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Huusko K, Manninen OH, Myrsky E, Stark S. Soil fungal and bacterial communities reflect differently tundra vegetation state transitions and soil physico-chemical properties. THE NEW PHYTOLOGIST 2024; 243:407-422. [PMID: 38750646 DOI: 10.1111/nph.19808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/23/2024] [Indexed: 06/07/2024]
Abstract
Strong disturbances may induce ecosystem transitions into new alternative states that sustain through plant-soil interactions, such as the transition of dwarf shrub-dominated into graminoid-dominated vegetation by herbivory in tundra. Little evidence exists on soil microbial communities in alternative states, and along the slow process of ecosystem return into the predisturbance state. We analysed vegetation, soil microbial communities and activities as well as soil physico-chemical properties in historical reindeer enclosures in northernmost Finland in the following plot types: control heaths in the surrounding tundra; graminoid-dominated; 'shifting'; and recovered dwarf shrub-dominated vegetation inside enclosures. Soil fungal communities followed changes in vegetation, whereas bacterial communities were more affected by soil physico-chemical properties. Graminoid plots were characterized by moulds, pathotrophs and dark septate endophytes. Ericoid mycorrhizal and saprotrophic fungi were typical for control and recovered plots. Soil microbial communities inside the enclosures showed historical contingency, as their spatial variation was high in recovered plots despite the vegetation being more homogeneous. Self-maintaining feedback loops between plant functional types, soil microbial communities, and carbon and nutrient mineralization act effectively to stabilize alternative vegetation states, but once predisturbance vegetation reestablishes itself, soil microbial communities and physico-chemical properties return back towards their predisturbance state.
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Affiliation(s)
- Karoliina Huusko
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu, FI-90014, Finland
| | - Outi H Manninen
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
| | - Eero Myrsky
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
| | - Sari Stark
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
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2
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Slate ML, Antoninka A, Bailey L, Berdugo MB, Callaghan DA, Cárdenas M, Chmielewski MW, Fenton NJ, Holland-Moritz H, Hopkins S, Jean M, Kraichak BE, Lindo Z, Merced A, Oke T, Stanton D, Stuart J, Tucker D, Coe KK. Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles. THE NEW PHYTOLOGIST 2024; 242:2411-2429. [PMID: 38659154 DOI: 10.1111/nph.19772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.
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Affiliation(s)
- Mandy L Slate
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Anita Antoninka
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Lydia Bailey
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Monica B Berdugo
- Plant Ecology and Geobotany, Department of Biology, University of Marburg, Karl-von-Frisch Str. 8, 35043, Marburg, Germany
| | - Des A Callaghan
- Bryophyte Surveys Ltd, Almondsbury, South Gloucestershire, BS32 4DU, UK
| | - Mariana Cárdenas
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | | | - Nicole J Fenton
- Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Hannah Holland-Moritz
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, 03824, USA
| | - Samantha Hopkins
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Mélanie Jean
- Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Bier Ekaphan Kraichak
- Department of Botany, Faculty of Science, Kasetsart University in Bangkok, Bangkok, 10900, Thailand
| | - Zoë Lindo
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Amelia Merced
- Department of Biology, University of Puerto Rico Río Piedras, San Juan, PR, 00925, USA
| | - Tobi Oke
- Wildlife Conservation Society & School of Environment & Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8, Canada
| | - Daniel Stanton
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Julia Stuart
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, 49931, USA
- Mountain Planning Service Group, US Forest Service, Lakewood, CO, 80401, USA
| | - Daniel Tucker
- School of Environmental Studies, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Kirsten K Coe
- Department of Biology, Middlebury College, Middlebury, VT, 05753, USA
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3
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Baev V, Gecheva G, Apostolova E, Gozmanova M, Yahubyan G. Exploring the Metatranscriptome of Bacterial Communities of Two Moss Species Thriving in Different Environments-Terrestrial and Aquatic. PLANTS (BASEL, SWITZERLAND) 2024; 13:1210. [PMID: 38732425 PMCID: PMC11085137 DOI: 10.3390/plants13091210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
Mosses host diverse bacterial communities essential for their fitness, nutrient acquisition, stress tolerance, and pathogen defense. Understanding the microbiome's taxonomic composition is the first step, but unraveling their functional capabilities is crucial for grasping their ecological significance. Metagenomics characterizes microbial communities by composition, while metatranscriptomics explores gene expression, providing insights into microbiome functionality beyond the structure. Here, we present for the first time a metatranscriptomic study of two moss species, Hypnum cupressiforme (Hedw.) and Platyhypnidium riparioides (Hedw.) Dixon., renowned as key biomonitors of atmospheric and water pollution. Our investigation extends beyond taxonomic profiling and offers a profound exploration of moss bacterial communities. Pseudomonadota and Actinobacteria are the dominant bacterial phyla in both moss species, but their proportions differ. In H. cupressiforme, Actinobacteria make up 62.45% and Pseudomonadota 32.48%, while in P. riparioides, Actinobacteria account for only 25.67% and Pseudomonadota 69.08%. This phylum-level contrast is reflected in genus-level differences. Our study also shows the expression of most genes related to nitrogen cycling across both microbiomes. Additionally, functional annotation highlights disparities in pathway prevalence, including carbon dioxide fixation, photosynthesis, and fatty acid biosynthesis, among others. These findings hint at potential metabolic distinctions between microbial communities associated with different moss species, influenced by their specific genotypes and habitats. The integration of metatranscriptomic data holds promise for enhancing our understanding of bryophyte-microbe partnerships, opening avenues for novel applications in conservation, bioremediation, and sustainable agriculture.
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Affiliation(s)
- Vesselin Baev
- Department of Molecular Biology, Faculty of Biology, University of Plovdiv, Tzar Assen 24, 4000 Plovdiv, Bulgaria; (E.A.); (M.G.)
| | - Gana Gecheva
- Department of Ecology and Environmental Conservation, Faculty of Biology, University of Plovdiv, Tzar Assen 24, 4000 Plovdiv, Bulgaria;
| | - Elena Apostolova
- Department of Molecular Biology, Faculty of Biology, University of Plovdiv, Tzar Assen 24, 4000 Plovdiv, Bulgaria; (E.A.); (M.G.)
| | - Mariyana Gozmanova
- Department of Molecular Biology, Faculty of Biology, University of Plovdiv, Tzar Assen 24, 4000 Plovdiv, Bulgaria; (E.A.); (M.G.)
| | - Galina Yahubyan
- Department of Molecular Biology, Faculty of Biology, University of Plovdiv, Tzar Assen 24, 4000 Plovdiv, Bulgaria; (E.A.); (M.G.)
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Williams TJ, Allen MA, Ray AE, Benaud N, Chelliah DS, Albanese D, Donati C, Selbmann L, Coleine C, Ferrari BC. Novel endolithic bacteria of phylum Chloroflexota reveal a myriad of potential survival strategies in the Antarctic desert. Appl Environ Microbiol 2024; 90:e0226423. [PMID: 38372512 PMCID: PMC10952385 DOI: 10.1128/aem.02264-23] [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: 12/15/2023] [Accepted: 01/02/2024] [Indexed: 02/20/2024] Open
Abstract
The ice-free McMurdo Dry Valleys of Antarctica are dominated by nutrient-poor mineral soil and rocky outcrops. The principal habitat for microorganisms is within rocks (endolithic). In this environment, microorganisms are provided with protection against sub-zero temperatures, rapid thermal fluctuations, extreme dryness, and ultraviolet and solar radiation. Endolithic communities include lichen, algae, fungi, and a diverse array of bacteria. Chloroflexota is among the most abundant bacterial phyla present in these communities. Among the Chloroflexota are four novel classes of bacteria, here named Candidatus Spiritibacteria class. nov. (=UBA5177), Candidatus Martimicrobia class. nov. (=UBA4733), Candidatus Tarhunnaeia class. nov. (=UBA6077), and Candidatus Uliximicrobia class. nov. (=UBA2235). We retrieved 17 high-quality metagenome-assembled genomes (MAGs) that represent these four classes. Based on genome predictions, all these bacteria are inferred to be aerobic heterotrophs that encode enzymes for the catabolism of diverse sugars. These and other organic substrates are likely derived from lichen, algae, and fungi, as metabolites (including photosynthate), cell wall components, and extracellular matrix components. The majority of MAGs encode the capacity for trace gas oxidation using high-affinity uptake hydrogenases, which could provide energy and metabolic water required for survival and persistence. Furthermore, some MAGs encode the capacity to couple the energy generated from H2 and CO oxidation to support carbon fixation (atmospheric chemosynthesis). All encode mechanisms for the detoxification and efflux of heavy metals. Certain MAGs encode features that indicate possible interactions with other organisms, such as Tc-type toxin complexes, hemolysins, and macroglobulins.IMPORTANCEThe ice-free McMurdo Dry Valleys of Antarctica are the coldest and most hyperarid desert on Earth. It is, therefore, the closest analog to the surface of the planet Mars. Bacteria and other microorganisms survive by inhabiting airspaces within rocks (endolithic). We identify four novel classes of phylum Chloroflexota, and, based on interrogation of 17 metagenome-assembled genomes, we predict specific metabolic and physiological adaptations that facilitate the survival of these bacteria in this harsh environment-including oxidation of trace gases and the utilization of nutrients (including sugars) derived from lichen, algae, and fungi. We propose that such adaptations allow these endolithic bacteria to eke out an existence in this cold and extremely dry habitat.
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Affiliation(s)
- Timothy J. Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Michelle A. Allen
- School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Angelique E. Ray
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Nicole Benaud
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Devan S. Chelliah
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Davide Albanese
- Research and Innovation Center, Fondazione Edmund Mach, San Michele all’Adige, Italy
| | - Claudio Donati
- Research and Innovation Center, Fondazione Edmund Mach, San Michele all’Adige, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università, Viterbo, Italy
- Mycological Section, Italian Antarctic National Museum (MNA), Genova, Italy
| | - Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università, Viterbo, Italy
| | - Belinda C. Ferrari
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, Australia
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5
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Groß C, Hossen S, Dittrich S, Knorr KH, Borken W, Noll M. Biological nitrogen fixation, diversity and community structure of diazotrophs in two mosses in 25 temperate forests. Environ Microbiol 2024; 26:e16555. [PMID: 38148519 DOI: 10.1111/1462-2920.16555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 11/27/2023] [Indexed: 12/28/2023]
Abstract
Many moss species are associated with nitrogen (N)-fixing bacteria (diazotrophs) that support the N supply of mosses. Our knowledge relates primarily to pristine ecosystems with low atmospheric N input, but knowledge of biological N fixation (BNF) and diazotrophic communities in mosses in temperate forests with high N deposition is limited. We measured BNF rates using the direct stable isotope method and studied the total and potentially active diazotrophic communities in two abundant mosses, Brachythecium rutabulum and Hypnum cupressiforme, both growing on lying deadwood trunks in 25 temperate forest sites. BNF rates in both mosses were similar to those observed in moss species of pristine ecosystems. H. cupressiforme fixed three times more N2 and exhibited lower diazotrophic richness than B. rutabulum. Frankia was the most prominent diazotroph followed by cyanobacteria Nostoc. Manganese, iron, and molybdenum contents in mosses were positively correlated with BNF and diazotrophic communities. Frankia maintained high BNF rates in H. cupressiforme and B. rutabulum even under high chronic N deposition in Central European forests. Moss N concentration and 15 N abundance indicate a rather minor contribution of BNF to the N nutrition of these mosses.
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Affiliation(s)
- Christina Groß
- Department of Soil Ecology, University of Bayreuth, Bayreuth, Germany
| | - Shakhawat Hossen
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, Coburg, Germany
| | - Sebastian Dittrich
- Biodiversity and Conservation, Technical University of Dresden, Tharandt, Germany
| | - Klaus-Holger Knorr
- Institute of Landscape Ecology, Ecohydrology and Biogeochemistry Group, University of Münster, Münster, Germany
| | - Werner Borken
- Department of Soil Ecology, University of Bayreuth, Bayreuth, Germany
| | - Matthias Noll
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, Coburg, Germany
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6
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Li L, Huang D, Hu Y, Rudling NM, Canniffe DP, Wang F, Wang Y. Globally distributed Myxococcota with photosynthesis gene clusters illuminate the origin and evolution of a potentially chimeric lifestyle. Nat Commun 2023; 14:6450. [PMID: 37833297 PMCID: PMC10576062 DOI: 10.1038/s41467-023-42193-7] [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: 02/24/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
Photosynthesis is a fundamental biogeochemical process, thought to be restricted to a few bacterial and eukaryotic phyla. However, understanding the origin and evolution of phototrophic organisms can be impeded and biased by the difficulties of cultivation. Here, we analyzed metagenomic datasets and found potential photosynthetic abilities encoded in the genomes of uncultivated bacteria within the phylum Myxococcota. A putative photosynthesis gene cluster encoding a type-II reaction center appears in at least six Myxococcota families from three classes, suggesting vertical inheritance of these genes from an early common ancestor, with multiple independent losses in other lineages. Analysis of metatranscriptomic datasets indicate that the putative myxococcotal photosynthesis genes are actively expressed in various natural environments. Furthermore, heterologous expression of myxococcotal pigment biosynthesis genes in a purple bacterium supports that the genes can drive photosynthetic processes. Given that predatory abilities are thought to be widespread across Myxococcota, our results suggest the intriguing possibility of a chimeric lifestyle (combining predatory and photosynthetic abilities) in members of this phylum.
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Affiliation(s)
- Liuyang Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Danyue Huang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Yaoxun Hu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nicola M Rudling
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Daniel P Canniffe
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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7
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Ortiz-Rivero J, Garrido-Benavent I, Heiðmarsson S, de los Ríos A. Moss and Liverwort Covers Structure Soil Bacterial and Fungal Communities Differently in the Icelandic Highlands. MICROBIAL ECOLOGY 2023; 86:1893-1908. [PMID: 36802019 PMCID: PMC10497656 DOI: 10.1007/s00248-023-02194-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Cryptogamic covers extend over vast polar tundra regions and their main components, e.g., bryophytes and lichens, are frequently the first visible colonizers of deglaciated areas. To understand their role in polar soil development, we analyzed how cryptogamic covers dominated by different bryophyte lineages (mosses and liverworts) influence the diversity and composition of edaphic bacterial and fungal communities as well as the abiotic attributes of underlying soils in the southern part of the Highlands of Iceland. For comparison, the same traits were examined in soils devoid of bryophyte covers. We measured an increase in soil C, N, and organic matter contents coupled with a lower pH in association with bryophyte cover establishment. However, liverwort covers showed noticeably higher C and N contents than moss covers. Significant changes in diversity and composition of bacterial and fungal communities were revealed between (a) bare and bryophyte-covered soils, (b) bryophyte covers and the underlying soils, and (c) moss and liverworts covers. These differences were more obvious for fungi than bacteria, and involved different lineages of saprotrophic and symbiotic fungi, which suggests a certain specificity of microbial taxa to particular bryophyte groups. In addition, differences observed in the spatial structure of the two bryophyte covers may be also responsible for the detected differences in microbial community diversity and composition. Altogether, our findings indicate that soil microbial communities and abiotic attributes are ultimately affected by the composition of the most conspicuous elements of cryptogamic covers in polar regions, which is of great value to predict the biotic responses of these ecosystems to future climate change.
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Affiliation(s)
- Javier Ortiz-Rivero
- Department of Biogeochemistry and Microbial Ecology, National Museum of Natural Sciences (MNCN-CSIC), C/ Serrano 115 dpdo, E-28045 Madrid, Spain
| | - Isaac Garrido-Benavent
- Departament de Botànica i Geologia, Fac. CC. Biològiques, Universitat de València, C/ Doctor Moliner 50, E-46100 Burjassot, Valencia Spain
| | - Starri Heiðmarsson
- Icelandic Institute of Natural History, Akureyri Division, Borgir Nordurslod, 600 Akureyri, Iceland
- Present address: Northwest Iceland Nature Research Centre, Aðalgötu 2, 550 Sauðárkrókur, Iceland
| | - Asunción de los Ríos
- Department of Biogeochemistry and Microbial Ecology, National Museum of Natural Sciences (MNCN-CSIC), C/ Serrano 115 dpdo, E-28045 Madrid, Spain
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8
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Yin X, Martineau C, Samad A, Fenton NJ. Out of site, out of mind: Changes in feather moss phyllosphere microbiota in mine offsite boreal landscapes. Front Microbiol 2023; 14:1148157. [PMID: 37089542 PMCID: PMC10113616 DOI: 10.3389/fmicb.2023.1148157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/14/2023] [Indexed: 04/07/2023] Open
Abstract
Plant-microbe interactions play a crucial role in maintaining biodiversity and ecological services in boreal forest biomes. Mining for minerals, and especially the emission of heavy metal-enriched dust from mine sites, is a potential threat to biodiversity in offsite landscapes. Understanding the impacts of mining on surrounding phyllosphere microbiota is especially lacking. To investigate this, we characterized bacterial and fungal communities in the phyllosphere of feather moss Pleurozium schreberi (Brid). Mitt in boreal landscapes near six gold mine sites at different stages of the mine lifecycle. We found that (1) both mining stage and ecosystem type are drivers of the phyllosphere microbial community structure in mine offsite landscapes; (2) Bacterial alpha diversity is more sensitive than fungal alpha diversity to mining stage, while beta diversity of both groups is impacted; (3) mixed and deciduous forests have a higher alpha diversity and a distinct microbial community structure when compared to coniferous and open canopy ecosystems; (4) the strongest effects are detectable within 0.2 km from operating mines. These results confirmed the presence of offsite effects of mine sites on the phyllosphere microbiota in boreal forests, as well as identified mining stage and ecosystem type as drivers of these effects. Furthermore, the footprint was quantified at 0.2 km, providing a reference distance within which mining companies and policy makers should pay more attention during ecological assessment and for the development of mitigation strategies. Further studies are needed to assess how these offsite effects of mines affect the functioning of boreal ecosystems.
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Affiliation(s)
- Xiangbo Yin
- NSERC-UQAT Industrial Chair in Northern Biodiversity in a Mining Context, Rouyn-Noranda, QC, Canada
- Centre d’Étude de la Forêt, Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC, Canada
- *Correspondence: Xiangbo Yin,
| | - Christine Martineau
- NSERC-UQAT Industrial Chair in Northern Biodiversity in a Mining Context, Rouyn-Noranda, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Abdul Samad
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Nicole J. Fenton
- NSERC-UQAT Industrial Chair in Northern Biodiversity in a Mining Context, Rouyn-Noranda, QC, Canada
- Centre d’Étude de la Forêt, Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC, Canada
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9
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Kubota M, Matsushita N, Nakamura T, Fukuda K. Nitrogen fixation and nifH gene diversity in cyanobacteria living on feather mosses in a subalpine forest of Mt. Fuji. Oecologia 2023; 201:749-760. [PMID: 36808304 PMCID: PMC10038973 DOI: 10.1007/s00442-023-05334-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/07/2023] [Indexed: 02/23/2023]
Abstract
In the boreal forests, feather mosses such as Hylocomium splendens and Pleurozium schreberi are colonized by cyanobacteria, which provide large amounts of nitrogen to forest ecosystems through nitrogen fixation. Although these feather mosses are also ubiquitous in subalpine forests of East Asia, little is known regarding their associated cyanobacteria and their ability to fix nitrogen. In this study, we investigated (1) whether cyanobacteria co-exist and fix nitrogen in the two species of feather mosses that cover the ground surface in a subalpine forest of Mt. Fuji, (2) whether cyanobacteria belonging to a common cluster with boreal forests are found in feather mosses in Mt. Fuji, and (3) whether moss-associated nitrogen fixation rates differed among moss growing substrates, canopy openness, and moss nitrogen concentrations in the same forest area. Our results showed that cyanobacteria colonized feather mosses in the subalpine forests of Mt. Fuji and acetylene reduction rates as an index of nitrogen fixation tended to be higher in H. splendens than in P. schreberi. Based on analysis of the nifH gene, 43 bacterial operational taxonomic units (OTUs) were identified, 28 of which represented cyanobacteria. Among the five clusters of cyanobacteria classified based on their nifH gene and identified in northern Europe, four (Nostoc cluster I, Nostoc cluster II, Stigonema cluster, and nifH2 cluster) were also found at Mt. Fuji. The acetylene reduction rate differed depending on the moss growing substrate and the total nitrogen concentration of moss shoots, and a strong negative correlation was observed with the total nitrogen concentration.
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Affiliation(s)
- Masayuki Kubota
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan.
| | - Norihisa Matsushita
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan
| | - Toshihiko Nakamura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan
| | - Kenji Fukuda
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan
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10
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Klarenberg IJ, Keuschnig C, Salazar A, Benning LG, Vilhelmsson O. Moss and underlying soil bacterial community structures are linked to moss functional traits. Ecosphere 2023. [DOI: 10.1002/ecs2.4447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
Affiliation(s)
- Ingeborg J. Klarenberg
- Natural Resource Sciences University of Akureyri Akureyri Iceland
- Faculty of Life and Environmental Sciences University of Iceland Reykjavík Iceland
- Department of Ecological Science Vrije Universiteit Amsterdam Amsterdam Netherlands
| | - Christoph Keuschnig
- Environmental Microbial Genomics Laboratoire Ampère, CNRS, École Centrale de Lyon Écully France
- German Research Centre for Geosciences (GFZ) Interface Geochemistry Potsdam Germany
| | - Alejandro Salazar
- Faculty of Environmental and Forest Sciences Agricultural University of Iceland Reykjavík Iceland
| | - Liane G. Benning
- German Research Centre for Geosciences (GFZ) Interface Geochemistry Potsdam Germany
- Department of Earth Sciences Free University of Berlin Berlin Germany
| | - Oddur Vilhelmsson
- Natural Resource Sciences University of Akureyri Akureyri Iceland
- BioMedical Center University of Iceland Reykjavík Iceland
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11
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Yabe S, Muto K, Abe K, Yokota A, Staudigel H, Tebo BM. Vulcanimicrobium alpinus gen. nov. sp. nov., the first cultivated representative of the candidate phylum "Eremiobacterota", is a metabolically versatile aerobic anoxygenic phototroph. ISME COMMUNICATIONS 2022; 2:120. [PMID: 37749227 PMCID: PMC9758169 DOI: 10.1038/s43705-022-00201-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 11/07/2022] [Accepted: 11/10/2022] [Indexed: 09/27/2023]
Abstract
The previously uncultured phylum "Candidatus Eremiobacterota" is globally distributed and often abundant in oligotrophic environments. Although it includes lineages with the genetic potential for photosynthesis, one of the most important metabolic pathways on Earth, the absence of pure cultures has limited further insights into its ecological and physiological traits. We report the first successful isolation of a "Ca. Eremiobacterota" strain from a fumarolic ice cave on Mt. Erebus volcano (Antarctica). Polyphasic analysis revealed that this organism is an aerobic anoxygenic photoheterotrophic bacterium with a unique lifestyle, including bacteriochlorophyll a production, CO2 fixation, a high CO2 requirement, and phototactic motility using type IV-pili, all of which are highly adapted to polar and fumarolic environments. The cells are rods or filaments with a vesicular type intracytoplasmic membrane system. The genome encodes novel anoxygenic Type II photochemical reaction centers and bacteriochlorophyll synthesis proteins, forming a deeply branched monophyletic clade distinct from known phototrophs. The first cultured strain of the eighth phototrophic bacterial phylum which we name Vulcanimicrobium alpinus gen. nov., sp. nov. advances our understanding of ecology and evolution of photosynthesis.
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Affiliation(s)
- Shuhei Yabe
- Department of Microbial Resources, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi, 980-0845, Japan.
- Hazaka Plant Research Center, Kennan Eisei Kogyo Co., Ltd., Sendai, Miyagi, 989-1311, Japan.
| | - Kiyoaki Muto
- Department of Microbial Resources, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi, 980-0845, Japan
| | - Keietsu Abe
- Department of Microbial Resources, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi, 980-0845, Japan
| | - Akira Yokota
- Department of Microbial Resources, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi, 980-0845, Japan
| | - Hubert Staudigel
- Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093, USA
| | - Bradley M Tebo
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195, USA
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12
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Arróniz-Crespo M, Bougoure J, Murphy DV, Cutler NA, Souza-Egipsy V, Chaput DL, Jones DL, Ostle N, Wade SC, Clode PL, DeLuca TH. Revealing the transfer pathways of cyanobacterial-fixed N into the boreal forest through the feather-moss microbiome. FRONTIERS IN PLANT SCIENCE 2022; 13:1036258. [PMID: 36570951 PMCID: PMC9780503 DOI: 10.3389/fpls.2022.1036258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
INTRODUCTION Biological N2 fixation in feather-mosses is one of the largest inputs of new nitrogen (N) to boreal forest ecosystems; however, revealing the fate of newly fixed N within the bryosphere (i.e. bryophytes and their associated organisms) remains uncertain. METHODS Herein, we combined 15N tracers, high resolution secondary ion mass-spectrometry (NanoSIMS) and a molecular survey of bacterial, fungal and diazotrophic communities, to determine the origin and transfer pathways of newly fixed N2 within feather-moss (Pleurozium schreberi) and its associated microbiome. RESULTS NanoSIMS images reveal that newly fixed N2, derived from cyanobacteria, is incorporated into moss tissues and associated bacteria, fungi and micro-algae. DISCUSSION These images demonstrate that previous assumptions that newly fixed N2 is sequestered into moss tissue and only released by decomposition are not correct. We provide the first empirical evidence of new pathways for N2 fixed in feather-mosses to enter the boreal forest ecosystem (i.e. through its microbiome) and discuss the implications for wider ecosystem function.
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Affiliation(s)
- María Arróniz-Crespo
- School of Natural Sciences, Bangor University, Bangor, United Kingdom
- School of Agricultural Engineering, CEIGRAM, Universidad Politecnica de Madrid, Madrid, Spain
| | - Jeremy Bougoure
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
| | - Daniel V. Murphy
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
- Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Nick A. Cutler
- Department of Geography, Scott Polar Research Institute, Cambridge, United Kingdom
- School of Geography, Politics and Sociology, Newcastle University, Newcastle, United Kingdom
| | - Virginia Souza-Egipsy
- Servicio de Microscopıa Electronica, Instituto Ciencias Agrarias CSIC, Madrid, Spain
| | | | - Davey L. Jones
- School of Natural Sciences, Bangor University, Bangor, United Kingdom
- Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Nicholas Ostle
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Stephen C. Wade
- Advanced Microscopy and Bioimaging, Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Peta L. Clode
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
| | - Thomas H. DeLuca
- Department of Forest Ecosystems & Society, College of Forestry, Oregon State University, Corvallis, OR, United States
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13
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Sridhar B, Lawrence GB, Debenport SJ, Fahey TJ, Buckley DH, Wilhelm RC, Goodale CL. Watershed-scale liming reveals the short- and long-term effects of pH on the forest soil microbiome and carbon cycling. Environ Microbiol 2022; 24:6184-6199. [PMID: 35799501 DOI: 10.1111/1462-2920.16119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 06/28/2022] [Indexed: 01/12/2023]
Abstract
Soil microbial community composition routinely correlates with pH, reflecting both direct pH effects on microbial physiology and long-term biogeochemical feedbacks. We used two watershed-scale liming experiments to identify short- (2 years) and long-term (25 years) changes in the structure and function of bacterial and fungal communities in organic horizons (Oe and Oa ) of acid forest soils. Liming increased soil pH, extractable calcium, and soil carbon stocks, reduced biomass-specific respiration, and caused major changes in the soil microbiome in the short and long term. More taxa responded to liming in the short term (70%) than in the long term (30%), with most showing consistent directional responses at both sites. The ratio of change in relative abundance between limed and reference sites was twofold higher at the long than the short-term site, indicating that the effects of liming grew over time. Liming impacts were most pronounced in fungi, as steep declines of dominant ectomycorrhizal fungi (Cenococcum and Russula) occurred at both sites. Liming favoured neutrophilic bacteria over acidophilic populations according to estimated environmental pH optima. Collectively, these results demonstrate that a liming-induced change of one pH unit has an immediate and persistent effect on the structure and function of microbial communities in acid forest soils. The corresponding suppression of respiration indicates that anthropogenic alterations of soil pH, as driven by acid deposition or liming, can affect forest floor C stocks due to pH-driven shifts in community structure.
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Affiliation(s)
- Bhavya Sridhar
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | | | - Spencer J Debenport
- School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Timothy J Fahey
- Department of Natural Resources, Cornell University, Ithaca, New York, USA
| | - Daniel H Buckley
- School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Roland C Wilhelm
- School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Christine L Goodale
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
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14
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Wang M, Sun H, Xu Z. Analysis of Blueberry Plant Rhizosphere Bacterial Diversity and Selection of Plant Growth Promoting Rhizobacteria. Curr Microbiol 2022; 79:331. [DOI: 10.1007/s00284-022-03031-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 09/08/2022] [Indexed: 11/03/2022]
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15
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Renaudin M, Laforest-Lapointe I, Bellenger JP. Unraveling global and diazotrophic bacteriomes of boreal forest floor feather mosses and their environmental drivers at the ecosystem and at the plant scale in North America. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 837:155761. [PMID: 35533858 DOI: 10.1016/j.scitotenv.2022.155761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 06/14/2023]
Abstract
Feather mosses are abundant cryptogams of the boreal forest floor and shelter a broad diversity of bacteria who have important ecological functions (e.g., decomposition, nutrient cycling). In particular, nitrogen (N2-) fixation performed by feather moss-associated diazotrophs constitutes an important entry of nitrogen in the boreal forest ecosystem. However, the composition of the feather moss bacteriome and its environmental drivers are still unclear. Using cDNA amplicon sequencing of the 16S rRNA and nifH genes and cyanobacterial biomass quantification, we explored the active global and diazotrophic bacterial communities of two dominant feather moss species (i) at the ecosystem scale, along a 500-km climatic and nutrient deposition gradient in the North American boreal forest, and (ii) at the plant scale, along the moss shoot senescence gradient. We found that cyanobacteria were major actors of the feather moss bacteriome, accounting for 33% of global bacterial communities and 65% of diazotrophic communities, and that several cyanobacterial and methanotrophic genera were contributing to N2-fixation. Moreover, we showed that bacteria were occupying ecological niches along the moss shoot, with phototrophs being dominant in the apical part and methanotrophs being dominant in the basal part. Finally, climate (temperature, precipitation), environmental variables (moss species, month, tree density) and nutrients (nitrogen, phosphorus, molybdenum, vanadium, iron) strongly shaped global and diazotrophic bacteriomes. In summary, this work presents evidence that the feather moss bacteriome plays crucial roles in supporting moss growth, health, and decomposition, as well as in the boreal forest carbon and nitrogen cycles. This study also highlights the substantial effects of climate and nutrients on the feather moss bacteriome, suggesting the importance of understanding the impacts of global change on moss-associated bacterial growth and activity.
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Affiliation(s)
- Marie Renaudin
- Centre Sève, Département de Chimie, Université de Sherbrooke, J1K 2R1 Sherbrooke, QC, Canada.
| | | | - Jean-Philippe Bellenger
- Centre Sève, Département de Chimie, Université de Sherbrooke, J1K 2R1 Sherbrooke, QC, Canada.
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16
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Rousk K. Biotic and abiotic controls of nitrogen fixation in cyanobacteria-moss associations. THE NEW PHYTOLOGIST 2022; 235:1330-1335. [PMID: 35687087 DOI: 10.1111/nph.18264] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Most mosses are colonized by nitrogen (N)-fixing cyanobacteria. This discovery is relatively recent, which can explain the large knowledge gaps the field is now tackling. For instance, while we have a good understanding of the abiotic controls (e.g. nutrient availability, increased temperature), we still do not know much about the biotic controls of N2 fixation in mosses. I propose here that we should endeavour to position moss-cyanobacteria associations along the mutualism-parasitism continuum under varying abiotic conditions (e.g. nutrient availability). This would finally unravel the nature of the relationship between the partners and will be a big leap in our understanding of the evolution of plant-bacteria interactions using moss-cyanobacteria associations as a model system.
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Affiliation(s)
- Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
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17
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Jassey VEJ, Hamard S, Lepère C, Céréghino R, Corbara B, Küttim M, Leflaive J, Leroy C, Carrias JF. Photosynthetic microorganisms effectively contribute to bryophyte CO 2 fixation in boreal and tropical regions. ISME COMMUNICATIONS 2022; 2:64. [PMID: 37938283 PMCID: PMC9723567 DOI: 10.1038/s43705-022-00149-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/28/2022] [Accepted: 07/05/2022] [Indexed: 04/26/2023]
Abstract
Photosynthetic microbes are omnipresent in land and water. While they critically influence primary productivity in aquatic systems, their importance in terrestrial ecosystems remains largely overlooked. In terrestrial systems, photoautotrophs occur in a variety of habitats, such as sub-surface soils, exposed rocks, and bryophytes. Here, we study photosynthetic microbial communities associated with bryophytes from a boreal peatland and a tropical rainforest. We interrogate their contribution to bryophyte C uptake and identify the main drivers of that contribution. We found that photosynthetic microbes take up twice more C in the boreal peatland (~4.4 mg CO2.h-1.m-2) than in the tropical rainforest (~2.4 mg CO2.h-1.m-2), which corresponded to an average contribution of 4% and 2% of the bryophyte C uptake, respectively. Our findings revealed that such patterns were driven by the proportion of photosynthetic protists in the moss microbiomes. Low moss water content and light conditions were not favourable to the development of photosynthetic protists in the tropical rainforest, which indirectly reduced the overall photosynthetic microbial C uptake. Our investigations clearly show that photosynthetic microbes associated with bryophyte effectively contribute to moss C uptake despite species turnover. Terrestrial photosynthetic microbes clearly have the capacity to take up atmospheric C in bryophytes living under various environmental conditions, and therefore potentially support rates of ecosystem-level net C exchanges with the atmosphere.
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Affiliation(s)
- Vincent E J Jassey
- Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université Toulouse 3-Paul Sabatier (UT3), CNRS, 31062, Toulouse, France.
| | - Samuel Hamard
- Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université Toulouse 3-Paul Sabatier (UT3), CNRS, 31062, Toulouse, France
| | - Cécile Lepère
- Laboratoire Microorganismes, Génome Et Environnement (LMGE), Université Clermont Auvergne, CNRS, Clermont-Ferrand, France
| | - Régis Céréghino
- Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université Toulouse 3-Paul Sabatier (UT3), CNRS, 31062, Toulouse, France
| | - Bruno Corbara
- Laboratoire Microorganismes, Génome Et Environnement (LMGE), Université Clermont Auvergne, CNRS, Clermont-Ferrand, France
| | - Martin Küttim
- Institute of Ecology, School of Natural Sciences and Health, Tallinn University, Uus-Sadama 5, 10120, Tallinn, Estonia
| | - Joséphine Leflaive
- Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université Toulouse 3-Paul Sabatier (UT3), CNRS, 31062, Toulouse, France
| | - Céline Leroy
- AMAP, Univ Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, France
- ECOFOG, AgroParisTech, CIRAD, CNRS, INRAE, Université de Guyane, Université des Antilles, Campus Agronomique, Kourou, France
| | - Jean-François Carrias
- Laboratoire Microorganismes, Génome Et Environnement (LMGE), Université Clermont Auvergne, CNRS, Clermont-Ferrand, France
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18
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Alvarenga DO, Rousk K. Unraveling host-microbe interactions and ecosystem functions in moss-bacteria symbioses. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4473-4486. [PMID: 35728619 DOI: 10.1093/jxb/erac091] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Mosses are non-vascular plants usually found in moist and shaded areas, with great ecological importance in several ecosystems. This is especially true in northern latitudes, where mosses are responsible for up to 100% of primary production in some ecosystems. Mosses establish symbiotic associations with unique bacteria that play key roles in the carbon and nitrogen cycles. For instance, in boreal environments, more than 35% of the nitrogen fixed by diazotrophic symbionts in peatlands is transferred to mosses, directly affecting carbon fixation by the hosts, while moss-associated methanotrophic bacteria contribute 10-30% of moss carbon. Further, half of ecosystem N input may derive from moss-cyanobacteria associations in pristine ecosystems. Moss-bacteria interactions have consequences on a global scale since northern environments sequester 20% of all the carbon generated by forests in the world and stock at least 32% of global terrestrial carbon. Different moss hosts influence bacteria in distinct ways, which suggests that threats to mosses also threaten unique microbial communities with important ecological and biogeochemical consequences. Since their origin ~500 Ma, mosses have interacted with bacteria, making these associations ideal models for understanding the evolution of plant-microbe associations and their contribution to biogeochemical cycles.
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Affiliation(s)
- Danillo O Alvarenga
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Kathrin Rousk
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
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19
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Klarenberg IJ, Keuschnig C, Russi Colmenares AJ, Warshan D, Jungblut AD, Jónsdóttir IS, Vilhelmsson O. Long-term warming effects on the microbiome and nifH gene abundance of a common moss species in sub-Arctic tundra. THE NEW PHYTOLOGIST 2022; 234:2044-2056. [PMID: 34719786 DOI: 10.1111/nph.17837] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 10/17/2021] [Indexed: 06/13/2023]
Abstract
Bacterial communities form the basis of biogeochemical processes and determine plant growth and health. Mosses harbour diverse bacterial communities that are involved in nitrogen fixation and carbon cycling. Global climate change is causing changes in aboveground plant biomass and shifting species composition in the Arctic, but little is known about the response of moss microbiomes in these environments. Here, we studied the total and potentially active bacterial communities associated with Racomitrium lanuginosum in response to a 20-yr in situ warming in an Icelandic heathland. We evaluated the effect of warming and warming-induced shrub expansion on the moss bacterial community composition and diversity, and nifH gene abundance. Warming changed both the total and the potentially active bacterial community structure, while litter abundance only affected the total bacterial community structure. The abundance of nifH genes was negatively affected by litter abundance. We also found shifts in the potentially nitrogen-fixing community, with Nostoc decreasing and noncyanobacterial diazotrophs increasing in relative abundance. Our data suggest that the moss microbial community and potentially nitrogen fixing taxa will be sensitive to future warming, partly via changes in litter and shrub abundance.
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Affiliation(s)
- Ingeborg J Klarenberg
- Natural Resource Sciences, University of Akureyri, Borgir i Nordurslod, Akureyri, 600, Iceland
- Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 102, Reykjavík, Iceland
| | - Christoph Keuschnig
- Environmental Microbial Genomics, Laboratoire Ampère, École Centrale de Lyon, Université de Lyon, Avenue Guy de Collongue 36, Écully, 69134, France
| | - Ana J Russi Colmenares
- Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 102, Reykjavík, Iceland
| | - Denis Warshan
- Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 102, Reykjavík, Iceland
| | - Anne D Jungblut
- Life Sciences Department, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Ingibjörg S Jónsdóttir
- Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 102, Reykjavík, Iceland
| | - Oddur Vilhelmsson
- Natural Resource Sciences, University of Akureyri, Borgir i Nordurslod, Akureyri, 600, Iceland
- BioMedical Center, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
- School of Biological Sciences, University of Reading, Whiteknights, Reading, RG6 6AJ, UK
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20
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Rodríguez-Rodríguez JC, Bergeron Y, Kembel SW, Fenton NJ. Dominance of coniferous and broadleaved trees drives bacterial associations with boreal feather mosses. Environ Microbiol 2022; 24:3517-3528. [PMID: 35416394 DOI: 10.1111/1462-2920.16013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/09/2022] [Accepted: 04/09/2022] [Indexed: 12/01/2022]
Abstract
The composition of ecologically important moss-associated bacterial communities seems to be mainly driven by host species but may also be shaped by environmental conditions related with tree dominance. The moss phyllosphere has been studied in coniferous forests while broadleaf forests remain understudied. To determine if host species or environmental conditions defined by tree dominance drives the bacterial diversity in the moss phyllosphere, we used 16S rRNA gene amplicon sequencing to quantify changes in bacterial communities as a function of host species (Pleurozium schreberi and Ptilium crista-castrensis) and forest type (coniferous black spruce versus deciduous broadleaf trembling aspen) in eastern Canada. The overall composition of moss phyllosphere was defined by the interaction of both factors, though most of bacterial phyla were determined by a strong effect of forest type. Bacterial α-diversity was highest in spruce forests, while there was greater turnover (β-diversity) and higher γ-diversity in aspen forests. Unexpectedly, Cyanobacteria were much more relatively abundant in aspen than in spruce forests, with the cyanobacteria family Nostocaceae differing the most between forest types. Our results advance the understanding of moss-associated microbial communities among coniferous and broadleaf deciduous forests, which are important with the increasing changes in tree dominance in the boreal system. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Juanita C Rodríguez-Rodríguez
- Forest Research Institute (IRF) , Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC J9X 5E4, Canada. 2 Département des sciences biologiques, Université du Québec à Montréal (UQAM), Montréal, QC, H2L 2C4, Canada
| | - Yves Bergeron
- Forest Research Institute (IRF) , Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC J9X 5E4, Canada. 2 Département des sciences biologiques, Université du Québec à Montréal (UQAM), Montréal, QC, H2L 2C4, Canada
| | | | - Nicole J Fenton
- Forest Research Institute (IRF) , Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC J9X 5E4, Canada. 2 Département des sciences biologiques, Université du Québec à Montréal (UQAM), Montréal, QC, H2L 2C4, Canada
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21
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Defining the
Sphagnum
Core Microbiome across the North American Continent Reveals a Central Role for Diazotrophic Methanotrophs in the Nitrogen and Carbon Cycles of Boreal Peatland Ecosystems. mBio 2022. [PMCID: PMC8863050 DOI: 10.1128/mbio.03714-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peat mosses of the genus Sphagnum are ecosystem engineers that frequently predominate over photosynthetic production in boreal peatlands. Sphagnum spp. host diverse microbial communities capable of nitrogen fixation (diazotrophy) and methane oxidation (methanotrophy), thereby potentially supporting plant growth under severely nutrient-limited conditions. Moreover, diazotrophic methanotrophs represent a possible “missing link” between the carbon and nitrogen cycles, but the functional contributions of the Sphagnum-associated microbiome remain in question. A combination of metagenomics, metatranscriptomics, and dual-isotope incorporation assays was applied to investigate Sphagnum microbiome community composition across the North American continent and provide empirical evidence for diazotrophic methanotrophy in Sphagnum-dominated ecosystems. Remarkably consistent prokaryotic communities were detected in over 250 Sphagnum SSU rRNA libraries from peatlands across the United States (5 states, 17 bog/fen sites, 18 Sphagnum species), with 12 genera of the core microbiome comprising 60% of the relative microbial abundance. Additionally, nitrogenase (nifH) and SSU rRNA gene amplicon analysis revealed that nitrogen-fixing populations made up nearly 15% of the prokaryotic communities, predominated by Nostocales cyanobacteria and Rhizobiales methanotrophs. While cyanobacteria comprised the vast majority (>95%) of diazotrophs detected in amplicon and metagenome analyses, obligate methanotrophs of the genus Methyloferula (order Rhizobiales) accounted for one-quarter of transcribed nifH genes. Furthermore, in dual-isotope tracer experiments, members of the Rhizobiales showed substantial incorporation of 13CH4 and 15N2 isotopes into their rRNA. Our study characterizes the core Sphagnum microbiome across large spatial scales and indicates that diazotrophic methanotrophs, here defined as obligate methanotrophs of the rare biosphere (Methyloferula spp. of the Rhizobiales) that also carry out diazotrophy, play a keystone role in coupling of the carbon and nitrogen cycles in nutrient-poor peatlands.
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22
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Zhang Q, Wei P, Banda JF, Ma L, Mao W, Li H, Hao C, Dong H. Succession of Microbial Communities in Waste Soils of an Iron Mine in Eastern China. Microorganisms 2021; 9:2463. [PMID: 34946065 PMCID: PMC8704403 DOI: 10.3390/microorganisms9122463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/09/2021] [Accepted: 11/27/2021] [Indexed: 11/16/2022] Open
Abstract
The reclamation of mine dump is largely centered on the role played by microorganisms. However, the succession of microbial community structure and function in ecological restoration of the mine soils is still poorly understood. In this study, soil samples with different stacking time were collected from the dump of an iron mine in China and the physicochemical characteristics and microbial communities of these samples were comparatively investigated. The results showed that the fresh bare samples had the lowest pH, highest ion concentration, and were the most deficient in nutrients while the acidity and ion concentration of old bare samples decreased significantly, and the nutritional conditions improved remarkably. Vegetated samples had the weakest acidity, lowest ion concentration, and the highest nutrient concentration. In the fresh mine soils, the iron/sulfur-oxidizers such as Acidiferrobacter and Sulfobacillus were dominant, resulting in the strongest acidity. Bacteria from genera Acidibacter, Metallibacterium, and phyla Cyanobacteria, WPS-2 were abundant in the old bare samples, which contributed to the pH increase and TOC accumulation respectively. Acidobacteriota predominated in the vegetated samples and promoted nutrient enrichment and plant growth significantly. The microbial diversity and evenness of the three types of soils increased gradually, with more complex microbial networks, suggesting that the microbial community became more mature with time and microorganisms co-evolved with the mine soils.
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Affiliation(s)
- Qin Zhang
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Pengfei Wei
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Joseph Frazer Banda
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Linqiang Ma
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Weiao Mao
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Hongyi Li
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Chunbo Hao
- School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China; (Q.Z.); (P.W.); (J.F.B.); (L.M.); (W.M.); (H.L.)
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
| | - Hailiang Dong
- Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH 45056, USA
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Rosa LH, da Costa Coelho L, Pinto OHB, Carvalho-Silva M, Convey P, Rosa CA, Câmara PEAS. Ecological succession of fungal and bacterial communities in Antarctic mosses affected by a fairy ring disease. Extremophiles 2021; 25:471-481. [PMID: 34480232 DOI: 10.1007/s00792-021-01240-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/26/2021] [Indexed: 01/04/2023]
Abstract
We evaluated fungal and bacterial diversity in an established moss carpet on King George Island, Antarctica, affected by 'fairy ring' disease using metabarcoding. A total of 127 fungal and 706 bacterial taxa were assigned. Ascomycota dominated the fungal assemblages, followed by Basidiomycota, Rozellomycota, Chytridiomycota, Mortierellomycota and Monoblepharomycota. The fungal community displayed high indices of diversity, richness and dominance, which increased from healthy through infected to dead moss samples. A range of fungal taxa were more abundant in dead rather than healthy or fairy ring moss samples. Bacterial diversity and richness were greatest in healthy moss and least within the infected fairy ring. The dominant prokaryotic phyla were Actinobacteriota, Proteobacteria, Bacteroidota and Cyanobacteria. Cyanophyceae sp., whilst consistently dominant, were less abundant in fairy ring samples. Our data confirmed the presence and abundance of a range of plant pathogenic fungi, supporting the hypothesis that the disease is linked with multiple fungal taxa. Further studies are required to characterise the interactions between plant pathogenic fungi and their host Antarctic mosses. Monitoring the dynamics of mutualist, phytopathogenic and decomposer microorganisms associated with moss carpets may provide bioindicators of moss health.
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Affiliation(s)
- Luiz Henrique Rosa
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
| | - Lívia da Costa Coelho
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | | | - Peter Convey
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.,Department of Zoology, University of Johannesburg, Johannesburg, South Africa
| | - Carlos Augusto Rosa
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
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Nelson JM, Hauser DA, Li FW. The diversity and community structure of symbiotic cyanobacteria in hornworts inferred from long-read amplicon sequencing. AMERICAN JOURNAL OF BOTANY 2021; 108:1731-1744. [PMID: 34533221 DOI: 10.1002/ajb2.1729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/16/2021] [Accepted: 05/17/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Nitrogen-fixing endosymbioses with cyanobacteria have evolved independently in five very different plant lineages. Expanding knowledge of these symbioses promises to improve the understanding of symbiosis evolution and broaden the toolkit for agricultural engineering to reduce artificial fertilizer use. Here we focused on hornworts, a bryophyte lineage in which all members host cyanobacteria, and investigated factors shaping the diversity of their cyanobiont communities. METHODS We sampled hornworts and adjacent soils in upstate New York throughout the hornwort growing season. We included all three sympatric hornwort species in the area, allowing us to directly compare partner selectivity. To profile cyanobacteria communities, we established a metabarcoding protocol targeting rbcL-X with PacBio long reads. RESULTS The hornwort cyanobionts detected were phylogenetically diverse, including clades that do not contain other known plant symbionts. We found significant overlap between hornwort cyanobionts and soil cyanobacteria, a pattern not previously reported in other plant-cyanobacteria symbioses. Cyanobiont communities differed between host plants only centimeters apart, but we did not detect an effect of sampling time or host species on the cyanobacterial community structure. CONCLUSIONS This study expands the phylogenetic diversity of known symbiotic cyanobacteria. Our analyses suggest that hornwort cyanobionts have a tight connection to the soil background, and we found no evidence that time within growing season, host species, or distance at the scale of meters strongly govern cyanobacteria community assembly. This study provides a critical foundation for further study of the ecology, evolution, and interaction dynamics of plant-cyanobacteria symbiosis.
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Affiliation(s)
| | | | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, NY, USA
- Plant Biology Section, Cornell University, Ithaca, NY, USA
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25
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Candidatus Eremiobacterota, a metabolically and phylogenetically diverse terrestrial phylum with acid-tolerant adaptations. THE ISME JOURNAL 2021; 15:2692-2707. [PMID: 33753881 PMCID: PMC8397712 DOI: 10.1038/s41396-021-00944-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/11/2021] [Accepted: 02/18/2021] [Indexed: 02/01/2023]
Abstract
Candidatus phylum Eremiobacterota (formerly WPS-2) is an as-yet-uncultured bacterial clade that takes its name from Ca. Eremiobacter, an Antarctic soil aerobe proposed to be capable of a novel form of chemolithoautotrophy termed atmospheric chemosynthesis, that uses the energy derived from atmospheric H2-oxidation to fix CO2 through the Calvin-Benson-Bassham (CBB) cycle via type 1E RuBisCO. To elucidate the phylogenetic affiliation and metabolic capacities of Ca. Eremiobacterota, we analysed 63 public metagenome-assembled genomes (MAGs) and nine new MAGs generated from Antarctic soil metagenomes. These MAGs represent both recognized classes within Ca. Eremiobacterota, namely Ca. Eremiobacteria and UBP9. Ca. Eremiobacteria are inferred to be facultatively acidophilic with a preference for peptides and amino acids as nutrient sources. Epifluorescence microscopy revealed Ca. Eremiobacteria cells from Antarctica desert soil to be coccoid in shape. Two orders are recognized within class Ca. Eremiobacteria: Ca. Eremiobacterales and Ca. Baltobacterales. The latter are metabolically versatile, with individual members having genes required for trace gas driven autotrophy, anoxygenic photosynthesis, CO oxidation, and anaerobic respiration. UBP9, here renamed Ca. Xenobia class. nov., are inferred to be obligate heterotrophs with acidophilic adaptations, but individual members having highly divergent metabolic capacities compared to Ca. Eremiobacteria, especially with regard to respiration and central carbon metabolism. We conclude Ca. Eremiobacterota to be an ecologically versatile phylum with the potential to thrive under an array of "extreme" environmental conditions.
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Wicaksono WA, Cernava T, Berg C, Berg G. Bog ecosystems as a playground for plant-microbe coevolution: bryophytes and vascular plants harbour functionally adapted bacteria. MICROBIOME 2021; 9:170. [PMID: 34380552 PMCID: PMC8359052 DOI: 10.1186/s40168-021-01117-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/21/2021] [Indexed: 05/05/2023]
Abstract
BACKGROUND Bogs are unique ecosystems inhabited by distinctive, coevolved assemblages of organisms, which play a global role for carbon storage, climate stability, water quality and biodiversity. To understand ecology and plant-microbe co-occurrence in bogs, we selected 12 representative species of bryophytes and vascular plants and subjected them to a shotgun metagenomic sequencing approach. We explored specific plant-microbe associations as well as functional implications of the respective communities on their host plants and the bog ecosystem. RESULTS Microbial communities were shown to be functionally adapted to their plant hosts; a higher colonization specificity was found for vascular plants. Bryophytes that commonly constitute the predominant Sphagnum layer in bogs were characterized by a higher bacterial richness and diversity. Each plant group showed an enrichment of distinct phylogenetic and functional bacterial lineages. Detailed analyses of the metabolic potential of 28 metagenome-assembled genomes (MAGs) supported the observed functional specification of prevalent bacteria. We found that novel lineages of Betaproteobacteria and Actinobacteria in the bog environment harboured genes required for carbon fixation via RuBisCo. Interestingly, several of the highly abundant bacteria in both plant types harboured pathogenicity potential and carried similar virulence factors as found with corresponding human pathogens. CONCLUSIONS The unexpectedly high specificity of the plant microbiota reflects intimate plant-microbe interactions and coevolution in bog environments. We assume that the detected pathogenicity factors might be involved in coevolution processes, but the finding also reinforces the role of the natural plant microbiota as a potential reservoir for human pathogens. Overall, the study demonstrates how plant-microbe assemblages can ensure stability, functioning and ecosystem health in bogs. It also highlights the role of bog ecosystems as a playground for plant-microbe coevolution. Video abstract.
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Affiliation(s)
- Wisnu Adi Wicaksono
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Christian Berg
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
- Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Potsdam, Germany
- Institute for Biochemistry and Biology, University of Postdam, Postdam, Germany
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27
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The relationship of C and N stable isotopes to high-latitude moss-associated N 2 fixation. Oecologia 2021; 197:283-295. [PMID: 34319437 DOI: 10.1007/s00442-021-05005-7] [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: 02/11/2021] [Accepted: 07/23/2021] [Indexed: 10/20/2022]
Abstract
Moss-associated N2 fixation by epiphytic microbes is a key biogeochemical process in nutrient-limited high-latitude ecosystems. Abiotic drivers, such as temperature and moisture, and the identity of host mosses are critical sources of variation in N2 fixation rates. An understanding of the potential interaction between these factors is essential for predicting N inputs as moss communities change with the climate. To further understand the drivers and results of N2 fixation rate variation, we obtained natural abundance values of C and N isotopes and an associated rate of N2 fixation with 15N2 gas incubations in 34 moss species collected in three regions across Alaska, USA. We hypothesized that δ15N values would increase toward 0‰ with higher N2 fixation to reflect the increasing contribution of fixed N2 in moss biomass. Second, we hypothesized that δ13C and N2 fixation would be positively related, as enriched δ13C signatures reflect abiotic conditions favorable to N2 fixation. We expected that the magnitude of these relationships would vary among types of host mosses, reflecting differences in anatomy and habitat. We found little support for our first hypothesis, with only a modest positive relationship between N2 fixation rates and δ15N in a structural equation model. We found a significant positive relationship between δ13C and N2 fixation only in Hypnales, where the probability of N2 fixation activity reached 95% when δ13C values exceeded - 30.4‰. We conclude that moisture and temperature interact strongly with host moss identity in determining the extent to which abiotic conditions impact associated N2 fixation rates.
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28
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Câmara PEAS, Convey P, Rangel SB, Konrath M, Barreto CC, Pinto OHB, Silva MC, Henriques DK, de Oliveira HC, Rosa LH. The largest moss carpet transplant in Antarctica and its bryosphere cryptic biodiversity. Extremophiles 2021; 25:369-384. [PMID: 34117569 DOI: 10.1007/s00792-021-01235-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/01/2021] [Indexed: 01/16/2023]
Abstract
As part of the reconstruction of the Brazilian Antarctic Station on King George Island, three areas of moss carpet were transplanted to minimize the impact of the new facilities on the local biodiversity. A total of 650 m2 of moss carpet was transplanted to neighboring but previously uncolonized locations and has subsequently survived for the last 3 years. Antarctic moss carpets typically comprise low moss species diversity and are often monospecific. We investigated the cryptic biodiversity that was transplanted along with the carpets using a metabarcoding approach through high throughput sequencing. We targeted 16S rRNA for Bacteria and Archaea, ITS for Fungi and Viridiplantae and Cox1 for Metazoa. We detected DNA representing 263 taxa from five Kingdoms (Chromista, Fungi, Metazoa, Protista and Viridiplantae), two Domains (Archaea and Bacteria) and 33 Phyla associated with the carpet. This diversity included one Archaea, 189 Bacteria, 24 Chromista, 19 Fungi, eight Metazoa, seven Protista and 16 Viridiplantae. Bacteria was the most abundant, rich and diverse group, with Chromista second in diversity and richness. Metazoa was less diverse but second highest in dominance. This is the first study to attempt transplanting a significant area of moss carpet to minimize anthropogenic environmental damage in Antarctica and to use metabarcoding as a proxy to assess diversity associated with Antarctic moss carpets, further highlighting the importance of such habitats for other organisms and their importance for conservation.
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Affiliation(s)
| | | | - Sandro B Rangel
- Instituto Brasileiro Do Meio Ambiente, IBAMA, Brasilia, Brazil
| | - Marcelo Konrath
- China National Electronics Import and Export Corporation, CEIEC, Beijing, China
| | | | - Otavio H B Pinto
- Departamento de Biologia Molecular, Universidade de Brasília, Brasilia, Brazil
| | | | | | | | - Luiz H Rosa
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Abstract
Members of the bacterial phylum Gemmatimonadota are ubiquitous in most natural environments and represent one of the top 10 most abundant bacterial phyla in soil. Sequences affiliated with Gemmatimonadota were also reported from diverse aquatic habitats; however, it remains unknown whether they are native organisms or represent bacteria passively transported from sediment or soil. To address this question, we analyzed metagenomes constructed from five freshwater lakes in central Europe. Based on the 16S rRNA gene frequency, Gemmatimonadota represented from 0.02 to 0.6% of all bacteria in the epilimnion and between 0.1 and 1% in the hypolimnion. These proportions were independently confirmed using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Some cells in the epilimnion were attached to diatoms (Fragilaria sp.) or cyanobacteria (Microcystis sp.), which suggests a close association with phytoplankton. In addition, we reconstructed 45 metagenome-assembled genomes (MAGs) related to Gemmatimonadota. They represent several novel lineages, which persist in the studied lakes during the seasons. Three lineages contained photosynthesis gene clusters. One of these lineages was related to Gemmatimonas phototrophica and represented the majority of Gemmatimonadota retrieved from the lakes’ epilimnion. The other two lineages came from hypolimnion and probably represented novel photoheterotrophic genera. None of these phototrophic MAGs contained genes for carbon fixation. Since most of the identified MAGs were present during the whole year and cells associated with phytoplankton were observed, we conclude that they represent truly limnic Gemmatimonadota distinct from the previously described species isolated from soils or sediments. IMPORTANCE Photoheterotrophic bacterial phyla such as Gemmatimonadota are key components of many natural environments. Its first photoheterotrophic cultured member, Gemmatimonas phototrophica, was isolated in 2014 from a shallow lake in the Gobi Desert. It contains a unique type of photosynthetic complex encoded by a set of genes which were likely received via horizontal transfer from Proteobacteria. We were intrigued to discover how widespread this group is in the natural environment. In the presented study, we analyzed 45 metagenome-assembled genomes (MAGs) that were obtained from five freshwater lakes in Switzerland and Czechia. Interestingly, it was found that phototrophic Gemmatimonadota are relatively common in euphotic zones of the studied lakes, whereas heterotrophic Gemmatimonadota prevail in deeper waters. Moreover, our analysis of the MAGs documented that these freshwater species contain almost the same set of photosynthesis genes identified before in Gemmatimonas phototrophica originating from the Gobi Desert.
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Kollar LM, Kiel S, James AJ, Carnley CT, Scola DN, Clark TN, Khanal T, Rosenstiel TN, Gall ET, Grieshop K, McDaniel SF. The genetic architecture of sexual dimorphism in the moss Ceratodon purpureus. Proc Biol Sci 2021; 288:20202908. [PMID: 33715431 PMCID: PMC7944104 DOI: 10.1098/rspb.2020.2908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/02/2021] [Indexed: 12/12/2022] Open
Abstract
A central problem in evolutionary biology is to identify the forces that maintain genetic variation for fitness in natural populations. Sexual antagonism, in which selection favours different variants in males and females, can slow the transit of a polymorphism through a population or can actively maintain fitness variation. The amount of sexually antagonistic variation to be expected depends in part on the genetic architecture of sexual dimorphism, about which we know relatively little. Here, we used a multivariate quantitative genetic approach to examine the genetic architecture of sexual dimorphism in a scent-based fertilization syndrome of the moss Ceratodon purpureus. We found sexual dimorphism in numerous traits, consistent with a history of sexually antagonistic selection. The cross-sex genetic correlations (rmf) were generally heterogeneous with many values indistinguishable from zero, which typically suggests that genetic constraints do not limit the response to sexually antagonistic selection. However, we detected no differentiation between the female- and male-specific trait (co)variance matrices (Gf and Gm, respectively), meaning the evolution of sexual dimorphism may be constrained. The cross-sex cross-trait covariance matrix B contained both symmetric and asymmetric elements, indicating that the response to sexually antagonistic or sexually concordant selection, and the constraint to sexual dimorphism, are highly dependent on the traits experiencing selection. The patterns of genetic variances and covariances among these fitness components is consistent with partly sex-specific genetic architectures having evolved in order to partially resolve multivariate genetic constraints (i.e. sexual conflict), enabling the sexes to evolve towards their sex-specific multivariate trait optima.
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Affiliation(s)
- Leslie M. Kollar
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Scott Kiel
- Center for Life in Extreme Environments, Portland State University, Portland, OR 97207, USA
| | - Ashley J. James
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Cody T. Carnley
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Danielle N. Scola
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Taylor N. Clark
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Tikahari Khanal
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Todd N. Rosenstiel
- Center for Life in Extreme Environments, Portland State University, Portland, OR 97207, USA
| | - Elliott T. Gall
- Maseeh College of Engineering and Computer Science, Portland State University, Portland, OR 97207, USA
| | - Karl Grieshop
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Stuart F. McDaniel
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
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Holland-Moritz H, Stuart JEM, Lewis LR, Miller SN, Mack MC, Ponciano JM, McDaniel SF, Fierer N. The bacterial communities of Alaskan mosses and their contributions to N 2-fixation. MICROBIOME 2021; 9:53. [PMID: 33622403 PMCID: PMC7903681 DOI: 10.1186/s40168-021-01001-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/08/2021] [Indexed: 05/14/2023]
Abstract
BACKGROUND Mosses in high-latitude ecosystems harbor diverse bacterial taxa, including N2-fixers which are key contributors to nitrogen dynamics in these systems. Yet the relative importance of moss host species, and environmental factors, in structuring these microbial communities and their N2-fixing potential remains unclear. We studied 26 boreal and tundra moss species across 24 sites in Alaska, USA, from 61 to 69° N. We used cultivation-independent approaches to characterize the variation in moss-associated bacterial communities as a function of host species identity and site characteristics. We also measured N2-fixation rates via 15N2 isotopic enrichment and identified potential N2-fixing bacteria using available literature and genomic information. RESULTS Host species identity and host evolutionary history were both highly predictive of moss microbiome composition, highlighting strong phylogenetic coherence in these microbial communities. Although less important, light availability and temperature also influenced composition of the moss microbiome. Finally, we identified putative N2-fixing bacteria specific to some moss hosts, including potential N2-fixing bacteria outside well-studied cyanobacterial clades. CONCLUSIONS The strong effect of host identity on moss-associated bacterial communities demonstrates mosses' utility for understanding plant-microbe interactions in non-leguminous systems. Our work also highlights the likely importance of novel bacterial taxa to N2-fixation in high-latitude ecosystems. Video Abstract.
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Affiliation(s)
- Hannah Holland-Moritz
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO USA
| | - Julia E. M. Stuart
- Center for Ecosystem Science and Society and the Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ USA
| | - Lily R. Lewis
- Provost’s Office, University of Florida, Gainesville, FL USA
| | - Samantha N. Miller
- Center for Ecosystem Science and Society and the Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ USA
| | - Michelle C. Mack
- Center for Ecosystem Science and Society and the Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ USA
| | | | | | - Noah Fierer
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO USA
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Ward LM, Shih PM. Granick revisited: Synthesizing evolutionary and ecological evidence for the late origin of bacteriochlorophyll via ghost lineages and horizontal gene transfer. PLoS One 2021; 16:e0239248. [PMID: 33507911 PMCID: PMC7842958 DOI: 10.1371/journal.pone.0239248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 12/29/2020] [Indexed: 11/19/2022] Open
Abstract
Photosynthesis-both oxygenic and more ancient anoxygenic forms-has fueled the bulk of primary productivity on Earth since it first evolved more than 3.4 billion years ago. However, the early evolutionary history of photosynthesis has been challenging to interpret due to the sparse, scattered distribution of metabolic pathways associated with photosynthesis, long timescales of evolution, and poor sampling of the true environmental diversity of photosynthetic bacteria. Here, we reconsider longstanding hypotheses for the evolutionary history of phototrophy by leveraging recent advances in metagenomic sequencing and phylogenetics to analyze relationships among phototrophic organisms and components of their photosynthesis pathways, including reaction centers and individual proteins and complexes involved in the multi-step synthesis of (bacterio)-chlorophyll pigments. We demonstrate that components of the photosynthetic apparatus have undergone extensive, independent histories of horizontal gene transfer. This suggests an evolutionary mode by which modular components of phototrophy are exchanged between diverse taxa in a piecemeal process that has led to biochemical innovation. We hypothesize that the evolution of extant anoxygenic photosynthetic bacteria has been spurred by ecological competition and restricted niches following the evolution of oxygenic Cyanobacteria and the accumulation of O2 in the atmosphere, leading to the relatively late evolution of bacteriochlorophyll pigments and the radiation of diverse crown group anoxygenic phototrophs. This hypothesis expands on the classic "Granick hypothesis" for the stepwise evolution of biochemical pathways, synthesizing recent expansion in our understanding of the diversity of phototrophic organisms as well as their evolving ecological context through Earth history.
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Affiliation(s)
- Lewis M. Ward
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, United States of America
| | - Patrick M. Shih
- Department of Plant Biology, University of California, Davis, California, United States of America
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, California, United States of America
- Genome Center, University of California, Davis, California, United States of America
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Pecundo MH, Chang ACG, Chen T, dela Cruz TEE, Ren H, Li N. Full-Length 16S rRNA and ITS Gene Sequencing Revealed Rich Microbial Flora in Roots of Cycas spp. in China. Evol Bioinform Online 2021; 17:1176934321989713. [PMID: 33613025 PMCID: PMC7868495 DOI: 10.1177/1176934321989713] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 12/30/2020] [Indexed: 11/30/2022] Open
Abstract
Cycads have developed a complex root system categorized either as normal or coralloid roots. Past literatures revealed that a great diversity of key microbes is associated with these roots. This recent study aims to comprehensively determine the diversity and community structure of bacteria and fungi associated with the roots of two Cycas spp. endemic to China, Cycas debaoensis Zhong & Chen and Cycas fairylakea D.Y. Wang using high-throughput amplicon sequencing of the full-length 16S rRNA (V1-V9 hypervariable) and short fragment ITS region. The total DNA from 12 root samples were extracted, amplified, sequenced, and analyzed. Resulting sequences were clustered into 61 bacteria and 2128 fungal OTUs. Analysis of community structure revealed that the coralloid roots were dominated mostly by the nitrogen-fixer Nostocaceae but also contain other non-diazotrophic bacteria. The sequencing of entire 16S rRNA gene identified four different strains of cyanobacteria under the heterocystous genera Nostoc and Desmonostoc. Meanwhile, the top bacterial families in normal roots were Xanthobacteraceae, Burkholderiaceae, and Bacillaceae. Moreover, a diverse fungal community was also found in the roots of cycads and the predominating families were Ophiocordycipitaceae, Nectriaceae, Bionectriaceae, and Trichocomaceae. Our results demonstrated that bacterial diversity in normal roots of C. fairylakea is higher in richness and abundance than C. debaoensis. On the other hand, a slight difference, albeit insignificant, was noted for the diversity of fungi among root types and host species as the number of shared taxa is relatively high (67%). Our results suggested that diverse microbes are present in roots of cycads which potentially interact together to support cycads survival. Our study provided additional knowledge on the microbial diversity and composition in cycads and thus expanding our current knowledge on cycad-microbe association. Our study also considered the possible impact of ex situ conservation on cyanobiont community of cycads.
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Affiliation(s)
- Melissa H Pecundo
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Fairy Lake Botanical Garden, Chinese Academy of Sciences, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Aimee Caye G Chang
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Fairy Lake Botanical Garden, Chinese Academy of Sciences, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
- Department of Biological Sciences, College of Science, University of Santo Tomas, Manila, Philippines
| | - Tao Chen
- Fairy Lake Botanical Garden, Chinese Academy of Sciences, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Thomas Edison E dela Cruz
- Department of Biological Sciences, College of Science, University of Santo Tomas, Manila, Philippines
| | - Hai Ren
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Nan Li
- Fairy Lake Botanical Garden, Chinese Academy of Sciences, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
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Tveit AT, Kiss A, Winkel M, Horn F, Hájek T, Svenning MM, Wagner D, Liebner S. Environmental patterns of brown moss- and Sphagnum-associated microbial communities. Sci Rep 2020; 10:22412. [PMID: 33376244 PMCID: PMC7772339 DOI: 10.1038/s41598-020-79773-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/02/2020] [Indexed: 11/08/2022] Open
Abstract
Northern peatlands typically develop through succession from fens dominated by the moss family Amblystegiaceae to bogs dominated by the moss genus Sphagnum. How the different plants and abiotic environmental conditions provided in Amblystegiaceae and Sphagnum peat shape the respective moss associated microbial communities is unknown. Through a large-scale molecular and biogeochemical study spanning Arctic, sub-Arctic and temperate regions we assessed how the endo- and epiphytic microbial communities of natural northern peatland mosses relate to peatland type (Sphagnum and Amblystegiaceae), location, moss taxa and abiotic environmental variables. Microbial diversity and community structure were distinctly different between Amblystegiaceae and Sphagnum peatlands, and within each of these two peatland types moss taxon explained the largest part of microbial community variation. Sphagnum and Amblystegiaceae shared few (< 1% of all operational taxonomic units (OTUs)) but strikingly abundant (up to 65% of relative abundance) OTUs. This core community overlapped by one third with the Sphagnum-specific core-community. Thus, the most abundant microorganisms in Sphagnum that are also found in all the Sphagnum plants studied, are the same OTUs as those few shared with Amblystegiaceae. Finally, we could confirm that these highly abundant OTUs were endophytes in Sphagnum, but epiphytes on Amblystegiaceae. We conclude that moss taxa and abiotic environmental variables associate with particular microbial communities. While moss taxon was the most influential parameter, hydrology, pH and temperature also had significant effects on the microbial communities. A small though highly abundant core community is shared between Sphagnum and Amblystegiaceae.
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Affiliation(s)
- Alexander Tøsdal Tveit
- UiT The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway
| | - Andrea Kiss
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany
| | - Matthias Winkel
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany
| | - Fabian Horn
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany
| | - Tomáš Hájek
- University of South Bohemia, Faculty of Science, České Budějovice, Czech Republic
| | - Mette Marianne Svenning
- UiT The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway
| | - Dirk Wagner
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany
- University of Potsdam, Institute of Geosciences, Potsdam, Germany
| | - Susanne Liebner
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany.
- University of Potsdam, Institute of Biochemistry and Biology, Potsdam, Germany.
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Klarenberg IJ, Keuschnig C, Warshan D, Jónsdóttir IS, Vilhelmsson O. The Total and Active Bacterial Community of the Chlorolichen Cetraria islandica and Its Response to Long-Term Warming in Sub-Arctic Tundra. Front Microbiol 2020; 11:540404. [PMID: 33391192 PMCID: PMC7775390 DOI: 10.3389/fmicb.2020.540404] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 11/30/2020] [Indexed: 01/04/2023] Open
Abstract
Lichens are traditionally defined as a symbiosis between a fungus and a green alga and or a cyanobacterium. This idea has been challenged by the discovery of bacterial communities inhabiting the lichen thalli. These bacteria are thought to contribute to the survival of lichens under extreme and changing environmental conditions. How these changing environmental conditions affect the lichen-associated bacterial community composition remains unclear. We describe the total (rDNA-based) and potentially metabolically active (rRNA-based) bacterial community of the lichen Cetaria islandica and its response to long-term warming using a 20-year warming experiment in an Icelandic sub-Arctic tundra. 16S rRNA and rDNA amplicon sequencing showed that the orders Acetobacterales (of the class Alphaproteobacteria) and Acidobacteriales (of the phylum Acidobacteria) dominated the bacterial community. Numerous amplicon sequence variants (ASVs) could only be detected in the potentially active community but not in the total community. Long-term warming led to increases in relative abundance of bacterial taxa on class, order and ASV level. Warming altered the relative abundance of ASVs of the most common bacterial genera, such as Granulicella and Endobacter. The potentially metabolically active bacterial community was also more responsive to warming than the total community. Our results suggest that the bacterial community of the lichen C. islandica is dominated by acidophilic taxa and harbors disproportionally active rare taxa. We also show for the first time that climate warming can lead to shifts in lichen-associated bacterial community composition.
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Affiliation(s)
- Ingeborg J. Klarenberg
- Natural Resource Sciences, University of Akureyri, Akureyri, Iceland
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - Christoph Keuschnig
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France
| | - Denis Warshan
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | | | - Oddur Vilhelmsson
- Natural Resource Sciences, University of Akureyri, Akureyri, Iceland
- BioMedical Center, University of Iceland, Reykjavík, Iceland
- School of Biological Sciences, University of Reading, Reading, United Kingdom
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36
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Jean M, Holland-Moritz H, Melvin AM, Johnstone JF, Mack MC. Experimental assessment of tree canopy and leaf litter controls on the microbiome and nitrogen fixation rates of two boreal mosses. THE NEW PHYTOLOGIST 2020; 227:1335-1349. [PMID: 32299141 DOI: 10.1111/nph.16611] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
Nitrogen (N2 )-fixing moss microbial communities play key roles in nitrogen cycling of boreal forests. Forest type and leaf litter inputs regulate moss abundance, but how they control moss microbiomes and N2 -fixation remains understudied. We examined the impacts of forest type and broadleaf litter on microbial community composition and N2 -fixation rates of Hylocomium splendens and Pleurozium schreberi. We conducted a moss transplant and leaf litter manipulation experiment at three sites with paired paper birch (Betula neoalaskana) and black spruce (Picea mariana) stands in Alaska. We characterized bacterial communities using marker gene sequencing, determined N2 -fixation rates using stable isotopes (15 N2 ) and measured environmental covariates. Mosses native to and transplanted into spruce stands supported generally higher N2 -fixation and distinct microbial communities compared to similar treatments in birch stands. High leaf litter inputs shifted microbial community composition for both moss species and reduced N2 -fixation rates for H. splendens, which had the highest rates. N2 -fixation was positively associated with several bacterial taxa, including cyanobacteria. The moss microbiome and environmental conditions controlled N2 -fixation at the stand and transplant scales. Predicted shifts from spruce- to deciduous-dominated stands will interact with the relative abundances of mosses supporting different microbiomes and N2 -fixation rates, which could affect stand-level N inputs.
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Affiliation(s)
- Mélanie Jean
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
| | - Hannah Holland-Moritz
- Cooperative Institute for Research in Environmental Sciences and Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - April M Melvin
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Independent researcher, Washington, DC, 20001, USA
| | - Jill F Johnstone
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Michelle C Mack
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
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37
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Stuart JEM, Holland-Moritz H, Lewis LR, Jean M, Miller SN, McDaniel SF, Fierer N, Ponciano JM, Mack MC. Host Identity as a Driver of Moss-Associated N2 Fixation Rates in Alaska. Ecosystems 2020. [DOI: 10.1007/s10021-020-00534-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Sheremet A, Jones GM, Jarett J, Bowers RM, Bedard I, Culham C, Eloe-Fadrosh EA, Ivanova N, Malmstrom RR, Grasby SE, Woyke T, Dunfield PF. Ecological and genomic analyses of candidate phylum WPS-2 bacteria in an unvegetated soil. Environ Microbiol 2020; 22:3143-3157. [PMID: 32372527 DOI: 10.1111/1462-2920.15054] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 12/01/2022]
Abstract
Members of the bacterial candidate phylum WPS-2 (or Eremiobacterota) are abundant in several dry, bare soil environments. In a bare soil deposited by an extinct iron-sulfur spring, we found that WPS-2 comprised up to 24% of the bacterial community and up to 108 cells per g of soil based on 16S rRNA gene sequencing and quantification. A single genus-level cluster (Ca. Rubrimentiphilum) predominated in bare soils but was less abundant in adjacent forest. Nearly complete genomes of Ca. Rubrimentiphilum were recovered as single amplified genomes (SAGs) and metagenome-assembled genomes (MAGs). Surprisingly, given the abundance of WPS-2 in bare soils, the genomes did not indicate any capacity for autotrophy, phototrophy, or trace gas metabolism. Instead, they suggest a predominantly aerobic organoheterotrophic lifestyle, perhaps based on scavenging amino acids, nucleotides, and complex oligopeptides, along with lithotrophic capacity on thiosulfate. Network analyses of the entire community showed that some species of Chloroflexi, Actinobacteria, and candidate phylum AD3 (or Dormibacterota) co-occurred with Ca. Rubrimentiphilum and may represent ecological or metabolic partners. We propose that Ca. Rubrimentiphilum act as efficient heterotrophic scavengers. Combined with previous studies, these data suggest that the phylum WPS-2 includes bacteria with diverse metabolic capabilities.
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Affiliation(s)
- Andriy Sheremet
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Gareth M Jones
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Jessica Jarett
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Robert M Bowers
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Isaac Bedard
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Cassandra Culham
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | | | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Rex R Malmstrom
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | | | - Tanja Woyke
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
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Juottonen H, Männistö M, Tiirola M, Kytöviita MM. Cryptogams signify key transitions of bacteria and fungi in Arctic sand dune succession. THE NEW PHYTOLOGIST 2020; 226:1836-1849. [PMID: 32017117 DOI: 10.1111/nph.16469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/28/2020] [Indexed: 05/26/2023]
Abstract
Primary succession models focus on aboveground vascular plants. However, the prevalence of mosses and lichens, that is cryptogams, suggests they play a role in soil successions. Here, we explore whether effects of cryptogams on belowground microbes can facilitate progressive shifts in sand dune succession. We linked aboveground vegetation, belowground bacterial and fungal communities, and soil chemical properties in six successional stages in Arctic inland sand dunes: bare sand, grass, moss, lichen, ericoid heath and mountain birch forest. Compared with the bare sand and grass stages, microbial biomass and the proportion of fungi increased in the moss stage, and later stage microbial groups appeared despite the absence of their host plants. Microbial communities of the lichen stage resembled the communities in the vascular plant stages. Bacterial communities correlated better with soil chemical variables than with vegetation and vice versa for fungal communities. The correlation of fungi with vegetation increased with vascular vegetation. Distinct bacterial and fungal patterns of biomass, richness and plant-microbe interactions showed that the aboveground vegetation change structured the bacterial and fungal community differently. The asynchrony of aboveground vs belowground changes suggests that cryptogams can drive succession towards vascular plant dominance through microbially mediated facilitation in eroded Arctic soil.
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Affiliation(s)
- Heli Juottonen
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland
| | - Minna Männistö
- Natural Resources Institute Finland (Luke), 96300, Rovaniemi, Finland
| | - Marja Tiirola
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland
| | - Minna-Maarit Kytöviita
- Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland
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40
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Contrasting bacteriome of the hornwort Leiosporoceros dussii in two nearby sites with emphasis on the hornwort-cyanobacterial symbiosis. Symbiosis 2020. [DOI: 10.1007/s13199-020-00680-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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41
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Hough M, McClure A, Bolduc B, Dorrepaal E, Saleska S, Klepac-Ceraj V, Rich V. Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient. Front Microbiol 2020; 11:796. [PMID: 32499761 PMCID: PMC7243355 DOI: 10.3389/fmicb.2020.00796] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/03/2020] [Indexed: 02/01/2023] Open
Abstract
Plant-associated microbiomes are structured by environmental conditions and plant associates, both of which are being altered by climate change. The future structure of plant microbiomes will depend on the, largely unknown, relative importance of each. This uncertainty is particularly relevant for arctic peatlands, which are undergoing large shifts in plant communities and soil microbiomes as permafrost thaws, and are potentially appreciable sources of climate change feedbacks due to their soil carbon (C) storage. We characterized phyllosphere and rhizosphere microbiomes of six plant species, and bulk peat, across a permafrost thaw progression (from intact permafrost, to partially- and fully-thawed stages) via 16S rRNA gene amplicon sequencing. We tested the hypothesis that the relative influence of biotic versus environmental filtering (the role of plant species versus thaw-defined habitat) in structuring microbial communities would differ among phyllosphere, rhizosphere, and bulk peat. Using both abundance- and phylogenetic-based approaches, we found that phyllosphere microbial composition was more strongly explained by plant associate, with little influence of habitat, whereas in the rhizosphere, plant and habitat had similar influence. Network-based community analyses showed that keystone taxa exhibited similar patterns with stronger responses to drivers. However, plant associates appeared to have a larger influence on organisms belonging to families associated with methane-cycling than the bulk community. Putative methanogens were more strongly influenced by plant than habitat in the rhizosphere, and in the phyllosphere putative methanotrophs were more strongly influenced by plant than was the community at large. We conclude that biotic effects can be stronger than environmental filtering, but their relative importance varies among microbial groups. For most microbes in this system, biotic filtering was stronger aboveground than belowground. However, for putative methane-cyclers, plant associations have a stronger influence on community composition than environment despite major hydrological changes with thaw. This suggests that plant successional dynamics may be as important as hydrological changes in determining microbial relevance to C-cycling climate feedbacks. By partitioning the degree that plant versus environmental filtering drives microbiome composition and function we can improve our ability to predict the consequences of warming for C-cycling in other arctic areas undergoing similar permafrost thaw transitions.
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Affiliation(s)
- Moira Hough
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, United States
| | - Amelia McClure
- Department of Biological Sciences, Wellesley College, Wellesley, MA, United States
| | - Benjamin Bolduc
- Department of Microbiology, College of Arts and Sciences, The Ohio State University, Columbus, OH, United States
| | - Ellen Dorrepaal
- Climate Impacts Research Centre, Umeå University, Umeå, Sweden
| | - Scott Saleska
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, United States
| | - Vanja Klepac-Ceraj
- Department of Biological Sciences, Wellesley College, Wellesley, MA, United States
| | - Virginia Rich
- Department of Microbiology, College of Arts and Sciences, The Ohio State University, Columbus, OH, United States
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42
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Cavalier-Smith T, Chao EEY. Multidomain ribosomal protein trees and the planctobacterial origin of neomura (eukaryotes, archaebacteria). PROTOPLASMA 2020. [PMID: 31900730 DOI: 10.1007/s00709-019-01442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Palaeontologically, eubacteria are > 3× older than neomura (eukaryotes, archaebacteria). Cell biology contrasts ancestral eubacterial murein peptidoglycan walls and derived neomuran N-linked glycoprotein coats/walls. Misinterpreting long stems connecting clade neomura to eubacteria on ribosomal sequence trees (plus misinterpreted protein paralogue trees) obscured this historical pattern. Universal multiprotein ribosomal protein (RP) trees, more accurate than rRNA trees, are taxonomically undersampled. To reduce contradictions with genically richer eukaryote trees and improve eubacterial phylogeny, we constructed site-heterogeneous and maximum-likelihood universal three-domain, two-domain, and single-domain trees for 143 eukaryotes (branching now congruent with 187-protein trees), 60 archaebacteria, and 151 taxonomically representative eubacteria, using 51 and 26 RPs. Site-heterogeneous trees greatly improve eubacterial phylogeny and higher classification, e.g. showing gracilicute monophyly, that many 'rDNA-phyla' belong in Proteobacteria, and reveal robust new phyla Synthermota and Aquithermota. Monoderm Posibacteria and Mollicutes (two separate wall losses) are both polyphyletic: multiple outer membrane losses in Endobacteria occurred separately from Actinobacteria; neither phylum is related to Chloroflexi, the most divergent prokaryotes, which originated photosynthesis (new model proposed). RP trees support an eozoan root for eukaryotes and are consistent with archaebacteria being their sisters and rooted between Filarchaeota (=Proteoarchaeota, including 'Asgardia') and Euryarchaeota sensu-lato (including ultrasimplified 'DPANN' whose long branches often distort trees). Two-domain trees group eukaryotes within Planctobacteria, and archaebacteria with Planctobacteria/Sphingobacteria. Integrated molecular/palaeontological evidence favours negibacterial ancestors for neomura and all life. Unique presence of key pre-neomuran characters favours Planctobacteria only as ancestral to neomura, which apparently arose by coevolutionary repercussions (explained here in detail, including RP replacement) of simultaneous outer membrane and murein loss. Planctobacterial C-1 methanotrophic enzymes are likely ancestral to archaebacterial methanogenesis and β-propeller-α-solenoid proteins to eukaryotic vesicle coats, nuclear-pore-complexes, and intraciliary transport. Planctobacterial chaperone-independent 4/5-protofilament microtubules and MamK actin-ancestors prepared for eukaryote intracellular motility, mitosis, cytokinesis, and phagocytosis. We refute numerous wrong ideas about the universal tree.
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Affiliation(s)
| | - Ema E-Yung Chao
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
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43
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Cavalier-Smith T, Chao EEY. Multidomain ribosomal protein trees and the planctobacterial origin of neomura (eukaryotes, archaebacteria). PROTOPLASMA 2020; 257:621-753. [PMID: 31900730 PMCID: PMC7203096 DOI: 10.1007/s00709-019-01442-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 09/19/2019] [Indexed: 05/02/2023]
Abstract
Palaeontologically, eubacteria are > 3× older than neomura (eukaryotes, archaebacteria). Cell biology contrasts ancestral eubacterial murein peptidoglycan walls and derived neomuran N-linked glycoprotein coats/walls. Misinterpreting long stems connecting clade neomura to eubacteria on ribosomal sequence trees (plus misinterpreted protein paralogue trees) obscured this historical pattern. Universal multiprotein ribosomal protein (RP) trees, more accurate than rRNA trees, are taxonomically undersampled. To reduce contradictions with genically richer eukaryote trees and improve eubacterial phylogeny, we constructed site-heterogeneous and maximum-likelihood universal three-domain, two-domain, and single-domain trees for 143 eukaryotes (branching now congruent with 187-protein trees), 60 archaebacteria, and 151 taxonomically representative eubacteria, using 51 and 26 RPs. Site-heterogeneous trees greatly improve eubacterial phylogeny and higher classification, e.g. showing gracilicute monophyly, that many 'rDNA-phyla' belong in Proteobacteria, and reveal robust new phyla Synthermota and Aquithermota. Monoderm Posibacteria and Mollicutes (two separate wall losses) are both polyphyletic: multiple outer membrane losses in Endobacteria occurred separately from Actinobacteria; neither phylum is related to Chloroflexi, the most divergent prokaryotes, which originated photosynthesis (new model proposed). RP trees support an eozoan root for eukaryotes and are consistent with archaebacteria being their sisters and rooted between Filarchaeota (=Proteoarchaeota, including 'Asgardia') and Euryarchaeota sensu-lato (including ultrasimplified 'DPANN' whose long branches often distort trees). Two-domain trees group eukaryotes within Planctobacteria, and archaebacteria with Planctobacteria/Sphingobacteria. Integrated molecular/palaeontological evidence favours negibacterial ancestors for neomura and all life. Unique presence of key pre-neomuran characters favours Planctobacteria only as ancestral to neomura, which apparently arose by coevolutionary repercussions (explained here in detail, including RP replacement) of simultaneous outer membrane and murein loss. Planctobacterial C-1 methanotrophic enzymes are likely ancestral to archaebacterial methanogenesis and β-propeller-α-solenoid proteins to eukaryotic vesicle coats, nuclear-pore-complexes, and intraciliary transport. Planctobacterial chaperone-independent 4/5-protofilament microtubules and MamK actin-ancestors prepared for eukaryote intracellular motility, mitosis, cytokinesis, and phagocytosis. We refute numerous wrong ideas about the universal tree.
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Affiliation(s)
| | - Ema E-Yung Chao
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
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44
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Ward LM, Lingappa UF, Grotzinger JP, Fischer WW. Microbial mats in the Turks and Caicos Islands reveal diversity and evolution of phototrophy in the Chloroflexota order Aggregatilineales. ENVIRONMENTAL MICROBIOME 2020; 15:9. [PMID: 33902735 PMCID: PMC8067394 DOI: 10.1186/s40793-020-00357-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/19/2020] [Indexed: 05/03/2023]
Abstract
Genome-resolved metagenomic sequencing approaches have led to a substantial increase in the recognized diversity of microorganisms; this included the discovery of novel metabolic pathways in previously recognized clades, and has enabled a more accurate determination of the extant distribution of key metabolisms and how they evolved over Earth history. Here, we present metagenome-assembled genomes of members of the Chloroflexota (formerly Chloroflexi or Green Nonsulfur Bacteria) order Aggregatilineales (formerly SBR1031 or Thermofonsia) discovered from sequencing of thick and expansive microbial mats present in an intertidal lagoon on Little Ambergris Cay in the Turks and Caicos Islands. These taxa included multiple new lineages of Type 2 reaction center-containing phototrophs that were not closely related to previously described phototrophic Chloroflexota-revealing a rich and intricate history of horizontal gene transfer and the evolution of phototrophy and other core metabolic pathways within this widespread phylum.
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Affiliation(s)
- Lewis M Ward
- Department of Earth & Planetary Sciences, Harvard University, Cambridge, MA, 02138, USA.
| | - Usha F Lingappa
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - John P Grotzinger
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Woodward W Fischer
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
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45
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Kox MAR, van den Elzen E, Lamers LPM, Jetten MSM, van Kessel MAHJ. Microbial nitrogen fixation and methane oxidation are strongly enhanced by light in Sphagnum mosses. AMB Express 2020; 10:61. [PMID: 32236738 PMCID: PMC7109220 DOI: 10.1186/s13568-020-00994-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/16/2020] [Indexed: 12/25/2022] Open
Abstract
Peatlands have acted as C-sinks for millennia, storing large amounts of carbon, of which a significant amount is yearly released as methane (CH4). Sphagnum mosses are a key genus in many peat ecosystems and these mosses live in close association with methane-oxidizing and nitrogen-fixing microorganisms. To disentangle mechanisms which may control Sphagnum-associated methane-oxidation and nitrogen-fixation, we applied four treatments to Sphagnum mosses from a pristine peatland in Finland: nitrogen fertilization, phosphorus fertilization, CH4 addition and light. N and P fertilization resulted in nutrient accumulation in the moss tissue, but did not increase Sphagnum growth. While net CO2 fixation rates remained unaffected in the N and P treatment, net CH4 emissions decreased because of enhanced CH4 oxidation. CH4 addition did not affect Sphagnum performance in the present set-up. Light, however, clearly stimulated the activity of associated nitrogen-fixing and methane-oxidizing microorganisms, increasing N2 fixation rates threefold and CH4 oxidation rates fivefold. This underlines the strong connection between Sphagnum and associated N2 fixation and CH4 oxidation. It furthermore indicates that phototrophy is a strong control of microbial activity, which can be directly or indirectly.
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Affiliation(s)
- Martine A R Kox
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Eva van den Elzen
- Department of Aquatic Ecology and Environmental Biology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Leon P M Lamers
- Department of Aquatic Ecology and Environmental Biology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Maartje A H J van Kessel
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
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Noh HJ, Lee YM, Park CH, Lee HK, Cho JC, Hong SG. Microbiome in Cladonia squamosa Is Vertically Stratified According to Microclimatic Conditions. Front Microbiol 2020; 11:268. [PMID: 32161575 PMCID: PMC7053493 DOI: 10.3389/fmicb.2020.00268] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 02/05/2020] [Indexed: 11/21/2022] Open
Abstract
Lichens are miniature ecosystems that contain fungi, microalgae, and bacteria. It is generally accepted that symbiosis between mycobiont and photobiont and microbial contribution to the ecosystem support the wide distribution of lichens in terrestrial ecosystems, including polar areas. The composition of symbiotic components can be affected by subtle microenvironmental differences within a thallus, as well as large-scale climate differences. In this study, we investigated fine-scale profiles of algal, fungal, and bacterial compositions through horizontal and vertical positions of the Antarctic lichen Cladonia squamosa colonies by next-generation sequencing of the nuclear large subunit rRNA gene (nucLSU) of eukaryotes and the 16S rRNA gene of bacteria. Apical parts of thalli were exposed to strong light, low moisture, and high variability of temperature compared with basal parts. Microbial diversity increased from apical parts to basal parts of thalli. Asterochloris erici was the major photobiont in apical positions of thalli, but other microalgal operational taxonomic units (OTUs) of Trebouxiophyceae and Ulvophyceae were major microalgal components in basal positions. Photochemical responses of algal components from apical and basal parts of thalli were quite different under variable temperature and humidity conditions. Several fungal OTUs that belonged to Arthoniomycetes and Lecanoromycetes, and diverse bacterial OTUs that belonged to Alphaproteobacteria, Acidobacteria_Gp1, and candidate division WPS-2 showed a clear distribution pattern according to their vertical positions within thalli. The overall lichen microbiome was significantly differentiated by the vertical position within a thallus. These results imply that different microclimate are formed at different lichen thallus parts, which can affect microbial compositions and physiological responses according to positions within the thalli.
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Affiliation(s)
- Hyun-Ju Noh
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, South Korea
- Department of Biological Sciences, Inha University, Incheon, South Korea
| | - Yung Mi Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Chae Haeng Park
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Hong Kum Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Jang-Cheon Cho
- Department of Biological Sciences, Inha University, Incheon, South Korea
| | - Soon Gyu Hong
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, South Korea
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47
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Structural and functional differentiation of bacterial communities in post-coal mining reclamation soils of South Africa: bioindicators of soil ecosystem restoration. Sci Rep 2020; 10:1759. [PMID: 32019965 PMCID: PMC7000389 DOI: 10.1038/s41598-020-58576-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/13/2020] [Indexed: 11/22/2022] Open
Abstract
Soil microbial communities are suitable soil ecosystem health indicators due to their sensitivity to management practices and role in soil ecosystem processes. Presently, information on structural and functional differentiation of bacterial communities in post-coal mining reclamation soils of South Africa is sparse. Here, bacterial communities in three post-coal mining reclamation soils were investigated using community-level physiological profiling (CLPP), enzyme activities, and next-generation sequencing of 16S rRNA gene. Inferences were drawn in reference to adjacent unmined soils. CLPP-based species diversity and proportionality did not differ significantly (P > 0.05) whereas activities of β-glucosidase, urease and phosphatases were significantly (P < 0.05) influenced by site and soil history (reclaimed vs unmined). Bacterial communities were influenced (PERMANOVA, P < 0.05) by soil history and site differences, with several phylotypes differentially abundant between soils. Contrastingly, predicted functional capabilities of bacterial communities were not different (PERMANOVA, P > 0.05), suggesting redundancy in bacterial community functions between reclamation and unmined soils. Silt content, bulk density, pH, electrical conductivity, Na and Ca significantly influenced soil bacterial communities. Overall, results indicate that bacterial community structure reflects underlying differences between soil ecosystems, and suggest the restoration of bacterial diversity and functions over chronological age in reclamation soils.
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48
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Diel changes and diversity of pufM expression in freshwater communities of anoxygenic phototrophic bacteria. Sci Rep 2019; 9:18766. [PMID: 31822744 PMCID: PMC6904477 DOI: 10.1038/s41598-019-55210-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/25/2019] [Indexed: 01/21/2023] Open
Abstract
The anoxygenic phototrophic bacteria (APB) are an active component of aquatic microbial communities. While DNA-based studies have delivered a detailed picture of APB diversity, they cannot provide any information on the activity of individual species. Therefore, we focused on the expression of a photosynthetic gene by APB communities in two freshwater lakes (Cep lake and the Římov Reservoir) in the Czech Republic. First, we analyzed expression levels of pufM during the diel cycle using RT-qPCR. The transcription underwent a strong diel cycle and was inhibited during the day in both lakes. Then, we compared DNA- (total) and RNA-based (active) community composition by sequencing pufM amplicon libraries. We observed large differences in expression activity among different APB phylogroups. While the total APB community in the Římov Reservoir was dominated by Betaproteobacteria, Alphaproteobacteria prevailed in the active library. A different situation was encountered in the oligotrophic lake Cep where Betaproteobacteria (order Burkholderiales) dominated both the DNA and RNA libraries. Interestingly, in Cep lake we found smaller amounts of highly active uncultured phototrophic Chloroflexi, as well as phototrophic Gemmatimonadetes. Despite the large diversity of APB communities, light repression of pufM expression seems to be a common feature of all aerobic APB present in the studied lakes.
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Fazi S, Ungaro F, Venturi S, Vimercati L, Cruz Viggi C, Baronti S, Ugolini F, Calzolari C, Tassi F, Vaselli O, Raschi A, Aulenta F. Microbiomes in Soils Exposed to Naturally High Concentrations of CO 2 (Bossoleto Mofette Tuscany, Italy). Front Microbiol 2019; 10:2238. [PMID: 31681186 PMCID: PMC6797827 DOI: 10.3389/fmicb.2019.02238] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 09/12/2019] [Indexed: 01/05/2023] Open
Abstract
Direct and indirect effects of extremely high geogenic CO2 levels, commonly occurring in volcanic and hydrothermal environments, on biogeochemical processes in soil are poorly understood. This study investigated a sinkhole in Italy where long-term emissions of thermometamorphic-derived CO2 are associated with accumulation of carbon in the topsoil and removal of inorganic carbon in low pH environments at the bottom of the sinkhole. The comparison between interstitial soil gasses and those collected in an adjacent bubbling pool and the analysis of the carbon isotopic composition of CO2 and CH4 clearly indicated the occurrence of CH4 oxidation and negligible methanogenesis in soils at the bottom of the sinkhole. Extremely high CO2 concentrations resulted in higher microbial abundance (up to 4 × 109 cell g-1 DW) and a lower microbial diversity by favoring bacteria already reported to be involved in acetogenesis in mofette soils (i.e., Firmicutes, Chloroflexi, and Acidobacteria). Laboratory incubations to test the acetogenic and methanogenic potential clearly showed that all the mofette soil supplied with hydrogen gas displayed a remarkable CO2 fixation potential, primarily due to the activity of acetogenic microorganisms. By contrast, negligible production of acetate occurred in control tests incubated with the same soils, under identical conditions, without the addition of hydrogen. In this study, we report how changes in diversity and functions of the soil microbial community - induced by high CO2 concentration - create peculiar biogeochemical profile. CO2 emission affects carbon cycling through: (i) inhibition of the decomposition of the organic carbon and (ii) promotion of CO2-fixation via the acetyl-CoA pathway. Sites naturally exposed to extremely high CO2 levels could potentially represent an untapped source of microorganisms with unique capabilities to catalytically convert CO2 into valuable organic chemicals and fuels.
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Affiliation(s)
- Stefano Fazi
- Water Research Institute, National Research Council (IRSA-CNR), Rome, Italy
| | - Fabrizio Ungaro
- Institute of BioEconomy - National Research Council (IBE-CNR), Florence, Italy
| | - Stefania Venturi
- Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Florence, Italy.,Department of Earth Sciences, University of Florence, Florence, Italy
| | - Lara Vimercati
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, United States
| | | | - Silvia Baronti
- Institute of BioEconomy - National Research Council (IBE-CNR), Florence, Italy
| | - Francesca Ugolini
- Institute of BioEconomy - National Research Council (IBE-CNR), Florence, Italy
| | - Costanza Calzolari
- Institute of BioEconomy - National Research Council (IBE-CNR), Florence, Italy
| | - Franco Tassi
- Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Florence, Italy.,Department of Earth Sciences, University of Florence, Florence, Italy
| | - Orlando Vaselli
- Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Florence, Italy.,Department of Earth Sciences, University of Florence, Florence, Italy
| | - Antonio Raschi
- Institute of BioEconomy - National Research Council (IBE-CNR), Florence, Italy
| | - Federico Aulenta
- Water Research Institute, National Research Council (IRSA-CNR), Rome, Italy
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50
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Jugnia L, Manno D, Hendry M, Tartakovsky B. Removal of heavy metals in a flow‐through vertical microbial electrolysis cell. CAN J CHEM ENG 2019. [DOI: 10.1002/cjce.23568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Louis‐B. Jugnia
- Energy, Mining and Environment Research CentreNational Research Council Canada 6100 Royalmount Avenue, Montréal QC Canada
| | - Dominic Manno
- Energy, Mining and Environment Research CentreNational Research Council Canada 6100 Royalmount Avenue, Montréal QC Canada
| | - Meghan Hendry
- National Defence Garrison Petawawa 4 CDSG Environmental Services 101 Menin Road, Building S‐600 P.O. Box 9999 Stn Main, Petawawa ON Canada
| | - Boris Tartakovsky
- Energy, Mining and Environment Research CentreNational Research Council Canada 6100 Royalmount Avenue, Montréal QC Canada
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