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Growth Characteristics of Ectomycorrhizal Seedlings of Quercus glauca, Quercus salicina, Quercus myrsinaefolia, and Castanopsis cuspidata Planted in Calcareous Soil. FORESTS 2016. [DOI: 10.3390/f7110266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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102
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Associations between an Invasive Plant (Taeniatherum caput-medusae, Medusahead) and Soil Microbial Communities. PLoS One 2016; 11:e0163930. [PMID: 27685330 PMCID: PMC5042559 DOI: 10.1371/journal.pone.0163930] [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: 05/12/2016] [Accepted: 09/16/2016] [Indexed: 11/19/2022] Open
Abstract
Understanding plant-microbe relationships can be important for developing management strategies for invasive plants, particularly when these relationships interact with underlying variables, such as habitat type and seedbank density, to mediate control efforts. In a field study located in California, USA, we investigated how soil microbial communities differ across the invasion front of Taeniatherum caput-medusae (medusahead), an annual grass that has rapidly invaded most of the western USA. Plots were installed in habitats where medusahead invasion is typically successful (open grassland) and typically not successful (oak woodland). Medusahead was seeded into plots at a range of densities (from 0-50,000 seeds/m2) to simulate different levels of invasion. We found that bacterial and fungal soil community composition were significantly different between oak woodland and open grassland habitats. Specifically, ectomycorrhizal fungi were more abundant in oak woodlands while arbuscular mycorrhizal fungi and plant pathogens were more abundant in open grasslands. We did not find a direct effect of medusahead density on soil microbial communities across the simulated invasion front two seasons after medusahead were seeded into plots. Our results suggest that future medusahead management initiatives might consider plant-microbe interactions.
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103
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Peter M, Kohler A, Ohm RA, Kuo A, Krützmann J, Morin E, Arend M, Barry KW, Binder M, Choi C, Clum A, Copeland A, Grisel N, Haridas S, Kipfer T, LaButti K, Lindquist E, Lipzen A, Maire R, Meier B, Mihaltcheva S, Molinier V, Murat C, Pöggeler S, Quandt CA, Sperisen C, Tritt A, Tisserant E, Crous PW, Henrissat B, Nehls U, Egli S, Spatafora JW, Grigoriev IV, Martin FM. Ectomycorrhizal ecology is imprinted in the genome of the dominant symbiotic fungus Cenococcum geophilum. Nat Commun 2016; 7:12662. [PMID: 27601008 PMCID: PMC5023957 DOI: 10.1038/ncomms12662] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 07/21/2016] [Indexed: 12/13/2022] Open
Abstract
The most frequently encountered symbiont on tree roots is the ascomycete Cenococcum geophilum, the only mycorrhizal species within the largest fungal class Dothideomycetes, a class known for devastating plant pathogens. Here we show that the symbiotic genomic idiosyncrasies of ectomycorrhizal basidiomycetes are also present in C. geophilum with symbiosis-induced, taxon-specific genes of unknown function and reduced numbers of plant cell wall-degrading enzymes. C. geophilum still holds a significant set of genes in categories known to be involved in pathogenesis and shows an increased genome size due to transposable elements proliferation. Transcript profiling revealed a striking upregulation of membrane transporters, including aquaporin water channels and sugar transporters, and mycorrhiza-induced small secreted proteins (MiSSPs) in ectomycorrhiza compared with free-living mycelium. The frequency with which this symbiont is found on tree roots and its possible role in water and nutrient transport in symbiosis calls for further studies on mechanisms of host and environmental adaptation.
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Affiliation(s)
- Martina Peter
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Annegret Kohler
- INRA, UMR INRA-Université de Lorraine ‘Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, INRA-Nancy, 54280 Champenoux, France
| | - Robin A. Ohm
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
- Microbiology, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Alan Kuo
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | | | - Emmanuelle Morin
- INRA, UMR INRA-Université de Lorraine ‘Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, INRA-Nancy, 54280 Champenoux, France
| | - Matthias Arend
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Kerrie W. Barry
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Manfred Binder
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Cindy Choi
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Alicia Clum
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Alex Copeland
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Nadine Grisel
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Sajeet Haridas
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Tabea Kipfer
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Erika Lindquist
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Renaud Maire
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Barbara Meier
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Sirma Mihaltcheva
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Virginie Molinier
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Claude Murat
- INRA, UMR INRA-Université de Lorraine ‘Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, INRA-Nancy, 54280 Champenoux, France
| | - Stefanie Pöggeler
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University Göttingen, 37077 Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - C. Alisha Quandt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109 USA
| | - Christoph Sperisen
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Andrew Tritt
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Emilie Tisserant
- INRA, UMR INRA-Université de Lorraine ‘Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, INRA-Nancy, 54280 Champenoux, France
| | - Pedro W. Crous
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernard Henrissat
- Centre National de la Recherche Scientifique, UMR 7257, F-13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille University, F-13288 Marseille, France
- INRA, USC 1408 AFMB, F-13288 Marseille, France
- Department of Biological Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Uwe Nehls
- University of Bremen, Botany, Leobenerstr. 2, 28359 Bremen, Germany
| | - Simon Egli
- Swiss Federal Research Institute WSL, Forest Dynamics, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Joseph W. Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331 USA
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute (JGI), Walnut Creek, California 94598, USA
| | - Francis M. Martin
- INRA, UMR INRA-Université de Lorraine ‘Interactions Arbres/Microorganismes', Laboratoire d'Excellence ARBRE, INRA-Nancy, 54280 Champenoux, France
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104
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Hagedorn F, Joseph J, Peter M, Luster J, Pritsch K, Geppert U, Kerner R, Molinier V, Egli S, Schaub M, Liu JF, Li M, Sever K, Weiler M, Siegwolf RTW, Gessler A, Arend M. Recovery of trees from drought depends on belowground sink control. NATURE PLANTS 2016; 2:16111. [PMID: 27428669 DOI: 10.1038/nplants.2016.111] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/20/2016] [Indexed: 05/21/2023]
Abstract
Climate projections predict higher precipitation variability with more frequent dry extremes(1). CO2 assimilation of forests decreases during drought, either by stomatal closure(2) or by direct environmental control of sink tissue activities(3). Ultimately, drought effects on forests depend on the ability of forests to recover, but the mechanisms controlling ecosystem resilience are uncertain(4). Here, we have investigated the effects of drought and drought release on the carbon balances in beech trees by combining CO2 flux measurements, metabolomics and (13)CO2 pulse labelling. During drought, net photosynthesis (AN), soil respiration (RS) and the allocation of recent assimilates below ground were reduced. Carbohydrates accumulated in metabolically resting roots but not in leaves, indicating sink control of the tree carbon balance. After drought release, RS recovered faster than AN and CO2 fluxes exceeded those in continuously watered trees for months. This stimulation was related to greater assimilate allocation to and metabolization in the rhizosphere. These findings show that trees prioritize the investment of assimilates below ground, probably to regain root functions after drought. We propose that root restoration plays a key role in ecosystem resilience to drought, in that the increased sink activity controls the recovery of carbon balances.
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Affiliation(s)
- Frank Hagedorn
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Jobin Joseph
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Chair of Hydrology, Faculty of Environment and Natural Resources, University of Freiburg, Fahnenbergplatz, 79098 Freiburg, Germany
| | - Martina Peter
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Jörg Luster
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Karin Pritsch
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Uwe Geppert
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Rene Kerner
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Virginie Molinier
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Simon Egli
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Marcus Schaub
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Jian-Feng Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Xiangshan Road, 100091 Beijing, China
| | - Maihe Li
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Krunoslav Sever
- Department of Forest Genetics, Dendrology and Botany, Faculty of Forestry, University of Zagreb, Svetošimunska 25, HR-10000 Zagreb, Croatia
| | - Markus Weiler
- Chair of Hydrology, Faculty of Environment and Natural Resources, University of Freiburg, Fahnenbergplatz, 79098 Freiburg, Germany
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes Group, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Institute for Landscape Biogeochemistry, Leibnitz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Altensteinstrasse 6, 14195 Berlin, Germany
| | - Matthias Arend
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- School of Forest Science and Resource Management, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
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105
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Xu H, Cooke JEK, Kemppainen M, Pardo AG, Zwiazek JJ. Hydraulic conductivity and aquaporin transcription in roots of trembling aspen (Populus tremuloides) seedlings colonized by Laccaria bicolor. MYCORRHIZA 2016; 26:441-451. [PMID: 26861480 DOI: 10.1007/s00572-016-0681-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 01/26/2016] [Indexed: 06/05/2023]
Abstract
Ectomycorrhizal fungi have been reported to increase root hydraulic conductivity (L pr) by altering apoplastic and plasma membrane intrinsic protein (PIP)-mediated cell-to-cell water transport pathways in associated roots, or to have little effect on root water transport, depending on the interacting species and imposed stresses. In this study, we investigated the water transport properties and PIP transcription in roots of aspen (Populus tremuloides) seedlings colonized by the wild-type strain of Laccaria bicolor and by strains overexpressing a major fungal water-transporting aquaporin JQ585595. Inoculation of aspen seedlings with L. bicolor resulted in about 30 % colonization rate of root tips, which developed dense mantle and the Hartig net that was restricted in the modified root epidermis. Transcript abundance of the aspen aquaporins PIP1;2, PIP2;1, and PIP2;2 decreased in colonized root tips. Root colonization by JQ585595-overexpressing strains had no significant impact on seedling shoot water potentials, gas exchange, or dry mass; however, it led to further decrease in transcript abundance of PIP1;2 and PIP2;3 and the significantly lower L pr than in non-inoculated roots. These results, taken together with our previous study that showed enhanced root water hydraulics of L. bicolor-colonized white spruce (Picea glauca), suggest that the impact of L. bicolor on root hydraulics varies by the ectomycorrhiza-associated tree species.
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Affiliation(s)
- Hao Xu
- Department of Renewable Resources, University of Alberta, Edmonton, T6G 2E3, Canada
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9, Canada
| | - Minna Kemppainen
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bernal, Argentina
| | - Alejandro G Pardo
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bernal, Argentina
| | - Janusz J Zwiazek
- Department of Renewable Resources, University of Alberta, Edmonton, T6G 2E3, Canada.
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106
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Schlesinger WH, Dietze MC, Jackson RB, Phillips RP, Rhoades CC, Rustad LE, Vose JM. Forest biogeochemistry in response to drought. GLOBAL CHANGE BIOLOGY 2016; 22:2318-2328. [PMID: 26403995 DOI: 10.1111/gcb.13105] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/04/2015] [Indexed: 06/05/2023]
Abstract
Trees alter their use and allocation of nutrients in response to drought, and changes in soil nutrient cycling and trace gas flux (N2 O and CH4 ) are observed when experimental drought is imposed on forests. In extreme droughts, trees are increasingly susceptible to attack by pests and pathogens, which can lead to major changes in nutrient flux to the soil. Extreme droughts often lead to more common and more intense forest fires, causing dramatic changes in the nutrient storage and loss from forest ecosystems. Changes in the future manifestation of drought will affect carbon uptake and storage in forests, leading to feedbacks to the Earth's climate system. We must improve the recognition of drought in nature, our ability to manage our forests in the face of drought, and the parameterization of drought in earth system models for improved predictions of carbon uptake and storage in the world's forests.
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Affiliation(s)
| | - Michael C Dietze
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Robert B Jackson
- Department of Earth System Science, Stanford University, Y2E2 Building, 379B, Stanford, CA, 94305, USA
| | - Richard P Phillips
- Department of Biology, Indiana University, 1 E 3rd Street, Bloomington, IN, 47405, USA
| | - Charles C Rhoades
- U.S.D.A., Forest Service, Rocky Mountain Research Station, 240 West Prospect Road, Fort Collins, CO, 80526, USA
| | - Lindsey E Rustad
- U.S.D.A., Forest Service, Northern Research Station, 271 Mast Rd, Durham, NH, 03824, USA
| | - James M Vose
- U.S.D.A., Forest Service, Southern Research Station, NC State University, Campus Box 8008, Raleigh, NC, 27695, USA
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107
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Revillini D, Gehring CA, Johnson NC. The role of locally adapted mycorrhizas and rhizobacteria in plant–soil feedback systems. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12668] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Revillini
- Department of Biological Sciences Northern Arizona University PO Box 5640 Flagstaff AZ 86011 USA
| | - Catherine A. Gehring
- Department of Biological Sciences Northern Arizona University PO Box 5640 Flagstaff AZ 86011 USA
| | - Nancy Collins Johnson
- Department of Biological Sciences Northern Arizona University PO Box 5640 Flagstaff AZ 86011 USA
- School of Earth Sciences and Environmental Sustainability Northern Arizona University PO Box 5694 Flagstaff AZ 86011 USA
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108
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Navarro-RóDenas A, Xu H, Kemppainen M, Pardo AG, Zwiazek JJ. Laccaria bicolor aquaporin LbAQP1 is required for Hartig net development in trembling aspen (Populus tremuloides). PLANT, CELL & ENVIRONMENT 2015; 38:2475-86. [PMID: 25857333 DOI: 10.1111/pce.12552] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/22/2015] [Indexed: 05/27/2023]
Abstract
The development of ectomycorrhizal associations is crucial for growth of many forest trees. However, the signals that are exchanged between the fungus and the host plant during the colonization process are still poorly understood. In this study, we have identified the relationship between expression patterns of Laccaria bicolor aquaporin LbAQP1 and the development of ectomycorrhizal structures in trembling aspen (Populus tremuloides) seedlings. The peak expression of LbAQP1 was 700-fold higher in the hyphae within the root than in the free-living mycelium after 24 h of direct interaction with the roots. Moreover, in LbAQP1 knock-down strains, a non-mycorrhizal phenotype was developed without the Hartig net and the expression of the mycorrhizal effector protein MiSSP7 quickly declined after an initial peak on day 5 of interaction of the fungal hyphae with the roots. The increase in the expression of LbAQP1 required a direct contact of the fungus with the root and it modulated the expression of MiSSP7. We have also determined that LbAQP1 facilitated NO, H2 O2 and CO2 transport when heterologously expressed in yeast. The report demonstrates that the L. bicolor aquaporin LbAQP1 acts as a molecular signalling channel, which is fundamental for the development of Hartig net in root tips of P. tremuloides.
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Affiliation(s)
| | - Hao Xu
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
| | - Minna Kemppainen
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bernal, Provincia de Buenos Aires, B1876BXD, Argentina
| | - Alejandro G Pardo
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bernal, Provincia de Buenos Aires, B1876BXD, Argentina
| | - Janusz J Zwiazek
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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109
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Bonal D, Burban B, Stahl C, Wagner F, Hérault B. The response of tropical rainforests to drought-lessons from recent research and future prospects. ANNALS OF FOREST SCIENCE 2015; 73:27-44. [PMID: 27069374 PMCID: PMC4810888 DOI: 10.1007/s13595-015-0522-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 08/24/2015] [Indexed: 05/10/2023]
Abstract
KEY MESSAGE We review the recent findings on the influence of drought on tree mortality, growth or ecosystem functioning in tropical rainforests. Drought plays a major role in shaping tropical rainforests and the response mechanisms are highly diverse and complex. The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical rainforests on the three continents. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance. CONTEXT Tropical rainforest ecosystems are characterized by high annual rainfall. Nevertheless, rainfall regularly fluctuates during the year and seasonal soil droughts do occur. Over the past decades, a number of extreme droughts have hit tropical rainforests, not only in Amazonia but also in Asia and Africa. The influence of drought events on tree mortality and growth or on ecosystem functioning (carbon and water fluxes) in tropical rainforest ecosystems has been studied intensively, but the response mechanisms are complex. AIMS Herein, we review the recent findings related to the response of tropical forest ecosystems to seasonal and extreme droughts and the current knowledge about the future of these ecosystems. RESULTS This review emphasizes the progress made over recent years and the importance of the studies conducted under extreme drought conditions or in through-fall exclusion experiments in understanding the response of these ecosystems. It also points to the great diversity and complexity of the response of tropical rainforest ecosystems to drought. CONCLUSION The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical forest regions. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance.
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Affiliation(s)
- Damien Bonal
- />INRA, UMR « Ecologie et Ecophysiologie Forestières », Université de Lorraine-INRA, F-54280 Champenoux, France
| | - Benoit Burban
- />INRA, UMR «Ecologie des Forêts de Guyane», AgroParisTech-CIRAD-INRA-CNRS-Université de Guyane-Université des Antilles, Campus Agronomique, 97387 Kourou, Guyane Française France
| | - Clément Stahl
- />CIRAD, UMR « Ecologie des Forêts de Guyane », AgroParisTech- CIRAD-INRA-CNRS-Université de Guyane-Université des Antilles, Campus Agronomique, 97387 Kourou, Guyane Française France
- />University of Antwerpen, Campus Agronomique, 97387 Kourou, Guyane Française France
| | - Fabien Wagner
- />National Institute for Space Research (INPE), São José dos Campos, SP 12227-010 Brazil
| | - Bruno Hérault
- />CIRAD, UMR « Ecologie des Forêts de Guyane », AgroParisTech- CIRAD-INRA-CNRS-Université de Guyane-Université des Antilles, Campus Agronomique, 97387 Kourou, Guyane Française France
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110
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Brunner I, Herzog C, Dawes MA, Arend M, Sperisen C. How tree roots respond to drought. FRONTIERS IN PLANT SCIENCE 2015; 6:547. [PMID: 26284083 PMCID: PMC4518277 DOI: 10.3389/fpls.2015.00547] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/06/2015] [Indexed: 05/17/2023]
Abstract
The ongoing climate change is characterized by increased temperatures and altered precipitation patterns. In addition, there has been an increase in both the frequency and intensity of extreme climatic events such as drought. Episodes of drought induce a series of interconnected effects, all of which have the potential to alter the carbon balance of forest ecosystems profoundly at different scales of plant organization and ecosystem functioning. During recent years, considerable progress has been made in the understanding of how aboveground parts of trees respond to drought and how these responses affect carbon assimilation. In contrast, processes of belowground parts are relatively underrepresented in research on climate change. In this review, we describe current knowledge about responses of tree roots to drought. Tree roots are capable of responding to drought through a variety of strategies that enable them to avoid and tolerate stress. Responses include root biomass adjustments, anatomical alterations, and physiological acclimations. The molecular mechanisms underlying these responses are characterized to some extent, and involve stress signaling and the induction of numerous genes, leading to the activation of tolerance pathways. In addition, mycorrhizas seem to play important protective roles. The current knowledge compiled in this review supports the view that tree roots are well equipped to withstand drought situations and maintain morphological and physiological functions as long as possible. Further, the reviewed literature demonstrates the important role of tree roots in the functioning of forest ecosystems and highlights the need for more research in this emerging field.
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Affiliation(s)
- Ivano Brunner
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
| | - Claude Herzog
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
- Swiss Federal Institute of Technology ZürichZürich, Switzerland
| | - Melissa A. Dawes
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
| | - Matthias Arend
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
| | - Christoph Sperisen
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
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Xu H, Kemppainen M, El Kayal W, Lee SH, Pardo AG, Cooke JEK, Zwiazek JJ. Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings. THE NEW PHYTOLOGIST 2015; 205:757-70. [PMID: 25323307 DOI: 10.1111/nph.13098] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 08/27/2014] [Indexed: 05/20/2023]
Abstract
The contribution of hyphae to water transport in ectomycorrhizal (ECM) white spruce (Picea glauca) seedlings was examined by altering expression of a major water-transporting aquaporin in Laccaria bicolor. Picea glauca was inoculated with wild-type (WT), mock transgenic or L. bicolor aquaporin JQ585595-overexpressing (OE) strains and exposed to root temperatures ranging from 5 to 20°C to examine the root water transport properties, physiological responses and plasma membrane intrinsic protein (PIP) expression in colonized plants. Mycorrhization increased shoot water potential, transpiration, net photosynthetic rates, root hydraulic conductivity and root cortical cell hydraulic conductivity in seedlings. At 20°C, OE plants had higher root hydraulic conductivity compared with WT plants and the increases were accompanied by higher expression of P. glauca PIP GQ03401_M18.1 in roots. In contrast to WT L. bicolor, the effects of OE fungi on root and root cortical cell hydraulic conductivities were abolished at 10 and 5°C in the absence of major changes in the examined transcript levels of P. glauca root PIPs. The results provide evidence for the importance of fungal aquaporins in root water transport of mycorrhizal plants. They also demonstrate links between hyphal water transport, root aquaporin expression and root water transport in ECM plants.
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Affiliation(s)
- Hao Xu
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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112
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Warren JM, Hanson PJ, Iversen CM, Kumar J, Walker AP, Wullschleger SD. Root structural and functional dynamics in terrestrial biosphere models--evaluation and recommendations. THE NEW PHYTOLOGIST 2015; 205:59-78. [PMID: 25263989 DOI: 10.1111/nph.13034] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/07/2014] [Indexed: 05/29/2023]
Abstract
There is wide breadth of root function within ecosystems that should be considered when modeling the terrestrial biosphere. Root structure and function are closely associated with control of plant water and nutrient uptake from the soil, plant carbon (C) assimilation, partitioning and release to the soils, and control of biogeochemical cycles through interactions within the rhizosphere. Root function is extremely dynamic and dependent on internal plant signals, root traits and morphology, and the physical, chemical and biotic soil environment. While plant roots have significant structural and functional plasticity to changing environmental conditions, their dynamics are noticeably absent from the land component of process-based Earth system models used to simulate global biogeochemical cycling. Their dynamic representation in large-scale models should improve model veracity. Here, we describe current root inclusion in models across scales, ranging from mechanistic processes of single roots to parameterized root processes operating at the landscape scale. With this foundation we discuss how existing and future root functional knowledge, new data compilation efforts, and novel modeling platforms can be leveraged to enhance root functionality in large-scale terrestrial biosphere models by improving parameterization within models, and introducing new components such as dynamic root distribution and root functional traits linked to resource extraction.
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Affiliation(s)
- Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN, 37831-6301, USA
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113
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Linking Populus euphratica hydraulic redistribution to diversity assembly in the arid desert zone of Xinjiang, China. PLoS One 2014; 9:e109071. [PMID: 25275494 PMCID: PMC4183514 DOI: 10.1371/journal.pone.0109071] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 09/07/2014] [Indexed: 11/19/2022] Open
Abstract
The hydraulic redistribution (HR) of deep-rooted plants significantly improves the survival of shallow-rooted shrubs and herbs in arid deserts, which subsequently maintain species diversity. This study was conducted in the Ebinur desert located in the western margin of the Gurbantonggut Desert. Isotope tracing, community investigation and comparison analysis were employed to validate the HR of Populus euphratica and to explore its effects on species richness and abundance. The results showed that, P. euphratica has HR. Shrubs and herbs that grew under the P. euphratica canopy (under community: UC) showed better growth than the ones growing outside (Outside community: OC), exhibiting significantly higher species richness and abundance in UC than OC (p<0.05) along the plant growing season. Species richness and abundance were significantly logarithmically correlated with the P. euphratica crown area in UC (R2 = 0.51 and 0.84, p<0.001). In conclusion, P. euphratica HR significantly ameliorates the water conditions of the shallow soil, which then influences the diversity assembly in arid desert communities.
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114
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Nehls U, Dietz S. Fungal aquaporins: cellular functions and ecophysiological perspectives. Appl Microbiol Biotechnol 2014; 98:8835-51. [PMID: 25213914 DOI: 10.1007/s00253-014-6049-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 08/13/2014] [Accepted: 08/15/2014] [Indexed: 12/21/2022]
Abstract
Three aspects have to be taken into consideration when discussing cellular water and solute permeability of fungal cells: cell wall properties, membrane permeability, and transport through proteinaceous pores (the main focus of this review). Yet, characterized major intrinsic proteins (MIPs) can be grouped into three functional categories: (mainly) water transporting aquaporins, aquaglyceroporins that confer preferentially solute permeability (e.g., glycerol and ammonia), and bifunctional aquaglyceroporins that can facilitate efficient water and solute transfer. Two ancestor proteins, a water (orthodox aquaporin) and a solute facilitator (aquaglyceroporin), are supposed to give rise to today's MIPs. Based on primary sequences of fungal MIPs, orthodox aquaporins/X-intrinsic proteins (XIPs) and FPS1-like/Yfl054-like/other aquaglyceroporins are supposed to be respective sister groups. However, at least within the fungal kingdom, no easy functional conclusion can be drawn from the phylogenetic position of a given protein within the MIP pedigree. In consequence, ecophysiological prediction of MIP relevance is not feasible without detailed functional analysis of the respective protein and expression studies. To illuminate the diverse MIP implications in fungal lifestyle, our current knowledge about protein function in two organisms, baker's yeast and the Basidiomycotic Laccaria bicolor, an ectomycorrhizal model fungus, was exemplarily summarized in this review. MIP function has been investigated in such a depth in Saccharomyces cerevisiae that a system-wide view is possible. Yeast lifestyle, however, is special in many circumstances. Therefore, L. bicolor as filamentous Basidiomycete was added and allows insight into a very different way of life. Special emphasis was laid in this review onto ecophysiological interpretation of MIP function.
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Affiliation(s)
- Uwe Nehls
- Botany, University of Bremen, Leobenerstr. 2, 28359, Bremen, Germany,
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115
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Mohan JE, Cowden CC, Baas P, Dawadi A, Frankson PT, Helmick K, Hughes E, Khan S, Lang A, Machmuller M, Taylor M, Witt CA. Mycorrhizal fungi mediation of terrestrial ecosystem responses to global change: mini-review. FUNGAL ECOL 2014. [DOI: 10.1016/j.funeco.2014.01.005] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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116
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Aguilar-Trigueros CA, Powell JR, Anderson IC, Antonovics J, Rillig MC. Ecological understanding of root-infecting fungi using trait-based approaches. TRENDS IN PLANT SCIENCE 2014; 19:432-438. [PMID: 24613596 DOI: 10.1016/j.tplants.2014.02.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/31/2014] [Accepted: 02/08/2014] [Indexed: 06/03/2023]
Abstract
Classification schemes have been popular to tame the diversity of root-infecting fungi. However, the usefulness of these schemes is limited to descriptive purposes. We propose that a shift to a multidimensional trait-based approach to disentangle the saprotrophic-symbiotic continuum will provide a better framework to understand fungal evolutionary ecology. Trait information reflecting the separation of root-infecting fungi from free-living soil relatives will help to understand the evolutionary process of symbiosis, the role that species interactions play in maintaining their large diversity in soil and in planta, and their contributions at the ecosystem level. Methodological advances in several areas such as microscopy, plant immunology, and metatranscriptomics represent emerging opportunities to populate trait databases.
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Affiliation(s)
- Carlos A Aguilar-Trigueros
- Institut für Biologie, Plant Ecology, Freie Universität Berlin, D-14195 Berlin, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research, D-14195 Berlin, Germany
| | - Jeff R Powell
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith NSW 2751, Australia
| | - Ian C Anderson
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith NSW 2751, Australia
| | - Janis Antonovics
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Matthias C Rillig
- Institut für Biologie, Plant Ecology, Freie Universität Berlin, D-14195 Berlin, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research, D-14195 Berlin, Germany.
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117
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Matimati I, Verboom GA, Cramer MD. Do hydraulic redistribution and nocturnal transpiration facilitate nutrient acquisition in Aspalathus linearis? Oecologia 2014; 175:1129-42. [PMID: 24972698 DOI: 10.1007/s00442-014-2987-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 05/29/2014] [Indexed: 11/28/2022]
Abstract
The significance of soil water redistribution by roots and nocturnal transpiration for nutrient acquisition were assessed for deep-rooted 3-year-old leguminous Aspalathus linearis shrubs of the Cape Floristic Region (South Africa). We hypothesised that hydraulic redistribution and nocturnal transpiration facilitate nutrient acquisition by releasing moisture in shallow soil to enable acquisition of shallow-soil nutrients during the summer drought periods and by driving water fluxes from deep to shallow soil powering mass-flow nutrient acquisition, respectively. A. linearis was supplied with sub-surface (1-m-deep) irrigation rates of 0, 2 or 4 L day(-1 )plant(-1). Some plants were unfertilized, whilst others were surface- or deep-fertilized (1 m depth) with Na(15)NO3 and CaP/FePO4. We also supplied deuterium oxide ((2)H2O) at 1 m depth at dusk and measured its predawn redistribution to shallow soil and plant stems. Hydraulic redistribution of deep water was substantial across all treatments, accounting for 34-72 % of surface-soil predawn moisture. Fourteen days after fertilization, the surface-fertilized plants exhibited increased hydraulic redistribution and increased (15)N and P acquisition with higher rates of deep-irrigation. Deep-fertilization also increased hydraulic redistribution to surface soils, although these plants additionally accumulated (2)H2O in their stem tissue overnight, probably due to nocturnal transpiration. Plants engaged in nocturnal transpiration also increased (15)N and P acquisition from deep fertilizer sources. Thus, both nocturnal transpiration and hydraulic redistribution increased acquisition of shallow soil N and P, possibly through a combination of increased nutrient availability and mobility.
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Affiliation(s)
- Ignatious Matimati
- Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, 7701, South Africa
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118
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Lothamer K, Brown SP, Mattox JD, Jumpponen A. Comparison of root-associated communities of native and non-native ectomycorrhizal hosts in an urban landscape. MYCORRHIZA 2014; 24:267-280. [PMID: 24221903 DOI: 10.1007/s00572-013-0539-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/28/2013] [Indexed: 06/02/2023]
Abstract
Non-native tree species are often used as ornamentals in urban landscapes. However, their root-associated fungal communities remain yet to be examined in detail. Here, we compared richness, diversity and community composition of ectomycorrhizosphere fungi in general and ectomycorrhizal (EcM) fungi in particular between a non-native Pinus nigra and a native Quercus macrocarpa across a growing season in urban parks using 454-pyrosequencing. Our data show that, while the ectomycorrhizosphere community richness and diversity did not differ between the two host, the EcM communities associated with the native host were often more species rich and included more exclusive members than those of the non-native hosts. In contrast, the ectomycorrhizosphere communities of the two hosts were compositionally clearly distinct in nonmetric multidimensional ordination analyses, whereas the EcM communities were only marginally so. Taken together, our data suggest EcM communities with broad host compatibilities and with a limited numbers of taxa with preference to the non-native host. Furthermore, many common fungi in the non-native Pinus were not EcM taxa, suggesting that the fungal communities of the non-native host may be enriched in non-mycorrhizal fungi at the cost of the EcM taxa. Finally, while our colonization estimates did not suggest a shortage in EcM inoculum for either host in urban parks, the differences in the fungi associated with the two hosts emphasize the importance of using native hosts in urban environments as a tool to conserve endemic fungal diversity and richness in man-made systems.
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Affiliation(s)
- K Lothamer
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
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119
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Calvo-Polanco M, Molina S, Zamarreño AM, García-Mina JM, Aroca R. The symbiosis with the arbuscular mycorrhizal fungus Rhizophagus irregularis drives root water transport in flooded tomato plants. PLANT & CELL PHYSIOLOGY 2014; 55:1017-1029. [PMID: 24553847 DOI: 10.1093/pcp/pcu035] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
It is known that the presence of arbuscular mycorrhizal fungi within the plant roots enhances the tolerance of the host plant to different environmental stresses, although the positive effect of the fungi in plants under waterlogged conditions has not been well studied. Tolerance of plants to flooding can be achieved through different molecular, physiological and anatomical adaptations, which will affect their water uptake capacity and therefore their root hydraulic properties. Here, we investigated the root hydraulic properties under non-flooded and flooded conditions in non-mycorrhizal tomato plants and plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. Only flooded mycorrhizal plants increased their root hydraulic conductivity, and this effect was correlated with a higher expression of the plant aquaporin SlPIP1;7 and the fungal aquaporin GintAQP1. There was also a higher abundance of the PIP2 protein phoshorylated at Ser280 in mycorrhizal flooded plants. The role of plant hormones (ethylene, ABA and IAA) in root hydraulic properties was also taken into consideration, and it was concluded that, in mycorrhizal flooded plants, ethylene has a secondary role regulating root hydraulic conductivity whereas IAA may be the key hormone that allows the enhancement of root hydraulic conductivity in mycorrhizal plants under low oxygen conditions.
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Affiliation(s)
- Monica Calvo-Polanco
- Estación Experimental del Zaidín (CSIC), Department of Soil Microbiology and Symbiotic Systems, C/Profesor Albareda 1, 18008 Granada, Spain
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120
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Bárzana G, Aroca R, Bienert GP, Chaumont F, Ruiz-Lozano JM. New insights into the regulation of aquaporins by the arbuscular mycorrhizal symbiosis in maize plants under drought stress and possible implications for plant performance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:349-63. [PMID: 24593244 DOI: 10.1094/mpmi-09-13-0268-r] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The relationship between modulation by arbuscular mycorrhizae (AM) of aquaporin expression in the host plant and changes in root hydraulic conductance, plant water status, and performance under stressful conditions is not well known. This investigation aimed to elucidate how the AM symbiosis modulates the expression of the whole set of aquaporin genes in maize plants under different growing and drought stress conditions, as well as to characterize some of these aquaporins in order to shed further light on the molecules that may be involved in the mycorrhizal responses to drought. The AM symbiosis regulated a wide number of aquaporins in the host plant, comprising members of the different aquaporin subfamilies. The regulation of these genes depends on the watering conditions and the severity of the drought stress imposed. Some of these aquaporins can transport water and also other molecules which are of physiological importance for plant performance. AM plants grew and developed better than non-AM plants under the different conditions assayed. Thus, for the first time, this study relates the well-known better performance of AM plants under drought stress to not only the water movement in their tissues but also the mobilization of N compounds, glycerol, signaling molecules, or metalloids with a role in abiotic stress tolerance. Future studies should elucidate the specific function of each aquaporin isoform regulated by the AM symbiosis in order to shed further light on how the symbiosis alters the plant fitness under stressful conditions.
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121
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Pena R, Polle A. Attributing functions to ectomycorrhizal fungal identities in assemblages for nitrogen acquisition under stress. THE ISME JOURNAL 2014; 8:321-30. [PMID: 24030593 PMCID: PMC3906819 DOI: 10.1038/ismej.2013.158] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 07/25/2013] [Accepted: 08/08/2013] [Indexed: 11/09/2022]
Abstract
Mycorrhizal fungi have a key role in nitrogen (N) cycling, particularly in boreal and temperate ecosystems. However, the significance of ectomycorrhizal fungal (EMF) diversity for this important ecosystem function is unknown. Here, EMF taxon-specific N uptake was analyzed via (15)N isotope enrichment in complex root-associated assemblages and non-mycorrhizal root tips in controlled experiments. Specific (15)N enrichment in ectomycorrhizas, which represents the N influx and export, as well as the exchange of (15)N with the N pool of the root tip, was dependent on the fungal identity. Light or water deprivation revealed interspecific response diversity for N uptake. Partial taxon-specific N fluxes for ectomycorrhizas were assessed, and the benefits of EMF assemblages for plant N nutrition were estimated. We demonstrated that ectomycorrhizal assemblages provide advantages for inorganic N uptake compared with non-mycorrhizal roots under environmental constraints but not for unstressed plants. These benefits were realized via stress activation of distinct EMF taxa, which suggests significant functional diversity within EMF assemblages. We developed and validated a model that predicts net N flux into the plant based on taxon-specific (15)N enrichment in ectomycorrhizal root tips. These results open a new avenue to characterize the functional traits of EMF taxa in complex communities.
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Affiliation(s)
- Rodica Pena
- Forest Botany and Tree Physiology, Georg-August Universität Göttingen, Büsgenweg 2, Göttingen, Germany
| | - Andrea Polle
- Forest Botany and Tree Physiology, Georg-August Universität Göttingen, Büsgenweg 2, Göttingen, Germany
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122
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123
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Casieri L, Ait Lahmidi N, Doidy J, Veneault-Fourrey C, Migeon A, Bonneau L, Courty PE, Garcia K, Charbonnier M, Delteil A, Brun A, Zimmermann S, Plassard C, Wipf D. Biotrophic transportome in mutualistic plant-fungal interactions. MYCORRHIZA 2013; 23:597-625. [PMID: 23572325 DOI: 10.1007/s00572-013-0496-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 03/13/2013] [Indexed: 05/08/2023]
Abstract
Understanding the mechanisms that underlie nutrient use efficiency and carbon allocation along with mycorrhizal interactions is critical for managing croplands and forests soundly. Indeed, nutrient availability, uptake and exchange in biotrophic interactions drive plant growth and modulate biomass allocation. These parameters are crucial for plant yield, a major issue in the context of high biomass production. Transport processes across the polarized membrane interfaces are of major importance in the functioning of the established mycorrhizal association as the symbiotic relationship is based on a 'fair trade' between the fungus and the host plant. Nutrient and/or metabolite uptake and exchanges, at biotrophic interfaces, are controlled by membrane transporters whose regulation patterns are essential for determining the outcome of plant-fungus interactions and adapting to changes in soil nutrient quantity and/or quality. In the present review, we summarize the current state of the art regarding transport systems in the two major forms of mycorrhiza, namely ecto- and arbuscular mycorrhiza.
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Affiliation(s)
- Leonardo Casieri
- UMR Agroécologie INRA 1347/Agrosup/Université de Bourgogne, Pôle Interactions Plantes Microorganismes ERL 6300 CNRS, BP 86510, 21065, Dijon Cedex, France,
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124
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Korhonen A, Lehto T, Repo T. Frost hardiness of mycorrhizal (Hebeloma sp.) and non-mycorrhizal Scots pine roots. MYCORRHIZA 2013; 23:551-559. [PMID: 23558517 DOI: 10.1007/s00572-013-0497-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 03/17/2013] [Indexed: 06/02/2023]
Abstract
The frost hardiness (FH) of mycorrhizal [ectomycorrhizal (ECM)] and non-mycorrhizal (NM) Scots pine (Pinus sylvestris) seedlings was studied to assess whether mycorrhizal symbiosis affected the roots' tolerance of below-zero temperatures. ECM (Hebeloma sp.) and NM seedlings were cultivated in a growth chamber for 18 weeks. After 13 weeks' growth in long-day and high-temperature (LDHT) conditions, a half of the ECM and NM seedlings were moved into a chamber with short-day and low-temperature (SDLT) conditions to cold acclimate. After exposures to a range of below-zero temperatures, the FH of the roots was assessed by means of the relative electrolyte leakage test. The FH was determined as the inflection point of the temperature-response curve. No significant difference was found between the FH of mycorrhizal and non-mycorrhizal roots in LDHT (-8.9 and -9.8 °C) or SDLT (-7.5 and -6.8 °C). The mycorrhizal treatment had no significant effect on the total dry mass, the allocation of dry mass among the roots and needles or nutrient accumulation. The mycorrhizal treatment with Hebeloma sp. did not affect the FH of Scots pine in this experimental setup. More information is needed on the extent to which mycorrhizas tolerate low temperatures, especially with different nutrient contents and different mycorrhiza fungi.
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Affiliation(s)
- Anna Korhonen
- Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, 80101, Joensuu, Finland,
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125
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Navarro-Ródenas A, Bárzana G, Nicolás E, Carra A, Schubert A, Morte A. Expression analysis of aquaporins from desert truffle mycorrhizal symbiosis reveals a fine-tuned regulation under drought. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1068-78. [PMID: 23656332 DOI: 10.1094/mpmi-07-12-0178-r] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We have performed the isolation, functional characterization, and expression analysis of aquaporins in roots and leaves of Helianthemum almeriense, in order to evaluate their roles in tolerance to water deficit. Five cDNAs, named HaPIP1;1, HaPIP1;2, HaPIP2;1, HaPIP2;2, and HaTIP1;1, were isolated from H. almeriense. A phylogenetic analysis of deduced proteins confirmed that they belong to the water channel proteins family. The HaPIP1;1, HaPIP2;1, and HaTIP1;1 genes encode functional water channel proteins, as indicated by expression assays in Saccharomyces cerevisiae, showing divergent roles in the transport of water, CO2, and NH3. The expression patterns of the genes isolated from H. almeriense and of a previously described gene from Terfezia claveryi (TcAQP1) were analyzed in mycorrhizal and nonmycorrhizal plants cultivated under well-watered or drought-stress conditions. Some of the studied aquaporins were subjected to fine-tuned expression only under drought-stress conditions. A beneficial effect on plant physiological parameters was observed in mycorrhizal plants with respect to nonmycorrhizal ones. Moreover, stress induced a change in the mycorrhizal type formed, which was more intracellular under drought stress. The combination of a high intracellular colonization, together with the fine-tuned expression of aquaporins could result in a morphophysiological adaptation of this symbiosis to drought conditions.
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Affiliation(s)
- Alfonso Navarro-Ródenas
- Departamento Biología Vegetal Botánica, Facultad de Biología, Universidad de Murcia, Murcia, Spain
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126
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Liu XP, Gong CM, Fan YY, Eiblmeier M, Zhao Z, Han G, Rennenberg H. Response pattern of amino compounds in phloem and xylem of trees to soil drought depends on drought intensity and root symbiosis. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15 Suppl 1:101-108. [PMID: 22845058 DOI: 10.1111/j.1438-8677.2012.00647.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study aimed to identify drought-mediated differences in amino nitrogen (N) composition and content of xylem and phloem in trees having different symbiotic N(2)-fixing bacteria. Under controlled water availability, 1-year-old seedlings of Robinia pseudoacacia (nodules with Rhizobium), Hippophae rhamnoides (symbiosis with Frankia) and Buddleja alternifolia (no such root symbiosis) were exposed to control, medium drought and severe drought, corresponding soil water content of 70-75%, 45-50% and 30-35% of field capacity, respectively. Composition and content of amino compounds in xylem sap and phloem exudates were analysed as a measure of N nutrition. Drought strongly reduced biomass accumulation in all species, but amino N content in xylem and phloem remained unaffected only in R. pseudoacacia. In H. rhamnoides and B. alternifolia, amino N in phloem remained constant, but increased in xylem of both species in response to drought. There were differences in composition of amino compounds in xylem and phloem of the three species in response to drought. Proline concentrations in long-distance transport pathways of all three species were very low, below the limit of detection in phloem of H. rhamnoides and in phloem and xylem of B. alternifolia. Apparently, drought-mediated changes in N composition were much more connected with species-specific changes in C:N ratios. Irrespective of soil water content, the two species with root symbioses did not show similar features for the different types of symbiosis, neither in N composition nor in N content. There was no immediate correlation between symbiotic N fixation and drought-mediated changes in amino N in the transport pathways.
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Affiliation(s)
- X-P Liu
- Department of Plant Physiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China.
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127
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Herzog C, Peter M, Pritsch K, Günthardt-Goerg MS, Egli S. Drought and air warming affects abundance and exoenzyme profiles of Cenococcum geophilum associated with Quercus robur, Q. petraea and Q. pubescens. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15 Suppl 1:230-237. [PMID: 22686410 DOI: 10.1111/j.1438-8677.2012.00614.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The present study aimed to elucidate the influence of drought and elevated temperature on relative abundance and functioning of the ectomycorrhizal fungus Cenococcum geophilum on three oak species differing in adaptation to a warm and dry climate. The experiment QUERCO comprised three Quercus species (Q. robur, Q. petraea, Q. pubescens) grown for 3 years under four treatments: elevated air temperature, drought, a combination of the two, and control. Fine root samples were analysed for relative abundance and potential extracellular enzyme activities of ectomycorrhizae of C. geophilum, a fungal species known to be drought resistant. The relative abundance of C. geophilum on the roots of the oak species was significantly increased by temperature, decreased by drought, but unchanged in the combined treatment compared to the control. Although the extent of treatment effects differed among oak species, no significant influence of tree species on relative abundance of C. geophilum was detected. Exoenzyme activities of C. geophilum on Q. robur and Q. petraea (but not Q. pubescens) significantly increased in the combined treatment, but for all oak species were reduced under drought and air warming alone compared to the control. There was a significant negative correlation between abundance of C. geophilum and its leucine aminopeptidase activity. As this enzyme is not frequent among ectomycorrhizal fungi, this emphasises the functional importance of C. geophilum in the ectomycorrhizal community. Our results indicate that increased temperature and drought will influence the relative abundance and enzyme activity of C. geophilum. However, both the Quercus species and C. geophilum tolerated warming and strong drought.
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Affiliation(s)
- C Herzog
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, Birmensdorf, Switzerland.
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128
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Arbuscular Mycorrhizal Fungi and the Tolerance of Plants to Drought and Salinity. SOIL BIOLOGY 2013. [DOI: 10.1007/978-3-642-39317-4_14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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129
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Günthardt-Goerg MS, Kuster TM, Arend M, Vollenweider P. Foliage response of young central European oaks to air warming, drought and soil type. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15 Suppl 1:185-97. [PMID: 23009690 DOI: 10.1111/j.1438-8677.2012.00665.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Three Central European oak species, with four provenances each, were experimentally tested in 16 large model ecosystem chambers for their response to passive air warming (AW, ambient +1-2 °C), drought (D, -43 to -60% irrigation) and their combination (AWD) for 3 years on two forest soil types of pH 4 or 7. Throughout the entire experiment, the influence of the different ambient and experimental climates on the oak trees was strong. The morphological traits of the Quercus species were affected in opposing ways in AW and D treatments, with a neutral effect in the AWD treatment. Biochemical parameters and LMA showed low relative plasticity compared to the morphological and growth parameters. The high plasticity in physiologically important parameters of the three species, such as number of intercalary veins or leaf size, indicated good drought acclimation properties. The soil type influenced leaf chlorophyll concentration, C/N and area more than drought, whereas foliage mass was more dependent on drought than on soil type. Through comparison of visible symptom development with the water deficits, a drought tolerance threshold of -1.3 MPa was determined. Although Q. pubescens had xeromorphic leaf characteristics (small leaf size, lower leaf water content, high LMA, pilosity, more chlorophyll, higher C/N) and less response to the treatments than Q. petraea and Q. robur, it suffered more leaf drought injury and shedding of leaves than Q. petraea. However, if foliage mass were used as the criterion for sustainable performance under a future climate, Q. robur would be the most appropriate species.
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Affiliation(s)
- M S Günthardt-Goerg
- Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, Switzerland.
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130
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131
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Davey ML, Heegaard E, Halvorsen R, Kauserud H, Ohlson M. Amplicon-pyrosequencing-based detection of compositional shifts in bryophyte-associated fungal communities along an elevation gradient. Mol Ecol 2012. [DOI: 10.1111/mec.12122] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marie L. Davey
- Department of Ecology and Natural Resource Management; Norwegian University of Life Sciences; PO Box 5003 NO-1432 Ås Norway
- Microbial Evolution Research Group (MERG); Department of Biology; University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
| | - Einar Heegaard
- Norwegian Forest and Landscape Institute; Fanaflaten 4 NO-5244 Fana Norway
| | - Rune Halvorsen
- Department of Botany, Natural History Museum; University of Oslo; PO Box 1172 Blindern NO-0318 Oslo Norway
| | - Håvard Kauserud
- Microbial Evolution Research Group (MERG); Department of Biology; University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
| | - Mikael Ohlson
- Department of Ecology and Natural Resource Management; Norwegian University of Life Sciences; PO Box 5003 NO-1432 Ås Norway
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132
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Giovannetti M, Balestrini R, Volpe V, Guether M, Straub D, Costa A, Ludewig U, Bonfante P. Two putative-aquaporin genes are differentially expressed during arbuscular mycorrhizal symbiosis in Lotus japonicus. BMC PLANT BIOLOGY 2012; 12:186. [PMID: 23046713 PMCID: PMC3533510 DOI: 10.1186/1471-2229-12-186] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 09/18/2012] [Indexed: 05/03/2023]
Abstract
BACKGROUND Arbuscular mycorrhizas (AM) are widespread symbioses that provide great advantages to the plant, improving its nutritional status and allowing the fungus to complete its life cycle. Nevertheless, molecular mechanisms that lead to the development of AM symbiosis are not yet fully deciphered. Here, we have focused on two putative aquaporin genes, LjNIP1 and LjXIP1, which resulted to be upregulated in a transcriptomic analysis performed on mycorrhizal roots of Lotus japonicus. RESULTS A phylogenetic analysis has shown that the two putative aquaporins belong to different functional families: NIPs and XIPs. Transcriptomic experiments have shown the independence of their expression from their nutritional status but also a close correlation with mycorrhizal and rhizobial interaction. Further transcript quantification has revealed a good correlation between the expression of one of them, LjNIP1, and LjPT4, the phosphate transporter which is considered a marker gene for mycorrhizal functionality. By using laser microdissection, we have demonstrated that one of the two genes, LjNIP1, is expressed exclusively in arbuscule-containing cells. LjNIP1, in agreement with its putative role as an aquaporin, is capable of transferring water when expressed in yeast protoplasts. Confocal analysis have demonstrated that eGFP-LjNIP1, under its endogenous promoter, accumulates in the inner membrane system of arbusculated cells. CONCLUSIONS Overall, the results have shown different functionality and expression specificity of two mycorrhiza-inducible aquaporins in L. japonicus. One of them, LjNIP1 can be considered a novel molecular marker of mycorrhizal status at different developmental stages of the arbuscule. At the same time, LjXIP1 results to be the first XIP family aquaporin to be transcriptionally regulated during symbiosis.
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Affiliation(s)
- Marco Giovannetti
- Department of Life Sciences and Systems Biology, University of Torino and IPP-CNR, Viale Mattioli 25, Torino, 10125, Italy
| | - Raffaella Balestrini
- Department of Life Sciences and Systems Biology, University of Torino and IPP-CNR, Viale Mattioli 25, Torino, 10125, Italy
| | - Veronica Volpe
- Department of Life Sciences and Systems Biology, University of Torino and IPP-CNR, Viale Mattioli 25, Torino, 10125, Italy
| | - Mike Guether
- Department of Life Sciences and Systems Biology, University of Torino and IPP-CNR, Viale Mattioli 25, Torino, 10125, Italy
- Botanical Institute, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, D-76187, Germany
| | - Daniel Straub
- Institute of Crop Science, University of Hohenheim, Fruwirthstrasse 20, Stuttgart, 70599, Germany
| | - Alex Costa
- Department of Life Sciences, University of Milano, Via Celoria 26, Milano, 20133, Italy
| | - Uwe Ludewig
- Institute of Crop Science, University of Hohenheim, Fruwirthstrasse 20, Stuttgart, 70599, Germany
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Torino and IPP-CNR, Viale Mattioli 25, Torino, 10125, Italy
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133
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Davey ML, Heegaard E, Halvorsen R, Ohlson M, Kauserud H. Seasonal trends in the biomass and structure of bryophyte-associated fungal communities explored by 454 pyrosequencing. THE NEW PHYTOLOGIST 2012; 195:844-856. [PMID: 22758207 DOI: 10.1111/j.1469-8137.2012.04215.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bryophytes are a dominant vegetation component of the boreal forest, but little is known about their associated fungal communities, including seasonal variation within them. Seasonal variation in the fungal biomass and composition of fungal communities associated with three widespread boreal bryophytes was investigated using HPLC assays of ergosterol and amplicon pyrosequencing of the internal transcribed spacer 2 (ITS2) region of rDNA. The bryophyte phyllosphere community was dominated by Ascomycota. Fungal biomass did not decline appreciably in winter (P=0.272). Significant host-specific patterns in seasonal variation of biomass were detected (P=0.003). Although seasonal effects were not the primary factors structuring community composition, collection date significantly explained (P=0.001) variation not attributed to locality, host, and tissue. Community homogenization and a reduction in turnover occurred with the onset of frost events and subzero air and soil temperatures. Fluctuations in the relative abundance of particular fungal groups seem to reflect the nature of their association with mosses, although conclusions are drawn with caution because of potential methodological bias. The moss-associated fungal community is dynamic, exhibiting seasonal turnover in composition and relative abundance of different fungal groups, and significant fungal biomass is present year-round, suggesting a winter-active fungal community.
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Affiliation(s)
- Marie L Davey
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, PO Box 1066 Blindern, NO-0316 Oslo, Norway
| | - Einar Heegaard
- Norwegian Forest and Landscape Institute, Fanaflaten 4, NO-5244 Fana, Norway
| | - Rune Halvorsen
- Department of Botany, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway
| | - Mikael Ohlson
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway
| | - Håvard Kauserud
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, PO Box 1066 Blindern, NO-0316 Oslo, Norway
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134
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Kipfer T, Wohlgemuth T, van der Heijden MGA, Ghazoul J, Egli S. Growth response of drought-stressed Pinus sylvestris seedlings to single- and multi-species inoculation with ectomycorrhizal fungi. PLoS One 2012; 7:e35275. [PMID: 22496914 PMCID: PMC3320646 DOI: 10.1371/journal.pone.0035275] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 03/14/2012] [Indexed: 11/18/2022] Open
Abstract
Many trees species form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve nutrient and water acquisition of their host. Until now it is unclear whether the species richness of ECM fungi is beneficial for tree seedling performance, be it during moist conditions or drought. We performed a pot experiment using Pinus sylvestris seedlings inoculated with four selected ECM fungi (Cenococcum geophilum, Paxillus involutus, Rhizopogon roseolus and Suillus granulatus) to investigate (i) whether these four ECM fungi, in monoculture or in species mixtures, affect growth of P. sylvestris seedlings, and (ii) whether this effect can be attributed to species number per se or to species identity. Two different watering regimes (moist vs. dry) were applied to examine the context-dependency of the results. Additionally, we assessed the activity of eight extracellular enzymes in the root tips. Shoot growth was enhanced in the presence of S. granulatus, but not by any other ECM fungal species. The positive effect of S. granulatus on shoot growth was more pronounced under moist (threefold increase) than under dry conditions (twofold increase), indicating that the investigated ECM fungi did not provide additional support during drought stress. The activity of secreted extracellular enzymes was higher in S. granulatus than in any other species. In conclusion, our findings suggest that ECM fungal species composition may affect seedling performance in terms of aboveground biomass.
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Affiliation(s)
- Tabea Kipfer
- Forest Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
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135
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Bárzana G, Aroca R, Paz JA, Chaumont F, Martinez-Ballesta MC, Carvajal M, Ruiz-Lozano JM. Arbuscular mycorrhizal symbiosis increases relative apoplastic water flow in roots of the host plant under both well-watered and drought stress conditions. ANNALS OF BOTANY 2012; 109:1009-17. [PMID: 22294476 PMCID: PMC3310489 DOI: 10.1093/aob/mcs007] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND AND AIMS The movement of water through mycorrhizal fungal tissues and between the fungus and roots is little understood. It has been demonstrated that arbuscular mycorrhizal (AM) symbiosis regulates root hydraulic properties, including root hydraulic conductivity. However, it is not clear whether this effect is due to a regulation of root aquaporins (cell-to-cell pathway) or to enhanced apoplastic water flow. Here we measured the relative contributions of the apoplastic versus the cell-to-cell pathway for water movement in roots of AM and non-AM plants. METHODS We used a combination of two experiments using the apoplastic tracer dye light green SF yellowish and sodium azide as an inhibitor of aquaporin activity. Plant water and physiological status, root hydraulic conductivity and apoplastic water flow were measured. KEY RESULTS Roots of AM plants enhanced significantly relative apoplastic water flow as compared with non-AM plants and this increase was evident under both well-watered and drought stress conditions. The presence of the AM fungus in the roots of the host plants was able to modulate the switching between apoplastic and cell-to-cell water transport pathways. CONCLUSIONS The ability of AM plants to switch between water transport pathways could allow a higher flexibility in the response of these plants to water shortage according to the demand from the shoot.
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Affiliation(s)
- Gloria Bárzana
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (EEZ-CSIC), Profesor Albareda no. 1, 18008 Granada, Spain
| | - Ricardo Aroca
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (EEZ-CSIC), Profesor Albareda no. 1, 18008 Granada, Spain
| | - José Antonio Paz
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (EEZ-CSIC), Profesor Albareda no. 1, 18008 Granada, Spain
| | - François Chaumont
- Institut des Sciences de la Vie, Université catholique de Louvain, Croix du Sud 4-15, B-1348, Louvain-la-Neuve, Belgium
| | - Mari Carmen Martinez-Ballesta
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Department of Plant Nutrition, PO Box 164, Campus de Espinardo 30100-Murcia, Spain
| | - Micaela Carvajal
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Department of Plant Nutrition, PO Box 164, Campus de Espinardo 30100-Murcia, Spain
| | - Juan Manuel Ruiz-Lozano
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (EEZ-CSIC), Profesor Albareda no. 1, 18008 Granada, Spain
- For correspondence. E-mail
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Simard SW, Beiler KJ, Bingham MA, Deslippe JR, Philip LJ, Teste FP. Mycorrhizal networks: Mechanisms, ecology and modelling. FUNGAL BIOL REV 2012. [DOI: 10.1016/j.fbr.2012.01.001] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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137
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Neumann RB, Cardon ZG. The magnitude of hydraulic redistribution by plant roots: a review and synthesis of empirical and modeling studies. THE NEW PHYTOLOGIST 2012; 194:337-352. [PMID: 22417121 DOI: 10.1111/j.1469-8137.2012.04088.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hydraulic redistribution (HR) - the movement of water from moist to dry soil through plant roots - occurs worldwide within a range of different ecosystems and plant species. The proposed ecological and hydrologic impacts of HR include increasing dry-season transpiration and photosynthetic rates, prolonging the life span of fine roots and maintaining root-soil contact in dry soils, and moving rainwater down into deeper soil layers where it does not evaporate. In this review, we compile estimates of the magnitude of HR from ecosystems around the world, using representative empirical and modeling studies from which we could extract amounts of water redistributed by plant root systems. The reported average magnitude of HR varies by nearly two orders of magnitude across ecosystems, from 0.04 to 1.3 mm H(2)O d(-1) in the empirical literature, and from 0.1 to 3.23 mm H(2)O d(-1) in the modeling literature. Using these synthesized data, along with other published studies, we examine this variation in the magnitude of upward and downward HR, considering effects of plant, soil and ecosystem characteristics, as well as effects of methodological details (in both empirical and modeling studies) on estimates of HR. We take both ecological and hydrologic perspectives.
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Affiliation(s)
- Rebecca B Neumann
- Department of Civil and Environmental Engineering, 201 More Hall, University of Washington, Seattle, WA 98195, USA
| | - Zoe G Cardon
- The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
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138
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Prieto I, Armas C, Pugnaire FI. Water release through plant roots: new insights into its consequences at the plant and ecosystem level. THE NEW PHYTOLOGIST 2012; 193:830-841. [PMID: 22250761 DOI: 10.1111/j.1469-8137.2011.04039.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Hydraulic redistribution (HR) is the passive movement of water between different soil parts via plant root systems, driven by water potential gradients in the soil-plant interface. New data suggest that HR is a heterogeneous and patchy process. In this review we examine the main biophysical and environmental factors controlling HR and its main implications at the plant, community and ecosystem levels. Experimental evidence and the use of novel modelling approaches suggest that HR may have important implications at the community scale, affecting net primary productivity as well as water and vegetation dynamics. Globally, HR may influence hydrological and biogeochemical cycles and, ultimately, climate.
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Affiliation(s)
- Iván Prieto
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
| | - Cristina Armas
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
| | - Francisco I Pugnaire
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
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139
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Pereira E, Coelho V, Tavares RM, Lino-Neto T, Baptista P. Effect of competitive interactions between ectomycorrhizal and saprotrophic fungi on Castanea sativa performance. MYCORRHIZA 2012; 22:41-49. [PMID: 21484339 DOI: 10.1007/s00572-011-0379-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/28/2011] [Indexed: 05/30/2023]
Abstract
In Northeast of Portugal, the macrofungal community associated to chestnut tree (Castanea sativa Mill.) is rich and diversified. Among fungal species, the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare are common in this habitat. The aim of the present work was to assess the effect of the interaction between both fungi on growth, nutritional status, and physiology of C. sativa seedlings. In pot experiments, C. sativa seedlings were inoculated with P. tinctorius and H. fasciculare individually or in combination. Inoculation with P. tinctorius stimulated the plant growth and resulted in increased foliar-N, foliar-P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tinctorius. This result could be related to the inhibition of ectomycorrhizal fungus root colonization as a result of antagonism or to the competition for nutrient sources. If chestnut seedlings have been previously inoculated with P. tinctorius, the subsequent inoculation of H. fasciculare 30 days later did not affect root colonization, and mycorrhization benefits were observed. This work confirms an antagonistic interaction between ectomycorrhizal and saprotrophic fungi with consequences on the ectomycorrhizal host physiology. Although P. tinctorius is effective in promoting growth of host trees by establishing mycorrhizae, in the presence of other fungi, it may not always be able to interact with host roots due to an inability to compete with certain fungi.
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Affiliation(s)
- Eric Pereira
- CIMO/School of Agriculture, Polytechnic Institute of Bragança, Bragança, Portugal
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140
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Fini A, Frangi P, Amoroso G, Piatti R, Faoro M, Bellasio C, Ferrini F. Effect of controlled inoculation with specific mycorrhizal fungi from the urban environment on growth and physiology of containerized shade tree species growing under different water regimes. MYCORRHIZA 2011; 21:703-719. [PMID: 21472449 DOI: 10.1007/s00572-011-0370-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 03/02/2011] [Indexed: 05/27/2023]
Abstract
The aim of this work was to evaluate the effects of selected mycorrhiza obtained in the urban environment on growth, leaf gas exchange, and drought tolerance of containerized plants growing in the nursery. Two-year-old uniform Acer campestre L., Tilia cordata Mill., and Quercus robur L. were inoculated with a mixture of infected roots and mycelium of selected arbuscular (maple, linden) and/or ectomycorrhiza (linden, oak) fungi and grown in well-watered or water shortage conditions. Plant biomass and leaf area were measured 1 and 2 years after inoculation. Leaf gas exchange, chlorophyll fluorescence, and water relations were measured during the first and second growing seasons after inoculation. Our data suggest that the mycelium-based inoculum used in this experiment was able to colonize the roots of the tree species growing in the nursery. Plant biomass was affected by water shortage, but not by inoculation. Leaf area was affected by water regime and, in oak and linden, by inoculation. Leaf gas exchange was affected by inoculation and water stress. V(cmax) and J(max) were increased by inoculation and decreased by water shortage in all species. F(v)/F(m) was also generally higher in inoculated plants than in control. Changes in PSII photochemistry and photosynthesis may be related to the capacity of inoculated plants to maintain less negative leaf water potential under drought conditions. The overall data suggest that inoculated plants were better able to maintain physiological activity during water stress in comparison to non-inoculated plants.
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Affiliation(s)
- Alessio Fini
- Department of Plant, Soil and Environmental Science, University of Florence, viale delle Idee 30, 50019, Sesto Fiorentino (FI), Italy.
| | - Piero Frangi
- Centro MiRT, Fondazione Minoprio, viale Raimondi 54, 22070, Vertemate con Minoprio (CO), Italy
| | - Gabriele Amoroso
- Centro MiRT, Fondazione Minoprio, viale Raimondi 54, 22070, Vertemate con Minoprio (CO), Italy
| | - Riccardo Piatti
- Centro MiRT, Fondazione Minoprio, viale Raimondi 54, 22070, Vertemate con Minoprio (CO), Italy
| | - Marco Faoro
- Centro MiRT, Fondazione Minoprio, viale Raimondi 54, 22070, Vertemate con Minoprio (CO), Italy
| | - Chandra Bellasio
- Department of Plant, Soil and Environmental Science, University of Florence, viale delle Idee 30, 50019, Sesto Fiorentino (FI), Italy
| | - Francesco Ferrini
- Department of Plant, Soil and Environmental Science, University of Florence, viale delle Idee 30, 50019, Sesto Fiorentino (FI), Italy
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141
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Siemens JA, Calvo-Polanco M, Zwiazek JJ. Hebeloma crustuliniforme facilitates ammonium and nitrate assimilation in trembling aspen (Populus tremuloides) seedlings. TREE PHYSIOLOGY 2011; 31:1238-1250. [PMID: 22011965 DOI: 10.1093/treephys/tpr104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study examined the role of ectomycorrhizal associations in nitrogen assimilation of Populus tremuloides seedlings. Seedlings were inoculated with Hebeloma crustuliniforme and compared with non-inoculated plants. Nitrogen-metabolizing enzymatic properties were also determined in H. crustuliniforme grown in sterile culture. The seedlings and fungal cultures were subjected to nitrogen treatments (including NO₃⁻, NH₄⁺ and a combination of NO₃⁻ + NH₄⁺) for 2 months to examine the effects on growth, nitrogen-assimilating enzyme activities and xylem sap concentrations of NH₄⁺ and NO₃⁻. Seedlings were also provided for 3 days with ¹⁵N-labeled NH₄⁺ and NO₃⁻, and leaf and root ¹⁵N content relative to total nitrogen was measured. Both NO₃⁻ and NH₄⁺ were effective in supporting seedling growth when either form was provided separately. When NO₃⁻ and NH₄⁺ were provided together, seedling growth decreased while enzymatic assimilation of NH₄⁺ increased. Additionally, nitrogen assimilation in inoculated seedlings was less affected by the form of nitrogen compared with non-inoculated plants. Fungal ability to enzymatically respond to and assimilate NH₄⁺ combined with aspen's enzymatic responsiveness to NO₃⁻ was likely the reason for efficient assimilation of both nitrogen forms by mycorrhizal plants.
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Affiliation(s)
- J Aurea Siemens
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Bldg, Edmonton, AB T6G2E3, Canada
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