The pathogen on the other hand secreted cysteine peptidase to restrict free growth of P. sphaeroides. The expression of both DSE P. sphaeroides and pathogen H. parviporum genes encoding plant growth promotion products were equally detected in both dual and tripartite interaction systems. This was further supported by the presence of tryptophan-dependent indolic compound in liquid culture of P. sphaeroides. Norway spruce and Arabidopsis seedlings treated with P. sphaeroides culture filtrate exhibited auxin-like phenotypes, such as enhanced root hairs, and primary root elongation at low concentration but shortened primary root at high concentration. The results suggested that the presence of the endophyte had strong repressive or suppressive effect on H. parviporum transcripts encoding genes involved in nutrient acquisition.
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Affiliation(s)
- Kai Wang
- Corresponding authors: K.Wang (; ) and F.Asiegbu ()
| | - Zilan Wen
- Department of Forest Sciences, University of Helsinki, PO Box 27, Helsinki FIN-00014, Finland
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Malicka M, Magurno F, Piotrowska-Seget Z. Plant association with dark septate endophytes: When the going gets tough (and stressful), the tough fungi get going. CHEMOSPHERE 2022; 302:134830. [PMID: 35525444 DOI: 10.1016/j.chemosphere.2022.134830] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 06/14/2023]
Abstract
Dark septate endophytes (DSEs) comprise a diverse and ubiquitous group of fungal generalists with broad habitat niches that robustly colonize the roots of plants in stressful environments. DSEs possess adaptation strategies that determine their high tolerance to heavy metal (HM) contamination, drought, and salinity. Most DSEs developed efficient melanin-dependent and melanin-independent mechanisms of HM detoxification and osmoprotection, including intracellular immobilization and extracellular efflux of HMs and excess ions, and the scavenging of reactive oxygen species. DSEs form mutualistic relationship with plants according to the hypothesis of "habitat-adapted associations", supporting the survival of their hosts under stressful conditions. As saprophytes, DSEs mineralize a complex soil substrate improving plants' nutrition and physiological parameters. They can protect the host plant from HMs by limiting HM accumulation in plant tissues and causing their sequestration in root cell walls as insoluble compounds, preventing further HM translocation to shoots. The presence of DSE in drought-affected plants can substantially ameliorate the physiology and architecture of root systems, improving their hydraulic properties. Plant growth-promoting features, supported by the versatility and easy culturing of DSEs, determine their high potential to enhance phytoremediation and revegetation projects for HM-contaminated, saline, and desertic lands reclamation.
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Affiliation(s)
- Monika Malicka
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28 Street, 40-032 Katowice, Poland.
| | - Franco Magurno
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28 Street, 40-032 Katowice, Poland
| | - Zofia Piotrowska-Seget
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28 Street, 40-032 Katowice, Poland
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Metabarcoding of fungal assemblages in Vaccinium myrtillus endosphere suggests colonization of above-ground organs by some ericoid mycorrhizal and DSE fungi. Sci Rep 2022; 12:11013. [PMID: 35773465 PMCID: PMC9246922 DOI: 10.1038/s41598-022-15154-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 06/20/2022] [Indexed: 11/10/2022] Open
Abstract
Plants harbor in their external surfaces and internal tissues a highly diverse and finely structured microbial assembly, the microbiota. Each plant compartment usually represents a unique ecological niche hosting a distinct microbial community and niche differentiation, which may mirror distinct functions of a specialized microbiota, has been mainly investigated for bacteria. Far less is known for the fungal components of the plant-associated microbiota. Here, we applied a metabarcoding approach to describe the fungal assemblages in different organs of Vaccinium myrtillus plants (Ericaceae) collected in a subalpine meadow in North-West Italy, and identified specific taxa enriched in internal tissues of roots, stems, leaves and flowers. We also traced the distribution of some important fungi commonly associated with plants of the family Ericaceae, namely the ericoid mycorrhizal (ErM) fungi and the dark septate endophytes (DSE), both playing important roles in plant growth and health. Operational taxonomic units attributed to established ErM fungal species in the genus Hyaloscypha and to DSE species in the Phialocephala-Acephala applanata complex (PAC) were found in all the plant organs. Mycorrhizal fungi are thought to be strictly associated with the plant roots, and this first observation of ErM fungi in the above-ground organs of the host plant may be explained by the evolutionary closeness of ErM fungi in the genus Hyaloscypha with non mycorrhizal fungal endophytes. This is also witnessed by the closer similarities of the ErM fungal genomes with the genomes of plant endophytes than with those of other mycorrhizal fungi, such as arbuscular or ectomycorrhizal fungi.
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Vaghefi N, Kusch S, Németh MZ, Seress D, Braun U, Takamatsu S, Panstruga R, Kiss L. Beyond Nuclear Ribosomal DNA Sequences: Evolution, Taxonomy, and Closest Known Saprobic Relatives of Powdery Mildew Fungi ( Erysiphaceae) Inferred From Their First Comprehensive Genome-Scale Phylogenetic Analyses. Front Microbiol 2022; 13:903024. [PMID: 35756050 PMCID: PMC9218914 DOI: 10.3389/fmicb.2022.903024] [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: 03/23/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Powdery mildew fungi (Erysiphaceae), common obligate biotrophic pathogens of many plants, including important agricultural and horticultural crops, represent a monophyletic lineage within the Ascomycota. Within the Erysiphaceae, molecular phylogenetic relationships and DNA-based species and genera delimitations were up to now mostly based on nuclear ribosomal DNA (nrDNA) phylogenies. This is the first comprehensive genome-scale phylogenetic analysis of this group using 751 single-copy orthologous sequences extracted from 24 selected powdery mildew genomes and 14 additional genomes from Helotiales, the fungal order that includes the Erysiphaceae. Representative genomes of all powdery mildew species with publicly available whole-genome sequencing (WGS) data that were of sufficient quality were included in the analyses. The 24 powdery mildew genomes included in the analysis represented 17 species belonging to eight out of 19 genera recognized within the Erysiphaceae. The epiphytic genera, all but one represented by multiple genomes, belonged each to distinct, well-supported lineages. Three hemiendophytic genera, each represented by a single genome, together formed the hemiendophytic lineage. Out of the 14 other taxa from the Helotiales, Arachnopeziza araneosa, a saprobic species, was the only taxon that grouped together with the 24 genome-sequenced powdery mildew fungi in a monophyletic clade. The close phylogenetic relationship between the Erysiphaceae and Arachnopeziza was revealed earlier by a phylogenomic study of the Leotiomycetes. Further analyses of powdery mildew and Arachnopeziza genomes may discover signatures of the evolutionary processes that have led to obligate biotrophy from a saprobic way of life. A separate phylogeny was produced using the 18S, 5.8S, and 28S nrDNA sequences of the same set of powdery mildew specimens and compared to the genome-scale phylogeny. The nrDNA phylogeny was largely congruent to the phylogeny produced using 751 orthologs. This part of the study has revealed multiple contamination and other quality issues in some powdery mildew genomes. We recommend that the presence of 28S, internal transcribed spacer (ITS), and 18S nrDNA sequences in powdery mildew WGS datasets that are identical to those determined by Sanger sequencing should be used to assess the quality of assemblies, in addition to the commonly used Benchmarking Universal Single-Copy Orthologs (BUSCO) values.
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Affiliation(s)
- Niloofar Vaghefi
- Centre for Crop Health, Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, QLD, Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Stefan Kusch
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
| | - Márk Z. Németh
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Budapest, Hungary
| | - Diána Seress
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Budapest, Hungary
| | - Uwe Braun
- Department of Geobotany and Botanical Garden, Herbarium, Institute for Biology, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - Susumu Takamatsu
- Laboratory of Plant Pathology, Faculty of Bioresources, Mie University, Tsu, Japan
| | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
| | - Levente Kiss
- Centre for Crop Health, Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, QLD, Australia
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Budapest, Hungary
- Centre for Research and Development, Eszterházy Károly Catholic University, Eger, Hungary
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Wen Z, Terhonen E, Asiegbu FO. The dark septate endophyte Phialocephala sphaeroides confers growth fitness benefits and mitigates pathogenic effects of Heterobasidion on Norway spruce. TREE PHYSIOLOGY 2022; 42:891-906. [PMID: 34791486 PMCID: PMC9000907 DOI: 10.1093/treephys/tpab147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 11/09/2021] [Indexed: 05/27/2023]
Abstract
Forest trees frequently interact with a diverse range of microorganisms including dark septate endophytes (DSEs) and fungal pathogens. Plant defense responses to either individual pathogens or endophytes have been widely studied, but very little is known on the effect of coinfection on host defenses. To study the impact of coinfection or tripartite interaction on plant growth and host defenses, Norway spruce (Picea abies (L.) Karst) seedlings were inoculated with a DSE Phialocephala sphaeroides or with a root pathogen Heterobasidion parviporum Niemela & Korhonen or coinfected with both fungi. The results showed that the DSE promoted the root growth of spruce seedlings. Control seedlings without any inoculum were subjected to sequencing and used as a baseline for identification of differentially expressed genes (DEGs). RNA-seq analysis of seedlings inoculated with P. sphaeroides, infected with H. parviporum or coinfected with both fungi resulted in a total of 5269 DEGs. The majority of DEGs were found in P. sphaeroides-inoculated seedlings. Lignin biosynthesis pathways were generally activated during fungal infections. The pattern was distinct with endophyte inoculation. The majority of the genes in the flavonoid biosynthesis pathway were generally suppressed during fungal infections. A specific transcriptional response to P. sphaeroides inoculation was the increased transcripts of genes involved in jasmonic acid biosynthesis, mitogen-activated protein kinases signaling pathway, plant hormone signal transduction and calcium-mediated signaling. This may have potentially contributed to promoting the root growth of seedlings. Although the coinfection suppressed the induction of numerous genes, no negative effect on the growth of the spruce seedlings occurred. We conclude that the subsequent H. parviporum infection triggered reprogramming of host metabolism. Conversely, the endophyte (P. sphaeroides), on the other hand, counteracted the negative effects of H. parviporum on the growth of the spruce seedlings.
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Affiliation(s)
- Zilan Wen
- Faculty of Agriculture and Forestry, University of Helsinki, Helsinki 00790, Finland
| | - Eeva Terhonen
- Natural Resources Institute Finland (Luke), Helsinki 00790, Finland
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Ruotsalainen AL, Kauppinen M, Wäli PR, Saikkonen K, Helander M, Tuomi J. Dark septate endophytes: mutualism from by-products? TRENDS IN PLANT SCIENCE 2022; 27:247-254. [PMID: 34756535 DOI: 10.1016/j.tplants.2021.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/31/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Plant roots are abundantly colonized by dark septate endophytic (DSE) fungi in virtually all ecosystems. DSE fungi are functionally heterogeneous and their relationships with plants range from antagonistic to mutualistic. Here, we consider the role of by-product benefits in DSE and other root-fungal symbioses. We compared host investments against symbiont-derived benefits for the host plant and categorized these benefits as by-products or benefits requiring reciprocal investment from the host. By-product benefits may provide the variability required for the evolution of invested mutualisms between the host and symbiont. We suggest that DSE could be considered as 'a by-product mutualist transitional phase' in the evolution of cooperative mycorrhizal symbionts from saprotrophic fungi.
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Affiliation(s)
- Anna L Ruotsalainen
- Department of Ecology and Genetics, POB 3000, University of Oulu, FI-90014 Oulu, Finland.
| | - Miia Kauppinen
- Biodiversity Unit, University of Turku, FI-20014 Turku, Finland
| | - Piippa R Wäli
- Department of Ecology and Genetics, POB 3000, University of Oulu, FI-90014 Oulu, Finland; Natural Resources Institute Finland (Luke), Ounasjoentie 6, FI-96200 Rovaniemi, Finland
| | - Kari Saikkonen
- Biodiversity Unit, University of Turku, FI-20014 Turku, Finland
| | - Marjo Helander
- Department of Biology, University of Turku, FI-20014 Turku, Finland
| | - Juha Tuomi
- Meritie 43, FI-29900 Merikarvia, Finland
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Nagel JH, Wingfield MJ, Slippers B. Increased abundance of secreted hydrolytic enzymes and secondary metabolite gene clusters define the genomes of latent plant pathogens in the Botryosphaeriaceae. BMC Genomics 2021; 22:589. [PMID: 34348651 PMCID: PMC8336260 DOI: 10.1186/s12864-021-07902-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/30/2021] [Indexed: 01/11/2023] Open
Abstract
Background The Botryosphaeriaceae are important plant pathogens, but also have the ability to establish asymptomatic infections that persist for extended periods in a latent state. In this study, we used comparative genome analyses to shed light on the genetic basis of the interactions of these fungi with their plant hosts. For this purpose, we characterised secreted hydrolytic enzymes, secondary metabolite biosynthetic gene clusters and general trends in genomic architecture using all available Botryosphaeriaceae genomes, and selected Dothideomycetes genomes. Results The Botryosphaeriaceae genomes were rich in carbohydrate-active enzymes (CAZymes), proteases, lipases and secondary metabolic biosynthetic gene clusters (BGCs) compared to other Dothideomycete genomes. The genomes of Botryosphaeria, Macrophomina, Lasiodiplodia and Neofusicoccum, in particular, had gene expansions of the major constituents of the secretome, notably CAZymes involved in plant cell wall degradation. The Botryosphaeriaceae genomes were shown to have moderate to high GC contents and most had low levels of repetitive DNA. The genomes were not compartmentalized based on gene and repeat densities, but genes of secreted enzymes were slightly more abundant in gene-sparse regions. Conclusion The abundance of secreted hydrolytic enzymes and secondary metabolite BGCs in the genomes of Botryosphaeria, Macrophomina, Lasiodiplodia, and Neofusicoccum were similar to those in necrotrophic plant pathogens and some endophytes of woody plants. The results provide a foundation for comparative genomic analyses and hypotheses to explore the mechanisms underlying Botryosphaeriaceae host-plant interactions. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07902-w.
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Affiliation(s)
- Jan H Nagel
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0001, South Africa.
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0001, South Africa
| | - Bernard Slippers
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0001, South Africa
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12
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Identification of Oxygen-Independent Pathways for Pyridine Nucleotide and Coenzyme A Synthesis in Anaerobic Fungi by Expression of Candidate Genes in Yeast. mBio 2021; 12:e0096721. [PMID: 34154398 PMCID: PMC8262920 DOI: 10.1128/mbio.00967-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Neocallimastigomycetes are unique examples of strictly anaerobic eukaryotes. This study investigates how these anaerobic fungi bypass reactions involved in synthesis of pyridine nucleotide cofactors and coenzyme A that, in canonical fungal pathways, require molecular oxygen. Analysis of Neocallimastigomycetes proteomes identified a candidate l-aspartate-decarboxylase (AdcA) and l-aspartate oxidase (NadB) and quinolinate synthase (NadA), constituting putative oxygen-independent bypasses for coenzyme A synthesis and pyridine nucleotide cofactor synthesis. The corresponding gene sequences indicated acquisition by ancient horizontal gene transfer (HGT) events involving bacterial donors. To test whether these enzymes suffice to bypass corresponding oxygen-requiring reactions, they were introduced into fms1Δ and bna2Δ Saccharomyces cerevisiae strains. Expression of nadA and nadB from Piromyces finnis and adcA from Neocallimastix californiae conferred cofactor prototrophy under aerobic and anaerobic conditions. This study simulates how HGT can drive eukaryotic adaptation to anaerobiosis and provides a basis for elimination of auxotrophic requirements in anaerobic industrial applications of yeasts and fungi. IMPORTANCE NAD (NAD+) and coenzyme A (CoA) are central metabolic cofactors whose canonical biosynthesis pathways in fungi require oxygen. Anaerobic gut fungi of the Neocallimastigomycota phylum are unique eukaryotic organisms that adapted to anoxic environments. Analysis of Neocallimastigomycota genomes revealed that these fungi might have developed oxygen-independent biosynthetic pathways for NAD+ and CoA biosynthesis, likely acquired through horizontal gene transfer (HGT) from prokaryotic donors. We confirmed functionality of these putative pathways under anaerobic conditions by heterologous expression in the yeast Saccharomyces cerevisiae. This approach, combined with sequence comparison, offers experimental insight on whether HGT events were required and/or sufficient for acquiring new traits. Moreover, our results demonstrate an engineering strategy for enabling S. cerevisiae to grow anaerobically in the absence of the precursor molecules pantothenate and nicotinate, thereby contributing to alleviate oxygen requirements and to move closer to prototrophic anaerobic growth of this industrially relevant yeast.
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13
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He X, Yuan Z. Near-Chromosome-Level Genome Assembly of the Dark Septate Endophyte Laburnicola rhizohalophila: A Model for Investigating Root-Fungus Symbiosis. Genome Biol Evol 2021; 13:6133230. [PMID: 33570561 PMCID: PMC7936028 DOI: 10.1093/gbe/evab026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2021] [Indexed: 11/14/2022] Open
Abstract
The novel DSE Laburnicola rhizohalophila (Pleosporales, Ascomycota) is frequently found in the halophytic seepweed (Suaeda salsa). In this article, we report a near-chromosome-level hybrid assembly of this fungus using a combination of short-read Illumina data to polish assemblies generated from long-read Nanopore data. The reference genome for L. rhizohalophila was assembled into 26 scaffolds with a total length of 64.0 Mb and a N50 length of 3.15 Mb. Of them, 17 scaffolds approached the length of intact chromosomes, and 5 had telomeres at one end only. A total of 10,891 gene models were predicted. Intriguingly, 27.5 Mb of repeat sequences that accounted for 42.97% of the genome was identified, and long terminal repeat retrotransposons were the most frequent known transposable elements, indicating that transposable element proliferation contributes to its increased genome size. BUSCO analyses using the Fungi_odb10 data set showed that 95.0% of genes were complete. In addition, 292 carbohydrate active enzymes, 33 secondary metabolite clusters, and 84 putative effectors were identified in silico. The resulting high-quality assembly and genome features are not only an important resource for further research on understanding the mechanism of root-fungi symbiotic interactions but will also contribute to comparative analyses of genome biology and evolution within Pleosporalean species.
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Affiliation(s)
- Xinghua He
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China.,Nanjing Forestry University, Nanjing, China.,Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, China
| | - Zhilin Yuan
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China.,Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, China
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14
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Kohout P, Sudová R, Brabcová V, Vosolsobě S, Baldrian P, Albrechtová J. Forest Microhabitat Affects Succession of Fungal Communities on Decomposing Fine Tree Roots. Front Microbiol 2021; 12:541583. [PMID: 33584602 PMCID: PMC7876299 DOI: 10.3389/fmicb.2021.541583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 01/06/2021] [Indexed: 01/16/2023] Open
Abstract
Belowground litter derived from tree roots has been shown as a principal source of soil organic matter in coniferous forests. Fate of tree root necromass depends on fungal communities developing on the decaying roots. Local environmental conditions which affect composition of tree root mycobiome may also influence fungal communities developing on decaying tree roots. Here, we assessed fungal communities associated with decaying roots of Picea abies decomposing in three microhabitats: soil with no vegetation, soil with ericoid shrubs cover, and P. abies deadwood, for a 2-year period. Forest microhabitat showed stronger effect on structuring fungal communities associated with decaying roots compared to living roots. Some ericoid mycorrhizal fungi showed higher relative abundance on decaying roots in soils under ericoid shrub cover, while saprotrophic fungi had higher relative abundance in roots decomposing inside deadwood. Regardless of the studied microhabitat, we observed decline of ectomycorrhizal fungi and increase of endophytic fungi during root decomposition. Interestingly, we found substantially more fungal taxa with unknown ecology in late stages of root decomposition, indicating that highly decomposed roots may represent so far overlooked niche for soil fungi. Our study shows the importance of microhabitats on the fate of the decomposing spruce roots.
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Affiliation(s)
- Petr Kohout
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Institute of Botany of the Czech Academy of Sciences, Pruhonice, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Radka Sudová
- Institute of Botany of the Czech Academy of Sciences, Pruhonice, Czechia
| | - Vendula Brabcová
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Stanislav Vosolsobě
- Institute of Botany of the Czech Academy of Sciences, Pruhonice, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Petr Baldrian
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jana Albrechtová
- Institute of Botany of the Czech Academy of Sciences, Pruhonice, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
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15
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Pintye A, Knapp DG. Two pleosporalean root-colonizing fungi, Fuscosphaeria hungarica gen. et sp. nov. and Delitschia chaetomioides, from a semiarid grassland in Hungary. Mycol Prog 2021. [DOI: 10.1007/s11557-020-01655-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractIn this study, we investigated two unidentified lineages of root-colonizing fungi belonging to the order Pleosporales (Dothideomycetes), which were isolated from Festuca vaginata (Poaceae), a dominant grass species in the semiarid sandy grasslands of Hungary. For molecular phylogenetic studies, seven loci (internal transcribed spacer, partial large subunit and small subunit region of nrRNA, partial transcription elongation factor 1-α, RNA polymerase II largest subunit, RNA polymerase II second largest subunit, and ß-tubulin genes) were amplified and sequenced. Based on morphology and multilocus phylogenetic analyses, we found that one lineage belonged to Delitschia chaetomioides P. Karst. (Delitschiaceae), and the isolates of the other lineage represented a novel monotypic genus in the family Trematosphaeriaceae (suborder Massarineae). For this lineage, we proposed a new genus, Fuscosphaeria, represented by a single species, F. hungarica. In both lineages, only immature and degenerated sporocarps could be induced. These were sterile, black, globose, or depressed globose structures with numerous mycelioid appendages submerged in culture media or on the surface of autoclaved plant materials. Both species are first reported here as root-colonizing fungi.
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16
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Gaber DA, Berthelot C, Camehl I, Kovács GM, Blaudez D, Franken P. Salt Stress Tolerance of Dark Septate Endophytes Is Independent of Melanin Accumulation. Front Microbiol 2020; 11:562931. [PMID: 33362727 PMCID: PMC7758464 DOI: 10.3389/fmicb.2020.562931] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 11/18/2020] [Indexed: 12/11/2022] Open
Abstract
Dark septate endophytes (DSEs) represent a diverse group of root-endophytic fungi that have been isolated from plant roots in many different natural and anthropogenic ecosystems. Melanin is widespread in eukaryotic organisms and possesses various functions such as protecting human skin from UV radiation, affecting the virulence of pathogens, and playing a role in development and physiology of insects. Melanin is a distinctive feature of the cell walls of DSEs and has been thought to protect these fungi from abiotic stress. Melanin in DSEs is assumed to be synthesized via the 1,8-dihydroxynaphthalene (DHN) pathway. Its function in alleviation of salt stress is not yet known. The aims of this study were: (i) investigating the growth responses of three DSEs (Periconia macrospinosa, Cadophora sp., and Leptodontidium sp.) to salt stress, (ii) analyzing melanin production under salt stress and, (iii) testing the role of melanin in salt stress tolerance of DSEs. The study shows that the three DSE species can tolerate high salt concentrations. Melanin content increased in the hyphae of all DSEs at 100 mM salt, but decreased at 500 mM. This was not reflected in the RNA accumulation of the gene encoding scytalone dehydratase which is involved in melanin biosynthesis. The application of tricyclazole, a DHN-melanin biosynthesis inhibitor, did not affect either salt stress tolerance or the accumulation of sodium in the hyphae. In addition, melanin biosynthesis mutants of Leptodontidium sp. did not show decreased growth performance compared to the wild-type, especially not at high salt concentrations. This indicates that DSEs can live under salt stress and withstand these conditions regardless of melanin accumulation.
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Affiliation(s)
- Dalia A. Gaber
- Leibniz-Institute of Vegetable and Ornamental Crops, Grossbeeren, Germany
- Institute of Biology, Humboldt University, Berlin, Germany
| | | | - Iris Camehl
- Leibniz-Institute of Vegetable and Ornamental Crops, Grossbeeren, Germany
| | - Gábor M. Kovács
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
- Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | | | - Philipp Franken
- Leibniz-Institute of Vegetable and Ornamental Crops, Grossbeeren, Germany
- Institute of Biology, Humboldt University, Berlin, Germany
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17
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Vohník M. Ericoid mycorrhizal symbiosis: theoretical background and methods for its comprehensive investigation. MYCORRHIZA 2020; 30:671-695. [PMID: 33043410 PMCID: PMC7548138 DOI: 10.1007/s00572-020-00989-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 09/14/2020] [Indexed: 05/20/2023]
Abstract
Despite decades of intensive research (especially from 1970s to 1990s), the ericoid mycorrhizal (ErM) hair root is still largely terra incognita and this simplified guide is intended to revive and promote the study of its mycobiota. Basic theoretical knowledge on the ErM symbiosis is summarized, followed by practical advices on Ericaceae root sample collection and handling, microscopic observations and photo-documentation of root fungal colonization, mycobiont isolation, maintenance and identification and resynthesis experiments with ericoid plants. The necessity of a proper selection of the root material and its surface sterilization prior to mycobiont isolation is stressed, together with the need of including suitable control treatments in inoculation experiments. The culture-dependent approach employing plating of single short (~ 2 mm) hair root segments on nutrient media is substantiated as a useful tool for characterization of Ericaceae root-associated fungal communities; it targets living mycelium and provides metabolically active cultures that can be used in physiological experiments and taxonomic studies, thus providing essential reference material for culture-independent approaches. On the other hand, it is stressed that not every mycobiont isolated from an ericoid hair root necessarily represent an ErM fungus. Likewise, not every intracellular hyphal coil formed in the Ericaceae rhizodermis necessarily represents the ErM symbiosis. Taxonomy of the most important ericoid mycobionts is updated, mutualism in the ErM symbiosis is briefly discussed from the mycobiont perspective, and some interesting lines of possible future research are highlighted.
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Affiliation(s)
- Martin Vohník
- Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Průhonice, 252 43, Czech Republic.
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18
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Queiroz CBD, Santana MF. Prediction of the secretomes of endophytic and nonendophytic fungi reveals similarities in host plant infection and colonization strategies. Mycologia 2020; 112:491-503. [PMID: 32286912 DOI: 10.1080/00275514.2020.1716566] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Endophytic fungi are microorganisms that inhabit internal plant tissues without causing apparent damage. During the infection process, both endophytic and phytopathogenic fungi secrete proteins to resist or supplant the plant's defense mechanisms. This study analyzed the predicted secretomes of six species of endophytic fungi and compared them with predicted secretomes of eight fungal species with different lifestyles: saprophytic, necrotrophic, hemibiotrophic, and biotrophic. The sizes of the predicted secretomes varied from 260 to 1640 proteins, and the predicted secretomes have a wide diversity of CAZymes, proteases, and conserved domains. Regarding the CAZymes in the secretomes of the analyzed fungi, the most abundant CAZyme families were glycosyl hydrolase and serine proteases. Several predicted proteins have characteristics similar to those found in small, secreted proteins with effector characteristics (SSPEC). The most abundant conserved domains, besides those found in the SSPEC, have oxidation activities, indicating that these proteins can protect the fungus against oxidative stress, against domains with protease activity, which may be involved in the mechanisms of nutrition, or against lytic enzymes secreted by the host plant. This study demonstrates that secretomes of endophytic and nonendophytic fungi share an arsenal of proteins important in the process of infection and colonization of host plants.
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Affiliation(s)
- Casley Borges de Queiroz
- Laboratório de Biologia Molecular, Embrapa Amazônia Ocidental , Rodovia AM 10, km 29, s/n, CEP: 69010-970, Manaus, Amazonas, Brazil
| | - Mateus Ferreira Santana
- Departamento de Microbiologia (BIOAGRO), Universidade Federal de Viçosa , CEP: 36570-900, Viçosa, Minas Gerais, Brazil
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19
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Landolt M, Stroheker S, Queloz V, Gall A, Sieber TN. Does water availability influence the abundance of species of the Phialocephala fortinii s.l. – Acephala applanata complex (PAC) in roots of pubescent oak (Quercus pubescens) and Scots pine (Pinus sylvestris)? FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2019.100904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Tanney J, Seifert K. Mollisiaceae: An overlooked lineage of diverse endophytes. Stud Mycol 2020; 95:293-380. [PMID: 32855742 PMCID: PMC7426276 DOI: 10.1016/j.simyco.2020.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 02/15/2020] [Accepted: 02/15/2020] [Indexed: 01/04/2023] Open
Abstract
Mollisia is a taxonomically neglected discomycete genus (Helotiales, Leotiomycetes) of commonly encountered saprotrophs on decaying plant tissues throughout temperate regions. The combination of indistinct morphological characters, more than 700 names in the literature, and lack of reference DNA sequences presents a major challenge when working with Mollisia. Unidentified endophytes, including strains that produced antifungal or antiinsectan secondary metabolites, were isolated from conifer needles in New Brunswick and placed with uncertainty in Phialocephala and Mollisia, necessitating a more comprehensive treatment of these genera. In this study, morphology and multigene phylogenetic analyses were used to explore the taxonomy of Mollisiaceae, including Mollisia, Phialocephala, and related genera, using new field collections, herbarium specimens, and accessioned cultures and sequences. The phylogeny of Mollisiaceae was reconstructed and compared using the nuc internal transcribed spacer rDNA (ITS) barcode and partial sequences of the 28S nuc rDNA (LSU) gene, largest subunit of RNA polymerase II (RPB1), DNA topoisomerase I (TOP1), and the hypothetical protein Lipin/Ned1/Smp2 (LNS2). The results show that endophytism is common throughout the Mollisiaceae lineage in a diverse range of hosts but is infrequently attributed to Mollisia because of a paucity of reference sequences. Generic boundaries within Mollisiaceae are poorly resolved and based on phylogenetic evidence the family included species placed in Acephala, Acidomelania, Barrenia, Bispora, Cheirospora, Cystodendron, Fuscosclera, Hysteronaevia, Loramyces, Mollisia, Neopyrenopeziza, Obtectodiscus, Ombrophila, Patellariopsis, Phialocephala, Pulvinata, Tapesia (=Mollisia), and Trimmatostroma. Taxonomic novelties included the description of five novel Mollisia species and five novel Phialocephala species and the synonymy of Fuscosclera with Phialocephala, Acidomelania with Mollisia, and Loramycetaceae with Mollisiaceae.
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Affiliation(s)
- J.B. Tanney
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, 506 Burnside Road, Victoria, British Columbia, V8Z 1M5, Canada
| | - K.A. Seifert
- Ottawa Research and Development Centre, Biodiversity (Mycology and Microbiology), Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, Ontario, K1A 0C6, Canada
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
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21
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Wang YL, Gao C, Chen L, Ji NN, Wu BW, Lü PP, Li XC, Qian X, Maitra P, Babalola BJ, Zheng Y, Guo LD. Community Assembly of Endophytic Fungi in Ectomycorrhizae of Betulaceae Plants at a Regional Scale. Front Microbiol 2020; 10:3105. [PMID: 32038548 PMCID: PMC6986194 DOI: 10.3389/fmicb.2019.03105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 12/23/2019] [Indexed: 11/13/2022] Open
Abstract
The interaction between aboveground and belowground biotic communities drives community assembly of plants and soil microbiota. As an important component of belowground microorganisms, root-associated fungi play pivotal roles in biodiversity maintenance and community assembly of host plants. The Betulaceae plants form ectomycorrhizae with soil fungi and widely distribute in various ecosystems. However, the community assembly of endophytic fungi in ectomycorrhizae is less investigated at a large spatial scale. Here, we examined the endophytic fungal communities in ectomycorrhizae of 22 species in four genera belonging to Betulaceae in Chinese forest ecosystems, using Illumina Miseq sequencing of internal transcribed spacer 2 amplicons. The relative contribution of host phylogeny, climate and soil (environmental filtering) and geographic distance (dispersal limitation) on endophytic fungal community was disentangled. In total, 2,106 endophytic fungal operational taxonomic units (OTUs) were obtained at a 97% sequence similarity level, dominated by Leotiomycetes, Agaricomycetes, Eurotiomycetes, and Sordariomycetes. The endophytic fungal OTU richness was significantly related with host phylogeny, geographic distance, soil and climate. The endophytic fungal community composition was significantly affected by host phylogeny (19.5% of variation explained in fungal community), geographic distance (11.2%), soil (6.1%), and climate (1.4%). This finding suggests that environmental filtering by plant and abiotic variables coupled with dispersal limitation linked to geographic distance determines endophytic fungal community assembly in ectomycorrhizae of Betulaceae plants, with host phylogeny being a stronger determinant than other predictor variables at the regional scale.
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Affiliation(s)
- Yong-Long Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Cheng Gao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Liang Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Niu-Niu Ji
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Bin-Wei Wu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Peng-Peng Lü
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xing-Chun Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xin Qian
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Pulak Maitra
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Busayo Joshua Babalola
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yong Zheng
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Geographical Science, Fujian Normal University, Fuzhou, China
| | - Liang-Dong Guo
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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22
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Vohník M, Borovec O, Kolaříková Z, Sudová R, Réblová M. Extensive sampling and high-throughput sequencing reveal Posidoniomycesatricolor gen. et sp. nov. (Aigialaceae, Pleosporales) as the dominant root mycobiont of the dominant Mediterranean seagrass Posidoniaoceanica. MycoKeys 2019; 55:59-86. [PMID: 31303813 PMCID: PMC6609996 DOI: 10.3897/mycokeys.55.35682] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/06/2019] [Indexed: 11/12/2022] Open
Abstract
Seagrasses provide invaluable ecosystem services yet very little is known about their root mycobiont diversity and distribution. Here we focused on the dominant Mediterranean seagrass Posidoniaoceanica and assessed its root mycobiome at 32 localities covering most of the ecoregions in the NW Mediterranean Sea using light and scanning electron microscopy and tag-encoded 454-pyrosequencing. Microscopy revealed that the recently discovered dark septate endophytic association specific for P.oceanica is present at all localities and pyrosequencing confirmed that the P.oceanica root mycobiome is dominated by a single undescribed pleosporalean fungus, hitherto unknown from other hosts and ecosystems. Its numerous slow-growing isolates were obtained from surface-sterilised root segments at one locality and after prolonged cultivation, several of them produced viable sterile mycelium. To infer their phylogenetic relationships we sequenced and analysed the large (LSU) and small (SSU) subunit nrDNA, the ITS nrDNA and the DNA-directed RNA polymerase II (RPB2). The fungus represents an independent marine biotrophic lineage in the Aigialaceae (Pleosporales) and is introduced here as Posidoniomycesatricolor gen. et sp. nov. Its closest relatives are typically plant-associated saprobes from marine, terrestrial and freshwater habitats in Southeast Asia and Central America. This study expands our knowledge and diversity of the Aigialaceae, adds a new symbiotic lifestyle to this family and provides a formal name for the dominant root mycobiont of the dominant Mediterranean seagrass.
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Affiliation(s)
- Martin Vohník
- Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Lesní 322, 252 43 Průhonice, Czech RepublicInstitute of Botany, Czech Academy of SciencesPrůhoniceCzech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech RepublicCharles UniversityPragueCzech Republic
| | - Ondřej Borovec
- Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Lesní 322, 252 43 Průhonice, Czech RepublicInstitute of Botany, Czech Academy of SciencesPrůhoniceCzech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech RepublicCharles UniversityPragueCzech Republic
| | - Zuzana Kolaříková
- Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Lesní 322, 252 43 Průhonice, Czech RepublicInstitute of Botany, Czech Academy of SciencesPrůhoniceCzech Republic
| | - Radka Sudová
- Department of Mycorrhizal Symbioses, Institute of Botany, Czech Academy of Sciences, Lesní 322, 252 43 Průhonice, Czech RepublicInstitute of Botany, Czech Academy of SciencesPrůhoniceCzech Republic
| | - Martina Réblová
- Department of Taxonomy, Institute of Botany, Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech RepublicInstitute of Botany, Czech AcademyPrůhoniceCzech Republic
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23
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Rigerte L, Blumenstein K, Terhonen E. New R-Based Methodology to Optimize the Identification of Root Endophytes against Heterobasidion parviporum. Microorganisms 2019; 7:E102. [PMID: 30959873 PMCID: PMC6517935 DOI: 10.3390/microorganisms7040102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 01/05/2023] Open
Abstract
Many root fungal endophytes inhabiting forest trees have potential impact on the health and disease progression of certain tree species. Hence, the screening of root endophytes for their biocontrol abilities is relevant for their potential to protect their hosts against invaders. The aim of this research is to screen for the potential inhibitory effects of selected conifer root endophytes during interaction, in vitro, with the root rot pathogen, Heterobasidion parviporum. Here, we introduce a guideline that facilitates the use of root fungal endophytes as biocontrol agents. We isolated fungal root endophytes from eight different conifers. These root fungal endophytes were evaluated for their antagonism against the root rot pathogen, H. parviporum, by means of paired-culture antagonism assays. We determined the antagonism of the isolated root fungal endophytes to elucidate potential biocontrol applications. For the analysis, a software package in R was developed. Endophyte candidates with antagonistic potential were identified.
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Affiliation(s)
- Linda Rigerte
- Forest Pathology Research Group, Büsgen-Institute, Department of Forest Botany and Tree Physiology, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany.
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24
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Perotto S, Daghino S, Martino E. Ericoid mycorrhizal fungi and their genomes: another side to the mycorrhizal symbiosis? THE NEW PHYTOLOGIST 2018; 220:1141-1147. [PMID: 29851103 DOI: 10.1111/nph.15218] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/08/2018] [Indexed: 05/20/2023]
Abstract
Contents Summary 1141 I. Introduction 1141 II. The ericoid mycorrhizal lifestyle 1141 III. Lessons from the mycorrhizal fungal genomes 1142 IV. ERM fungi: a discordant voice in the mycorrhizal choir 1143 V. An endophytic niche for ERM fungi 1144 VI. Specialised vs unspecialised mycorrhizal fungi? 1145 VII. Conclusions and perspectives 1145 Acknowledgements 1146 References 1146 SUMMARY: The genome of an organism bears the signature of its lifestyle, and organisms with similar life strategies are expected to share common genomic traits. Indeed, ectomycorrhizal and arbuscular mycorrhizal fungi share some genomic traits, such as the expansion of gene families encoding taxon-specific small secreted proteins, which are candidate effectors in the symbiosis, and a very small repertoire of plant cell wall-degrading enzymes. A large gene family coding for candidate effectors was also revealed in ascomycetous ericoid mycorrhizal (ERM) fungi, but these fungal genomes are characterised by a very high number of genes encoding degradative enzymes, mainly acting on plant cell wall components. We suggest that the genomic signature of ERM fungi mirrors a versatile life strategy, which allows them to occupy several ecological niches.
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Affiliation(s)
- Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
| | - Stefania Daghino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
| | - Elena Martino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
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Multi-omic Analyses of Extensively Decayed Pinus contorta Reveal Expression of a Diverse Array of Lignocellulose-Degrading Enzymes. Appl Environ Microbiol 2018; 84:AEM.01133-18. [PMID: 30097442 DOI: 10.1128/aem.01133-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/04/2018] [Indexed: 11/20/2022] Open
Abstract
Fungi play a key role cycling nutrients in forest ecosystems, but the mechanisms remain uncertain. To clarify the enzymatic processes involved in wood decomposition, the metatranscriptomics and metaproteomics of extensively decayed lodgepole pine were examined by RNA sequencing (RNA-seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), respectively. Following de novo metatranscriptome assembly, 52,011 contigs were searched for functional domains and homology to database entries. Contigs similar to basidiomycete transcripts dominated, and many of these were most closely related to ligninolytic white rot fungi or cellulolytic brown rot fungi. A diverse array of carbohydrate-active enzymes (CAZymes) representing a total of 132 families or subfamilies were identified. Among these were 672 glycoside hydrolases, including highly expressed cellulases or hemicellulases. The CAZymes also included 162 predicted redox enzymes classified within auxiliary activity (AA) families. Eighteen of these were manganese peroxidases, which are key components of ligninolytic white rot fungi. The expression of other redox enzymes supported the working of hydroquinone reduction cycles capable of generating reactive hydroxyl radicals. These have been implicated as diffusible oxidants responsible for cellulose depolymerization by brown rot fungi. Thus, enzyme diversity and the coexistence of brown and white rot fungi suggest complex interactions of fungal species and degradative strategies during the decay of lodgepole pine.IMPORTANCE The deconstruction of recalcitrant woody substrates is a central component of carbon cycling and forest health. Laboratory investigations have contributed substantially toward understanding the mechanisms employed by model wood decay fungi, but few studies have examined the physiological processes in natural environments. Herein, we identify the functional genes present in field samples of extensively decayed lodgepole pine (Pinus contorta), a major species distributed throughout the North American Rocky Mountains. The classified transcripts and proteins revealed a diverse array of oxidative and hydrolytic enzymes involved in the degradation of lignocellulose. The evidence also strongly supports simultaneous attack by fungal species employing different enzymatic strategies.
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Yurgel SN, Douglas GM, Dusault A, Percival D, Langille MGI. Dissecting Community Structure in Wild Blueberry Root and Soil Microbiome. Front Microbiol 2018; 9:1187. [PMID: 29922264 PMCID: PMC5996171 DOI: 10.3389/fmicb.2018.01187] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/16/2018] [Indexed: 11/16/2022] Open
Abstract
A complex network of functions and symbiotic interactions between a eukaryotic host and its microbiome is a the foundation of the ecological unit holobiont. However, little is known about how the non-fungal eukaryotic microorganisms fit in this complex network of host-microbiome interactions. In this study, we employed a unique wild blueberry ecosystem to evaluate plant-associated microbiota, encompassing both eukaryotic and bacterial communities. We found that, while soil microbiome serves as a foundation for root microbiome, plant-influenced species sorting had stronger effect on eukaryotes than on bacteria. Our study identified several fungal and protist taxa, which are correlated with decreased fruit production in wild blueberry agricultural ecosystems. The specific effect of species sorting in root microbiome resulted in an increase in relative abundance of fungi adapted to plant-associated life-style, while the relative abundance of non-fungal eukaryotes was decreased along the soil-endosphere continuum in the root, probably because of low adaptation of these microorganisms to host-plant defense responses. Analysis of community correlation networks indicated that bacterial and eukaryotic interactions became more complex along the soil-endosphere continuum and, in addition to extensive mutualistic interactions, co-exclusion also played an important role in shaping wild blueberry associated microbiome. Our study identified several potential hub taxa with important roles in soil fertility and/or plant-microbe interaction, suggesting the key role of these taxa in the interconnection between soils and plant health and overall microbial community structure. This study also provides a comprehensive view of the role of non-fungal eukaryotes in soil ecosystem.
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Affiliation(s)
- Svetlana N. Yurgel
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, Truro, NS, Canada
| | - Gavin M. Douglas
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Ashley Dusault
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, Truro, NS, Canada
| | - David Percival
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, Truro, NS, Canada
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Comparative genomics provides insights into the lifestyle and reveals functional heterogeneity of dark septate endophytic fungi. Sci Rep 2018; 8:6321. [PMID: 29679020 PMCID: PMC5910433 DOI: 10.1038/s41598-018-24686-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/06/2018] [Indexed: 01/09/2023] Open
Abstract
Dark septate endophytes (DSE) are a form-group of root endophytic fungi with elusive functions. Here, the genomes of two common DSE of semiarid areas, Cadophora sp. and Periconia macrospinosa were sequenced and analyzed with another 32 ascomycetes of different lifestyles. Cadophora sp. (Helotiales) and P. macrospinosa (Pleosporales) have genomes of 70.46 Mb and 54.99 Mb with 22,766 and 18,750 gene models, respectively. The majority of DSE-specific protein clusters lack functional annotation with no similarity to characterized proteins, implying that they have evolved unique genetic innovations. Both DSE possess an expanded number of carbohydrate active enzymes (CAZymes), including plant cell wall degrading enzymes (PCWDEs). Those were similar in three other DSE, and contributed a signal for the separation of root endophytes in principal component analyses of CAZymes, indicating shared genomic traits of DSE fungi. Number of secreted proteases and lipases, aquaporins, and genes linked to melanin synthesis were also relatively high in our fungi. In spite of certain similarities between our two DSE, we observed low levels of convergence in their gene family evolution. This suggests that, despite originating from the same habitat, these two fungi evolved along different evolutionary trajectories and display considerable functional differences within the endophytic lifestyle.
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Diversity of cultivable fungal endophytes in Paullinia cupana (Mart.) Ducke and bioactivity of their secondary metabolites. PLoS One 2018; 13:e0195874. [PMID: 29649297 PMCID: PMC5897019 DOI: 10.1371/journal.pone.0195874] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/30/2018] [Indexed: 11/19/2022] Open
Abstract
Paullinia cupana is associated with a diverse community of pathogenic and endophytic microorganisms. We isolated and identified endophytic fungal communities from the roots and seeds of P. cupana genotypes susceptible and tolerant to anthracnose that grow in two sites of the Brazilian Amazonia forest. We assessed the antibacterial, antitumor and genotoxic activity in vitro of compounds isolated from the strains Trichoderma asperellum (1BDA) and Diaporthe phaseolorum (8S). In concert, we identified eight fungal species not previously reported as endophytes; some fungal species capable of inhibiting pathogen growth; and the production of antibiotics and compounds with bacteriostatic activity against Pseudomonas aeruginosa in both susceptible and multiresistant host strains. The plant genotype, geographic location and specially the organ influenced the composition of P. cupana endophytic fungal community. Together, our findings identify important functional roles of endophytic species found within the microbiome of P. cupana. This hypothesis requires experimental validation to propose management of this microbiome with the objective of promoting plant growth and protection.
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Young E, Carey M, Meharg AA, Meharg C. Microbiome and ecotypic adaption of Holcus lanatus (L.) to extremes of its soil pH range, investigated through transcriptome sequencing. MICROBIOME 2018; 6:48. [PMID: 29554982 PMCID: PMC5859661 DOI: 10.1186/s40168-018-0434-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 03/05/2018] [Indexed: 05/26/2023]
Abstract
BACKGROUND Plants can adapt to edaphic stress, such as nutrient deficiency, toxicity and biotic challenges, by controlled transcriptomic responses, including microbiome interactions. Traditionally studied in model plant species with controlled microbiota inoculation treatments, molecular plant-microbiome interactions can be functionally investigated via RNA-Seq. Complex, natural plant-microbiome studies are limited, typically focusing on microbial rRNA and omitting functional microbiome investigations, presenting a fundamental knowledge gap. Here, root and shoot meta-transcriptome analyses, in tandem with shoot elemental content and root staining, were employed to investigate transcriptome responses in the wild grass Holcus lanatus and its associated natural multi-species eukaryotic microbiome. A full factorial reciprocal soil transplant experiment was employed, using plant ecotypes from two widely contrasting natural habitats, acid bog and limestone quarry soil, to investigate naturally occurring, and ecologically meaningful, edaphically driven molecular plant-microbiome interactions. RESULTS Arbuscular mycorrhizal (AM) and non-AM fungal colonization was detected in roots in both soils. Staining showed greater levels of non-AM fungi, and transcriptomics indicated a predominance of Ascomycota-annotated genes. Roots in acid bog soil were dominated by Phialocephala-annotated transcripts, a putative growth-promoting endophyte, potentially involved in N nutrition and ion homeostasis. Limestone roots in acid bog soil had greater expression of other Ascomycete genera and Oomycetes and lower expression of Phialocephala-annotated transcripts compared to acid ecotype roots, which corresponded with reduced induction of pathogen defense processes, particularly lignin biosynthesis in limestone ecotypes. Ascomycota dominated in shoots and limestone soil roots, but Phialocephala-annotated transcripts were insignificant, and no single Ascomycete genus dominated. Fusarium-annotated transcripts were the most common genus in shoots, with Colletotrichum and Rhizophagus (AM fungi) most numerous in limestone soil roots. The latter coincided with upregulation of plant genes involved in AM symbiosis initiation and AM-based P acquisition in an environment where P availability is low. CONCLUSIONS Meta-transcriptome analyses provided novel insights into H. lanatus transcriptome responses, associated eukaryotic microbiota functions and taxonomic community composition. Significant edaphic and plant ecotype effects were identified, demonstrating that meta-transcriptome-based functional analysis is a powerful tool for the study of natural plant-microbiome interactions.
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Affiliation(s)
- Ellen Young
- Institute for Global Food Security, Queens University Belfast, David Keir Building, Belfast, BT9 5BN Northern Ireland, UK
| | - Manus Carey
- Institute for Global Food Security, Queens University Belfast, David Keir Building, Belfast, BT9 5BN Northern Ireland, UK
| | - Andrew A. Meharg
- Institute for Global Food Security, Queens University Belfast, David Keir Building, Belfast, BT9 5BN Northern Ireland, UK
| | - Caroline Meharg
- Institute for Global Food Security, Queens University Belfast, David Keir Building, Belfast, BT9 5BN Northern Ireland, UK
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Kohout P, Charvátová M, Štursová M, Mašínová T, Tomšovský M, Baldrian P. Clearcutting alters decomposition processes and initiates complex restructuring of fungal communities in soil and tree roots. THE ISME JOURNAL 2018; 12:692-703. [PMID: 29335638 PMCID: PMC5864242 DOI: 10.1038/s41396-017-0027-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 10/01/2017] [Accepted: 10/02/2017] [Indexed: 12/23/2022]
Abstract
Forest management practices often severely affect forest ecosystem functioning. Tree removal by clearcutting is one such practice, producing severe impacts due to the total reduction of primary productivity. Here, we assessed changes to fungal community structure and decomposition activity in the soil, roots and rhizosphere of a Picea abies stand for a 2-year period following clearcutting compared to data from before tree harvest. We found that the termination of photosynthate flow through tree roots into soil is associated with profound changes in soil, both in decomposition processes and fungal community composition. The rhizosphere, representing an active compartment of high enzyme activity and high fungal biomass in the living stand, ceases to exist and starts to resemble bulk soil. Decomposing roots appear to separate from bulk soil and develop into hotspots of decomposition and important fungal biomass pools. We found no support for the involvement of ectomycorrhizal fungi in the decomposition of roots, but we found some evidence that root endophytic fungi may have an important role in the early stages of this process. In soil, activity of extracellular enzymes also decreased in the long term following the end of rhizodeposition by tree roots.
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Affiliation(s)
- Petr Kohout
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, 142 20, Praha 4, Czech Republic
- Department of Mycorrhizal Symbiosis, Institute of Botany of the CAS, Zámek 1, 252 43, Průhonice, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Praha 2, Czech Republic
| | - Markéta Charvátová
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, 142 20, Praha 4, Czech Republic
| | - Martina Štursová
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, 142 20, Praha 4, Czech Republic
| | - Tereza Mašínová
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, 142 20, Praha 4, Czech Republic
| | - Michal Tomšovský
- Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00, Brno, Czech Republic
| | - Petr Baldrian
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, 142 20, Praha 4, Czech Republic.
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Identification of fungi in shotgun metagenomics datasets. PLoS One 2018; 13:e0192898. [PMID: 29444186 PMCID: PMC5812651 DOI: 10.1371/journal.pone.0192898] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/31/2018] [Indexed: 01/22/2023] Open
Abstract
Metagenomics uses nucleic acid sequencing to characterize species diversity in different niches such as environmental biomes or the human microbiome. Most studies have used 16S rRNA amplicon sequencing to identify bacteria. However, the decreasing cost of sequencing has resulted in a gradual shift away from amplicon analyses and towards shotgun metagenomic sequencing. Shotgun metagenomic data can be used to identify a wide range of species, but have rarely been applied to fungal identification. Here, we develop a sequence classification pipeline, FindFungi, and use it to identify fungal sequences in public metagenome datasets. We focus primarily on animal metagenomes, especially those from pig and mouse microbiomes. We identified fungi in 39 of 70 datasets comprising 71 fungal species. At least 11 pathogenic species with zoonotic potential were identified, including Candida tropicalis. We identified Pseudogymnoascus species from 13 Antarctic soil samples initially analyzed for the presence of bacteria capable of degrading diesel oil. We also show that Candida tropicalis and Candida loboi are likely the same species. In addition, we identify several examples where contaminating DNA was erroneously included in fungal genome assemblies.
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Martino E, Morin E, Grelet GA, Kuo A, Kohler A, Daghino S, Barry KW, Cichocki N, Clum A, Dockter RB, Hainaut M, Kuo RC, LaButti K, Lindahl BD, Lindquist EA, Lipzen A, Khouja HR, Magnuson J, Murat C, Ohm RA, Singer SW, Spatafora JW, Wang M, Veneault-Fourrey C, Henrissat B, Grigoriev IV, Martin FM, Perotto S. Comparative genomics and transcriptomics depict ericoid mycorrhizal fungi as versatile saprotrophs and plant mutualists. THE NEW PHYTOLOGIST 2018; 217:1213-1229. [PMID: 29315638 DOI: 10.1111/nph.14974] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 11/25/2017] [Indexed: 05/10/2023]
Abstract
Some soil fungi in the Leotiomycetes form ericoid mycorrhizal (ERM) symbioses with Ericaceae. In the harsh habitats in which they occur, ERM plant survival relies on nutrient mobilization from soil organic matter (SOM) by their fungal partners. The characterization of the fungal genetic machinery underpinning both the symbiotic lifestyle and SOM degradation is needed to understand ERM symbiosis functioning and evolution, and its impact on soil carbon (C) turnover. We sequenced the genomes of the ERM fungi Meliniomyces bicolor, M. variabilis, Oidiodendron maius and Rhizoscyphus ericae, and compared their gene repertoires with those of fungi with different lifestyles (ecto- and orchid mycorrhiza, endophytes, saprotrophs, pathogens). We also identified fungal transcripts induced in symbiosis. The ERM fungal gene contents for polysaccharide-degrading enzymes, lipases, proteases and enzymes involved in secondary metabolism are closer to those of saprotrophs and pathogens than to those of ectomycorrhizal symbionts. The fungal genes most highly upregulated in symbiosis are those coding for fungal and plant cell wall-degrading enzymes (CWDEs), lipases, proteases, transporters and mycorrhiza-induced small secreted proteins (MiSSPs). The ERM fungal gene repertoire reveals a capacity for a dual saprotrophic and biotrophic lifestyle. This may reflect an incomplete transition from saprotrophy to the mycorrhizal habit, or a versatile life strategy similar to fungal endophytes.
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Affiliation(s)
- Elena Martino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Emmanuelle Morin
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Gwen-Aëlle Grelet
- Manaaki Whenua - Landcare Research, Ecosystems and Global Change Team, Gerald Street, PO Box 69040, Lincoln, 7640, New Zealand
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Annegret Kohler
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Stefania Daghino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
| | - Kerrie W Barry
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Nicolas Cichocki
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Alicia Clum
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Rhyan B Dockter
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Matthieu Hainaut
- Architecture et Fonction des Macromolécules Biologiques, UMR7257 Centre National de la Recherche Scientifique - Aix-Marseille Université, Case 932, 163 Avenue de Luminy, Marseille, 13288, France
- INRA, USC 1408 AFMB, Marseille, 13288, France
| | - Rita C Kuo
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Björn D Lindahl
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, 75007, Sweden
| | - Erika A Lindquist
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | | | - Jon Magnuson
- Pacific Northwest National Laboratory, Chemical and Biological Process Development Group, Richland, WA, 99354, USA
| | - Claude Murat
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Robin A Ohm
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
- Microbiology, Department of Biology, Utrecht University, 3508, TB Utrecht, the Netherlands
| | - Steven W Singer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Joseph W Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Mei Wang
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Claire Veneault-Fourrey
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
- Laboratoire d'Excellence ARBRE, Faculté des Sciences et Technologies, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Université de Lorraine, Campus Aiguillettes, BP 70239, Vandoeuvre les Nancy cedex, 54506, France
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR7257 Centre National de la Recherche Scientifique - Aix-Marseille Université, Case 932, 163 Avenue de Luminy, Marseille, 13288, France
- INRA, USC 1408 AFMB, Marseille, 13288, France
- Department of Biological Sciences, King Abdulaziz University - KSA, Jeddah, 21589, Saudi Arabia
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Francis M Martin
- INRA, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, 54280, Champenoux, France
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, 10125, Italy
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Robicheau BM, Bunbury-Blanchette AL, LaButti K, Grigoriev IV, Walker AK. The homothallic mating-type locus of the conifer needle endophyte Phialocephala scopiformis DAOMC 229536 (order Helotiales). Fungal Biol 2017; 121:1011-1024. [PMID: 29122173 DOI: 10.1016/j.funbio.2017.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 08/11/2017] [Accepted: 08/22/2017] [Indexed: 12/14/2022]
Abstract
We describe the complete mating-type (MAT) locus for Phialocephala scopiformis Canadian Collection of Fungal Cultures (DAOMC) 229536 - a basal lineage within Vibrisseaceae. This strain is of interest due to its ability to produce the important antiinsectan rugulosin. We also provide some of the first insights into the genome structure and gene inventory of nonclavicipitalean endophytes. Sequence was obtained through shotgun sequencing of the entire P. scopiformis genome, and the MAT locus was then determined by comparing this genomic sequence to known MAT loci within the Phialocephala fortinii s.l.-Acephala applanata species complex. We also tested the relative levels of sequence conservation for MAT genes within Vibrisseaceae (n = 10), as well as within the Helotiales (n = 27). Our results: (1) show a homothallic gene arrangement for P. scopiformis [MAT1-1-1, MAT1-2-1, and MAT1-1-3 genes are present], (2) increase the genomic survey of homothallism within Vibrisseaceae, (3) confirm that P. scopiformis contains a unique S-adenosyl-l-methionine-dependent methyltransferase (SAM-Mtase) gene proximal to its MAT locus, while also lacking a cytoskeleton assembly control protein (sla2) gene, and (4) indicate that MAT1-1-1 is the more useful molecular marker amongst the MAT genes for phylogenetic reconstructions aimed at tracking evolutionary shifts in reproductive strategy and/or MAT loci gene composition within the Helotiales.
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Affiliation(s)
- Brent M Robicheau
- Department of Biology, Acadia University, 33 Westwood Avenue, Wolfville, Nova Scotia B4P 2R6, Canada.
| | | | - Kurt LaButti
- U.S. Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA; Department of Plant and Microbial Biology, UC Berkeley, 111 Koshland Hall, Berkeley, California 94720, USA
| | - Allison K Walker
- Department of Biology, Acadia University, 33 Westwood Avenue, Wolfville, Nova Scotia B4P 2R6, Canada
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Donnart T, Piednoël M, Higuet D, Bonnivard É. Filamentous ascomycete genomes provide insights into Copia retrotransposon diversity in fungi. BMC Genomics 2017; 18:410. [PMID: 28545447 PMCID: PMC5445492 DOI: 10.1186/s12864-017-3795-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 05/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background The relative scarcity of Copia retrotransposons has been recently characterized in metazoans in comparison with the other superfamilies of LTR elements. Furthermore, Copia retrotransposons have often a particular dynamics that results in a highly predominant single clade of elements within a large host taxon, such as the GalEa-like retrotransposons in crustaceans. Taking advantage of the skyrocketing amount of genomic data available for fungi, we carried out the first large-scale comparative genomic analysis of the Copia clades in filamentous ascomycetes. Results Screening 30 completely sequenced genomes allowed us to identify more than 2500 Copia copies with conserved LTR, which are distributed in 138 families. Their characterization revealed that fungal Copia diversity is much broader than previously thought with at least 27 clades, 23 of which likely correspond to new ones. While the Copia copy number is low in most species, the two clades GalEa and FunCo1 are widely distributed and highly dominate Copia content as they both account for 80% of the detected sequences. Conclusions In Fungi, GalEa retrotransposons are restricted to Pezizomycotina in which they can make up an outstandingly high proportion of the genome (up to 10% in Cenococcum geophilum). At last, we revealed that fungal GalEa elements structurally differ from all other Copia elements with an absence of Primer Binding Site. These elements however harbor a Conserved Hairpin Site which is probably essential for their transposition. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3795-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tifenn Donnart
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France
| | - Mathieu Piednoël
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, D-50829, Cologne, Germany
| | - Dominique Higuet
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France
| | - Éric Bonnivard
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France.
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