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Alvarenga DO, Clasen LA, Thomsen AMR, Andersen RF, Rousk K. Light drives nitrogen fixation in tropical montane cloud forests in Costa Rica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 940:173631. [PMID: 38823705 DOI: 10.1016/j.scitotenv.2024.173631] [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: 04/06/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
Tropical montane cloud forests are high altitude ecosystems characterized by very high ambient humidity, which favors organisms that depend on the environment for their water status, such as bryophytes and their nitrogen-fixing symbionts. Bryophyte-associated N2 fixation is a major source of new N in several northern environments, but their contributions to the N cycle in other ecosystems is still poorly understood. In this work, we evaluated N2 fixation rates associated with epiphytic bryophytes growing along the stems of pumpwood trees (Cecropia sp.) as well as in surrounding litter and soil from a primary and a secondary cloud forests in the Talamanca Mountain Range, Costa Rica. Nitrogen fixation was significantly higher in substrates from the secondary forest compared to those from the primary forest. Overall, N2 fixation rates associated with epiphytic bryophytes were 57 times those of litter and 270 times what was measured in soil. Further, light intensity was the major factor influencing N2 fixation rates in all substrates. Increased access to light in disturbed cloud forests may therefore favor bryophyte-associated N2 fixation, potentially contributing to the recovery of these ecosystems.
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Affiliation(s)
- Danillo Oliveira Alvarenga
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark.
| | - Lina Avila Clasen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Amanda Maria Rydgren Thomsen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Rune Fromm Andersen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
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Nawaz T, Gu L, Fahad S, Saud S, Bleakley B, Zhou R. Exploring Sustainable Agriculture with Nitrogen-Fixing Cyanobacteria and Nanotechnology. Molecules 2024; 29:2534. [PMID: 38893411 PMCID: PMC11173783 DOI: 10.3390/molecules29112534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 06/21/2024] Open
Abstract
The symbiotic relationship between nitrogen-fixing cyanobacteria and plants offers a promising avenue for sustainable agricultural practices and environmental remediation. This review paper explores the molecular interactions between nitrogen-fixing cyanobacteria and nanoparticles, shedding light on their potential synergies in agricultural nanotechnology. Delving into the evolutionary history and specialized adaptations of cyanobacteria, this paper highlights their pivotal role in fixing atmospheric nitrogen, which is crucial for ecosystem productivity. The review discusses the unique characteristics of metal nanoparticles and their emerging applications in agriculture, including improved nutrient delivery, stress tolerance, and disease resistance. It delves into the complex mechanisms of nanoparticle entry into plant cells, intracellular transport, and localization, uncovering the impact on root-shoot translocation and systemic distribution. Furthermore, the paper elucidates cellular responses to nanoparticle exposure, emphasizing oxidative stress, signaling pathways, and enhanced nutrient uptake. The potential of metal nanoparticles as carriers of essential nutrients and their implications for nutrient-use efficiency and crop yield are also explored. Insights into the modulation of plant stress responses, disease resistance, and phytoremediation strategies demonstrate the multifaceted benefits of nanoparticles in agriculture. Current trends, prospects, and challenges in agricultural nanotechnology are discussed, underscoring the need for responsible and safe nanoparticle utilization. By harnessing the power of nitrogen-fixing cyanobacteria and leveraging the unique attributes of nanoparticles, this review paves the way for innovative, sustainable, and efficient agricultural practices.
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Affiliation(s)
- Taufiq Nawaz
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Liping Gu
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Shah Fahad
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
- Department of Agronomy, Abdul Wali Khan University Mardan, Mardan 23200, KP, Pakistan
| | - Shah Saud
- College of Life Science, Linyi University, Linyi 276000, China
| | - Bruce Bleakley
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Ruanbao Zhou
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
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3
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Li X, Hu D, Du J, He L. Understanding mercury accumulation in mosses of two subalpine forests in China. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134266. [PMID: 38626682 DOI: 10.1016/j.jhazmat.2024.134266] [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: 12/19/2023] [Revised: 03/10/2024] [Accepted: 04/08/2024] [Indexed: 04/18/2024]
Abstract
The role of forest ecosystems in the global mercury (Hg) biogeochemical cycle is widely recognized; however, using litterfall as a surrogate to assess the Hg sink function of forests encounters limitations. We investigated the accumulation characteristics and influencing factors of Hg in mosses from two remote subalpine forests in southwestern China. The results indicated that there was high Hg accumulation in subalpine forest mosses, with average concentrations of 82 ± 49 ng g-1 for total mercury (THg) and 1.3 ± 0.8 ng g-1 for methylmercury (MeHg). We demonstrated that the accumulation capacity of Hg in mosses was significantly dependent on species and substrates (micro-habitats), the mosses on tree trunks exhibited significantly elevated Hg accumulation levels (THg 132 ± 56 ng g-1, MeHg 1.6 ± 0.2 ng g-1) compared to mosses in other substrates. The surface morphologies and biochemical components of leaf (phyllidia), such as cation exchange capacity (CEC), pectin, uronic acid, and metallothionein, play a crucial role in the accumulation of Hg by mosses. These findings provide valuable insights into Hg accumulation in forest mosses. Suggesting that the contribution of mosses Hg accumulation should be considered when assessing atmospheric Hg sinks of forests.
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Affiliation(s)
- Xiaohui Li
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Dan Hu
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
| | - Jie Du
- Jiuzhaigou Scenic Area Administration, Zhangzha, Jiuzhaigou, Sichuan 623402, China.
| | - Lei He
- College of Life Science, Sichuan Normal University, No. 1819, Chenglong Road, Chengdu, Sichuan 610101, China.
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Ochoa-Hueso R, Eldridge DJ, Berdugo M, Trivedi P, Sokoya B, Cano-Díaz C, Abades S, Alfaro F, Bamigboye AR, Bastida F, Blanco-Pastor JL, de Los Rios A, Durán J, Geisen S, Grebenc T, Illán JG, Liu YR, Makhalanyane TP, Mamet S, Molina-Montenegro MA, Moreno JL, Nahberger TU, Peñaloza-Bojacá GF, Plaza C, Rey A, Rodríguez A, Siebe C, Singh BK, Teixido AL, Torres-Díaz C, Wang L, Wang J, Wang J, Zaady E, Zhou X, Zhou XQ, Tedersoo L, Delgado-Baquerizo M. Unearthing the soil-borne microbiome of land plants. GLOBAL CHANGE BIOLOGY 2024; 30:e17295. [PMID: 38804108 DOI: 10.1111/gcb.17295] [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: 09/04/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 05/29/2024]
Abstract
Plant-soil biodiversity interactions are fundamental for the functioning of terrestrial ecosystems. Yet, the existence of a set of globally distributed topsoil microbial and small invertebrate organisms consistently associated with land plants (i.e., their consistent soil-borne microbiome), together with the environmental preferences and functional capabilities of these organisms, remains unknown. We conducted a standardized field survey under 150 species of land plants, including 58 species of bryophytes and 92 of vascular plants, across 124 locations from all continents. We found that, despite the immense biodiversity of soil organisms, the land plants evaluated only shared a small fraction (less than 1%) of all microbial and invertebrate taxa that were present across contrasting climatic and soil conditions and vegetation types. These consistent taxa were dominated by generalist decomposers and phagotrophs and their presence was positively correlated with the abundance of functional genes linked to mineralization. Finally, we showed that crossing environmental thresholds in aridity (aridity index of 0.65, i.e., the transition from mesic to dry ecosystems), soil pH (5.5; i.e., the transition from acidic to strongly acidic soils), and carbon (less than 2%, the lower limit of fertile soils) can result in drastic disruptions in the associations between land plants and soil organisms, with potential implications for the delivery of soil ecosystem processes under ongoing global environmental change.
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Affiliation(s)
- Raúl Ochoa-Hueso
- Department of Biology, Botany Area, University of Cádiz, Vitivinicultural and Agri-Food Research Institute (IVAGRO), Cádiz, Spain
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - David J Eldridge
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of NSW, Sydney, New South Wales, Australia
| | - Miguel Berdugo
- Departmento de Biodiversidad, Ecología y Evolución, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Madrid, Spain
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Pankaj Trivedi
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, USA
| | - Blessing Sokoya
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
| | - Concha Cano-Díaz
- CISAS - Center for Research and Development in Agrifood Systems and Sustainability, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial Nun'Álvares, Viana do Castelo, Portugal
| | | | - Fernando Alfaro
- GEMA Center for Genomics, Ecology & Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, Santiago, Chile
| | - Adebola R Bamigboye
- Natural History Museum (Botany Unit), Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Felipe Bastida
- CEBAS-CSIC, Campus Universitario de Espinardo, Murcia, Spain
| | - José L Blanco-Pastor
- Department of Biology, Botany Area, University of Cádiz, Vitivinicultural and Agri-Food Research Institute (IVAGRO), Cádiz, Spain
| | - Asunción de Los Rios
- Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Jorge Durán
- Misión Biológica de Galicia, Consejo Superior de Investigaciones Científicas, Pontevedra, Spain
| | - Stefan Geisen
- Laboratory of Nematology, Wageningen University, Wageningen, The Netherlands
| | - Tine Grebenc
- Slovenian Forestry Institute, Ljubljana, Slovenia
| | - Javier G Illán
- Department of Entomology, Washington State University, Pullman, Washington, USA
| | - Yu-Rong Liu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Steven Mamet
- College of Agriculture and Bioresources, Department of Soil Science, University of Saskatchewan, Saskatoon, Canada
| | | | - José L Moreno
- CEBAS-CSIC, Campus Universitario de Espinardo, Murcia, Spain
| | | | - Gabriel F Peñaloza-Bojacá
- Laboratório de Sistemática Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - César Plaza
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Ana Rey
- Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Alexandra Rodríguez
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Christina Siebe
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Penrith South, New South Wales, Australia
| | - Alberto L Teixido
- Departmento de Biodiversidad, Ecología y Evolución, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Madrid, Spain
| | - Cristian Torres-Díaz
- Grupo de Biodiversidad y Cambio Global (BCG), Departamento de Ciencias Básicas, Universidad del Bío-Bío, Chillán, Chile
| | - Ling Wang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun, China
| | - Jianyong Wang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun, China
| | - Juntao Wang
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Eli Zaady
- Department of Natural Resources, Agricultural Research Organization, Institute of Plant Sciences, Gilat Research Center, Negev, Israel
| | - Xiaobing Zhou
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Xinjiang, China
| | - Xin-Quan Zhou
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Leho Tedersoo
- Mycology and Microbiology Center, University of Tartu, Tartu, Estonia
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Sevilla, Spain
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Alvarenga DO, Priemé A, Rousk K. The Feather Moss Hylocomium splendens Affects the Transcriptional Profile of a Symbiotic Cyanobacterium in Relation to Acquisition and Turnover of Key Nutrients. MICROBIAL ECOLOGY 2024; 87:49. [PMID: 38427046 PMCID: PMC10907420 DOI: 10.1007/s00248-024-02363-6] [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: 11/10/2023] [Accepted: 02/21/2024] [Indexed: 03/02/2024]
Abstract
Moss-cyanobacteria symbioses were proposed to be based on nutrient exchange, with hosts providing C and S while bacteria provide N, but we still lack understanding of the underlying molecular mechanisms of their interactions. We investigated how contact between the ubiquitous moss Hylocomium splendens and its cyanobiont affects nutrient-related gene expression of both partners. We isolated a cyanobacterium from H. splendens and co-incubated it with washed H. splendens shoots. Cyanobacterium and moss were also incubated separately. After 1 week, we performed acetylene reduction assays to estimate N2 fixation and RNAseq to evaluate metatranscriptomes. Genes related to N2 fixation and the biosynthesis of several amino acids were up-regulated in the cyanobiont when hosted by the moss. However, S-uptake and the biosynthesis of the S-containing amino acids methionine and cysteine were down-regulated in the cyanobiont while the degradation of selenocysteine was up-regulated. In contrast, the number of differentially expressed genes in the moss was much lower, and almost no transcripts related to nutrient metabolism were affected. It is possible that, at least during the early stage of this symbiosis, the cyanobiont receives few if any nutrients from the host in return for N, suggesting that moss-cyanobacteria symbioses encompass relationships that are more plastic than a constant mutualist flow of nutrients.
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Affiliation(s)
- Danillo Oliveira Alvarenga
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.
- Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.
| | - Anders Priemé
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
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Kilner CL, Carrell AA, Wieczynski DJ, Votzke S, DeWitt K, Yammine A, Shaw J, Pelletier DA, Weston DJ, Gibert JP. Temperature and CO 2 interactively drive shifts in the compositional and functional structure of peatland protist communities. GLOBAL CHANGE BIOLOGY 2024; 30:e17203. [PMID: 38433341 DOI: 10.1111/gcb.17203] [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: 05/17/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 03/05/2024]
Abstract
Microbes affect the global carbon cycle that influences climate change and are in turn influenced by environmental change. Here, we use data from a long-term whole-ecosystem warming experiment at a boreal peatland to answer how temperature and CO2 jointly influence communities of abundant, diverse, yet poorly understood, non-fungi microbial Eukaryotes (protists). These microbes influence ecosystem function directly through photosynthesis and respiration, and indirectly, through predation on decomposers (bacteria and fungi). Using a combination of high-throughput fluid imaging and 18S amplicon sequencing, we report large climate-induced, community-wide shifts in the community functional composition of these microbes (size, shape, and metabolism) that could alter overall function in peatlands. Importantly, we demonstrate a taxonomic convergence but a functional divergence in response to warming and elevated CO2 with most environmental responses being contingent on organismal size: warming effects on functional composition are reversed by elevated CO2 and amplified in larger microbes but not smaller ones. These findings show how the interactive effects of warming and rising CO2 levels could alter the structure and function of peatland microbial food webs-a fragile ecosystem that stores upwards of 25% of all terrestrial carbon and is increasingly threatened by human exploitation.
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Affiliation(s)
- Christopher L Kilner
- Department of Biology, Duke University, Durham, North Carolina, USA
- Bird Conservancy of the Rockies, Fort Collins, Colorado, USA
| | - Alyssa A Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | | | - Samantha Votzke
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Katrina DeWitt
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Andrea Yammine
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Jonathan Shaw
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Dale A Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Jean P Gibert
- Department of Biology, Duke University, Durham, North Carolina, USA
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7
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Sjøgren TD, Wang Y, Rousk K. Nitrogen fixation associated with two cohabiting moss species expresses different patterns under Cu and Zn contamination. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:85701-85707. [PMID: 37393213 PMCID: PMC10404191 DOI: 10.1007/s11356-023-28404-0] [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: 01/02/2023] [Accepted: 06/19/2023] [Indexed: 07/03/2023]
Abstract
Nitrogen (N2) fixation by moss-associated cyanobacteria is an important N source in pristine ecosystems. Previous studies have shown that moss-associated N2 fixation is sensitive to anthropogenic N pollution. However, we still lack understanding of the effects of other factors derived from anthropogenic sources, such as heavy metal pollution on N2 fixation. To test this, we collected two dominant mosses (Pleurozium schreberi and Spaghnum palustre) from a temperate bog in Denmark and assessed their N2 fixation responses to simulated heavy metal pollution by adding 5 levels (plus a control) of copper (Cu, 0-0.05 mg g dw-1) and zinc (Zn, 0-0.1 mg g dw-1). Metal concentrations in both mosses increased linearly with Cu and Zn addition, but N2 fixation activity associated with S. palustre was to a greater extent negatively affected by both Cu and Zn additions than that associated with P. schreberi. Copper additions even promoted N2 fixation in P. schreberi. Hence, the heavy metal sensitivity of N2-fixing cyanobacteria is dependent on the host moss-species, and the vulnerability of ecosystems towards heavy metal pollution could vary depending on the dominant moss species.
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Affiliation(s)
- Toke Due Sjøgren
- Department of Biology, Center for Volatile Interactions (VOLT), University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
| | - Yinliu Wang
- Department of Biology, Center for Volatile Interactions (VOLT), University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
| | - Kathrin Rousk
- Department of Biology, Center for Volatile Interactions (VOLT), University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark.
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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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Yang Q, Liu Z, Houlton BZ, Gao D, Chang Q, Li H, Fan X, Liu B, Bai E. Isotopic evidence for increased carbon and nitrogen exchanges between peatland plants and their symbiotic microbes with rising atmospheric CO 2 concentrations since 15,000 cal. year BP. GLOBAL CHANGE BIOLOGY 2023; 29:1939-1950. [PMID: 36585918 DOI: 10.1111/gcb.16578] [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: 09/20/2022] [Revised: 11/29/2022] [Accepted: 12/16/2022] [Indexed: 05/28/2023]
Abstract
Whether nitrogen (N) availability will limit plant growth and removal of atmospheric CO2 by the terrestrial biosphere this century is controversial. Studies have suggested that N could progressively limit plant growth, as trees and soils accumulate N in slowly cycling biomass pools in response to increases in carbon sequestration. However, a question remains over whether longer-term (decadal to century) feedbacks between climate, CO2 and plant N uptake could emerge to reduce ecosystem-level N limitations. The symbioses between plants and microbes can help plants to acquire N from the soil or from the atmosphere via biological N2 fixation-the pathway through which N can be rapidly brought into ecosystems and thereby partially or completely alleviate N limitation on plant productivity. Here we present measurements of plant N isotope composition (δ15 N) in a peat core that dates to 15,000 cal. year BP to ascertain ecosystem-level N cycling responses to rising atmospheric CO2 concentrations. We find that pre-industrial increases in global atmospheric CO2 concentrations corresponded with a decrease in the δ15 N of both Sphagnum moss and Ericaceae when constrained for climatic factors. A modern experiment demonstrates that the δ15 N of Sphagnum decreases with increasing N2 -fixation rates. These findings suggest that plant-microbe symbioses that facilitate N acquisition are, over the long term, enhanced under rising atmospheric CO2 concentrations, highlighting an ecosystem-level feedback mechanism whereby N constraints on terrestrial carbon storage can be overcome.
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Affiliation(s)
- Qiannan Yang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Ziping Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Benjamin Z Houlton
- Department of Ecology and Evolutionary Biology and Department of Global Development, Cornell University, Ithaca, New York, USA
| | - Decai Gao
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Qing Chang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Hongkai Li
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Xianlei Fan
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Bai Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Edith Bai
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
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10
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Koranda M, Rinnan R, Michelsen A. Close coupling of plant functional types with soil microbial community composition drives soil carbon and nutrient cycling in tundra heath. PLANT AND SOIL 2023; 488:551-572. [PMID: 37600962 PMCID: PMC10435393 DOI: 10.1007/s11104-023-05993-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: 12/14/2022] [Accepted: 03/14/2023] [Indexed: 08/22/2023]
Abstract
Aims This study aimed at elucidating divergent effects of two dominant plant functional types (PFTs) in tundra heath, dwarf shrubs and mosses, on soil microbial processes and soil carbon (C) and nutrient availability, and thereby to enhance our understanding of the complex interactions between PFTs, soil microbes and soil functioning. Methods Samples of organic soil were collected under three dwarf shrub species (of distinct mycorrhizal association and life form) and three moss species in early and late growing season. We analysed soil C and nutrient pools, extracellular enzyme activities and phospholipid fatty acid profiles, together with a range of plant traits, soil and abiotic site characteristics. Results Shrub soils were characterised by high microbial biomass C and phosphorus and phosphatase activity, which was linked with a fungal-dominated microbial community, while moss soils were characterised by high soil nitrogen availability, peptidase and peroxidase activity associated with a bacterial-dominated microbial community. The variation in soil microbial community structure was explained by mycorrhizal association, root morphology, litter and soil organic matter quality and soil pH-value. Furthermore, we found that the seasonal variation in microbial biomass and enzyme activities over the growing season, likely driven by plant belowground C allocation, was most pronounced under the tallest shrub Betula nana. Conclusion Our study demonstrates a close coupling of PFTs with soil microbial communities, microbial decomposition processes and soil nutrient availability in tundra heath, which suggests potential strong impacts of global change-induced shifts in plant community composition on carbon and nutrient cycling in high-latitude ecosystems. Supplementary Information The online version contains supplementary material available at 10.1007/s11104-023-05993-w.
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Affiliation(s)
- Marianne Koranda
- Division of Terrestrial Ecosystem Research, Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, 1350 Copenhagen, Denmark
| | - Riikka Rinnan
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, 1350 Copenhagen, Denmark
| | - Anders Michelsen
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, 1350 Copenhagen, Denmark
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11
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Avila Clasen L, Permin A, Horwath AB, Metcalfe DB, Rousk K. Do Nitrogen and Phosphorus Additions Affect Nitrogen Fixation Associated with Tropical Mosses? PLANTS (BASEL, SWITZERLAND) 2023; 12:1443. [PMID: 37050067 PMCID: PMC10097241 DOI: 10.3390/plants12071443] [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: 12/09/2022] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Tropical cloud forests are characterized by abundant and biodiverse mosses which grow epiphytically as well as on the ground. Nitrogen (N)-fixing cyanobacteria live in association with most mosses, and contribute greatly to the N pool via biological nitrogen fixation (BNF). However, the availability of nutrients, especially N and phosphorus (P), can influence BNF rates drastically. To evaluate the effects of increased N and P availability on BNF in mosses, we conducted a laboratory experiment where we added N and P, in isolation and combined, to three mosses (Campylopus sp., Dicranum sp. and Thuidium peruvianum) collected from a cloud forest in Peru. Our results show that N addition almost completely inhibited BNF within a day, whereas P addition caused variable results across moss species. Low N2 fixation rates were observed in Campylopus sp. across the experiment. BNF in Dicranum sp. was decreased by all nutrients, while P additions seemed to promote BNF in T. peruvianum. Hence, each of the three mosses contributes distinctively to the ecosystem N pool depending on nutrient availability. Moreover, increased N input will likely significantly decrease BNF associated with mosses also in tropical cloud forests, thereby limiting N input to these ecosystems via the moss-cyanobacteria pathway.
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Affiliation(s)
- Lina Avila Clasen
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
| | - Aya Permin
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
| | - Aline B. Horwath
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | - Daniel B. Metcalfe
- Department of Physical Geography and Ecosystem Science, Lund University, 221 00 Lund, Sweden
- Department of Ecology and Environmental Science, University of Umeå, 907 36 Umeå, Sweden
| | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
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12
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Gao X, Wang X, Wu X, Shang Y, Mei X, Zhou S, Wei Q, Sun G, Dong Y, Cui W, Zhang H. Comparative Analyses of the Fecal Microbiome of Five Wild Black-Billed Capercaillie ( Tetrao parvirostris) Flocks. Animals (Basel) 2023; 13:ani13050923. [PMID: 36899780 PMCID: PMC10000248 DOI: 10.3390/ani13050923] [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: 11/15/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
Black-billed capercaillie (Tetrao parvirostris) was listed as a first-class state-protected animal because it was endangered in China (Category I). This study is the first to examine the diversity and composition of T. parvirostris gut microbiome in the wild. We collected fecal samples from five black-billed capercaillie flock roosting sites (each 20 km apart) in one day. Thirty fecal samples were sequenced with 16S rRNA gene amplicons on the Illumina HiSeq platform. This study is the first to analyze the fecal microbiome composition and diversity of black-billed capercaillie in the wild. At the phylum level, Camplyobacterota, Bacillota, Cyanobacteria, Actinomycetota, and Bacteroidota were the most abundant in the fecal microbiome of black-billed capercaillie. At the genus level, unidentified Chloroplast, Escherichia-Shigella, Faecalitalea, Bifidobacterium, and Halomonas were the dominant genera. Based on alpha and beta diversity analyses, we found no significant differences in the fecal microbiome between five flocks of black-billed capercaillie. Protein families: genetic information processing; protein families: signaling and cellular processes, carbohydrate metabolism; protein families: metabolism and energy metabolism are the main predicted functions of the black-billed capercaillie gut microbiome through the PICRUSt2 method. This study reveals the composition and structure of the fecal microbiome of the black-billed capercaillie under wild survival conditions, and this study provides scientific data for the comprehensive conservation of the black-billed capercaillie.
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13
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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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14
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Porada P, Bader MY, Berdugo MB, Colesie C, Ellis CJ, Giordani P, Herzschuh U, Ma Y, Launiainen S, Nascimbene J, Petersen I, Raggio Quílez J, Rodríguez-Caballero E, Rousk K, Sancho LG, Scheidegger C, Seitz S, Van Stan JT, Veste M, Weber B, Weston DJ. A research agenda for nonvascular photoautotrophs under climate change. THE NEW PHYTOLOGIST 2023; 237:1495-1504. [PMID: 36511294 DOI: 10.1111/nph.18631] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Nonvascular photoautotrophs (NVP), including bryophytes, lichens, terrestrial algae, and cyanobacteria, are increasingly recognized as being essential to ecosystem functioning in many regions of the world. Current research suggests that climate change may pose a substantial threat to NVP, but the extent to which this will affect the associated ecosystem functions and services is highly uncertain. Here, we propose a research agenda to address this urgent question, focusing on physiological and ecological processes that link NVP to ecosystem functions while also taking into account the substantial taxonomic diversity across multiple ecosystem types. Accordingly, we developed a new categorization scheme, based on microclimatic gradients, which simplifies the high physiological and morphological diversity of NVP and world-wide distribution with respect to several broad habitat types. We found that habitat-specific ecosystem functions of NVP will likely be substantially affected by climate change, and more quantitative process understanding is required on: (1) potential for acclimation; (2) response to elevated CO2 ; (3) role of the microbiome; and (4) feedback to (micro)climate. We suggest an integrative approach of innovative, multimethod laboratory and field experiments and ecophysiological modelling, for which sustained scientific collaboration on NVP research will be essential.
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Affiliation(s)
- Philipp Porada
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Maaike Y Bader
- Ecological Plant Geography, University of Marburg, Deutschhausstr. 10, 35032, Marburg, Germany
| | - Monica B Berdugo
- Ecological Plant Geography, University of Marburg, Deutschhausstr. 10, 35032, Marburg, Germany
| | - Claudia Colesie
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JW, UK
| | | | | | - Ulrike Herzschuh
- Polar Terrestrial Environmental Systems, Alfred Wegener Institute, Telegrafenberg A45, 14473, Potsdam, Germany
| | - Yunyao Ma
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Samuli Launiainen
- Ecosystems and Modeling, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790, Helsinki, Finland
| | - Juri Nascimbene
- BIOME Lab, Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum University of Bologna, 40126, Bologna, Italy
| | - Imke Petersen
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - José Raggio Quílez
- Department of Pharmacology, Pharmacognosy and Botany, Universidad Complutense de Madrid, E-28040, Madrid, Spain
| | | | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, København, Denmark
| | - Leopoldo G Sancho
- Department of Pharmacology, Pharmacognosy and Botany, Universidad Complutense de Madrid, E-28040, Madrid, Spain
| | - Christoph Scheidegger
- Biodiversity and Conservation Biology, Eidg. Forschungsanstalt WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
| | - Steffen Seitz
- Soil Science and Geomorphology, University of Tübingen, Rümelinstr. 19-23, 72070, Tübingen, Germany
| | - John T Van Stan
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA
| | - Maik Veste
- Institute of Environmental Sciences, Brandenburgische Technische Universität Cottbus-Senftenberg, Konrad-Wachsmann-Allee 6, 03046, Cottbus, Germany
| | - Bettina Weber
- Division of Plant Sciences, Institute for Biology, University of Graz, Holteigasse 6, A-8010, Graz, Austria
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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15
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Fastner J, Teikari J, Hoffmann A, Köhler A, Hoppe S, Dittmann E, Welker M. Cyanotoxins associated with macrophytes in Berlin (Germany) water bodies - Occurrence and risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159433. [PMID: 36244489 DOI: 10.1016/j.scitotenv.2022.159433] [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: 07/16/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Fatal dog poisoning after uptake of neurotoxic cyanobacteria associated with aquatic macrophytes in Tegeler See (Berlin, Germany) raised concerns about critical exposure of humans, especially children, to cyanotoxins produced by macrophyte associated cyanobacteria during recreational activity. From 2017 to 2021 a total of 398 samples of macrophytes washed ashore at bathing sites located at 19 Berlin lakes were analysed for anatoxins, microcystins, and cylindrospermopsins, as were 463 water samples taken in direct proximity to macrophyte accumulations. Cyanotoxins were detected in 66 % of macrophyte samples and 50 % of water samples, with anatoxins being the most frequently detected toxin group in macrophyte samples (58 %) and cylindrospermopsins in water samples (41 %). Microcoleus sp. associated with the water moss Fontinalis antipyretica was identified as anatoxin producing cyanobacterium in isolated strains as well as in field samples from Tegeler See. Anatoxin contents in macrophyte samples rarely exceeded 1 μg/g macrophyte fresh weight and peaked at 9. 2 μg/g f.w. Based on established toxicological points of departure, a critical anatoxin content of macrophyte samples of 3 μg/g f.w. is proposed. Five samples, all taken in Tegeler See and all associated with the water moss Fontinalis antipyretica, exceeded this value. Contents and concentrations of microcystins and cylindrospermopsins did not reach critical levels. The potential exposure risks to anatoxins for children and dogs are assessed and recommendations are given.
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Affiliation(s)
- Jutta Fastner
- German Environment Agency, Schichauweg 58, 12307 Berlin, Germany.
| | - Jonna Teikari
- Dept. of Agricultural Sciences, University of Helsinki, Finland
| | - Anja Hoffmann
- Berlin Brandenburg State Laboratory, Rudower Chaussee 39, 12489 Berlin, Germany
| | - Antje Köhler
- Berlin Senate Department for the Environment, Transport and Climate Protection, Am Köllnischen Park 3, Berlin 10179, Germany
| | - Sebastian Hoppe
- State Office for Health and Social Affairs (LAGeSo), Working Group Water Hygiene & Environmental Health, Turmstraße 21, 10559 Berlin, Germany
| | - Elke Dittmann
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany
| | - Martin Welker
- State Office for Health and Social Affairs (LAGeSo), Working Group Water Hygiene & Environmental Health, Turmstraße 21, 10559 Berlin, Germany
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16
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Alvarenga DO, Elmdam IV, Timm AB, Rousk K. Chemical Stimulation of Heterocyte Differentiation by the Feather Moss Hylocomium splendens: a Potential New Step in Plant-Cyanobacteria Symbioses. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02075-9. [PMID: 35859069 DOI: 10.1007/s00248-022-02075-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria associated with mosses play a key role in the nitrogen (N) cycle in unpolluted ecosystems. Mosses have been found to release molecules that induce morphophysiological changes in epiphytic cyanobionts. Nevertheless, the extent of moss influence on these microorganisms remains unknown. To evaluate how mosses or their metabolites influence N2 fixation rates by cyanobacteria, we assessed the nitrogenase activity, heterocyte frequency and biomass of a cyanobacterial strain isolated from the feather moss Hylocomium splendens and a non-symbiotic strain when they were either growing by themselves, together with H. splendens or exposed to H. splendens water, acetone, ethanol, or isopropanol extracts. The same cyanobacterial strains were added to another moss (Taxiphyllum barbieri) and a liverwort (Monosolenium tenerum) to assess if these bryophytes affect N2 fixation differently. Although no significant increases in nitrogenase activity by the cyanobacteria were observed when in contact with H. splendens shoots, both the symbiotic and non-symbiotic cyanobacteria increased nitrogenase activity as well as heterocyte frequency significantly upon exposure to H. splendens ethanol extracts. Contact with T. barbieri shoots, on the other hand, did lead to increases in nitrogenase activity, indicating low host-specificity to cyanobacterial activity. These findings suggest that H. splendens produces heterocyte-differentiating factors (HDFs) that are capable of stimulating cyanobacterial N2 fixation regardless of symbiotic competency. Based on previous knowledge about the chemical ecology and dynamics of moss-cyanobacteria interactions, we speculate that HDF expression by the host takes place in a hypothetical new step occurring after plant colonization and the repression of hormogonia.
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Affiliation(s)
- Danillo Oliveira Alvarenga
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen, Denmark.
| | - Isabella Vendel Elmdam
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | | | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen, Denmark
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17
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Chen KH, Nelson J. A scoping review of bryophyte microbiota: diverse microbial communities in small plant packages. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4496-4513. [PMID: 35536989 DOI: 10.1093/jxb/erac191] [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: 12/31/2021] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
Plant health depends not only on the condition of the plant itself but also on its diverse community of microbes, or microbiota. Just like the better-studied angiosperms, bryophytes (mosses, liverworts, and hornworts) harbor diverse communities of bacteria, archaea, fungi, and other microbial eukaryotes. Bryophytes are increasingly recognized as important model systems for understanding plant evolution, development, physiology, and symbiotic interactions. Much of the work on bryophyte microbiota in the past focused on specific symbiont types for each bryophyte group, but more recent studies are taking a broader view acknowledging the coexistence of diverse microbial communities in bryophytes. Therefore, this review integrates studies of bryophyte microbes from both perspectives to provide a holistic view of the existing research for each bryophyte group and on key themes. The systematic search also reveals the taxonomic and geographic biases in this field, including a severe under-representation of the tropics, very few studies on viruses or eukaryotic microbes beyond fungi, and a focus on mycorrhizal fungi studies in liverworts. Such gaps may have led to errors in conclusions about evolutionary patterns in symbiosis. This analysis points to a wealth of future research directions that promise to reveal how the distinct life cycles and physiology of bryophytes interact with their microbiota.
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Affiliation(s)
- Ko-Hsuan Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jessica Nelson
- Maastricht Science Programme, Maastricht University, Maastricht, The Netherlands
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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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Permin A, Horwath AB, Metcalfe DB, Priemé A, Rousk K. ‘High nitrogen‐fixing rates associated with ground‐covering mosses in a tropical mountain cloud forest will decrease drastically in a future climate’. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Aya Permin
- Terrestrial Ecology Section, Department of Biology University of Copenhagen Copenhagen Denmark
- Center for Permafrost (CENPERM) University of Copenhagen Copenhagen Denmark
| | - Aline B. Horwath
- Biological and Environmental Sciences, Faculty of Natural Sciences University of Stirling Stirling UK
| | - Daniel B. Metcalfe
- Department of Physical Geography and Ecosystem Science Lund University SE Lund Sweden
- Department of Ecology and Environmental Science SE Umeå Sweden
| | - Anders Priemé
- Center for Permafrost (CENPERM) University of Copenhagen Copenhagen Denmark
- Section of Microbiology, Department of Biology University of Copenhagen Copenhagen Denmark
| | - Kathrin Rousk
- Terrestrial Ecology Section, Department of Biology University of Copenhagen Copenhagen Denmark
- Center for Permafrost (CENPERM) University of Copenhagen Copenhagen Denmark
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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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Darnajoux R, Bradley R, Bellenger JP. In Vivo Temperature Dependency of Molybdenum and Vanadium Nitrogenase Activity in the Heterocystous Cyanobacteria Anabaena variabilis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:2760-2769. [PMID: 35073047 DOI: 10.1021/acs.est.1c05279] [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] [Indexed: 06/14/2023]
Abstract
The reduction of atmospheric dinitrogen by nitrogenase is a key component of terrestrial nitrogen cycling. Nitrogenases exist in several isoforms named after the metal present within their active center: the molybdenum (Mo), the vanadium (V), and the iron (Fe)-only nitrogenase. While earlier in vitro studies hint that the relative contribution of V nitrogenase to total BNF could be temperature-dependent, the effect of temperature on in vivo activity remains to be investigated. In this study, we characterize the in vivo effect of temperature (3-42 °C) on the activities of Mo nitrogenase and V nitrogenase in the heterocystous cyanobacteria Anabaena variabilis ATTC 29413 using the acetylene reduction assay by cavity ring-down absorption spectroscopy. We demonstrate that V nitrogenase becomes as efficient as Mo nitrogenase at temperatures below 10-15 °C. At temperatures above 22 °C, BNF seems to be limited by O2 availability to respiration in both enzymes. Furthermore, Anabaena variabilis cultures grown in Mo or V media achieved similar growth rates at temperatures below 20 °C. Considering the average temperature on earth is 15 °C, our findings further support the role of V nitrogenase as a viable backup enzymatic system for BNF in natural ecosystems.
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Affiliation(s)
- Romain Darnajoux
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
- Centre Sève, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Robert Bradley
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
- Centre Sève, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Jean-Philippe Bellenger
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
- Centre Sève, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
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Etto RM, Jesus EDC, Cruz LM, Schneider BSF, Tomachewski D, Urrea-Valencia S, Gonçalves DRP, Galvão F, Ayub RA, Curcio GR, Steffens MBR, Galvão CW. Influence of environmental factors on the tropical peatlands diazotrophic communities from the Southern Brazilian Atlantic Rain Forest. Lett Appl Microbiol 2021; 74:543-554. [PMID: 34951701 DOI: 10.1111/lam.13638] [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: 05/19/2021] [Revised: 10/10/2021] [Accepted: 12/17/2021] [Indexed: 11/26/2022]
Abstract
The tropical peatlands of southern Brazil are essential for the maintenance of the Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world. Although diazotrophic microorganisms are essential for the maintenance of this nitrogen limited ecosystem, so far studies have focused only on microorganisms involved in the carbon cycle. In this work, peat samples were collected from three tropical peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Our results showed that the structure of the diazotrophic communities in the Brazilian tropical peatlands differs in the evaluated seasons. The abundance of the genus Bradyrhizobium showed to be affected by rainfall and peat pH. Despite the shifts of the nitrogen fixing population in the tropical peatland caused by seasonality it showed to be constantly dominated by α-Proteobacteria followed by Cyanobacteria. In addition, more than 50% of nifH gene sequences have not been classified, indicating the necessity for more studies in tropical peatland, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland microorganisms, influencing the C stock.
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Affiliation(s)
- Rafael Mazer Etto
- Microbial Molecular Biology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
| | | | - Leonardo Magalhães Cruz
- Nucleus of Nitrogen Fixation, Federal University of Paraná, CEP, 81531-980, Curitiba - PR, Brazil
| | | | - Douglas Tomachewski
- Microbial Molecular Biology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
| | - Salomé Urrea-Valencia
- Microbial Molecular Biology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
| | - Daniel Ruiz Potma Gonçalves
- Microbial Molecular Biology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
| | - Franklin Galvão
- Forest Ecology Laboratory, Universidade Federal do Paraná, CEP, 80210-170, Curitiba - PR, Brazil
| | - Ricardo Antônio Ayub
- Applied Biotechnology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
| | | | | | - Carolina Weigert Galvão
- Microbial Molecular Biology Laboratory, State University of Ponta Grossa, CEP, 84030-900, Ponta Grossa - PR, Brazil
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24
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Alvarenga DO, Rousk K. Indirect effects of climate change inhibit N 2 fixation associated with the feathermoss Hylocomium splendens in subarctic tundra. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148676. [PMID: 34247067 DOI: 10.1016/j.scitotenv.2021.148676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/15/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Mosses can be responsible for up to 100% of net primary production in arctic and subarctic tundra, and their associations with diazotrophic cyanobacteria have an important role in increasing nitrogen (N) availability in these pristine ecosystems. Predictions about the consequences of climate change in subarctic environments point to increased N mineralization in soil and higher litter deposition due to warming. It is not clear yet how these indirect climate change effects impact moss-cyanobacteria associations and N2 fixation. This work aimed to evaluate the effects of increased N and litter input on biological N2 fixation rates associated with the feathermoss Hylocomium splendens from a tundra heath. H. splendens samples were collected near Abisko, northern Sweden, from a field experiment with annual additions of ammonium chloride and dried birch litter and the combination of both for three years. Samples were analyzed for N2 fixation, cyanobacterial colonization, C and N content and pH. Despite the high N additions, no significant differences in moss N content were found. However, differences between treatments were observed in N2 fixation rates, cyanobacterial colonization and pH, with the combined ammonium+litter treatment causing a significant reduction in the number of branch-colonizing cyanobacteria and N2 fixation, and ammonium additions significantly lowering moss pH. A significant, positive relationship was found between N2 fixation rates, moss colonization by cyanobacteria and pH levels, showing a clear drop in N2 fixation rates at lower pH levels even if larger cyanobacterial populations were present. These results suggest that increased N availability and litter deposition resulting from climate change not only interferes with N2 fixation directly, but also acidifies moss microhabitats and reduces the abundance of associated cyanobacteria, which could eventually impact the N cycle in the Subarctic.
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Affiliation(s)
- Danillo O Alvarenga
- Department of Biology, 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, 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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Extreme freeze-thaw cycles do not affect moss-associated nitrogen fixation across a temperature gradient, but affect nutrient loss from mosses. ACTA OECOLOGICA 2021. [DOI: 10.1016/j.actao.2021.103796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hupperts SF, Gerber S, Nilsson MC, Gundale MJ. Empirical and Earth system model estimates of boreal nitrogen fixation often differ: A pathway toward reconciliation. GLOBAL CHANGE BIOLOGY 2021; 27:5711-5725. [PMID: 34382301 DOI: 10.1111/gcb.15836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
The impacts of global environmental change on productivity in northern latitudes will be contingent on nitrogen (N) availability. In circumpolar boreal ecosystems, nonvascular plants (i.e., bryophytes) and associated N2 -fixing diazotrophs provide one of the largest known N inputs but are rarely accounted for in Earth system models. Instead, most models link N2 -fixation with the functioning of vascular plants. Neglecting nonvascular N2 -fixation may be contributing toward high uncertainty that currently hinders model predictions in northern latitudes, where nonvascular N2 -fixing plants are more common. Adequately accounting for nonvascular N2 -fixation and its drivers could subsequently improve predictions of future N availability and ultimately, productivity, in northern latitudes. Here, we review empirical evidence of boreal nonvascular N2 -fixation responses to global change factors (elevated CO2 , N deposition, warming, precipitation, and shading by vascular plants), and compare empirical findings with model predictions of N2 -fixation using nine Earth system models. The majority of empirical studies found positive effects of CO2 , warming, precipitation, or light on nonvascular N2 -fixation, but N deposition strongly downregulated N2 -fixation in most empirical studies. Furthermore, we found that the responses of N2 -fixation to elevated CO2 were generally consistent between models and very limited empirical data. In contrast, empirical-model comparisons suggest that all models we assessed, and particularly those that scale N2 -fixation with net primary productivity or evapotranspiration, may be overestimating N2 -fixation under increasing N deposition. Overestimations could generate erroneous predictions of future N stocks in boreal ecosystems unless models adequately account for the drivers of nonvascular N2 -fixation. Based on our comparisons, we recommend that models explicitly treat nonvascular N2 -fixation and that field studies include more targeted measurements to improve model structures and parameterization.
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Affiliation(s)
- Stefan F Hupperts
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Stefan Gerber
- Soil and Water Sciences Department, University of Florida, Gainesville, FL, USA
| | - Marie-Charlotte Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Michael J Gundale
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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Costantini MS, Medeiros MC, Crampton LH, Reed FA. Wild gut microbiomes reveal individuals, species, and location as drivers of variation in two critically endangered Hawaiian honeycreepers. PeerJ 2021; 9:e12291. [PMID: 34760361 PMCID: PMC8557688 DOI: 10.7717/peerj.12291] [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: 07/23/2021] [Accepted: 09/21/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The gut microbiome of animals is an important component that has strong influence on the health, fitness, and behavior of its host. Most research in the microbiome field has focused on human populations and commercially important species. However, researchers are now considering the link between endangered species conservation and the microbiome. In Hawai'i, several threats (e.g., avian malaria and habitat loss) have caused widespread population declines of Hawaiian honeycreepers (subfamily: Carduelinae). These threats can have a significant effect on the avian gut microbiome and may even lead to disruption of microbial function. However, the gut microbiome of honeycreeper in the wild has yet to be explored. METHODS We collected 13 and 42 fecal samples, respectively, from two critically endangered honeycreeper species, the 'akikiki (Oreomystis bairdi) and the 'akeke'e (Loxops caeruleirostris). The 16S rRNA gene was sequenced and processed though a MOTHUR-based bioinformatics pipeline. Bacterial ASVs were identified using the DADA2 program and bacterial community analyses, including alpha and beta diversity measures, were conducted using R packages Phyloseq and vegan. RESULTS A total of 8,958 bacterial ASVs were identified from the fecal samples. Intraspecific differences in the gut microbiome among individual birds explained most of the variation present in the dataset, however differences between species did exist. Both species had distinct microbiomes with minimal overlap in beta diversity. 'Akikiki had a more diverse microbiome compared to 'akeke'e. Additionally, small but stastically significant differences in beta diversity also exist between sampling location and sexes in 'akikiki. CONCLUSION 'Akikiki and 'akeke'e are currently the focus of captive breeding efforts and plans to translocate the two species to other islands are underway. This baseline knowledge will help inform management decisions for these honeycreeper species in their native habitats, on other islands, and in captivity.
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Affiliation(s)
- Maria S. Costantini
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaiʻi, United States
| | - Matthew C.I. Medeiros
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaiʻi, United States
- Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, Hawaií, United States
| | - Lisa H. Crampton
- Hawaiʻi Division of Forestry and Wildlife, Hanapepe, Hawaiʻi, United States
- Pacific Cooperative Studies Unit, University of Hawaiʻi, Honolulu, Hawaiʻi, United States
| | - Floyd A. Reed
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaiʻi, United States
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28
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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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29
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Koranda M, Michelsen A. Mosses reduce soil nitrogen availability in a subarctic birch forest via effects on soil thermal regime and sequestration of deposited nitrogen. THE JOURNAL OF ECOLOGY 2021; 109:1424-1438. [PMID: 33776135 PMCID: PMC7986113 DOI: 10.1111/1365-2745.13567] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/01/2020] [Indexed: 05/16/2023]
Abstract
In high-latitude ecosystems bryophytes are important drivers of ecosystem functions. Alterations in abundance of mosses due to global change may thus strongly influence carbon (C) and nitrogen (N) cycling and hence cause feedback on climate. The effects of mosses on soil microbial activity are, however, still poorly understood. Our study aims at elucidating how and by which mechanisms bryophytes influence microbial decomposition processes of soil organic matter and thus soil nutrient availability.We present results from a field experiment in a subarctic birch forest in northern Sweden, where we partly removed the moss cover and replaced it with an artificial soil cover for simulating moss effects on soil temperature and moisture. We combined this with a fertilization experiment with 15N-labelled N for analysing the effects of moss N sequestration on soil processes.Our results demonstrate the capacity of mosses to reduce soil N availability and retard N cycling. The comparison with artificial soil cover plots suggests that the effect of mosses on N cycling is linked to the thermal insulation capacity of mosses causing low average soil temperature in summer and strongly reduced soil temperature fluctuations, the latter also leading to a decreased frequency of freeze-thaw events in autumn and spring. Our results also showed, however, that the negative temperature effect of mosses on soil microbial activity was in part compensated by stimulatory effects of the moss layer, possibly linked to leaching of labile substrates from the moss. Furthermore, our results revealed that bryophytes efficiently sequester added N from wet deposition and thus prevent effects of increased atmospheric N deposition on soil N availability and soil processes. Synthesis. Our study emphasizes the important role of mosses in carbon and nutrient cycling in high-latitude ecosystems and the potential strong impacts of reductions in moss abundance on microbial decomposition processes and nutrient availability in subarctic and boreal forests.
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Affiliation(s)
- Marianne Koranda
- Terrestrial Ecology SectionDepartment of BiologyUniversity of CopenhagenCopenhagenDenmark
- Center for PermafrostUniversity of CopenhagenCopenhagenDenmark
- Division of Terrestrial Ecosystem ResearchCentre for Microbiology and Environmental Systems ScienceUniversity of ViennaViennaAustria
| | - Anders Michelsen
- Terrestrial Ecology SectionDepartment of BiologyUniversity of CopenhagenCopenhagenDenmark
- Center for PermafrostUniversity of CopenhagenCopenhagenDenmark
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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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31
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Netherway T, Bengtsson J, Krab EJ, Bahram M. Biotic interactions with mycorrhizal systems as extended nutrient acquisition strategies shaping forest soil communities and functions. Basic Appl Ecol 2021. [DOI: 10.1016/j.baae.2020.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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32
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Stuart RK, Pederson ERA, Weyman PD, Weber PK, Rassmussen U, Dupont CL. Bidirectional C and N transfer and a potential role for sulfur in an epiphytic diazotrophic mutualism. THE ISME JOURNAL 2020; 14:3068-3078. [PMID: 32814866 PMCID: PMC7784912 DOI: 10.1038/s41396-020-00738-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/09/2020] [Accepted: 08/05/2020] [Indexed: 01/23/2023]
Abstract
In nitrogen-limited boreal forests, associations between feathermoss and diazotrophic cyanobacteria control nitrogen inputs and thus carbon cycling, but little is known about the molecular regulators required for initiation and maintenance of these associations. Specifically, a benefit to the cyanobacteria is not known, challenging whether the association is a nutritional mutualism. Targeted mutagenesis of the cyanobacterial alkane sulfonate monooxygenase results in an inability to colonize feathermosses by the cyanobacterium Nostoc punctiforme, suggesting a role for organic sulfur in communication or nutrition. Isotope probing paired with high-resolution imaging mass spectrometry (NanoSIMS) demonstrated bidirectional elemental transfer between partners, with carbon and sulfur both being transferred to the cyanobacteria, and nitrogen transferred to the moss. These results support the hypothesis that moss and cyanobacteria enter a mutualistic exosymbiosis with substantial bidirectional material exchange of carbon and nitrogen and potential signaling through sulfur compounds.
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Affiliation(s)
- Rhona K Stuart
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| | - Eric R A Pederson
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91, Stockholm, Sweden
| | - Philip D Weyman
- J. Craig Venter Institute, La Jolla, CA, 92037, USA
- Zymergen Inc., Emeryville, CA, USA
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Ulla Rassmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91, Stockholm, Sweden
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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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Salemaa M, Kieloaho AJ, Lindroos AJ, Merilä P, Poikolainen J, Manninen S. Forest mosses sensitively indicate nitrogen deposition in boreal background areas. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114054. [PMID: 32078876 DOI: 10.1016/j.envpol.2020.114054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/27/2019] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Mosses take up nitrogen (N) mainly from precipitation through their surfaces, which makes them competent bioindicators of N deposition. We found positive relationships between the total N concentration (mossN%) of common terrestrial moss species (feather mosses Pleurozium schreberi and Hylocomium splendens, and a group of Dicranum species) and different forms of N deposition in 11-16 coniferous forests with low N deposition load in Finland. The mosses were collected either inside (Dicranum group) or both inside and outside (feather mosses) the forests. Deposition was monitored in situ as bulk deposition (BD) and stand throughfall (TF) and detected for ammonium (NH4+-N), nitrate (NO3--N), dissolved organic N (DON), and total N (Ntot, kg ha-1yr-1). Ntot deposition was lower in TF than BD indicating that tree canopies absorbed N from deposition in N limited boreal stands. However, mossN% was higher inside than outside the forests. In regression equations, inorganic N in BD predicted best the mossN% in openings, while DON in TF explained most variation of mossN% in forests. An asymptotic form of mossN% vs. TF Ntot curves in forests and free NH4+-N accumulation in tissues in the southern plots suggested mosses were near the N saturation state already at the Ntot deposition level of 3-5 kg ha-1yr-1. N leachate from ground litterfall apparently also contributed the N supply of mosses. Our study yielded new information on the sensitivity of boreal mosses to low N deposition and their response to different N forms in canopy TF entering moss layer. The equations predicting the Ntot deposition with mossN% showed a good fit both in forest sites and openings, especially in case of P. schreberi. However, the open site mossN% is a preferable predictor of N deposition in monitoring studies to minimize the effect of tree canopies and N leachate from litterfall on the estimates.
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Affiliation(s)
- Maija Salemaa
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790, Helsinki, Finland.
| | - Antti-Jussi Kieloaho
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790, Helsinki, Finland
| | - Antti-Jussi Lindroos
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790, Helsinki, Finland
| | - Päivi Merilä
- Natural Resources Institute Finland (Luke), Paavo Havaksentie 3, FI-90570, Oulu, Finland
| | - Jarmo Poikolainen
- Natural Resources Institute Finland (Luke), Paavo Havaksentie 3, FI-90570, Oulu, Finland
| | - Sirkku Manninen
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Helsingin yliopisto, Finland
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35
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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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36
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Simultaneous Metabarcoding of Eukaryotes and Prokaryotes to Elucidate the Community Structures within Tardigrade Microhabitats. DIVERSITY-BASEL 2020. [DOI: 10.3390/d12030110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Tardigrades are microscopic invertebrates that can withstand complete desiccation, but their interspecies interactions with prokaryotes and eukaryotes within their microhabitat remain relatively unexplored. Here, I utilized combined metabarcoding of eukaryotes and prokaryotes to simultaneously identify entire community structures within xeric and mesic mosses that harbor tardigrades. The populations of organisms within the microecosystems were successfully determined in 45 xeric moss samples and 47 mesic moss samples. Organismal composition was largely consistent regardless of the moss/lichen substrate, but significantly varied in the two tested locations, possibly because of the differences in environmental humidity. Xeric mosses containing xerophilic tardigrades and other anhydrobiotic invertebrates tended to have significantly limited biological diversity and prokaryotic population dominated by cyanobacteria, suggesting a selection due to extreme desiccation. A combined metabarcoding approach to identify both eukaryotes and prokaryotes can successfully elucidate community structures within microscopic ecosystems, and this can be a potential approach to study the microecology of meiofauna, including tardigrades.
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Li FW, Nishiyama T, Waller M, Frangedakis E, Keller J, Li Z, Fernandez-Pozo N, Barker MS, Bennett T, Blázquez MA, Cheng S, Cuming AC, de Vries J, de Vries S, Delaux PM, Diop IS, Harrison CJ, Hauser D, Hernández-García J, Kirbis A, Meeks JC, Monte I, Mutte SK, Neubauer A, Quandt D, Robison T, Shimamura M, Rensing SA, Villarreal JC, Weijers D, Wicke S, Wong GKS, Sakakibara K, Szövényi P. Anthoceros genomes illuminate the origin of land plants and the unique biology of hornworts. NATURE PLANTS 2020; 6:259-272. [PMID: 32170292 PMCID: PMC8075897 DOI: 10.1038/s41477-020-0618-2] [Citation(s) in RCA: 165] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 02/11/2020] [Indexed: 05/12/2023]
Abstract
Hornworts comprise a bryophyte lineage that diverged from other extant land plants >400 million years ago and bears unique biological features, including a distinct sporophyte architecture, cyanobacterial symbiosis and a pyrenoid-based carbon-concentrating mechanism (CCM). Here, we provide three high-quality genomes of Anthoceros hornworts. Phylogenomic analyses place hornworts as a sister clade to liverworts plus mosses with high support. The Anthoceros genomes lack repeat-dense centromeres as well as whole-genome duplication, and contain a limited transcription factor repertoire. Several genes involved in angiosperm meristem and stomatal function are conserved in Anthoceros and upregulated during sporophyte development, suggesting possible homologies at the genetic level. We identified candidate genes involved in cyanobacterial symbiosis and found that LCIB, a Chlamydomonas CCM gene, is present in hornworts but absent in other plant lineages, implying a possible conserved role in CCM function. We anticipate that these hornwort genomes will serve as essential references for future hornwort research and comparative studies across land plants.
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Affiliation(s)
- Fay-Wei Li
- Boyce Thompson Institute, Ithaca, NY, USA.
- Plant Biology Section, Cornell University, Ithaca, NY, USA.
| | - Tomoaki Nishiyama
- Advanced Science Research Center, Kanazawa University, Ishikawa, Japan
| | - Manuel Waller
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | | | - Jean Keller
- LRSV, Université de Toulouse, CNRS, UPS Castanet-Tolosan, Toulouse, France
| | - Zheng Li
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | | | - Michael S Barker
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Tom Bennett
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Miguel A Blázquez
- Instituto de Biología Molecular y Celular de Plantas, CSIC-Universidad Politécnica de Valencia, Valencia, Spain
| | - Shifeng Cheng
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Andrew C Cuming
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Jan de Vries
- Institute for Microbiology and Genetics, Department of Applied Bioinformatics, Georg-August University Göttingen, Göttingen, Germany
| | - Sophie de Vries
- Institute of Population Genetics, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Pierre-Marc Delaux
- LRSV, Université de Toulouse, CNRS, UPS Castanet-Tolosan, Toulouse, France
| | - Issa S Diop
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - C Jill Harrison
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Jorge Hernández-García
- Instituto de Biología Molecular y Celular de Plantas, CSIC-Universidad Politécnica de Valencia, Valencia, Spain
| | - Alexander Kirbis
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - John C Meeks
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA, USA
| | - Isabel Monte
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Sumanth K Mutte
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands
| | - Anna Neubauer
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - Dietmar Quandt
- Nees Institute for Biodiversity of Plants, University of Bonn, Bonn, Germany
| | - Tanner Robison
- Boyce Thompson Institute, Ithaca, NY, USA
- Plant Biology Section, Cornell University, Ithaca, NY, USA
| | - Masaki Shimamura
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Stefan A Rensing
- Faculty of Biology, Philipps University of Marburg, Marburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), University of Marburg, Marburg, Germany
| | - Juan Carlos Villarreal
- Department of Biology, Laval University, Quebec City, Quebec, Canada
- Smithsonian Tropical Research Institute, Balboa, Panamá
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands
| | - Susann Wicke
- Institute for Evolution and Biodiversity, University of Muenster, Münster, Germany
| | - Gane K-S Wong
- Department of Biological Sciences, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- BGI-Shenzhen, Shenzhen, China
| | | | - Péter Szövényi
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland.
- Zurich-Basel Plant Science Center, Zurich, Switzerland.
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van den Elzen E, Bengtsson F, Fritz C, Rydin H, Lamers LPM. Variation in symbiotic N2 fixation rates among Sphagnum mosses. PLoS One 2020; 15:e0228383. [PMID: 32017783 PMCID: PMC7001857 DOI: 10.1371/journal.pone.0228383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 01/14/2020] [Indexed: 11/18/2022] Open
Abstract
Biological nitrogen (N) fixation is an important process supporting primary production in ecosystems, especially in those where N availability is limiting growth, such as peatlands and boreal forests. In many peatlands, peat mosses (genus Sphagnum) are the prime ecosystem engineers, and like feather mosses in boreal forests, they are associated with a diverse community of diazotrophs (N2-fixing microorganisms) that live in and on their tissue. The large variation in N2 fixation rates reported in literature remains, however, to be explained. To assess the potential roles of habitat (including nutrient concentration) and species traits (in particular litter decomposability and photosynthetic capacity) on the variability in N2 fixation rates, we compared rates associated with various Sphagnum moss species in a bog, the surrounding forest and a fen in Sweden. We found appreciable variation in N2 fixation rates among moss species and habitats, and showed that both species and habitat conditions strongly influenced N2 fixation. We here show that higher decomposition rates, as explained by lower levels of decomposition-inhibiting compounds, and higher phosphorous (P) levels, are related with higher diazotrophic activity. Combining our findings with those of other studies, we propose a conceptual model in which both species-specific traits of mosses (as related to the trade-off between rapid photosynthesis and resistance to decomposition) and P availability, explain N2 fixation rates. This is expected to result in a tight coupling between P and N cycling in peatlands.
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Affiliation(s)
- Eva van den Elzen
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
| | - Fia Bengtsson
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre,
Uppsala University, Uppsala, Sweden
| | - Christian Fritz
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
| | - Håkan Rydin
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre,
Uppsala University, Uppsala, Sweden
| | - Leon P. M. Lamers
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
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39
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Molybdenum threshold for ecosystem scale alternative vanadium nitrogenase activity in boreal forests. Proc Natl Acad Sci U S A 2019; 116:24682-24688. [PMID: 31727845 PMCID: PMC6900544 DOI: 10.1073/pnas.1913314116] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Biological nitrogen fixation (BNF) is responsible for large new N inputs to terrestrial ecosystems, particularly in pristine, high-latitude areas undergoing rapid global change. The most common form of nitrogenase requires molybdenum (Mo) and Mo limitation of BNF is ubiquitous. Mo-free alternative forms of nitrogenase exist, but their roles in environmental BNF have remained uncertain. This study on N2-fixing cyanolichens provides extensive field evidence, at an ecosystem scale, that vanadium (V)-based nitrogenase greatly contributes to BNF when Mo availability is limited. Mo exposure data in circumboreal forests further suggest that V-based BNF is widespread. The results showcase the resilience of BNF to micronutrient limitation and reveal strong links between the biogeochemical cycle of macronutrients and micronutrients in terrestrial ecosystems. Biological nitrogen fixation (BNF) by microorganisms associated with cryptogamic covers, such as cyanolichens and bryophytes, is a primary source of fixed nitrogen in pristine, high-latitude ecosystems. On land, low molybdenum (Mo) availability has been shown to limit BNF by the most common form of nitrogenase (Nase), which requires Mo in its active site. Vanadium (V) and iron-only Nases have been suggested as viable alternatives to countering Mo limitation of BNF; however, field data supporting this long-standing hypothesis have been lacking. Here, we elucidate the contribution of vanadium nitrogenase (V-Nase) to BNF by cyanolichens across a 600-km latitudinal transect in eastern boreal forests of North America. Widespread V-Nase activity was detected (∼15–50% of total BNF rates), with most of the activity found in the northern part of the transect. We observed a 3-fold increase of V-Nase contribution during the 20-wk growing season. By including the contribution of V-Nase to BNF, estimates of new N input by cyanolichens increase by up to 30%. We find that variability in V-based BNF is strongly related to Mo availability, and we identify a Mo threshold of ∼250 ng·glichen−1 for the onset of V-based BNF. Our results provide compelling ecosystem-scale evidence for the use of the V-Nase as a surrogate enzyme that contributes to BNF when Mo is limiting. Given widespread findings of terrestrial Mo limitation, including the carbon-rich circumboreal belt where global change is most rapid, additional consideration of V-based BNF is required in experimental and modeling studies of terrestrial biogeochemistry.
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40
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Fudyma JD, Lyon J, AminiTabrizi R, Gieschen H, Chu RK, Hoyt DW, Kyle JE, Toyoda J, Tolic N, Heyman HM, Hess NJ, Metz TO, Tfaily MM. Untargeted metabolomic profiling of Sphagnum fallax reveals novel antimicrobial metabolites. PLANT DIRECT 2019; 3:e00179. [PMID: 31742243 PMCID: PMC6848953 DOI: 10.1002/pld3.179] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 05/06/2023]
Abstract
Sphagnum mosses dominate peatlands by employing harsh ecosystem tactics to prevent vascular plant growth and microbial degradation of these large carbon stores. Knowledge about Sphagnum-produced metabolites, their structure and their function, is important to better understand the mechanisms, underlying this carbon sequestration phenomenon in the face of climate variability. It is currently unclear which compounds are responsible for inhibition of organic matter decomposition and the mechanisms by which this inhibition occurs. Metabolite profiling of Sphagnum fallax was performed using two types of mass spectrometry (MS) systems and 1H nuclear magnetic resonance spectroscopy (1H NMR). Lipidome profiling was performed using LC-MS/MS. A total of 655 metabolites, including one hundred fifty-two lipids, were detected by NMR and LC-MS/MS-329 of which were novel metabolites (31 unknown lipids). Sphagum fallax metabolite profile was composed mainly of acid-like and flavonoid glycoside compounds, that could be acting as potent antimicrobial compounds, allowing Sphagnum to control its environment. Sphagnum fallax metabolite composition comparison against previously known antimicrobial plant metabolites confirmed this trend, with seventeen antimicrobial compounds discovered to be present in Sphagnum fallax, the majority of which were acids and glycosides. Biological activity of these compounds needs to be further tested to confirm antimicrobial qualities. Three fungal metabolites were identified providing insights into fungal colonization that may benefit Sphagnum. Characterizing the metabolite profile of Sphagnum fallax provided a baseline to understand the mechanisms in which Sphagnum fallax acts on its environment, its relation to carbon sequestration in peatlands, and provide key biomarkers to predict peatland C store changes (sequestration, emissions) as climate shifts.
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Affiliation(s)
- Jane D. Fudyma
- Department of Environmental ScienceUniversity of ArizonaTucsonAZUSA
| | - Jamee Lyon
- Department of Environmental ScienceUniversity of ArizonaTucsonAZUSA
| | | | - Hans Gieschen
- Department of Environmental ScienceUniversity of ArizonaTucsonAZUSA
| | - Rosalie K. Chu
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
| | - David W. Hoyt
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
| | - Jennifer E. Kyle
- Biological Sciences DivisionPacific Northwest National LaboratoryRichlandWAUSA
| | - Jason Toyoda
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
| | - Nikola Tolic
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
| | | | - Nancy J. Hess
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
| | - Thomas O. Metz
- Biological Sciences DivisionPacific Northwest National LaboratoryRichlandWAUSA
| | - Malak M. Tfaily
- Department of Environmental ScienceUniversity of ArizonaTucsonAZUSA
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWAUSA
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41
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Salemaa M, Lindroos AJ, Merilä P, Mäkipää R, Smolander A. N 2 fixation associated with the bryophyte layer is suppressed by low levels of nitrogen deposition in boreal forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 653:995-1004. [PMID: 30759623 DOI: 10.1016/j.scitotenv.2018.10.364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/25/2018] [Accepted: 10/27/2018] [Indexed: 06/09/2023]
Abstract
Biological fixation of atmospheric nitrogen (N2) by bryophyte-associated cyanobacteria is an important source of plant-available N in the boreal biome. Information on the factors that drive biological N2 fixation (BNF) rates is needed in order to understand the N dynamics of forests under a changing climate. We assessed the potential of several cryptogam species (the feather mosses Hylocomium splendens and Pleurozium schreberi, a group of Dicranum bryophytes, two liverworts, and Cladina lichens) to serve as associates of cyanobacteria or other N2-fixing bacteria (diazotrophs) using acetylene reduction assay (ARA). We tested the hypotheses that the legacy of chronic atmospheric N deposition reduces BNF in the three bryophyte species, sampled from 12 coniferous forests located at latitudes 60-68° N in Finland. In addition, we tested the effect of moisture and temperature on BNF. All species studied showed a BNF signal in the north, with the highest rates in feather mosses. In moss samples taken along the north-south gradient with an increasing N bulk deposition from 0.8 to 4.4 kg ha-1 year-1, we found a clear decrease in BNF in both feather mosses and Dicranum group. BNF turned off at N deposition of 3-4 kg ha-1 year-1. Inorganic N (NH4-N + NO3-N) best predicted the BNF rate among regression models with different forms of N deposition as explanatory variables. However, in southern spruce stands, tree canopies modified the N in throughfall so that dissolved organic N (DON) leached from canopies compensated for inorganic N retained therein. Here, both DON and inorganic N negatively affected BNF in H. splendens. In laboratory experiments, BNF increased with increasing temperature and moisture. Our results suggest that even relatively low N deposition suppresses BNF in bryophyte-associated diazotrophs. Further, BNF could increase in northern low-deposition areas, especially if climate warming leads to moister conditions, as predicted.
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Affiliation(s)
- Maija Salemaa
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
| | - Antti-Jussi Lindroos
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Päivi Merilä
- Natural Resources Institute Finland (Luke), P.O. Box 413, FI-90570 Oulu, Finland
| | - Raisa Mäkipää
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Aino Smolander
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland
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Holland-Moritz H, Stuart J, Lewis LR, Miller S, Mack MC, McDaniel SF, Fierer N. Novel bacterial lineages associated with boreal moss species. Environ Microbiol 2018; 20:2625-2638. [PMID: 29901277 DOI: 10.1111/1462-2920.14288] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/23/2018] [Accepted: 05/16/2018] [Indexed: 01/01/2023]
Abstract
Mosses are critical components of boreal ecosystems where they typically account for a large proportion of net primary productivity and harbour diverse bacterial communities that can be the major source of biologically-fixed nitrogen in these ecosystems. Despite their ecological importance, we have limited understanding of how microbial communities vary across boreal moss species and the extent to which local site conditions may influence the composition of these bacterial communities. We used marker gene sequencing to analyze bacterial communities associated with seven boreal moss species collected near Fairbanks, AK, USA. We found that host identity was more important than site in determining bacterial community composition and that mosses harbour diverse lineages of potential N2 -fixers as well as an abundance of novel taxa assigned to understudied bacterial phyla (including candidate phylum WPS-2). We performed shotgun metagenomic sequencing to assemble genomes from the WPS-2 candidate phylum and found that these moss-associated bacteria are likely anoxygenic phototrophs capable of carbon fixation via RuBisCo with an ability to utilize byproducts of photorespiration from hosts via a glyoxylate shunt. These results give new insights into the metabolic capabilities of understudied bacterial lineages that associate with mosses and the importance of plant hosts in shaping their microbiomes.
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Affiliation(s)
- Hannah Holland-Moritz
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA.,Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Julia Stuart
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Lily R Lewis
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Samantha Miller
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Michelle C Mack
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | | | - Noah Fierer
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA.,Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
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43
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van den Elzen E, van den Berg LJL, van der Weijden B, Fritz C, Sheppard LJ, Lamers LPM. Effects of airborne ammonium and nitrate pollution strongly differ in peat bogs, but symbiotic nitrogen fixation remains unaffected. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:732-740. [PMID: 28822940 DOI: 10.1016/j.scitotenv.2017.08.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 06/07/2023]
Abstract
Pristine bogs, peatlands in which vegetation is exclusively fed by rainwater (ombrotrophic), typically have a low atmospheric deposition of reactive nitrogen (N) (<0.5kgha-1y-1). An important additional N source is N2 fixation by symbiotic microorganisms (diazotrophs) in peat and mosses. Although the effects of increased total airborne N by anthropogenic emissions on bog vegetation are well documented, the important question remains how different N forms (ammonium, NH4+, versus nitrate, NO3-) affect N cycling, as their relative contribution to the total load strongly varies among regions globally. Here, we studied the effects of 11years of experimentally increased deposition (32 versus 8kgNha-1y-1) of either NH4+ or NO3- on N accumulation in three moss and one lichen species (Sphagnum capillifolium, S. papillosum, Pleurozium schreberi and Cladonia portentosa), N2 fixation rates of their symbionts, and potential N losses to peat soil and atmosphere, in a bog in Scotland. Increased input of both N forms led to 15-90% increase in N content for all moss species, without affecting their cover. The keystone species S. capillifolium showed 4 times higher N allocation into free amino acids, indicating N stress, but only in response to increased NH4+. In contrast, NO3- addition resulted in enhanced peat N mineralization linked to microbial NO3- reduction, increasing soil pH, N concentrations and N losses via denitrification. Unexpectedly, increased deposition from 8 to 32kgha-1y-1 in both N forms did not affect N2 fixation rates for any of the moss species and corresponded to an additional input of 5kgNha-1y-1 with a 100% S. capillifolium cover. Since both N forms clearly show differential effects on living Sphagnum and biogeochemical processes in the underlying peat, N form should be included in the assessment of the effects of N pollution on peatlands.
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Affiliation(s)
- Eva van den Elzen
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | | | - Bas van der Weijden
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Christian Fritz
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands; Centre for Energy and Environmental Studies, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Lucy J Sheppard
- Centre for Ecology & Hydrology Edinburgh, Bush Estate, Penicuik EH26 0QB, UK
| | - Leon P M Lamers
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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44
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Characterisation of a deep-water moss from the perennially ice-covered Lake Vanda, Antarctica. Polar Biol 2017. [DOI: 10.1007/s00300-017-2127-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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45
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Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils. Appl Environ Microbiol 2017; 83:AEM.03319-16. [PMID: 28213542 DOI: 10.1128/aem.03319-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/14/2017] [Indexed: 11/20/2022] Open
Abstract
The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils.IMPORTANCE Covering over 800 km2, land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of how vegetation, soil characteristics and microbial communities interact and drive soil functions.
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46
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Palviainen M, Pumpanen J, Berninger F, Ritala K, Duan B, Heinonsalo J, Sun H, Köster E, Köster K. Nitrogen balance along a northern boreal forest fire chronosequence. PLoS One 2017; 12:e0174720. [PMID: 28358884 PMCID: PMC5373610 DOI: 10.1371/journal.pone.0174720] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/14/2017] [Indexed: 12/02/2022] Open
Abstract
Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.
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Affiliation(s)
- Marjo Palviainen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Frank Berninger
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Kaisa Ritala
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Baoli Duan
- Institute of Mountain Hazards and Environment, Chengdu, China
| | - Jussi Heinonsalo
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Hui Sun
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Egle Köster
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Kajar Köster
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
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Elevated Atmospheric CO2 and Warming Stimulates Growth and Nitrogen Fixation in a Common Forest Floor Cyanobacterium under Axenic Conditions. FORESTS 2017. [DOI: 10.3390/f8030073] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Moss Mediates the Influence of Shrub Species on Soil Properties and Processes in Alpine Tundra. PLoS One 2016; 11:e0164143. [PMID: 27760156 PMCID: PMC5070840 DOI: 10.1371/journal.pone.0164143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 09/20/2016] [Indexed: 11/30/2022] Open
Abstract
In tundra ecosystems, bryophytes influence soil processes directly and indirectly through interactions with overstory shrub species. We experimentally manipulated moss cover and measured seasonal soil properties and processes under two species of deciduous shrubs with contrasting canopy structures, Salix planifolia pulchra and Betula glandulosa-nana complex. Soil properties (seasonal temperature, moisture and C:N ratios) and processes (seasonal litter decomposition and soil respiration) were measured over twelve months. Shrub species identity had the largest influence on summer soil temperatures and soil respiration rates, which were higher under Salix canopies. Mosses were associated with lower soil moisture irrespective of shrub identity, but modulated the effects of shrubs on winter soil temperatures and soil C:N ratios so that moss cover reduced differences in soil winter temperatures between shrub species and reduced C:N ratios under Betula but not under Salix canopies. Our results suggest a central role of mosses in mediating soil properties and processes, with their influence depending on shrub species identity. Such species-dependent effects need to be accounted for when forecasting vegetation dynamics under ongoing environmental changes.
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Warshan D, Bay G, Nahar N, Wardle DA, Nilsson MC, Rasmussen U. Seasonal variation in nifH abundance and expression of cyanobacterial communities associated with boreal feather mosses. THE ISME JOURNAL 2016; 10:2198-208. [PMID: 26918665 PMCID: PMC4989308 DOI: 10.1038/ismej.2016.17] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 12/16/2015] [Accepted: 01/08/2016] [Indexed: 11/13/2022]
Abstract
Dinitrogen (N2)-fixation by cyanobacteria living in symbiosis with pleurocarpous feather mosses (for example, Pleurozium schreberi and Hylocomium splendens) represents the main pathway of biological N input into N-depleted boreal forests. Little is known about the role of the cyanobacterial community in contributing to the observed temporal variability of N2-fixation. Using specific nifH primers targeting four major cyanobacterial clusters and quantitative PCR, we investigated how community composition, abundance and nifH expression varied by moss species and over the growing seasons. We evaluated N2-fixation rates across nine forest sites in June and September and explored the abundance and nifH expression of individual cyanobacterial clusters when N2-fixation is highest. Our results showed temporal and host-dependent variations of cyanobacterial community composition, nifH gene abundance and expression. N2-fixation was higher in September than June for both moss species, explained by higher nifH gene expression of individual clusters rather than higher nifH gene abundance or differences in cyanobacterial community composition. In most cases, 'Stigonema cluster' made up less than 29% of the total cyanobacterial community, but accounted for the majority of nifH gene expression (82-94% of total nifH expression), irrespective of sampling date or moss species. Stepwise multiple regressions showed temporal variations in N2-fixation being greatly explained by variations in nifH expression of the 'Stigonema cluster'. These results suggest that Stigonema is potentially the most influential N2-fixer in symbiosis with boreal forest feather mosses.
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Affiliation(s)
- Denis Warshan
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Guillaume Bay
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Nurun Nahar
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - David A Wardle
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Marie-Charlotte Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Ulla Rasmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
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50
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Timm CM, Pelletier DA, Jawdy SS, Gunter LE, Henning JA, Engle N, Aufrecht J, Gee E, Nookaew I, Yang Z, Lu TY, Tschaplinski TJ, Doktycz MJ, Tuskan GA, Weston DJ. Two Poplar-Associated Bacterial Isolates Induce Additive Favorable Responses in a Constructed Plant-Microbiome System. FRONTIERS IN PLANT SCIENCE 2016; 7:497. [PMID: 27200001 PMCID: PMC4845692 DOI: 10.3389/fpls.2016.00497] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/29/2016] [Indexed: 05/18/2023]
Abstract
The biological function of the plant-microbiome system is the result of contributions from the host plant and microbiome members. The Populus root microbiome is a diverse community that has high abundance of β- and γ-Proteobacteria, both classes which include multiple plant-growth promoting representatives. To understand the contribution of individual microbiome members in a community, we studied the function of a simplified community consisting of Pseudomonas and Burkholderia bacterial strains isolated from Populus hosts and inoculated on axenic Populus cutting in controlled laboratory conditions. Both strains increased lateral root formation and root hair production in Arabidopsis plate assays and are predicted to encode for different functions related to growth and plant growth promotion in Populus hosts. Inoculation individually, with either bacterial isolate, increased root growth relative to uninoculated controls, and while root area was increased in mixed inoculation, the interaction term was insignificant indicating additive effects of root phenotype. Complementary data including photosynthetic efficiency, whole-transcriptome gene expression and GC-MS metabolite expression data in individual and mixed inoculated treatments indicate that the effects of these bacterial strains are unique and additive. These results suggest that the function of a microbiome community may be predicted from the additive functions of the individual members.
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Affiliation(s)
- Collin M. Timm
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
- *Correspondence: Collin M. Timm
| | - Dale A. Pelletier
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Sara S. Jawdy
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Lee E. Gunter
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Jeremiah A. Henning
- Department of Ecology and Evolutionary Biology, University of TennesseeKnoxville, TN, USA
| | - Nancy Engle
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Jayde Aufrecht
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of TennesseeKnoxville, TN, USA
| | - Emily Gee
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Intawat Nookaew
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Zamin Yang
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Tse-Yuan Lu
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | | | | | - Gerald A. Tuskan
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - David J. Weston
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
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