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Audisio M, Muhr J, Polle A. Ectomycorrhizal fungi of Douglas-fir retain newly assimilated carbon derived from neighboring European beech. THE NEW PHYTOLOGIST 2024; 243:1980-1990. [PMID: 38952235 DOI: 10.1111/nph.19943] [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: 03/29/2024] [Accepted: 06/19/2024] [Indexed: 07/03/2024]
Abstract
Ectomycorrhizal (ECM) fungi distribute tree-derived carbon (C) via belowground hyphal networks in forest ecosystems. Here, we asked the following: (1) Is C transferred belowground to a neighboring tree retained in fungal structures or transported within the recipient tree? (2) Is the overlap of ectomycorrhizal fungi in mycorrhizal networks related to the amount of belowground C transfer? We used potted sapling pairs of European beech (Fagus sylvatica) and North-American Douglas-fir (Pseudotsuga menziesii) for 13CO2 pulse-labeling. We compared 13C transfer from beech (donor) to either beech or Douglas-fir (recipient) and identified the ECM species. We measured the 13C enrichment in soil, plant tissues, and ECM fractions of fungal-containing parts and plant transport tissues. In recipients, only fungal-containing tissue of ectomycorrhizas was significantly enriched in 13C and not the plant tissue. Douglas-fir recipients shared on average one ECM species with donors and had a lower 13C enrichment than beech recipients, which shared on average three species with donors. Our results support that recently assimilated C transferred belowground is shared among fungi colonizing tree roots but not among trees. In mixed forests with beech and Douglas-fir, the links for C movement might be hampered due to low mycorrhizal overlap with consequences for soil C cycling.
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Affiliation(s)
- Michela Audisio
- Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
| | - Jan Muhr
- Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
- Laboratory for Radio-isotopes, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
| | - Andrea Polle
- Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
- Laboratory for Radio-isotopes, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
- Centre for Sustainable Land Use, University of Göttingen, Göttingen, 37077, Germany
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2
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Robinson DG, Ammer C, Polle A, Bauhus J, Aloni R, Annighöfer P, Baskin TI, Blatt MR, Bolte A, Bugmann H, Cohen JD, Davies PJ, Draguhn A, Hartmann H, Hasenauer H, Hepler PK, Kohnle U, Lang F, Löf M, Messier C, Munné-Bosch S, Murphy A, Puettmann KJ, Marchant IQ, Raven PH, Robinson D, Sanders D, Seidel D, Schwechheimer C, Spathelf P, Steer M, Taiz L, Wagner S, Henriksson N, Näsholm T. Mother trees, altruistic fungi, and the perils of plant personification. TRENDS IN PLANT SCIENCE 2024; 29:20-31. [PMID: 37735061 DOI: 10.1016/j.tplants.2023.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 09/23/2023]
Abstract
There are growing doubts about the true role of the common mycorrhizal networks (CMN or wood wide web) connecting the roots of trees in forests. We question the claims of a substantial carbon transfer from 'mother trees' to their offspring and nearby seedlings through the CMN. Recent reviews show that evidence for the 'mother tree concept' is inconclusive or absent. The origin of this concept seems to stem from a desire to humanize plant life but can lead to misunderstandings and false interpretations and may eventually harm rather than help the commendable cause of preserving forests. Two recent books serve as examples: The Hidden Life of Trees and Finding the Mother Tree.
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Affiliation(s)
- David G Robinson
- Centre for Organismal Studies, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
| | - Christian Ammer
- Silvicuture and Forest Ecology of the Temperate Zones, University of Göttingen, Büsgenweg 1, 37077 Göttingen, Germany
| | - Andrea Polle
- Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Tennenbacherstr. 4, 79085 Freiburg im Breisgau, Germany
| | - Roni Aloni
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Peter Annighöfer
- Forest and Agroforest Systems, Technische Universität München, Hans-Carl-v.-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Tobias I Baskin
- Department of Biology, University of Massachusetts, 611 N. Pleasant St, Amherst, MA 01003, USA
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andreas Bolte
- Thünen Institute of Forest Ecosystems, A.-Möller-Str. 1, Haus 41/42, D-16225 Eberswalde, Germany
| | - Harald Bugmann
- Forest Ecology, Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
| | - Jerry D Cohen
- Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - Peter J Davies
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Andreas Draguhn
- Medical Faculty, Department of Neuro- and Senory Physiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Henrik Hartmann
- Julius Kühn Institute Federal Research Centre for Cultivated Plants, Institute for Forest Protection, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
| | - Hubert Hasenauer
- Institute of Silviculture, Department of Forest- and Soil Sciences, BOKU - University of Natural Resources and Life Sciences, Vienna, Peter-Jordan-Straße 82/II 1190, Wien, Austria
| | - Peter K Hepler
- Department of Biology, University of Massachusetts, 611 N. Pleasant St, Amherst, MA 01003, USA
| | - Ulrich Kohnle
- Department of Forest Growth, Forstliche Versuchs- und Forschungsanstalt Baden-Württemberg, Wonnhaldestraße 4, 79100 Freiburg, Germany
| | - Friederike Lang
- Chair of Soil Ecology, University of Freiburg, Bertholdstr. 17, 79098 Freiburg im Breisgau, Germany
| | - Magnus Löf
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Sundsvägen 3, P.O. Box 190, SE-234 22 Lomma, Sweden
| | - Christian Messier
- University of Quebec in Montréal (UQAM) and in Outaouais (UQO), Quebec, Canada
| | | | - Angus Murphy
- Plant Science and Landscape Architecture, University of Maryland, 5140 Plant Sciences Building 4291 Fieldhouse Drive College Park, MD 20742, USA
| | - Klaus J Puettmann
- Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331, USA
| | - Iván Quiroz Marchant
- Instituto Forestal, Calle Nueva Uno 3570 LT 4 Michaihue, San Pedro de la Paz, Concepción Chile, Chile
| | - Peter H Raven
- President Emeritus, Missouri Botanical Garden, 1037 Cy Ann Drive, Town and Country, MO 63017-8402, USA
| | - David Robinson
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
| | - Dale Sanders
- Department of Biology, University of York, Heslington York, YO10 5DD, UK
| | - Dominik Seidel
- Department for Spatial Structures and Digitization of Forests, Georg-August-Universität Göttingen, Büsgenweg 1, 37077 Göttingen, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 8, 85354 Freising, Germany
| | - Peter Spathelf
- Applied Silviculture, Eberswalde University for Sustainable Development, Alfred-Möller-Strasse 1, 16225 Eberswalde, Germany
| | - Martin Steer
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lincoln Taiz
- Molecular, Cell and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Sven Wagner
- Chair of Silviculture, Technische Universität Dresden, Pienner Str. 8, 01737 Tharandt, Germany
| | - Nils Henriksson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umea, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umea, Sweden
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3
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Klein T, Rog I, Livne-Luzon S, van der Heijden MG, Körner C. Belowground carbon transfer across mycorrhizal networks among trees: Facts, not fantasy. OPEN RESEARCH EUROPE 2023; 3:168. [PMID: 38152158 PMCID: PMC10751480 DOI: 10.12688/openreseurope.16594.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 12/29/2023]
Abstract
The mycorrhizal symbiosis between fungi and plants is among the oldest, ubiquitous and most important interactions in terrestrial life on Earth. Carbon (C) transfer across a common mycorrhizal network (CMN) was demonstrated over half a century ago in the lab ( Reid & Woods, 1969), and later in the field ( Simard et al., 1997a). Recent years have seen ample progress in this research direction, including evidence for ecological significance of carbon transfer ( Klein et al., 2016). Furthermore, specific cases where the architecture of mycorrhizal networks have been mapped ( Beiler et al., 2015) and CMN-C transfer from mature trees to seedlings has been demonstrated ( Orrego, 2018) have suggested that trees in forests are more connected than once thought ( Simard, 2021). In a recent Perspective, Karst et al. (2023) offered a valuable critical review warning of over-interpretation and positive citation bias in CMN research. It concluded that while there is evidence for C movement among plants, the importance of CMNs remains unclear, as noted by others too ( Henriksson et al., 2023). Here we argue that while some of these claims are justified, factual evidence about belowground C transfer across CMNs is solid and accumulating.
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Affiliation(s)
- Tamir Klein
- Weizmann Institute of Science, Rehovot, Center District, Israel
| | - Ido Rog
- Weizmann Institute of Science, Rehovot, Center District, Israel
- agroscope, Zuerich, Switzerland
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Henriksson N, Marshall J, Högberg MN, Högberg P, Polle A, Franklin O, Näsholm T. Re-examining the evidence for the mother tree hypothesis - resource sharing among trees via ectomycorrhizal networks. THE NEW PHYTOLOGIST 2023. [PMID: 37149889 DOI: 10.1111/nph.18935] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/19/2023] [Indexed: 05/09/2023]
Abstract
Seminal scientific papers positing that mycorrhizal fungal networks can distribute carbon (C) among plants have stimulated a popular narrative that overstory trees, or 'mother trees', support the growth of seedlings in this way. This narrative has far-reaching implications for our understanding of forest ecology and has been controversial in the scientific community. We review the current understanding of ectomycorrhizal C metabolism and observations on forest regeneration that make the mother tree narrative debatable. We then re-examine data and conclusions from publications that underlie the mother tree hypothesis. Isotopic labeling methods are uniquely suited for studying element fluxes through ecosystems, but the complexity of mycorrhizal symbiosis, low detection limits, and small carbon discrimination in biological processes can cause researchers to make important inferences based on miniscule shifts in isotopic abundance, which can be misleading. We conclude that evidence of a significant net C transfer via common mycorrhizal networks that benefits the recipients is still lacking. Furthermore, a role for fungi as a C pipeline between trees is difficult to reconcile with any adaptive advantages for the fungi. Finally, the hypothesis is neither supported by boreal forest regeneration patterns nor consistent with the understanding of physiological mechanisms controlling mycorrhizal symbiosis.
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Affiliation(s)
- Nils Henriksson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - John Marshall
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Mona N Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Peter Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Andrea Polle
- Forest Botany and Tree Physiology, Georg-August University of Göttingen, Büsgenweg 2, 37077, Göttingen, Germany
| | - Oskar Franklin
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, A-2361, Austria
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
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5
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Karst J, Jones MD, Hoeksema JD. Positive citation bias and overinterpreted results lead to misinformation on common mycorrhizal networks in forests. Nat Ecol Evol 2023; 7:501-511. [PMID: 36782032 DOI: 10.1038/s41559-023-01986-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 01/06/2023] [Indexed: 02/15/2023]
Abstract
A common mycorrhizal network (CMN) is formed when mycorrhizal fungal hyphae connect the roots of multiple plants of the same or different species belowground. Recently, CMNs have captured the interest of broad audiences, especially with respect to forest function and management. We are concerned, however, that recent claims in the popular media about CMNs in forests are disconnected from evidence, and that bias towards citing positive effects of CMNs has developed in the scientific literature. We first evaluated the evidence supporting three common claims. The claims that CMNs are widespread in forests and that resources are transferred through CMNs to increase seedling performance are insufficiently supported because results from field studies vary too widely, have alternative explanations or are too limited to support generalizations. The claim that mature trees preferentially send resources and defence signals to offspring through CMNs has no peer-reviewed, published evidence. We next examined how the results from CMN research are cited and found that unsupported claims have doubled in the past 25 years; a bias towards citing positive effects may obscure our understanding of the structure and function of CMNs in forests. We conclude that knowledge on CMNs is presently too sparse and unsettled to inform forest management.
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Affiliation(s)
- Justine Karst
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada.
| | - Melanie D Jones
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Jason D Hoeksema
- Department of Biology, University of Mississippi, Oxford, MS, USA
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6
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Meena M, Yadav G, Sonigra P, Nagda A, Mehta T, Swapnil P, Marwal A, Kumar S. Multifarious Responses of Forest Soil Microbial Community Toward Climate Change. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02051-3. [PMID: 35657425 DOI: 10.1007/s00248-022-02051-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Forest soils are a pressing subject of worldwide research owing to the several roles of forests such as carbon sinks. Currently, the living soil ecosystem has become dreadful as a consequence of several anthropogenic activities including climate change. Climate change continues to transform the living soil ecosystem as well as the soil microbiome of planet Earth. The majority of studies have aimed to decipher the role of forest soil bacteria and fungi to understand and predict the impact of climate change on soil microbiome community structure and their ecosystem in the environment. In forest soils, microorganisms live in diverse habitats with specific behavior, comprising bulk soil, rhizosphere, litter, and deadwood habitats, where their communities are influenced by biotic interactions and nutrient accessibility. Soil microbiome also drives multiple crucial steps in the nutrient biogeochemical cycles (carbon, nitrogen, phosphorous, and sulfur cycles). Soil microbes help in the nitrogen cycle through nitrogen fixation during the nitrogen cycle and maintain the concentration of nitrogen in the atmosphere. Soil microorganisms in forest soils respond to various effects of climate change, for instance, global warming, elevated level of CO2, drought, anthropogenic nitrogen deposition, increased precipitation, and flood. As the major burning issue of the globe, researchers are facing the major challenges to study soil microbiome. This review sheds light on the current scenario of knowledge about the effect of climate change on living soil ecosystems in various climate-sensitive soil ecosystems and the consequences for vegetation-soil-climate feedbacks.
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Affiliation(s)
- Mukesh Meena
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India.
| | - Garima Yadav
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India
| | - Priyankaraj Sonigra
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India
| | - Adhishree Nagda
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India
| | - Tushar Mehta
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India
| | - Prashant Swapnil
- Department of Botany, School of Biological Science, Central University of Punjab, Bhatinda, Punjab, 151401, India
| | - Avinash Marwal
- Department of Biotechnology, Vigyan Bhawan - Block B, New Campus, Mohanlal Sukhadia University, Udaipur, 313001, Rajasthan, India
| | - Sumit Kumar
- Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005, India
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7
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Figueiredo AF, Boy J, Guggenberger G. Common Mycorrhizae Network: A Review of the Theories and Mechanisms Behind Underground Interactions. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:735299. [PMID: 37744156 PMCID: PMC10512311 DOI: 10.3389/ffunb.2021.735299] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/23/2021] [Indexed: 09/26/2023]
Abstract
Most terrestrial plants establish symbiotic associations with mycorrhizal fungi for accessing essential plant nutrients. Mycorrhizal fungi have been frequently reported to interconnect plants via a common mycelial network (CMN), in which nutrients and signaling compounds can be exchanged between the connected plants. Several studies have been performed to demonstrate the potential effects of the CMN mediating resource transfer and its importance for plant fitness. Due to several contrasting results, different theories have been developed to predict benefits or disadvantages for host plants involved in the network and how it might affect plant communities. However, the importance of the mycelium connections for resources translocation compared to other indirect pathways, such as leakage of fungi hyphae and subsequent uptake by neighboring plant roots, is hard to distinguish and quantify. If resources can be translocated via mycelial connections in significant amounts that could affect plant fitness, it would represent an important tactic for plants co-existence and it could shape community composition and dynamics. Here, we report and critically discuss the most recent findings on studies aiming to evaluate and quantify resources translocation between plants sharing a CMN and predict the pattern that drives the movement of such resources into the CMN. We aim to point gaps and define open questions to guide upcoming studies in the area for a prospect better understanding of possible plant-to-plant interactions via CMN and its effect in shaping plants communities. We also propose new experiment set-ups and technologies that could be used to improve previous experiments. For example, the use of mutant lines plants with manipulation of genes involved in the symbiotic associations, coupled with labeling techniques to track resources translocation between connected plants, could provide a more accurate idea about resource allocation and plant physiological responses that are truly accountable to CMN.
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8
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Caruso KE, Horton JL, Hove AA. Assessing the Effect of Eastern Hemlock (Tsuga canadensis) Decline from Hemlock Woolly Adelgid (Adelges tsugae) Infestation on Ectomycorrhizal Colonization and Growth of Red Oak (Quercus rubra) Seedlings. AMERICAN MIDLAND NATURALIST 2021. [DOI: 10.1674/0003-0031-186.1.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
| | | | - Alisa A. Hove
- Biology Department, Warren Wilson College, Asheville, North Carolina 28815
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9
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Obase K. Effects of bacterial strains isolated from the ectomycorrhizal roots of Laccaria parva on sporocarp production by the fungus in vitro. MYCOSCIENCE 2020. [DOI: 10.1016/j.myc.2019.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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10
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Gómez-Hernández M, Ramírez-Antonio KG, Gándara E. Ectomycorrhizal and wood-decay macromycete communities along development stages of managed Pinus patula stands in Southwest Mexico. FUNGAL ECOL 2019. [DOI: 10.1016/j.funeco.2018.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Newbery DM, Neba GA. Micronutrients may influence the efficacy of ectomycorrhizas to support tree seedlings in a lowland African rain forest. Ecosphere 2019. [DOI: 10.1002/ecs2.2686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- David M. Newbery
- Institute of Plant Sciences University of Bern Altenbergrain 21 CH‐3013 Bern Switzerland
| | - Godlove A. Neba
- Department of Botany and Plant Physiology University of Buea P.O. Box 63 Buea S. W. Region Cameroon
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12
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Pickles BJ, Wilhelm R, Asay AK, Hahn AS, Simard SW, Mohn WW. Transfer of 13 C between paired Douglas-fir seedlings reveals plant kinship effects and uptake of exudates by ectomycorrhizas. THE NEW PHYTOLOGIST 2017; 214:400-411. [PMID: 27870059 DOI: 10.1111/nph.14325] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/08/2016] [Indexed: 05/27/2023]
Abstract
Processes governing the fixation, partitioning, and mineralization of carbon in soils are under increasing scrutiny as we develop a more comprehensive understanding of global carbon cycling. Here we examined fixation by Douglas-fir seedlings and transfer to associated ectomycorrhizal fungi, soil microbes, and full-sibling or nonsibling neighbouring seedlings. Stable isotope probing with 99% 13 C-CO2 was applied to trace 13 C-labelled photosynthate throughout plants, fungi, and soil microbes in an experiment designed to assess the effect of relatedness on 13 C transfer between plant pairs. The fixation and transfer of the 13 C label to plant, fungal, and soil microbial tissue was examined in biomass and phospholipid fatty acids. After a 6 d chase period, c. 26.8% of the 13 C remaining in the system was translocated below ground. Enrichment was proportionally greatest in ectomycorrhizal biomass. The presence of mesh barriers (0.5 or 35 μm) between seedlings did not restrict 13 C transfer. Fungi were the primary recipients of 13 C-labelled photosynthate throughout the system, representing 60-70% of total 13 C-enriched phospholipids. Full-sibling pairs exhibited significantly greater 13 C transfer to recipient roots in two of four Douglas-fir families, representing three- and fourfold increases (+ c. 4 μg excess 13 C) compared with nonsibling pairs. The existence of a root/mycorrhizal exudation-hyphal uptake pathway was supported.
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Affiliation(s)
- Brian J Pickles
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
- School of Biological Sciences, University of Reading, Harborne Building, Whiteknights, Reading, RG6 6AS, UK
| | - Roland Wilhelm
- Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Amanda K Asay
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Aria S Hahn
- Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Suzanne W Simard
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - William W Mohn
- Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
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13
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Deslippe JR, Hartmann M, Grayston SJ, Simard SW, Mohn WW. Stable isotope probing implicates a species of Cortinarius in carbon transfer through ectomycorrhizal fungal mycelial networks in Arctic tundra. THE NEW PHYTOLOGIST 2016; 210:383-90. [PMID: 26681156 DOI: 10.1111/nph.13797] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Affiliation(s)
- Julie R Deslippe
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Martin Hartmann
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Zuercherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Molecular Ecology, Institute for Sustainability Sciences, Agroscope, Reckenholzstrasse 191, CH-8046, Zurich, Switzerland
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Susan J Grayston
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Suzanne W Simard
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - William W Mohn
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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14
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Pickles BJ, Twieg BD, O'Neill GA, Mohn WW, Simard SW. Local adaptation in migrated interior Douglas-fir seedlings is mediated by ectomycorrhizas and other soil factors. THE NEW PHYTOLOGIST 2015; 207:858-71. [PMID: 25757098 DOI: 10.1111/nph.13360] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/10/2015] [Indexed: 05/05/2023]
Abstract
Separating edaphic impacts on tree distributions from those of climate and geography is notoriously difficult. Aboveground and belowground factors play important roles, and determining their relative contribution to tree success will greatly assist in refining predictive models and forestry strategies in a changing climate. In a common glasshouse, seedlings of interior Douglas-fir (Pseudotsuga menziesii var. glauca) from multiple populations were grown in multiple forest soils. Fungicide was applied to half of the seedlings to separate soil fungal and nonfungal impacts on seedling performance. Soils of varying geographic and climatic distance from seed origin were compared, using a transfer function approach. Seedling height and biomass were optimized following seed transfer into drier soils, whereas survival was optimized when elevation transfer was minimised. Fungicide application reduced ectomycorrhizal root colonization by c. 50%, with treated seedlings exhibiting greater survival but reduced biomass. Local adaptation of Douglas-fir populations to soils was mediated by soil fungi to some extent in 56% of soil origin by response variable combinations. Mediation by edaphic factors in general occurred in 81% of combinations. Soil biota, hitherto unaccounted for in climate models, interacts with biogeography to influence plant ranges in a changing climate.
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Affiliation(s)
- Brian J Pickles
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Brendan D Twieg
- UC Cooperative Extension, Humboldt and Del Norte Counties, Eureka, CA, 95503, USA
| | - Gregory A O'Neill
- Kalamalka Research Station, BC Ministry of Forests, Lands and Natural Resource Operations, 3401 Reservoir Road, Vernon, BC, V1B 2C7, Canada
| | - William W Mohn
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Suzanne W Simard
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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Botnen S, Vik U, Carlsen T, Eidesen PB, Davey ML, Kauserud H. Low host specificity of root-associated fungi at an Arctic site. Mol Ecol 2014; 23:975-85. [DOI: 10.1111/mec.12646] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 12/10/2013] [Accepted: 12/23/2013] [Indexed: 10/25/2022]
Affiliation(s)
- Synnøve Botnen
- Department of Biosciences; Section for Genetics and Evolutionary Biology (EVOGENE); University of Oslo; PO box 1066 Blindern NO-0316 Oslo Norway
- The University Centre in Svalbard; PO box 156 NO-9171 Longyearbyen Norway
| | - Unni Vik
- Department of Biosciences; Section for Genetics and Evolutionary Biology (EVOGENE); University of Oslo; PO box 1066 Blindern NO-0316 Oslo Norway
| | - Tor Carlsen
- Department of Biosciences; Section for Genetics and Evolutionary Biology (EVOGENE); University of Oslo; PO box 1066 Blindern NO-0316 Oslo Norway
| | | | - Marie L. Davey
- The University Centre in Svalbard; PO box 156 NO-9171 Longyearbyen Norway
| | - Håvard Kauserud
- Department of Biosciences; Section for Genetics and Evolutionary Biology (EVOGENE); University of Oslo; PO box 1066 Blindern NO-0316 Oslo Norway
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Pseudotsuga menziesii invasion in native forests of Patagonia, Argentina: What about mycorrhizas? ACTA OECOLOGICA 2013. [DOI: 10.1016/j.actao.2013.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kraigher H, Bajc M, Grebenc T. Mycorrhizosphere Complexity. DEVELOPMENTS IN ENVIRONMENTAL SCIENCE 2013. [DOI: 10.1016/b978-0-08-098349-3.00008-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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18
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Epron D, Bahn M, Derrien D, Lattanzi FA, Pumpanen J, Gessler A, Högberg P, Maillard P, Dannoura M, Gérant D, Buchmann N. Pulse-labelling trees to study carbon allocation dynamics: a review of methods, current knowledge and future prospects. TREE PHYSIOLOGY 2012; 32:776-98. [PMID: 22700544 DOI: 10.1093/treephys/tps057] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Pulse-labelling of trees with stable or radioactive carbon (C) isotopes offers the unique opportunity to trace the fate of labelled CO(2) into the tree and its release to the soil and the atmosphere. Thus, pulse-labelling enables the quantification of C partitioning in forests and the assessment of the role of partitioning in tree growth, resource acquisition and C sequestration. However, this is associated with challenges as regards the choice of a tracer, the methods of tracing labelled C in tree and soil compartments and the quantitative analysis of C dynamics. Based on data from 47 studies, the rate of transfer differs between broadleaved and coniferous species and decreases as temperature and soil water content decrease. Labelled C is rapidly transferred belowground-within a few days or less-and this transfer is slowed down by drought. Half-lives of labelled C in phloem sap (transfer pool) and in mature leaves (source organs) are short, while those of sink organs (growing tissues, seasonal storage) are longer. (13)C measurements in respiratory efflux at high temporal resolution provide the best estimate of the mean residence times of C in respiratory substrate pools, and the best basis for compartmental modelling. Seasonal C dynamics and allocation patterns indicate that sink strength variations are important drivers for C fluxes. We propose a conceptual model for temperate and boreal trees, which considers the use of recently assimilated C versus stored C. We recommend best practices for designing and analysing pulse-labelling experiments, and identify several topics which we consider of prime importance for future research on C allocation in trees: (i) whole-tree C source-sink relations, (ii) C allocation to secondary metabolism, (iii) responses to environmental change, (iv) effects of seasonality versus phenology in and across biomes, and (v) carbon-nitrogen interactions. Substantial progress is expected from emerging technologies, but the largest challenge remains to carry out in situ whole-tree labelling experiments on mature trees to improve our understanding of the environmental and physiological controls on C allocation.
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Affiliation(s)
- Daniel Epron
- Université de Lorraine, UMR 1137, Ecologie et Ecophysiologie Forestières, Faculté des Sciences, F-54500 Vandoeuvre-les-Nancy, France.
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Ectomycorrhizal Networks of Pseudotsuga menziesii var. glauca Trees Facilitate Establishment of Conspecific Seedlings Under Drought. Ecosystems 2011. [DOI: 10.1007/s10021-011-9502-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Bingham MA, Simard SW. Do mycorrhizal network benefits to survival and growth of interior Douglas-fir seedlings increase with soil moisture stress? Ecol Evol 2011; 1:306-16. [PMID: 22393502 PMCID: PMC3287316 DOI: 10.1002/ece3.24] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 11/24/2022] Open
Abstract
Facilitation of tree establishment by ectomycorrhizal (EM) networks (MNs) may become increasingly important as drought stress increases with climate change in some forested regions of North America. The objective of this study was to determine (1) whether temperature, CO(2) concentration ([CO(2)]), soil moisture, and MNs interact to affect plant establishment success, such that MNs facilitate establishment when plants are the most water stressed, and (2) whether transfer of C and water between plants through MNs plays a role in this. We established interior Douglas-fir (Pseudotsuga menziesiivar.glauca) seedlings in root boxes with and without the potential to form MNs with nearby conspecific seedlings that had consistent access to water via their taproots. We varied temperature, [CO(2)], and soil moisture in growth chambers. Douglas-fir seedling survival increased when the potential existed to form an MN. Growth increased with MN potential under the driest soil conditions, but decreased with temperature at 800 ppm [CO(2)]. Transfer of (13)C to receiver seedlings was unaffected by potential to form an MN with donor seedlings, but deuterated water (D(2)O) transfer increased with MN potential under ambient [CO(2)]. Chlorophyll fluorescence was reduced when seedlings had the potential to form an MN under high [CO(2)] and cool temperatures. We conclude that Douglas-fir seedling establishment in laboratory conditions is facilitated by MN potential where Douglas-fir seedlings have consistent access to water. Moreover, this facilitation appears to increase as water stress potential increases and water transfer via networks may play a role in this. These results suggest that conservation of MN potential may be important to forest regeneration where drought stress increases with climate change.
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Affiliation(s)
- Marcus A Bingham
- Department of Forest Sciences, University of British Columbia Vancouver, BC, V6T 1Z4, Canada
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Bent E, Kiekel P, Brenton R, Taylor DL. Root-associated ectomycorrhizal fungi shared by various boreal forest seedlings naturally regenerating after a fire in interior alaska and correlation of different fungi with host growth responses. Appl Environ Microbiol 2011; 77:3351-9. [PMID: 21441343 PMCID: PMC3126461 DOI: 10.1128/aem.02575-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 03/13/2011] [Indexed: 11/20/2022] Open
Abstract
The role of common mycorrhizal networks (CMNs) in postfire boreal forest successional trajectories is unknown. We investigated this issue by sampling a 50-m by 40-m area of naturally regenerating black spruce (Picea mariana), trembling aspen (Populus tremuloides), and paper birch (Betula papyrifera) seedlings at various distances from alder (Alnus viridis subsp. crispa), a nitrogen-fixing shrub, 5 years after wildfire in an Alaskan interior boreal forest. Shoot biomasses and stem diameters of 4-year-old seedlings were recorded, and the fungal community associated with ectomycorrhizal (ECM) root tips from each seedling was profiled using molecular techniques. We found distinct assemblages of fungi associated with alder compared with those associated with the other tree species, making the formation of CMNs between them unlikely. However, among the spruce, aspen, and birch seedlings, there were many shared fungi (including members of the Pezoloma ericae [Hymenoscyphus ericae] species aggregate, Thelephora terrestris, and Russula spp.), raising the possibility that these regenerating seedlings may form interspecies CMNs. Distance between samples did not influence how similar ECM root tip-associated fungal communities were, and of the fungal groups identified, only one of them was more likely to be shared between seedlings that were closer together, suggesting that the majority of fungi surveyed did not have a clumped distribution across the small scale of this study. The presence of some fungal ribotypes was associated with larger or smaller seedlings, suggesting that these fungi may play a role in the promotion or inhibition of seedling growth. The fungal ribotypes associated with larger seedlings were different between spruce, aspen, and birch, suggesting differential impacts of some host-fungus combinations. One may speculate that wildfire-induced shifts in a given soil fungal community could result in variation in the growth response of different plant species after fire and a shift in regenerating vegetation.
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Affiliation(s)
- Elizabeth Bent
- Department of Forest Mycology and Pathology, P.O. Box 7026, Swedish University of Agricultural Sciences (SLU), Ulls Väg 26A, SE-75007 Uppsala, Sweden.
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Bougoure JJ, Brundrett MC, Grierson PF. Carbon and nitrogen supply to the underground orchid, Rhizanthella gardneri. THE NEW PHYTOLOGIST 2010; 186:947-956. [PMID: 20353419 DOI: 10.1111/j.1469-8137.2010.03246.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
*Rhizanthella gardneri is a rare and fully subterranean orchid that is presumably obligately mycoheterotrophic. R. gardneri is thought to be linked via a common mycorrhizal fungus to co-occurring autotrophic shrubs, but there is no experimental evidence to support this supposition. *We used compartmentalized microcosms to investigate the R. gardneri tripartite relationship. (13)CO(2) was applied to foliage of Melaleuca scalena plants and [(13)C-(15)N]glycine was fed to the common mycorrhizal fungus, and both sources traced to R. gardneri plants. *In our microcosm trial, up to 5% of carbon (C) fed as (13)CO(2) to the autotrophic shrub was transferred to R. gardneri. R. gardneri also readily acquired soil C and nitrogen (N), where up to 6.2% of C and 22.5% of N fed as labelled glycine to soil was transferred via the fungus to R. gardneri after 240 h. *Our study confirms that R. gardneri is mycoheterotrophic and acquires nutrients via mycorrhizal fungus connections from an ectomycorrhizal autotrophic shrub and directly from the soil via the same fungus. This connection with a specific fungus is key to explaining why R. gardneri occurs exclusively under certain Melaleuca species at a very limited number of sites in Western Australia.
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Affiliation(s)
- Jeremy J Bougoure
- School of Plant Biology M090, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
- Present address: University of British Columbia, 3333 University Way, Kelowna, BC V1V1V7, Canada
| | - Mark C Brundrett
- School of Plant Biology M090, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Pauline F Grierson
- School of Plant Biology M090, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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23
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Voets L, Goubau I, Olsson PÃA, Merckx R, Declerck S. Absence of carbon transfer between Medicago truncatula plants linked by a mycorrhizal network, demonstrated in an experimental microcosm. FEMS Microbiol Ecol 2008; 65:350-60. [DOI: 10.1111/j.1574-6941.2008.00503.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Plamboeck AH, North M, Dawson TE. Conifer Seedling Survival Under Closed-Canopy And Manzanita Patches In the Sierra Nevada. ACTA ACUST UNITED AC 2008. [DOI: 10.3120/0024-9637-55.3.191] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Plamboeck AH, Dawson TE, Egerton-Warburton LM, North M, Bruns TD, Querejeta JI. Water transfer via ectomycorrhizal fungal hyphae to conifer seedlings. MYCORRHIZA 2007; 17:439-447. [PMID: 17333298 DOI: 10.1007/s00572-007-0119-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 02/07/2007] [Indexed: 05/14/2023]
Abstract
Little is known about water transfer via mycorrhizal hyphae to plants, despite its potential importance in seedling establishment and plant community development, especially in arid environments. Therefore, this process was investigated in the study reported in this paper in laboratory-based tripartite mesocosms containing the shrub Arctostaphylos viscida (manzanita) and young seedlings of sugar pine (Pinus lambertiana) and Douglas-fir (Pseudotsuga menziesii). The objectives were to determine whether water could be transported through mycorrhizal symbionts shared by establishing conifers and A. viscida and to compare the results obtained using two tracers: the stable isotope deuterium and the dye lucifer yellow carbohydrazide. Water containing the tracers was added to the central compartment containing single manzanita shrubs. The fungal hyphae were then collected as well as plant roots from coniferous seedlings in the other two compartments to determine whether water was transferred via fungal hyphae. In addition, the length of the hyphae and degree of mycorrhizal colonisation were determined. Internal transcribed spacer-restriction fragment length polymorphism (ITS-RFLP) analysis was used to identify the fungal species involved in dye (water) transfer. Results of the stable isotope analysis showed that water is transferred via mycorrhizal hyphae, but isotopically labelled water was only detected in Douglas-fir roots, not in sugar pine roots. In contrast, the fluorescent dye was transported via mycorrhizal hyphae to both Douglas-fir and sugar pine seedlings. Only 1 of 15 fungal morphotypes (identified as Atheliaceae) growing in the mesocosms transferred the dye. Differences were detected in the water transfer patterns indicated by the deuterium and fluorescent dye tracers, suggesting that the two labels are transported by different mechanisms in the same hyphae and/or that different fungal taxa transfer them via different routes to host plants. We conclude that both tracers can provide information on resource transfer between fungi and plants, but we cannot be sure that the dye transfer data provide accurate indications of water transfer rates and patterns. The isotopic tracer provides more direct indications of water movement and is therefore more suitable than the dye for studying water relations of plants and their associated mycorrhizal fungi.
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Affiliation(s)
- Agneta H Plamboeck
- Center for Stable Isotope Biogeochemistry, Department of Integrative Biology, University of California at Berkeley, Berkeley, CA, 94720, USA.
- Sierra Nevada Research Center, Department of Environmental Horticulture, University of California at Davis, Davis, CA, 95616, USA.
| | - Todd E Dawson
- Center for Stable Isotope Biogeochemistry, Department of Integrative Biology, University of California at Berkeley, Berkeley, CA, 94720, USA
| | | | - Malcolm North
- Sierra Nevada Research Center, Department of Environmental Horticulture, University of California at Davis, Davis, CA, 95616, USA
| | - Thomas D Bruns
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - José Ignacio Querejeta
- Departamento de Conservación de Suelos y Aguas, Centro de Edafología y Biología Aplicada del Segura-CSIC, Campus de Espinardo, P.O. Box 4195, Murcia, 30100, Spain
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Zijlstra JD, Van't Hof P, Baar J, Verkley GJ, Summerbell RC, Paradi I, Braakhekke WG, Berendse F. Diversity of symbiotic root endophytes of the Helotiales in ericaceous plants and the grass, Deschampsia flexuosa. Stud Mycol 2005. [DOI: 10.3114/sim.53.1.147] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
Most mycorrhizas are 'balanced' mutualistic associations in which the fungus and plant exchange commodities required for their growth and survival. Myco-heterotrophic plants have 'exploitative' mycorrhizas where transfer processes apparently benefit only plants. Exploitative associations are symbiotic (in the broad sense), but are not mutualistic. A new definition of mycorrhizas that encompasses all types of these associations while excluding other plant-fungus interactions is provided. This definition recognises the importance of nutrient transfer at an interface resulting from synchronised plant-fungus development. The diversity of interactions between mycorrhizal fungi and plants is considered. Mycorrhizal fungi also function as endophytes, necrotrophs and antagonists of host or non-host plants, with roles that vary during the lifespan of their associations. It is recommended that mycorrhizal associations are defined and classified primarily by anatomical criteria regulated by the host plant. A revised classification scheme for types and categories of mycorrhizal associations defined by these criteria is proposed. The main categories of vesicular-arbuscular mycorrhizal associations (VAM) are 'linear' or 'coiling', and of ectomycorrhizal associations (ECM) are 'epidermal' or 'cortical'. Subcategories of coiling VAM and epidermal ECM occur in certain host plants. Fungus-controlled features result in 'morphotypes' within categories of VAM and ECM. Arbutoid and monotropoid associations should be considered subcategories of epidermal ECM and ectendomycorrhizas should be relegated to an ECM morphotype. Both arbuscules and vesicles define mycorrhizas formed by glomeromycotan fungi. A new classification scheme for categories, subcategories and morphotypes of mycorrhizal associations is provided.
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Affiliation(s)
- Mark Brundrett
- School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, Crawley, Western Australia.
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Leake J, Johnson D, Donnelly D, Muckle G, Boddy L, Read D. Networks of power and influence: the role of mycorrhizal mycelium in controlling plant communities and agroecosystem functioning. ACTA ACUST UNITED AC 2004. [DOI: 10.1139/b04-060] [Citation(s) in RCA: 425] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Extraradical mycelia of mycorrhizal fungi are normally the hidden half of the symbiosis, but they are powerful underground influences upon biogeochemical cycling, the composition of plant communities, and agroecosystem functioning. Mycorrhizal mycelial networks are the most dynamic and functionally diverse components of the symbiosis, and recent estimates suggest they are empowered by receiving as much as 10% or more of the net photosynthate of their host plants. They often constitute 20%30% of total soil microbial biomass yet are undetected by standard measures of biomass used by soil scientists and agromomists. Mycorrhizal mycelia provide extensive pathways for carbon and nutrient fluxes through soil, often exceeding tens of metres per gram of soil. We consider the amounts of photosynthate power allocated to these mycelial networks and how this is used in fungal respiration, biomass, and growth and in influencing soil, plant, and ecosystem processes. The costs and functional benefits to plants linking to these networks are fungal specific and, because of variations in physiology and host specificity, are not shared equally; some plants even depend exclusively on these networks for carbon. We briefly assess the potential contribution of extraradical mycorrhizal mycelium to sustainable agriculture and maintenance of biodiversity and highlight technologies that promise new vistas and improved fine-scale resolution of the dynamic spatial and temporal functioning of these networks in soil.Key words: arbuscular mycorrhiza, ectomycorrhiza, extraradical mycelium, hyphal networks.
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Simard SW, Durall DM. Mycorrhizal networks: a review of their extent, function, and importance. ACTA ACUST UNITED AC 2004. [DOI: 10.1139/b04-116] [Citation(s) in RCA: 248] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known from laboratory studies that a single mycorrhizal fungal isolate can colonize different plant species, form interplant linkages, and provide a conduit for interplant transfer of isotopic carbon, nitrogen, phosphorus, or water. There is increasing laboratory and field evidence that the magnitude and direction of transfer is influenced by physiological sourcesink gradients between plants. There is also evidence that mycorrhizal fungi play a role in regulating transfer through their own sourcesink patterns, frequency of links, and mycorrhizal dependency. Although it is plausible that connections are extensive in nature, field studies have been hampered by our inability to observe them in situ and by belowground complexity. In future, isotopic tracers, morphological observations, microsatellite techniques, and fluorescent dyes will be useful in the study of networks in nature. Mycorrhizal networks have the potential to influence patterns of seedling establishment, interplant competition, plant diversity, and plant community dynamics, but studies in this area are just beginning. Future plant community studies would benefit from concurrent experimental use of fungal network controls, isotopic labeling, direct observation of interplant linkages, and long-term observation in the field. In this paper, we review recent literature on mycorrhizal networks and interplant carbon transfer, suggest future research directions, and highlight promising scientific approaches.Key words: common mycorrhizal network, carbon transfer, sourcesink, establishment, competition, diversity.
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Affiliation(s)
- Todd E. Dawson
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, California 94720;
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720;
| | - Stefania Mambelli
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, California 94720;
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720;
| | - Agneta H. Plamboeck
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, California 94720;
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720;
| | - Pamela H. Templer
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, California 94720;
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720;
| | - Kevin P. Tu
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, California 94720;
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720;
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The Role of Mycorrhizal Fungi in the Composition and Dynamics of Plant Communities: A Scaling Issue. PROGRESS IN BOTANY 2002. [DOI: 10.1007/978-3-642-56276-1_14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Wu B, Nara K, Hogetsu T. Can 14 C-labeled photosynthetic products move between Pinus densiflora seedlings linked by ectomycorrhizal mycelia? THE NEW PHYTOLOGIST 2001; 149:137-146. [PMID: 33853229 DOI: 10.1046/j.1469-8137.2001.00010.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
• Movement of 14 C-labeled photosynthetic products via ectomycorrhizal mycelia linking seedlings of Pinus densiflora is investigated here, a process which may have the potential to be highly ecologically significant. • Paired seedlings linked by hyphae of either an unidentified ectomycorrhizal fungus designated T01 or Pisolithus tinctorius were prepared by arranging mycorrhizal and nonmycorrhizal seedlings in an observation rhizobox and allowing mycelial links to form. Shoots of the initially mycorrhizal seedling were photosynthetically labeled with 14 CO2 and movement of 14 C chased by time-course autoradiography. • Within 3 d, 14 C was transferred to mycelia and mycorrhizas formed on the unlabeled seedling, but little 14 C was subsequently transferred to the roots and shoots. The reverse movement of label was also demonstrated. Mycelial fans of T01, with greater hyphal density, accumulated more 14 C than mycelia of P. tinctorius, whereas higher radioactivity was detected in hyphal strands than in the mycelial front of P. tinctorius. • Ectomycorrhizas and mycelia are strong sinks for photosynthetic products, and C transfer can occur bi-directionally in the mycelia. However, as yet no direct evidence indicates any benefit to receiver plants and, thus, supplementary supply of C to understory individuals may not be ecologically significant.
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Affiliation(s)
- Bingyun Wu
- Research Unit for Symbiotic Function, Asian Natural Environmental Science Center, The University of Tokyo, Midori-cho 1-1-8, Tanashi, Tokyo 188-0002, Japan
| | - Kazuhide Nara
- Research Unit for Symbiotic Function, Asian Natural Environmental Science Center, The University of Tokyo, Midori-cho 1-1-8, Tanashi, Tokyo 188-0002, Japan
| | - Taizo Hogetsu
- Research Unit for Symbiotic Function, Asian Natural Environmental Science Center, The University of Tokyo, Midori-cho 1-1-8, Tanashi, Tokyo 188-0002, Japan
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O'Dell TE, Ammirati JF, Schreiner EG. Species richness and abundance of ectomycorrhizal basidiomycete sporocarps on a moisture gradient in the Tsuga heterophylla zone. ACTA ACUST UNITED AC 2000. [DOI: 10.1139/b99-144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sporocarps of epigeous ectomycorrhizal fungi and vegetation data were collected from eight Tsuga heterophylla (Raf.) Sarg. - Pseudotsuga menziesii (Mirb.) Franco stands along a wet to dry gradient in Olympic National Park, Washington, U.S.A. One hundred and fifty species of ectomycorrhizal fungi were collected from a total sample area of 2.08 ha. Over 2 years, fungal species richness ranged from 19 to 67 taxa per stand. Sporocarp standing crop ranged from 0 to 3.8 kg/ha, averaging 0.58 kg/ha, 0.06 kg/ha in spring and 0.97 kg/ha in fall. Sporocarp standing crop and fungal species richness were correlated with precipitation. These results demonstrated that ectomycorrhizal fungal sporocarp abundance and species richness can be partly explained in terms of an environmental gradient.
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