1
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Zhang P, Huguet-Tapia J, Peng Z, Liu S, Obasa K, Block AK, White FF. Genome analysis and hyphal movement characterization of the hitchhiker endohyphal Enterobacter sp. from Rhizoctonia solani. Appl Environ Microbiol 2024; 90:e0224523. [PMID: 38319098 PMCID: PMC10952491 DOI: 10.1128/aem.02245-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 02/07/2024] Open
Abstract
Bacterial-fungal interactions are pervasive in the rhizosphere. While an increasing number of endohyphal bacteria have been identified, little is known about their ecology and impact on the associated fungal hosts and the surrounding environment. In this study, we characterized the genome of an Enterobacter sp. Crenshaw (En-Cren), which was isolated from the generalist fungal pathogen Rhizoctonia solani, and examined the genetic potential of the bacterium with regard to the phenotypic traits associated with the fungus. Overall, the En-Cren genome size was typical for members of the genus and was capable of free-living growth. The genome was 4.6 MB in size, and no plasmids were detected. Several prophage regions and genomic islands were identified that harbor unique genes in comparison with phylogenetically closely related Enterobacter spp. Type VI secretion system and cyanate assimilation genes were identified from the bacterium, while some common heavy metal resistance genes were absent. En-Cren contains the key genes for indole-3-acetic acid (IAA) and phenylacetic acid (PAA) biosynthesis, and produces IAA and PAA in vitro, which may impact the ecology or pathogenicity of the fungal pathogen in vivo. En-Cren was observed to move along hyphae of R. solani and on other basidiomycetes and ascomycetes in culture. The bacterial flagellum is essential for hyphal movement, while other pathways and genes may also be involved.IMPORTANCEThe genome characterization and comparative genomics analysis of Enterobacter sp. Crenshaw provided the foundation and resources for a better understanding of the ecology and evolution of this endohyphal bacteria in the rhizosphere. The ability to produce indole-3-acetic acid and phenylacetic acid may provide new angles to study the impact of phytohormones during the plant-pathogen interactions. The hitchhiking behavior of the bacterium on a diverse group of fungi, while inhibiting the growth of some others, revealed new areas of bacterial-fungal signaling and interaction, which have yet to be explored.
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Affiliation(s)
- Peiqi Zhang
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Jose Huguet-Tapia
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Zhao Peng
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- College of Plant Protection, Jilin Agricultural University, Changchun, Jilin, China
| | - Sanzhen Liu
- Department of Plant Pathology, Kansas State University, Manhattan, Kansas, USA
| | - Ken Obasa
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
- High Plains Plant Disease Diagnostic Lab, Texas A&M AgriLife Extension Service, Amarillo, Texas, USA
| | - Anna K. Block
- Chemistry Research Unit, US Department of Agriculture-Agricultural Research Service, Gainesville, Florida, USA
| | - Frank F. White
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
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2
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Zheng H, Chen T, Li W, Hong J, Xu J, Yu Z. Endosymbiotic bacteria within the nematode-trapping fungus Arthrobotrys musiformis and their potential roles in nitrogen cycling. Front Microbiol 2024; 15:1349447. [PMID: 38348183 PMCID: PMC10860758 DOI: 10.3389/fmicb.2024.1349447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/10/2024] [Indexed: 02/15/2024] Open
Abstract
Endosymbiotic bacteria (ESB) have important effects on their hosts, contributing to its growth, reproduction and biological functions. Although the effects of exogenous bacteria on the trap formation of nematode-trapping fungi (NTF) have been revealed, the effects of ESB on NTF remain unknown. In this study, we investigated the species diversity of ESB in the NTF Arthrobotrys musiformis using high-throughput sequencing and culture-dependent approaches, and compared bacterial profiles to assess the effects of strain source and culture media on A. musiformis. PICRUSt2 and FAPROTAX were used to predict bacterial function. Our study revealed that bacterial communities in A. musiformis displayed high diversity and heterogeneity, with Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria as the dominant phyla. The ESB between A. musiformis groups isolated from different habitats and cultured in the same medium were more similar to each other than the other groups isolated from the same habitat but cultured in different media. Function analysis predicted a broad and diverse functional repertoire of ESB in A. musiformis, and unveiled that ESB have the potential to function in five modules of the nitrogen metabolism. We isolated nitrogen-fixing and denitrifying bacteria from the ESB and demonstrated their effects on trap formation of A. musiformis. Among seven bacteria that we tested, three bacterial species Bacillus licheniformis, Achromobacter xylosoxidans and Stenotrophomonas maltophilia were found to be efficient in inducing trap formation. In conclusion, this study revealed extensive ESB diversity within NTF and demonstrated that these bacteria likely play important roles in nitrogen cycling, including nematode trap formation.
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Affiliation(s)
- Hua Zheng
- Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Tong Chen
- Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Wenjie Li
- Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Jianan Hong
- Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Zefen Yu
- Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, China
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Desirò A, Takashima Y, Bonito G, Nishizawa T, Narisawa K, Bonfante P. Investigating Endobacteria that Thrive Within Mucoromycota. Methods Mol Biol 2022; 2605:293-323. [PMID: 36520400 DOI: 10.1007/978-1-0716-2871-3_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Metagenomics approaches have revealed the importance of Mucoromycota in the evolution and functioning of plant microbiomes. Comprised of three subphyla (Glomeromycotina, Mortierellomycotina, and Mucoromycotina), this early diverging lineage of fungi encompasses species of mycorrhizal fungi, root endophytes, plant pathogens, and many decomposers of plant debris. Interestingly, several taxa of Mucoromycota share a common feature, that is, the presence of endobacteria within their mycelia and spores. The study of these endosymbiotic bacteria is still a challenging task. However, given recent improvements in the sensitivity of culture-free approaches, a deeper understanding of such microbial interactions is now possible and fuels an emerging research field. In this chapter, we report how Mucoromycota, in particular Mortierellomycotina, and their endobacteria can be investigated using a combination of diverse cellular biology, microscopy, and molecular techniques.
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Affiliation(s)
- Alessandro Desirò
- Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Yusuke Takashima
- Sugadaira Research Station, Mountain Science Center, University of Tsukuba, Nagano, Japan
| | - Gregory Bonito
- Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | | | | | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
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Telagathoti A, Probst M, Mandolini E, Peintner U. Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov.. Stud Mycol 2022; 103:25-58. [PMID: 37342154 PMCID: PMC10277274 DOI: 10.3114/sim.2022.103.02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/02/2022] [Indexed: 10/09/2023] Open
Abstract
Fungi are incredibly diverse, but they are unexplored, especially in the subalpine and alpine zone. Mortierellaceae are certainly one of the most abundant, species-rich, and widely distributed cultivable soil fungal families in terrestrial habitats, including subalpine and alpine zones. The phylogeny of Mortierellaceae was recently resolved based on current state of the art molecular techniques, and the paraphyletic genus Mortierella sensu lato (s.l.) was divided into 13 monophyletic genera. Our extensive sampling campaigns in the Austrian Alps resulted in 139 different Mortierellaceae pure culture isolates representing 13 new species. For the definition of taxa, we applied both classical morphological criteria, as well as modern DNA-based methods. Phylogenetic relationships were resolved based on the ribosomal DNA internal transcribed spacer (rDNA ITS), the large subunit (LSU), and the DNA-directed RNA polymerase II largest subunit 1 (RPB1). In this study, we proposed a new genus and described 13 new species belonging to the genera Entomortierella, Linnemannia, Mortierella and Podila. In addition, we proposed eight new combinations, re-defined E. jenkinii at species level, defined a neotype for M. alpina and lecto- as well as epitypes for M. fatshederae, M. jenkinii, and M. longigemmata. The rDNA ITS region is generally applied as classical barcoding gene for fungi. However, the obtained phylogenetic resolution is often too low for an accurate identification of closely related species of Mortierellaceae, especially for small sampling sizes. In such cases, unambiguous identification can be obtained based on morphological characters of pure culture isolates. Therefore, we also provide dichotomous keys for species identification within phylogenetic lineages. Taxonomic novelties: new genus: Tyroliella Telagathoti, Probst & Peintner; New species: Entomortierella galaxiae Telagathoti, M. Probst & Peintner, Linnemannia bainierella Telagathoti, M. Probst & Peintner, Linnemannia stellaris Telagathoti, M. Probst & Peintner, Linnemannia nimbosa Telagathoti, M. Probst & Peintner, Linnemannia mannui Telagathoti, M. Probst & Peintner, Linnemannia friederikiana Telagathoti, M. Probst & Peintner, Linnemannia scordiella Telagathoti, M. Probst & Peintner, Linnemannia solitaria Telagathoti, M. Probst & Peintner, Mortierella triangularis Telagathoti, M. Probst & Peintner, Mortierella lapis Telagathoti, M. Probst & Peintner, Podila himami Telagathoti, M. Probst & Peintner, Podila occulta Telagathoti, M. Probst & Peintner, Tyroliella animus-liberi Telagathoti, Probst & Peintner; New combinations: Entomortierella basiparvispora (W. Gams & Grinb.) Telagathoti, M. Probst & Peintner, Entomortierella jenkinii (A.L. Sm.) Telagathoti, M. Probst & Peintner; Entomortierella sugadairana (Y. Takash. et al.) Telagathoti, M. Probst & Peintner, Linnemannia zonata (Linnem. ex W. Gams) Telagathoti, M. Probst & Peintner, Linnemannia fluviae (Hyang B. Lee et al.) Telagathoti, M. Probst & Peintner, Linnemannia biramosa (Tiegh.) Telagathoti, M. Probst & Peintner, Linnemannia cogitans (Degawa) Telagathoti, M. Probst & Peintner, Tyroliella pseudozygospora (W. Gams & Carreiro) Telagathoti, M. Probst & Peintner; Epitypifications (basionyms): Mortierella bainieri var. jenkinii A.L. Sm., Mortierella fatshederae Linnem., Mortierella longigemmata Linnem. Neotypification (basionym): Mortierella alpina Peyronel. Citation: Telagathoti A, Probst M, Mandolini E, Peintner U (2022). Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov. Studies in Mycology 103: 25-58. doi: 10.3114/sim.2022.103.02.
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Affiliation(s)
- A. Telagathoti
- Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - M. Probst
- Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - E. Mandolini
- Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - U. Peintner
- Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
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5
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Wang R, Dong L, Chen Y, Wang S, Qu L. Third Generation Genome Sequencing Reveals That Endobacteria in Nematophagous Fungi Esteya vermicola Contain Multiple Genes Encoding for Nematicidal Proteins. Front Microbiol 2022; 13:842684. [PMID: 35591989 PMCID: PMC9111515 DOI: 10.3389/fmicb.2022.842684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Esteya vermicola is the first recorded endoparasitic nematophagous fungus with high infectivity capacity, attacking the pinewood nematode Bursaphelenchus xylophilus which causes pine wilt disease. Endosymbionts are found in the cytoplasm of E. vermicola from various geographical areas. We sequenced the genome of endobacteria residing in E. vermicola to discover possible biological functions of these widespread endobacteria. Multilocus phylogenetic analyses showed that the endobacteria form a previously unidentified lineage sister to Phyllobacterium myrsinacearum species. The number of genes in the endobacterium was 4542, with 87.8% of the proteins having a known function. It contained a high proportion of repetitive sequences, as well as more Acyl-CoA synthetase genes and genes encoding the electron transport chain, compared with compared with plant-associated P. zundukense Tri 48 and P. myrsinacearum DSM 5893. Thus, this symbiotic bacterium is likely to be more efficient in regulating gene expression and energy release. Furthermore, the endobacteria in nematophagous fungi Esteya vermicola contained multiple nematicidal subtilase/subtilisin encoding genes, so it is likely that endobacteria cooperate with the host to kill nematodes.
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Affiliation(s)
- Ruizhen Wang
- Beijing Floriculture Engineering Technology Research Centre, Beijing Botanical Garden, Beijing, China.,The Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
| | - Leiming Dong
- Beijing Floriculture Engineering Technology Research Centre, Beijing Botanical Garden, Beijing, China
| | - Yuequ Chen
- Forestry Resources Protection Institute, Jilin Provincial Academy of Forestry Sciences, Changchun, China
| | - Shuai Wang
- School of Pharmacy, Liaocheng University, Liaocheng, China
| | - Liangjian Qu
- The Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
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6
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Venice F, Desirò A, Silva G, Salvioli A, Bonfante P. The Mosaic Architecture of NRPS-PKS in the Arbuscular Mycorrhizal Fungus Gigaspora margarita Shows a Domain With Bacterial Signature. Front Microbiol 2020; 11:581313. [PMID: 33329443 PMCID: PMC7732545 DOI: 10.3389/fmicb.2020.581313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/29/2020] [Indexed: 12/31/2022] Open
Abstract
As obligate biotrophic symbionts, arbuscular mycorrhizal fungi (AMF) live in association with most land plants. Among them, Gigaspora margarita has been deeply investigated because of its peculiar features, i.e., the presence of an intracellular microbiota with endobacteria and viruses. The genome sequencing of this fungus revealed the presence of some hybrid non-ribosomal peptide synthases-polyketide synthases (NRPS-PKS) that have been rarely identified in AMF. The aim of this study is to describe the architecture of these NRPS-PKS sequences and to understand whether they are present in other fungal taxa related to G. margarita. A phylogenetic analysis shows that the ketoacyl synthase (KS) domain of one G. margarita NRPS-PKS clusters with prokaryotic sequences. Since horizontal gene transfer (HGT) has often been advocated as a relevant evolutionary mechanism for the spread of secondary metabolite genes, we hypothesized that a similar event could have interested the KS domain of the PKS module. The bacterial endosymbiont of G. margarita, Candidatus Glomeribacter gigasporarum (CaGg), was the first candidate as a donor, since it possesses a large biosynthetic cluster involving an NRPS-PKS. However, bioinformatics analyses do not confirm the hypothesis of a direct HGT from the endobacterium to the fungal host: indeed, endobacterial and fungal sequences show a different evolution and potentially different donors. Lastly, by amplifying a NRPS-PKS conserved fragment and mining the sequenced AMF genomes, we demonstrate that, irrespective of the presence of CaGg, G. margarita, and some other related Gigasporaceae possess such a sequence.
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Affiliation(s)
- Francesco Venice
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.,Institute for Sustainable Plant Protection (IPSP)-SS Turin-National Research Council (CNR), Turin, Italy
| | - Alessandro Desirò
- Department of Plant, Soil and Microbial Sciences, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI, United States
| | - Gladstone Silva
- Department of Mycology, Federal University of Pernambuco, Recife, Brazil
| | - Alessandra Salvioli
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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7
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Shao M, Sun C, Liu X, Wang X, Li W, Wei X, Li Q, Ju J. Upregulation of a marine fungal biosynthetic gene cluster by an endobacterial symbiont. Commun Biol 2020; 3:527. [PMID: 32968175 PMCID: PMC7511336 DOI: 10.1038/s42003-020-01239-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022] Open
Abstract
Fungal-bacterial associations are present in nature, playing important roles in ecological, evolutionary and medicinal processes. Here we report a fungus-bacterial symbiont from marine sediment. The bacterium lives inside the fungal mycelium yet is robust enough to survive independent of its host; the independently grown bacterium can infect the fungal host in vitro and continue to grow progenitively. The bacterial symbiont modulates the fungal host to biosynthesize a polyketide antimicrobial, spiromarmycin. Spiromarmycin appears to endow upon the symbiont pair a protective/defensive means of warding off competitor organisms, be they prokaryotic or eukaryotic microorganisms. Genomic analyses revealed the spiromarmycin biosynthetic machinery to be encoded, not by the bacterium, but rather the fungal host. This unique fungal-bacterial symbiotic relationship and the molecule/s resulting from it dramatically expand our knowledge of marine microbial diversity and shed important insights into endosymbionts and fungal-bacterial relationships. Shao et al. show that a bacterial symbiont drives its fungal host to biosynthesize a polyketide antimicrobial, spiromarmycin, fending off their competitors. They find that the spiromarmycin biosynthetic machinery is encoded by the fungal host. This study provides insights into the evolution of marine microbial diversity.
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Affiliation(s)
- Mingwei Shao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,College of Oceanology, University of Chinese Academy of Sciences, Beijing, 100049, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Changli Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Xiaoxiao Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Xiaoxue Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,College of Oceanology, University of Chinese Academy of Sciences, Beijing, 100049, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Wenli Li
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Xiaoyi Wei
- Key Laboratory of Plant Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Qinglian Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| | - Jianhua Ju
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China. .,College of Oceanology, University of Chinese Academy of Sciences, Beijing, 100049, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
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8
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Mycoavidus sp. Strain B2-EB: Comparative Genomics Reveals Minimal Genomic Features Required by a Cultivable Burkholderiaceae-Related Endofungal Bacterium. Appl Environ Microbiol 2020; 86:AEM.01018-20. [PMID: 32651207 DOI: 10.1128/aem.01018-20] [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] [Received: 05/01/2020] [Accepted: 07/02/2020] [Indexed: 01/01/2023] Open
Abstract
Obligate bacterial endosymbionts are critical to the existence of many eukaryotes. Such endobacteria are usually characterized by reduced genomes and metabolic dependence on the host, which may cause difficulty in isolating them in pure cultures. Family Burkholderiaceae-related endofungal bacteria affiliated with the Mycoavidus-Glomeribacter clade can be associated with the fungal subphyla Mortierellomycotina and Glomeromycotina. In this study, a cultivable endosymbiotic bacterium, Mycoavidus sp. strain B2-EB, present in the fungal host Mortierella parvispora was obtained successfully. The B2-EB genome (1.88 Mb) represents the smallest genome among the endofungal bacterium Mycoavidus cysteinexigens (2.64-2.80 Mb) of Mortierella elongata and the uncultured endosymbiont "Candidatus Glomeribacter gigasporarum" (1.37 to 2.36 Mb) of arbuscular mycorrhizal fungi. Despite a reduction in genome size, strain B2-EB displays a high genome completeness, suggesting a nondegenerative reduction in the B2-EB genome. Compared with a large proportion of transposable elements (TEs) in other known Mycoavidus genomes (7.2 to 11.5% of the total genome length), TEs accounted for only 2.4% of the B2-EB genome. This pattern, together with a high proportion of single-copy genes in the B2-EB genome, suggests that the B2-EB genome reached a state of relative evolutionary stability. These results represent the most streamlined structure among the cultivable endofungal bacteria and suggest the minimal genome features required by both an endofungal lifestyle and artificial culture. This study allows us to understand the genome evolution of Burkholderiaceae-related endosymbionts and to elucidate microbiological interactions.IMPORTANCE This study attempted the isolation of a novel endobacterium, Mycoavidus sp. B2-EB (JCM 33615), harbored in the fungal host Mortierella parvispora E1425 (JCM 39028). We report the complete genome sequence of this strain, which possesses a reduced genome size with relatively high genome completeness and a streamlined genome structure. The information indicates the minimal genomic features required by both the endofungal lifestyle and artificial cultivation, which furthers our understanding of genome reduction in fungal endosymbionts and extends the culture resources for biotechnological development on engineering synthetic microbiomes.
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9
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Takashima Y, Degawa Y, Nishizawa T, Ohta H, Narisawa K. Aposymbiosis of a Burkholderiaceae-Related Endobacterium Impacts on Sexual Reproduction of Its Fungal Host. Microbes Environ 2020; 35. [PMID: 32295978 PMCID: PMC7308579 DOI: 10.1264/jsme2.me19167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacterial endosymbionts inhabit diverse fungal lineages. Although the number of studies on bacteria is increasing, the mechanisms by which bacteria affect their fungal hosts remain unclear. We herein examined the homothallic isolate, Mortierella sugadairana YTM39, harboring a Burkholderiaceae-related endobacterium, which did not produce sexual spores. We successfully eliminated the bacterium from fungal isolates using ciprofloxacin treatment and asexual spore isolation for germinated asexual spores. Sexual spore formation by the fungus was restored by eliminating the bacterium from isolates. These results indicate that sexual reproduction by the fungus was inhibited by the bacterium. This is the first study on the sexual spore infertility of fungal hosts by endofungal bacteria.
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Affiliation(s)
- Yusuke Takashima
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Yousuke Degawa
- Sugadaira Research Station Mountain Science Center, University of Tsukuba
| | - Tomoyasu Nishizawa
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Hiroyuki Ohta
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Kazuhiko Narisawa
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
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10
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Uehling JK, Entler MR, Meredith HR, Millet LJ, Timm CM, Aufrecht JA, Bonito GM, Engle NL, Labbé JL, Doktycz MJ, Retterer ST, Spatafora JW, Stajich JE, Tschaplinski TJ, Vilgalys RJ. Microfluidics and Metabolomics Reveal Symbiotic Bacterial-Fungal Interactions Between Mortierella elongata and Burkholderia Include Metabolite Exchange. Front Microbiol 2019; 10:2163. [PMID: 31632357 PMCID: PMC6779839 DOI: 10.3389/fmicb.2019.02163] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/03/2019] [Indexed: 01/12/2023] Open
Abstract
We identified two poplar (Populus sp.)-associated microbes, the fungus, Mortierella elongata strain AG77, and the bacterium, Burkholderia strain BT03, that mutually promote each other’s growth. Using culture assays in concert with a novel microfluidic device to generate time-lapse videos, we found growth specific media differing in pH and pre-conditioned by microbial growth led to increased fungal and bacterial growth rates. Coupling microfluidics and comparative metabolomics data results indicated that observed microbial growth stimulation involves metabolic exchange during two ordered events. The first is an emission of fungal metabolites, including organic acids used or modified by bacteria. A second signal of unknown nature is produced by bacteria which increases fungal growth rates. We find this symbiosis is initiated in part by metabolic exchange involving fungal organic acids.
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Affiliation(s)
- Jessie K Uehling
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States.,Department of Biology, Duke University, Durham, NC, United States
| | - Matthew R Entler
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Hannah R Meredith
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.,Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Larry J Millet
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,The Bredesen Center, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Collin M Timm
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jayde A Aufrecht
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Gregory M Bonito
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Nancy L Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jessy L Labbé
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Genome Science & Technology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Mitchel J Doktycz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Genome Science & Technology, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Scott T Retterer
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Joseph W Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | | | - Rytas J Vilgalys
- Department of Biology, Duke University, Durham, NC, United States
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11
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Takashima Y, Seto K, Degawa Y, Guo Y, Nishizawa T, Ohta H, Narisawa K. Prevalence and Intra-Family Phylogenetic Divergence of Burkholderiaceae-Related Endobacteria Associated with Species of Mortierella. Microbes Environ 2018; 33:417-427. [PMID: 30531154 PMCID: PMC6307997 DOI: 10.1264/jsme2.me18081] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Endofungal bacteria are widespread within the phylum Mucoromycota, and these include Burkholderiaceae-related endobacteria (BRE). However, the prevalence of BRE in Mortierellomycotinan fungi and their phylogenetic divergence remain unclear. Therefore, we examined the prevalence of BRE in diverse species of Mortierella. We surveyed 238 isolates of Mortierella spp. mainly obtained in Japan that were phylogenetically classified into 59 species. BRE were found in 53 isolates consisting of 22 species of Mortierella. Among them, 20 species of Mortierella were newly reported as the fungal hosts of BRE. BRE in a Glomeribacter-Mycoavidus clade in the family Burkholderiaceae were separated phylogenetically into three groups. These groups consisted of a group containing Mycoavidus cysteinexigens, which is known to be associated with M. elongata, and two other newly distinguishable groups. Our results demonstrated that BRE were harbored by many species of Mortierella and those that associated with isolates of Mortierella spp. were more phylogenetically divergent than previously reported.
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Affiliation(s)
- Yusuke Takashima
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Kensuke Seto
- Mountain Science Center Sugadaira Research Station, University of Tsukuba
| | - Yousuke Degawa
- Mountain Science Center Sugadaira Research Station, University of Tsukuba
| | - Yong Guo
- Ibaraki University College of Agriculture
| | - Tomoyasu Nishizawa
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Hiroyuki Ohta
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
| | - Kazuhiko Narisawa
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology.,Ibaraki University College of Agriculture
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12
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Pawlowska TE, Gaspar ML, Lastovetsky OA, Mondo SJ, Real-Ramirez I, Shakya E, Bonfante P. Biology of Fungi and Their Bacterial Endosymbionts. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:289-309. [PMID: 30149793 DOI: 10.1146/annurev-phyto-080417-045914] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Heritable symbioses, in which endosymbiotic bacteria (EB) are transmitted vertically between host generations, are an important source of evolutionary novelties. A primary example of such symbioses is the eukaryotic cell with its EB-derived organelles. Recent discoveries suggest that endosymbiosis-related innovations can be also found in associations formed by early divergent fungi in the phylum Mucoromycota with heritable EB from two classes, Betaproteobacteria and Mollicutes. These symbioses exemplify novel types of host-symbiont interactions. Studies of these partnerships fuel theoretical models describing mechanisms that stabilize heritable symbioses, control the rate of molecular evolution, and enable the establishment of mutualisms. Lastly, by altering host phenotypes and metabolism, these associations represent an important instrument for probing the basic biology of the Mucoromycota hosts, which remain one of the least explored filamentous fungi.
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Affiliation(s)
- Teresa E Pawlowska
- School of Integrative Plant Science, Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, New York 14853, USA;
| | - Maria L Gaspar
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Olga A Lastovetsky
- School of Biology and Environmental Science and Earth Institute, University College Dublin, Dublin, Ireland
| | - Stephen J Mondo
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | | | - Evaniya Shakya
- School of Integrative Plant Science, Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, New York 14853, USA;
| | - Paola Bonfante
- Department of Life Sciences & Systems Biology, University of Torino, 10125 Torino, Italy
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13
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Abstract
The ecological modes of fungi are shaped not only by their intrinsic features and the environment in which they occur, but also by their interactions with diverse microbes. Here we explore the ecological and genomic features of diverse bacterial endosymbionts-endohyphal bacteria-that together are emerging as major determinants of fungal phenotypes and plant-fungi interactions. We first provide a historical perspective on the study of endohyphal bacteria. We then propose a functional classification of three main groups, providing an overview of their genomic, phylogenetic, and ecological traits. Last, we explore frontiers in the study of endohyphal bacteria, with special attention to those facultative and horizontally transmitted bacteria that associate with some of the most diverse lineages of fungi. Overall, our aim is to synthesize the rich literature from nearly 50 years of studies on endohyphal bacteria as a means to highlight potential applications and new research directions.
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14
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Sharmin D, Guo Y, Nishizawa T, Ohshima S, Sato Y, Takashima Y, Narisawa K, Ohta H. Comparative Genomic Insights into Endofungal Lifestyles of Two Bacterial Endosymbionts, Mycoavidus cysteinexigens and Burkholderia rhizoxinica. Microbes Environ 2018. [PMID: 29540638 PMCID: PMC5877345 DOI: 10.1264/jsme2.me17138] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endohyphal bacteria (EHB), dwelling within fungal hyphae, markedly affect the growth and metabolic potential of their hosts. To date, two EHB belonging to the family Burkholderiaceae have been isolated and characterized as new taxa, Burkholderia rhizoxinica (HKI 454T) and Mycoavidus cysteinexigens (B1-EBT), in Japan. Metagenome sequencing was recently reported for Mortierella elongata AG77 together with its endosymbiont M. cysteinexigens (Mc-AG77) from a soil/litter sample in the USA. In the present study, we elucidated the complete genome sequence of B1-EBT and compared it with those of Mc-AG77 and HKI 454T. The genomes of B1-EBT and Mc-AG77 contained a higher level of prophage sequences and were markedly smaller than that of HKI 454T. Although the B1-EBT and Mc-AG77 genomes lacked the chitinolytic enzyme genes responsible for invasion into fungal cells, they contained several predicted toxin-antitoxin systems including an insecticidal toxin complex and PIN domain imposing an addiction-like mechanism essential for endohyphal growth control during host colonization. Despite the different host fungi, the alignment of amino acid sequences showed that the HKI 454T genome consisted of 1,265 (32.6%) and 1,221 (31.5%) orthologous coding sequences (CDSs) with those of B1-EBT and Mc-AG77, respectively. This comparative study of three phylogenetically associated endosymbionts has provided insights into their origin and evolution, and suggests the later bacterial invasion and adaptation of B1-EBT to its host metabolism.
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Affiliation(s)
- Dilruba Sharmin
- Ibaraki University College of Agriculture, Department of Bioresource Science
| | - Yong Guo
- Ibaraki University College of Agriculture, Department of Bioresource Science
| | - Tomoyasu Nishizawa
- Ibaraki University College of Agriculture, Department of Bioresource Science.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology
| | - Shoko Ohshima
- Ibaraki University College of Agriculture, Department of Bioresource Science
| | - Yoshinori Sato
- Center for Conservation and Restoration Techniques, Tokyo National Research Institute for Cultural Properties
| | - Yusuke Takashima
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology
| | - Kazuhiko Narisawa
- Ibaraki University College of Agriculture, Department of Bioresource Science.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology
| | - Hiroyuki Ohta
- Ibaraki University College of Agriculture, Department of Bioresource Science.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology
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15
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Affiliation(s)
- Yong Guo
- College of Agriculture, Ibaraki University3–21–1 Chuuo, Ami, Inashiki, Ibaraki 300–0393Japan
| | - Kazuhiko Narisawa
- College of Agriculture, Ibaraki University3–21–1 Chuuo, Ami, Inashiki, Ibaraki 300–0393Japan
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16
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Hyde KD, Norphanphoun C, Abreu VP, Bazzicalupo A, Thilini Chethana KW, Clericuzio M, Dayarathne MC, Dissanayake AJ, Ekanayaka AH, He MQ, Hongsanan S, Huang SK, Jayasiri SC, Jayawardena RS, Karunarathna A, Konta S, Kušan I, Lee H, Li J, Lin CG, Liu NG, Lu YZ, Luo ZL, Manawasinghe IS, Mapook A, Perera RH, Phookamsak R, Phukhamsakda C, Siedlecki I, Soares AM, Tennakoon DS, Tian Q, Tibpromma S, Wanasinghe DN, Xiao YP, Yang J, Zeng XY, Abdel-Aziz FA, Li WJ, Senanayake IC, Shang QJ, Daranagama DA, de Silva NI, Thambugala KM, Abdel-Wahab MA, Bahkali AH, Berbee ML, Boonmee S, Bhat DJ, Bulgakov TS, Buyck B, Camporesi E, Castañeda-Ruiz RF, Chomnunti P, Doilom M, Dovana F, Gibertoni TB, Jadan M, Jeewon R, Jones EBG, Kang JC, Karunarathna SC, Lim YW, Liu JK, Liu ZY, Plautz HL, Lumyong S, Maharachchikumbura SSN, Matočec N, McKenzie EHC, Mešić A, Miller D, Pawłowska J, Pereira OL, Promputtha I, Romero AI, Ryvarden L, Su HY, Suetrong S, Tkalčec Z, Vizzini A, Wen TC, Wisitrassameewong K, Wrzosek M, Xu JC, Zhao Q, Zhao RL, Mortimer PE. Fungal diversity notes 603–708: taxonomic and phylogenetic notes on genera and species. FUNGAL DIVERS 2017. [DOI: 10.1007/s13225-017-0391-3] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Guo H, Glaeser SP, Alabid I, Imani J, Haghighi H, Kämpfer P, Kogel KH. The Abundance of Endofungal Bacterium Rhizobium radiobacter (syn. Agrobacterium tumefaciens) Increases in Its Fungal Host Piriformospora indica during the Tripartite Sebacinalean Symbiosis with Higher Plants. Front Microbiol 2017; 8:629. [PMID: 28450855 PMCID: PMC5390018 DOI: 10.3389/fmicb.2017.00629] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/28/2017] [Indexed: 11/13/2022] Open
Abstract
Rhizobium radiobacter (syn. Agrobacterium tumefaciens, syn. "Agrobacterium fabrum") is an endofungal bacterium of the fungal mutualist Piriformospora (syn. Serendipita) indica (Basidiomycota), which together form a tripartite Sebacinalean symbiosis with a broad range of plants. R. radiobacter strain F4 (RrF4), isolated from P. indica DSM 11827, induces growth promotion and systemic resistance in cereal crops, including barley and wheat, suggesting that R. radiobacter contributes to a successful symbiosis. Here, we studied the impact of endobacteria on the morphology and the beneficial activity of P. indica during interactions with plants. Low numbers of endobacteria were detected in the axenically grown P. indica (long term lab-cultured, lcPiri) whereas mycelia colonizing the plant root contained increased numbers of bacteria. Higher numbers of endobacteria were also found in axenic cultures of P. indica that was freshly re-isolated (riPiri) from plant roots, though numbers dropped during repeated axenic re-cultivation. Prolonged treatments of P. indica cultures with various antibiotics could not completely eliminate the bacterium, though the number of detectable endobacteria decreased significantly, resulting in partial-cured P. indica (pcPiri). pcPiri showed reduced growth in axenic cultures and poor sporulation. Consistent with this, pcPiri also showed reduced plant growth promotion and reduced systemic resistance against powdery mildew infection as compared with riPiri and lcPiri. These results are consistent with the assumption that the endobacterium R. radiobacter improves P. indica's fitness and thus contributes to the success of the tripartite Sebacinalean symbiosis.
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Affiliation(s)
- Huijuan Guo
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Stefanie P Glaeser
- Institute of Applied Microbiology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Ibrahim Alabid
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Jafargholi Imani
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Hossein Haghighi
- Institute of Applied Microbiology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Peter Kämpfer
- Institute of Applied Microbiology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
| | - Karl-Heinz Kogel
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University GiessenGiessen, Germany
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18
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Who lives in a fungus? The diversity, origins and functions of fungal endobacteria living in Mucoromycota. ISME JOURNAL 2017; 11:1727-1735. [PMID: 28387771 DOI: 10.1038/ismej.2017.21] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 01/07/2023]
Abstract
Bacterial interactions with plants and animals have been examined for many years; differently, only with the new millennium the study of bacterial-fungal interactions blossomed, becoming a new field of microbiology with relevance to microbial ecology, human health and biotechnology. Bacteria and fungi interact at different levels and bacterial endosymbionts, which dwell inside fungal cells, provide the most intimate example. Bacterial endosymbionts mostly occur in fungi of the phylum Mucoromycota and include Betaproteobacteria (Burkhoderia-related) and Mollicutes (Mycoplasma-related). Based on phylogenomics and estimations of divergence time, we hypothesized two different scenarios for the origin of these interactions (early vs late bacterial invasion). Sequencing of the genomes of fungal endobacteria revealed a significant reduction in genome size, particularly in endosymbionts of Glomeromycotina, as expected by their uncultivability and host dependency. Similar to endobacteria of insects, the endobacteria of fungi show a range of behaviours from mutualism to antagonism. Emerging results suggest that some benefits given by the endobacteria to their plant-associated fungal host may propagate to the interacting plant, giving rise to a three-level inter-domain interaction.
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19
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Partida‐Martínez LP. The fungal holobiont: Evidence from early diverging fungi. Environ Microbiol 2017; 19:2919-2923. [DOI: 10.1111/1462-2920.13731] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Laila P. Partida‐Martínez
- Departamento de Ingeniería GenéticaCentro de Investigación y de Estudios Avanzados del IPNIrapuato 36821, Gto México
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20
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Baltrus DA, Dougherty K, Arendt KR, Huntemann M, Clum A, Pillay M, Palaniappan K, Varghese N, Mikhailova N, Stamatis D, Reddy TBK, Ngan CY, Daum C, Shapiro N, Markowitz V, Ivanova N, Kyrpides N, Woyke T, Arnold AE. Absence of genome reduction in diverse, facultative endohyphal bacteria. Microb Genom 2017; 3:e000101. [PMID: 28348879 PMCID: PMC5361626 DOI: 10.1099/mgen.0.000101] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 12/04/2016] [Indexed: 01/03/2023] Open
Abstract
Fungi interact closely with bacteria, both on the surfaces of the hyphae and within their living tissues (i.e. endohyphal bacteria, EHB). These EHB can be obligate or facultative symbionts and can mediate diverse phenotypic traits in their hosts. Although EHB have been observed in many lineages of fungi, it remains unclear how widespread and general these associations are, and whether there are unifying ecological and genomic features can be found across EHB strains as a whole. We cultured 11 bacterial strains after they emerged from the hyphae of diverse Ascomycota that were isolated as foliar endophytes of cupressaceous trees, and generated nearly complete genome sequences for all. Unlike the genomes of largely obligate EHB, the genomes of these facultative EHB resembled those of closely related strains isolated from environmental sources. Although all analysed genomes encoded structures that could be used to interact with eukaryotic hosts, pathways previously implicated in maintenance and establishment of EHB symbiosis were not universally present across all strains. Independent isolation of two nearly identical pairs of strains from different classes of fungi, coupled with recent experimental evidence, suggests horizontal transfer of EHB across endophytic hosts. Given the potential for EHB to influence fungal phenotypes, these genomes could shed light on the mechanisms of plant growth promotion or stress mitigation by fungal endophytes during the symbiotic phase, as well as degradation of plant material during the saprotrophic phase. As such, these findings contribute to the illumination of a new dimension of functional biodiversity in fungi.
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Affiliation(s)
- David A Baltrus
- 1School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Kevin Dougherty
- 1School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Kayla R Arendt
- 1School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | | | - Alicia Clum
- 2Joint Genome Institute, Walnut Creek, CA, USA
| | | | | | | | | | | | - T B K Reddy
- 2Joint Genome Institute, Walnut Creek, CA, USA
| | | | - Chris Daum
- 2Joint Genome Institute, Walnut Creek, CA, USA
| | | | | | | | | | - Tanja Woyke
- 2Joint Genome Institute, Walnut Creek, CA, USA
| | - A Elizabeth Arnold
- 1School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA.,3Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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21
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Uehling J, Gryganskyi A, Hameed K, Tschaplinski T, Misztal PK, Wu S, Desirò A, Vande Pol N, Du Z, Zienkiewicz A, Zienkiewicz K, Morin E, Tisserant E, Splivallo R, Hainaut M, Henrissat B, Ohm R, Kuo A, Yan J, Lipzen A, Nolan M, LaButti K, Barry K, Goldstein AH, Labbé J, Schadt C, Tuskan G, Grigoriev I, Martin F, Vilgalys R, Bonito G. Comparative genomics of Mortierella elongata and its bacterial endosymbiont Mycoavidus cysteinexigens. Environ Microbiol 2017; 19:2964-2983. [PMID: 28076891 DOI: 10.1111/1462-2920.13669] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/05/2017] [Accepted: 01/07/2017] [Indexed: 12/13/2022]
Abstract
Endosymbiosis of bacteria by eukaryotes is a defining feature of cellular evolution. In addition to well-known bacterial origins for mitochondria and chloroplasts, multiple origins of bacterial endosymbiosis are known within the cells of diverse animals, plants and fungi. Early-diverging lineages of terrestrial fungi harbor endosymbiotic bacteria belonging to the Burkholderiaceae. We sequenced the metagenome of the soil-inhabiting fungus Mortierella elongata and assembled the complete circular chromosome of its endosymbiont, Mycoavidus cysteinexigens, which we place within a lineage of endofungal symbionts that are sister clade to Burkholderia. The genome of M. elongata strain AG77 features a core set of primary metabolic pathways for degradation of simple carbohydrates and lipid biosynthesis, while the M. cysteinexigens (AG77) genome is reduced in size and function. Experiments using antibiotics to cure the endobacterium from the host demonstrate that the fungal host metabolism is highly modulated by presence/absence of M. cysteinexigens. Independent comparative phylogenomic analyses of fungal and bacterial genomes are consistent with an ancient origin for M. elongata - M. cysteinexigens symbiosis, most likely over 350 million years ago and concomitant with the terrestrialization of Earth and diversification of land fungi and plants.
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Affiliation(s)
- J Uehling
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - A Gryganskyi
- LF Lambert Spawn Company Coatesville, PA, 19320, USA
| | - K Hameed
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - T Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - P K Misztal
- University of California Berkeley, Berkeley, CA, 94720, USA
| | - S Wu
- Arizona State University Tempe, AZ, 85281, USA
| | - A Desirò
- Plant Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - N Vande Pol
- Plant Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Z Du
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - A Zienkiewicz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - K Zienkiewicz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.,Department of Plant Biochemistry, Georg-August University, Göttingen, 37073, Germany
| | - E Morin
- Institut National de la Recherche Agronomique, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'excellence ARBRE, INRA-Nancy, Champenoux, 54280, France
| | - E Tisserant
- Institut National de la Recherche Agronomique, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'excellence ARBRE, INRA-Nancy, Champenoux, 54280, France
| | - R Splivallo
- Goethe University Frankfurt, Institute for Molecular Biosciences, 60438 Frankfurt, Germany Integrative Fungal Research Cluster (IPF), Frankfurt, 60325, Germany
| | - M Hainaut
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, 13288, France
| | - B Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, 13288, France
| | - R Ohm
- Microbiology, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - A Kuo
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - J Yan
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - A Lipzen
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - M Nolan
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - K LaButti
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - K Barry
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - A H Goldstein
- University of California Berkeley, Berkeley, CA, 94720, USA
| | - J Labbé
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - C Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - G Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - I Grigoriev
- Department of Energy, Joint Genome Institute, Oakland, CA, 94598, USA
| | - F Martin
- Institut National de la Recherche Agronomique, UMR 1136 INRA-Université de Lorraine 'Interactions Arbres/Microorganismes', Laboratoire d'excellence ARBRE, INRA-Nancy, Champenoux, 54280, France
| | - R Vilgalys
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - G Bonito
- Plant Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
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22
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Nazir R, Mazurier S, Yang P, Lemanceau P, van Elsas JD. The Ecological Role of Type Three Secretion Systems in the Interaction of Bacteria with Fungi in Soil and Related Habitats Is Diverse and Context-Dependent. Front Microbiol 2017; 8:38. [PMID: 28197129 PMCID: PMC5282467 DOI: 10.3389/fmicb.2017.00038] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/06/2017] [Indexed: 12/14/2022] Open
Abstract
Bacteria and fungi constitute important organisms in many ecosystems, in particular terrestrial ones. Both organismal groups contribute significantly to biogeochemical cycling processes. Ecological theory postulates that bacteria capable of receiving benefits from host fungi are likely to evolve efficient association strategies. The purpose of this review is to examine the mechanisms that underpin the bacterial interactions with fungi in soil and other systems, with special focus on the type III secretion system (T3SS). Starting with a brief description of the versatility of the T3SS as an interaction system with diverse eukaryotic hosts, we subsequently examine the recent advances made in our understanding of its contribution to interactions with soil fungi. The analysis used data sets ranging from circumstantial evidence to gene-knockout-based experimental data. The initial finding that the abundance of T3SSs in microbiomes is often enhanced in fungal-affected habitats like the mycosphere and the mycorrhizosphere is now substantiated with in-depth knowledge of the specific systems involved. Different fungal–interactive bacteria, in positive or negative associations with partner fungi, harbor and express T3SSs, with different ecological outcomes. In some particular cases, bacterial T3SSs have been shown to modulate the physiology of its fungal partner, affecting its ecological characteristics and consequently shaping its own habitat. Overall, the analyses of the collective data set revealed that diverse T3SSs have assumed diverse roles in the interactions of bacteria with host fungi, as driven by ecological and evolutionary niche requirements.
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Affiliation(s)
- Rashid Nazir
- Department of Environmental Sciences, COMSATS Institute of Information TechnologyAbbottabad, Pakistan; Department of Soil Environmental Science, Research Centre for Eco-environmental Sciences - Chinese Academy of SciencesBeijing, China
| | - Sylvie Mazurier
- Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique, Université Bourgogne Franche-Comté Dijon, France
| | - Pu Yang
- Department of Microbial Ecology, GELIFES, University of Groningen Groningen, Netherlands
| | - Philippe Lemanceau
- Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique, Université Bourgogne Franche-Comté Dijon, France
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, GELIFES, University of Groningen Groningen, Netherlands
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23
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Li Z, Yao Q, Dearth SP, Entler MR, Castro Gonzalez HF, Uehling JK, Vilgalys RJ, Hurst GB, Campagna SR, Labbé JL, Pan C. Integrated proteomics and metabolomics suggests symbiotic metabolism and multimodal regulation in a fungal-endobacterial system. Environ Microbiol 2017; 19:1041-1053. [DOI: 10.1111/1462-2920.13605] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/08/2016] [Accepted: 11/16/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Zhou Li
- Computer Science and Mathematics Division, Oak Ridge National Laboratory; Oak Ridge TN USA
- Chemical Sciences Division, Oak Ridge National Laboratory; Oak Ridge TN USA
| | - Qiuming Yao
- Computer Science and Mathematics Division, Oak Ridge National Laboratory; Oak Ridge TN USA
| | | | - Matthew R. Entler
- Graduate School of Genome Science and Technology, University of Tennessee-Oak Ridge National Laboratory; Knoxville TN USA
- Biosciences Division, Oak Ridge National Laboratory; Oak Ridge USA
| | | | | | | | - Gregory B. Hurst
- Chemical Sciences Division, Oak Ridge National Laboratory; Oak Ridge TN USA
| | | | - Jessy L. Labbé
- Biosciences Division, Oak Ridge National Laboratory; Oak Ridge USA
| | - Chongle Pan
- Computer Science and Mathematics Division, Oak Ridge National Laboratory; Oak Ridge TN USA
- Graduate School of Genome Science and Technology, University of Tennessee-Oak Ridge National Laboratory; Knoxville TN USA
- Biosciences Division, Oak Ridge National Laboratory; Oak Ridge USA
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24
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Vannini C, Carpentieri A, Salvioli A, Novero M, Marsoni M, Testa L, de Pinto MC, Amoresano A, Ortolani F, Bracale M, Bonfante P. An interdomain network: the endobacterium of a mycorrhizal fungus promotes antioxidative responses in both fungal and plant hosts. THE NEW PHYTOLOGIST 2016; 211:265-275. [PMID: 26914272 DOI: 10.1111/nph.13895] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/12/2016] [Indexed: 06/05/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) are obligate plant biotrophs that may contain endobacteria in their cytoplasm. Genome sequencing of Candidatus Glomeribacter gigasporarum revealed a reduced genome and dependence on the fungal host. RNA-seq analysis of the AMF Gigaspora margarita in the presence and absence of the endobacterium indicated that endobacteria have an important role in the fungal pre-symbiotic phase by enhancing fungal bioenergetic capacity. To improve the understanding of fungal-endobacterial interactions, iTRAQ (isobaric tags for relative and absolute quantification) quantitative proteomics was used to identify differentially expressed proteins in G. margarita germinating spores with endobacteria (B+), without endobacteria in the cured line (B-) and after application of the synthetic strigolactone GR24. Proteomic, transcriptomic and biochemical data identified several fungal and bacterial proteins involved in interspecies interactions. Endobacteria influenced fungal growth, calcium signalling and metabolism. The greatest effects were on fungal primary metabolism and respiration, which was 50% higher in B+ than in B-. A shift towards pentose phosphate metabolism was detected in B-. Quantification of carbonylated proteins indicated that the B- line had higher oxidative stress levels, which were also observed in two host plants. This study shows that endobacteria generate a complex interdomain network that affects AMF and fungal-plant interactions.
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Affiliation(s)
- Candida Vannini
- Department of Biotechnology and Life Science, Università dell'Insubria, via J.H. Dunant 3, I-21100, Varese, Italy
| | - Andrea Carpentieri
- Department of Chemical Sciences, Università di Napoli 'Federico II', via Cintia 4, I-80126, Napoli, Italy
| | - Alessandra Salvioli
- Department of Life Sciences and Systems Biology, Università di Torino, viale Mattioli 25, I-10125, Torino, Italy
| | - Mara Novero
- Department of Life Sciences and Systems Biology, Università di Torino, viale Mattioli 25, I-10125, Torino, Italy
| | - Milena Marsoni
- Department of Biotechnology and Life Science, Università dell'Insubria, via J.H. Dunant 3, I-21100, Varese, Italy
| | - Lorenzo Testa
- Department of Biotechnology and Life Science, Università dell'Insubria, via J.H. Dunant 3, I-21100, Varese, Italy
| | - Maria Concetta de Pinto
- Department of Biology, Università di Bari 'Aldo Moro', via E. Orabona 4, I-70125, Bari, Italy
| | - Angela Amoresano
- Department of Chemical Sciences, Università di Napoli 'Federico II', via Cintia 4, I-80126, Napoli, Italy
| | - Francesca Ortolani
- Department of Biotechnology and Life Science, Università dell'Insubria, via J.H. Dunant 3, I-21100, Varese, Italy
| | - Marcella Bracale
- Department of Biotechnology and Life Science, Università dell'Insubria, via J.H. Dunant 3, I-21100, Varese, Italy
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, Università di Torino, viale Mattioli 25, I-10125, Torino, Italy
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25
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Qi W, Vaughan L, Katharios P, Schlapbach R, Seth-Smith HMB. Host-Associated Genomic Features of the Novel Uncultured Intracellular Pathogen Ca. Ichthyocystis Revealed by Direct Sequencing of Epitheliocysts. Genome Biol Evol 2016; 8:1672-89. [PMID: 27190004 PMCID: PMC4943182 DOI: 10.1093/gbe/evw111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2016] [Indexed: 12/24/2022] Open
Abstract
Advances in single-cell and mini-metagenome sequencing have enabled important investigations into uncultured bacteria. In this study, we applied the mini-metagenome sequencing method to assemble genome drafts of the uncultured causative agents of epitheliocystis, an emerging infectious disease in the Mediterranean aquaculture species gilthead seabream. We sequenced multiple cyst samples and constructed 11 genome drafts from a novel beta-proteobacterial lineage, Candidatus Ichthyocystis. The draft genomes demonstrate features typical of pathogenic bacteria with an obligate intracellular lifestyle: a reduced genome of up to 2.6 Mb, reduced G + C content, and reduced metabolic capacity. Reconstruction of metabolic pathways reveals that Ca Ichthyocystis genomes lack all amino acid synthesis pathways, compelling them to scavenge from the fish host. All genomes encode type II, III, and IV secretion systems, a large repertoire of predicted effectors, and a type IV pilus. These are all considered to be virulence factors, required for adherence, invasion, and host manipulation. However, no evidence of lipopolysaccharide synthesis could be found. Beyond the core functions shared within the genus, alignments showed distinction into different species, characterized by alternative large gene families. These comprise up to a third of each genome, appear to have arisen through duplication and diversification, encode many effector proteins, and are seemingly critical for virulence. Thus, Ca Ichthyocystis represents a novel obligatory intracellular pathogenic beta-proteobacterial lineage. The methods used: mini-metagenome analysis and manual annotation, have generated important insights into the lifestyle and evolution of the novel, uncultured pathogens, elucidating many putative virulence factors including an unprecedented array of novel gene families.
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Affiliation(s)
- Weihong Qi
- Functional Genomics Center Zurich, University of Zurich, Switzerland
| | - Lloyd Vaughan
- Vetsuisse Faculty, Institute for Veterinary Pathology, University of Zurich, Switzerland
| | - Pantelis Katharios
- Hellenic Center for Marine Research, Institute of Marine Biology, Biotechnology and Aquaculture, Heraklion, Greece
| | - Ralph Schlapbach
- Functional Genomics Center Zurich, University of Zurich, Switzerland
| | - Helena M B Seth-Smith
- Functional Genomics Center Zurich, University of Zurich, Switzerland Vetsuisse Faculty, Institute for Veterinary Pathology, University of Zurich, Switzerland
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26
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27
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Arendt KR, Hockett KL, Araldi-Brondolo SJ, Baltrus DA, Arnold AE. Isolation of Endohyphal Bacteria from Foliar Ascomycota and In Vitro Establishment of Their Symbiotic Associations. Appl Environ Microbiol 2016; 82:2943-2949. [PMID: 26969692 PMCID: PMC4959084 DOI: 10.1128/aem.00452-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/03/2016] [Indexed: 12/16/2022] Open
Abstract
Endohyphal bacteria (EHB) can influence fungal phenotypes and shape the outcomes of plant-fungal interactions. Previous work has suggested that EHB form facultative associations with many foliar fungi in the Ascomycota. These bacteria can be isolated in culture, and fungi can be cured of EHB using antibiotics. Here, we present methods for successfully introducing EHB into axenic mycelia of strains representing two classes of Ascomycota. We first establish in vitro conditions favoring reintroduction of two strains of EHB (Luteibacter sp.) into axenic cultures of their original fungal hosts, focusing on fungi isolated from healthy plant tissue as endophytes: Microdiplodia sp. (Dothideomycetes) and Pestalotiopsis sp. (Sordariomycetes). We then demonstrate that these EHB can be introduced into a novel fungal host under the same conditions, successfully transferring EHB between fungi representing different classes. Finally, we manipulate conditions to optimize reintroduction in a focal EHB-fungal association. We show that EHB infections were initiated and maintained more often under low-nutrient culture conditions and when EHB and fungal hyphae were washed with MgCl2 prior to reassociation. Our study provides new methods for experimental assessment of the effects of EHB on fungal phenotypes and shows how the identity of the fungal host and growth conditions can define the establishment of these widespread and important symbioses.
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Affiliation(s)
- Kayla R Arendt
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Kevin L Hockett
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | | | - David A Baltrus
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - A Elizabeth Arnold
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA
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28
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Glaeser SP, Imani J, Alabid I, Guo H, Kumar N, Kämpfer P, Hardt M, Blom J, Goesmann A, Rothballer M, Hartmann A, Kogel KH. Non-pathogenic Rhizobium radiobacter F4 deploys plant beneficial activity independent of its host Piriformospora indica. THE ISME JOURNAL 2016; 10:871-84. [PMID: 26495996 PMCID: PMC4796927 DOI: 10.1038/ismej.2015.163] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 07/23/2015] [Accepted: 08/03/2015] [Indexed: 12/23/2022]
Abstract
The Alphaproteobacterium Rhizobium radiobacter F4 (RrF4) was originally characterized as an endofungal bacterium in the beneficial endophytic Sebacinalean fungus Piriformospora indica. Although attempts to cure P. indica from RrF4 repeatedly failed, the bacterium can easily be grown in pure culture. Here, we report on RrF4's genome and the beneficial impact the free-living bacterium has on plants. In contrast to other endofungal bacteria, the genome size of RrF4 is not reduced. Instead, it shows a high degree of similarity to the plant pathogenic R. radiobacter (formerly: Agrobacterium tumefaciens) C58, except vibrant differences in both the tumor-inducing (pTi) and the accessor (pAt) plasmids, which can explain the loss of RrF4's pathogenicity. Similar to its fungal host, RrF4 colonizes plant roots without host preference and forms aggregates of attached cells and dense biofilms at the root surface of maturation zones. RrF4-colonized plants show increased biomass and enhanced resistance against bacterial leaf pathogens. Mutational analysis showed that, similar to P. indica, resistance mediated by RrF4 was dependent on the plant's jasmonate-based induced systemic resistance (ISR) pathway. Consistent with this, RrF4- and P. indica-induced pattern of defense gene expression were similar. In clear contrast to P. indica, but similar to plant growth-promoting rhizobacteria, RrF4 colonized not only the root outer cortex but also spread beyond the endodermis into the stele. On the basis of our findings, RrF4 is an efficient plant growth-promoting bacterium.
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Affiliation(s)
- Stefanie P Glaeser
- Institute of Applied Microbiology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig- University Giessen, Giessen, Germany
| | - Jafargholi Imani
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University Giessen, Giessen, Germany
| | - Ibrahim Alabid
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University Giessen, Giessen, Germany
| | - Huijuan Guo
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University Giessen, Giessen, Germany
| | - Neelendra Kumar
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University Giessen, Giessen, Germany
| | - Peter Kämpfer
- Institute of Applied Microbiology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig- University Giessen, Giessen, Germany
| | - Martin Hardt
- Biomedical Research Centre Seltersberg-Imaging Unit, Justus-Liebig-University Giessen, Giessen, Germany
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Michael Rothballer
- Research Unit Microbe-Plant Interactions, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Anton Hartmann
- Research Unit Microbe-Plant Interactions, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Karl-Heinz Kogel
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-University Giessen, Giessen, Germany
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29
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Ohshima S, Sato Y, Fujimura R, Takashima Y, Hamada M, Nishizawa T, Narisawa K, Ohta H. Mycoavidus cysteinexigens gen. nov., sp. nov., an endohyphal bacterium isolated from a soil isolate of the fungus Mortierella elongata. Int J Syst Evol Microbiol 2016; 66:2052-2057. [PMID: 26920389 DOI: 10.1099/ijsem.0.000990] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An endohyphal bacterium (strain B1-EBT) living in association with the fungus Mortierella elongata FMR23-6 I-B1 was isolated from a fungal cell homogenate and studied for its taxonomic allocation. Cells were Gram-stain-negative, rod-shaped, non-spore-forming, non-motile, and negative for oxidase and catalase. Strain B1-EBT required cysteine for growth and grew at temperatures between 4 and 35 °C. A comparative analysis of 16S rRNA gene sequences revealed that strain B1-EBT forms a distinct clade in the family Burkholderiaceae, encompassing a group of endosymbionts associated with several soil isolates of M. elongata. The most closely related genus is 'Candidatus Glomeribacter gigasporarum', an endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. The major cellular fatty acids of strain B1-EBT were C16 : 0, summed feature 3 (C16 : 1ω7c and C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c or C18 : 1ω6c). Ubiquinone Q-8 was the only quinone detected. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unknown aminophospholipid and two unknown aminolipids. The DNA G+C content was 49.8 mol%. On the basis of phenotypic, chemotaxonomic, and phylogenetic characteristics, strain B1-EBT represents a novel genus and novel species in the family Burkholderiaceae, for which the name Mycoavidus cysteinexigens gen. nov., sp. nov. is proposed. The type strain is B1-EBT ( = JCM 30646T = LMG 28693T = NBRC 110909T).
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Affiliation(s)
- Shoko Ohshima
- Ibaraki University College of Agriculture,3-21-1 Chuo, Ami-machi, Ibaraki 300-0393,Japan
| | - Yoshinori Sato
- National Research Institute for Cultural Properties,Tokyo, 13-43 Ueno-park, Taito-ku, Tokyo 110-8713,Japan
| | - Reiko Fujimura
- Atmosphere and Ocean Research Institute, The University of Tokyo,5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8564,Japan
| | - Yusuke Takashima
- Ibaraki University College of Agriculture,3-21-1 Chuo, Ami-machi, Ibaraki 300-0393,Japan.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology,3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509,Japan
| | - Moriyuki Hamada
- Biological Resource Center, National Institute of Technology and Evaluation (NBRC),2-5-8 Kazusakamatari, Kisarazu-shi, Chiba 292-0818,Japan
| | - Tomoyasu Nishizawa
- Ibaraki University College of Agriculture,3-21-1 Chuo, Ami-machi, Ibaraki 300-0393,Japan
| | - Kazuhiko Narisawa
- Ibaraki University College of Agriculture,3-21-1 Chuo, Ami-machi, Ibaraki 300-0393,Japan.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology,3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509,Japan
| | - Hiroyuki Ohta
- Ibaraki University College of Agriculture,3-21-1 Chuo, Ami-machi, Ibaraki 300-0393,Japan.,United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology,3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509,Japan
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30
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Mosaic genome of endobacteria in arbuscular mycorrhizal fungi: Transkingdom gene transfer in an ancient mycoplasma-fungus association. Proc Natl Acad Sci U S A 2015; 112:7785-90. [PMID: 25964335 DOI: 10.1073/pnas.1501540112] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
For more than 450 million years, arbuscular mycorrhizal fungi (AMF) have formed intimate, mutualistic symbioses with the vast majority of land plants and are major drivers in almost all terrestrial ecosystems. The obligate plant-symbiotic AMF host additional symbionts, so-called Mollicutes-related endobacteria (MRE). To uncover putative functional roles of these widespread but yet enigmatic MRE, we sequenced the genome of DhMRE living in the AMF Dentiscutata heterogama. Multilocus phylogenetic analyses showed that MRE form a previously unidentified lineage sister to the hominis group of Mycoplasma species. DhMRE possesses a strongly reduced metabolic capacity with 55% of the proteins having unknown function, which reflects unique adaptations to an intracellular lifestyle. We found evidence for transkingdom gene transfer between MRE and their AMF host. At least 27 annotated DhMRE proteins show similarities to nuclear-encoded proteins of the AMF Rhizophagus irregularis, which itself lacks MRE. Nuclear-encoded homologs could moreover be identified for another AMF, Gigaspora margarita, and surprisingly, also the non-AMF Mortierella verticillata. Our data indicate a possible origin of the MRE-fungus association in ancestors of the Glomeromycota and Mucoromycotina. The DhMRE genome encodes an arsenal of putative regulatory proteins with eukaryotic-like domains, some of them encoded in putative genomic islands. MRE are highly interesting candidates to study the evolution and interactions between an ancient, obligate endosymbiotic prokaryote with its obligate plant-symbiotic fungal host. Our data moreover may be used for further targeted searches for ancient effector-like proteins that may be key components in the regulation of the arbuscular mycorrhiza symbiosis.
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