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Esteban R, Pollastri S, Brilli F, García-Plazaola JI, Odriozola I, Michelozzi M, Loreto F. Dehydration and rehydration differently affect photosynthesis and volatile monoterpenes in bryophytes with contrasting ecological traits. PHYSIOLOGIA PLANTARUM 2024; 176:e14395. [PMID: 38922932 DOI: 10.1111/ppl.14395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 04/10/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
Bryophytes desiccate rapidly when relative humidity decreases. The capacity to withstand dehydration depends on several ecological and physiological factors. Volatile organic compounds (VOCs) may have a role in enhancing tolerance to desiccating bryophytes. However, the functions of VOCs in bryophytes have received little attention so far. We aimed to investigate the impact of a dehydration-rehydration treatment on primary carbon metabolism and volatile terpenes (VTs) in three bryophytes with contrasting ecological traits: Vessicularia dubyana, Porella platyphylla and Pleurochaete squarrosa. First, we confirmed the desiccation sensitivity gradient of the species. Under fully hydrated conditions, the photosynthetic rate (A) was inversely associated with stress tolerance, with a lower rate in more tolerant species. The partial recovery of A in P. platyphylla and P. squarrosa after rehydration confirmed the desiccation tolerance of these two species. On the other hand, A did not recover after rehydration in V. dubyana. Regarding VT, each species exhibited a distinct VT profile under optimum hydration, with the highest VT pool found in the more desiccation-sensitive species (V. dubyana). However, the observed species-specific VT pattern could be associated with the ecological habitat of each species. P. squarrosa, a moss of dry habitats, may synthesize mainly non-volatile secondary metabolites as stress-defensive compounds. On the other hand, V. dubyana, commonly found submerged, may need to invest photosynthetically assimilated carbon to synthesize a higher amount of VTs to cope with transient water stress occurrence. Further research on the functions of VTs in bryophytes is needed to deepen our understanding of their ecological significance.
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Affiliation(s)
- Raquel Esteban
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/ EHU), Bilbao, Spain
| | - Susanna Pollastri
- Institute for Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), Sesto Fiorentino, Florence, Italy
| | - Federico Brilli
- Institute for Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), Sesto Fiorentino, Florence, Italy
| | | | - Iñaki Odriozola
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/ EHU), Bilbao, Spain
| | - Marco Michelozzi
- Institute of Biosciences and Bioresources (IBBR), National Research Council of Italy (CNR), Sesto Fiorentino, Florence, Italy
| | - Francesco Loreto
- Institute for Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), Sesto Fiorentino, Florence, Italy
- Department of Biology, University of Naples Federico II, Italy
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2
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Nikolić N, Zotz G, Bader MY. Modelling the carbon balance in bryophytes and lichens: Presentation of PoiCarb 1.0, a new model for explaining distribution patterns and predicting climate-change effects. AMERICAN JOURNAL OF BOTANY 2024; 111:e16266. [PMID: 38038342 DOI: 10.1002/ajb2.16266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023]
Abstract
PREMISE Bryophytes and lichens have important functional roles in many ecosystems. Insight into their CO2 -exchange responses to climatic conditions is essential for understanding current and predicting future productivity and biomass patterns, but responses are hard to quantify at time scales beyond instantaneous measurements. We present PoiCarb 1.0, a model to study how CO2 -exchange rates of these poikilohydric organisms change through time as a function of weather conditions. METHODS PoiCarb simulates diel fluctuations of CO2 exchange and estimates long-term carbon balances, identifying optimal and limiting climatic patterns. Modelled processes were net photosynthesis, dark respiration, evaporation and water uptake. Measured CO2 -exchange responses to light, temperature, atmospheric CO2 concentration, and thallus water content (calculated in a separate module) were used to parameterize the model's carbon module. We validated the model by comparing modelled diel courses of net CO2 exchange to such courses from field measurements on the tropical lichen Crocodia aurata. To demonstrate the model's usefulness, we simulated potential climate-change effects. RESULTS Diel patterns were reproduced well, and the modelled and observed diel carbon balances were strongly positively correlated. Simulated warming effects via changes in metabolic rates were consistently negative, while effects via faster drying were variable, depending on the timing of hydration. CONCLUSIONS Reproducing weather-dependent variation in diel carbon balances is a clear improvement compared to simply extrapolating short-term measurements or potential photosynthetic rates. Apart from predicting climate-change effects, future uses of PoiCarb include testing hypotheses about distribution patterns of poikilohydric organisms and guiding conservation strategies for species.
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Affiliation(s)
- Nada Nikolić
- Faculty of Geography, Ecological Plant Geography, University of Marburg, Germany
| | - Gerhard Zotz
- University of Oldenburg, Institute for Biology and Environmental Sciences, Functional Ecology of Plants, Germany
| | - Maaike Y Bader
- Faculty of Geography, Ecological Plant Geography, University of Marburg, Germany
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3
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Yang Q, Liu Z, Houlton BZ, Gao D, Chang Q, Li H, Fan X, Liu B, Bai E. Isotopic evidence for increased carbon and nitrogen exchanges between peatland plants and their symbiotic microbes with rising atmospheric CO 2 concentrations since 15,000 cal. year BP. GLOBAL CHANGE BIOLOGY 2023; 29:1939-1950. [PMID: 36585918 DOI: 10.1111/gcb.16578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/29/2022] [Accepted: 12/16/2022] [Indexed: 05/28/2023]
Abstract
Whether nitrogen (N) availability will limit plant growth and removal of atmospheric CO2 by the terrestrial biosphere this century is controversial. Studies have suggested that N could progressively limit plant growth, as trees and soils accumulate N in slowly cycling biomass pools in response to increases in carbon sequestration. However, a question remains over whether longer-term (decadal to century) feedbacks between climate, CO2 and plant N uptake could emerge to reduce ecosystem-level N limitations. The symbioses between plants and microbes can help plants to acquire N from the soil or from the atmosphere via biological N2 fixation-the pathway through which N can be rapidly brought into ecosystems and thereby partially or completely alleviate N limitation on plant productivity. Here we present measurements of plant N isotope composition (δ15 N) in a peat core that dates to 15,000 cal. year BP to ascertain ecosystem-level N cycling responses to rising atmospheric CO2 concentrations. We find that pre-industrial increases in global atmospheric CO2 concentrations corresponded with a decrease in the δ15 N of both Sphagnum moss and Ericaceae when constrained for climatic factors. A modern experiment demonstrates that the δ15 N of Sphagnum decreases with increasing N2 -fixation rates. These findings suggest that plant-microbe symbioses that facilitate N acquisition are, over the long term, enhanced under rising atmospheric CO2 concentrations, highlighting an ecosystem-level feedback mechanism whereby N constraints on terrestrial carbon storage can be overcome.
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Affiliation(s)
- Qiannan Yang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Ziping Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Benjamin Z Houlton
- Department of Ecology and Evolutionary Biology and Department of Global Development, Cornell University, Ithaca, New York, USA
| | - Decai Gao
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Qing Chang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Hongkai Li
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Xianlei Fan
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Bai Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Edith Bai
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
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4
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Serk H, Nilsson MB, Figueira J, Krüger JP, Leifeld J, Alewell C, Schleucher J. Organochemical Characterization of Peat Reveals Decomposition of Specific Hemicellulose Structures as the Main Cause of Organic Matter Loss in the Acrotelm. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:17410-17419. [PMID: 36399683 PMCID: PMC9730845 DOI: 10.1021/acs.est.2c03513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 10/30/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Peatlands store carbon in the form of dead organic residues. Climate change and human impact impose risks on the sustainability of the peatlands carbon balance due to increased peat decomposition. Here, we investigated molecular changes in the upper peat layers (0-40 cm), inferred from high-resolution vertical depth profiles, from a boreal peatland using two-dimensional 1H-13C nuclear magnetic resonance (NMR) spectroscopy, and comparison to δ13C, δ15N, and carbon and nitrogen content. Effects of hydrological conditions were investigated at respective sites: natural moist, drainage ditch, and natural dry. The molecular characterization revealed preferential degradation of specific side-chain linkages of xylan-type hemicelluloses within 0-14 cm at all sites, indicating organic matter losses up to 25%. In contrast, the xylan backbone, galactomannan-type hemicelluloses, and cellulose were more resistant to degradation and accumulated at the natural moist and drainage site. δ13C, δ15N, and carbon and nitrogen content did not correlate with specific hemicellulose structures but reflected changes in total carbohydrates. Our analysis provides novel insights into peat carbohydrate decomposition and indicates substantial organic matter losses in the acrotelm due to the degradation of specific hemicellulose structures. This suggests that variations in hemicellulose content and structure influence peat stability, which may have important implications with respect to climate change.
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Affiliation(s)
- Henrik Serk
- Department
of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
- Department
of Forest Ecology and Management, Swedish
University of Agricultural Sciences, SE-90183 Umeå, Sweden
| | - Mats B. Nilsson
- Department
of Forest Ecology and Management, Swedish
University of Agricultural Sciences, SE-90183 Umeå, Sweden
| | - João Figueira
- Department
of Chemistry, SciLife Lab, Umeå University, SE-90187 Umeå, Sweden
| | - Jan Paul Krüger
- UDATA
GmbH − Umwelt und Bildung, Hindenburgstrasse 1, 67433 Neustadt an der Weinstraße, Germany
- Departement
Umweltgeowissenschaften, Universität
Basel, Bernoullistrasse
30, CH-4056 Basel, Switzerland
| | - Jens Leifeld
- Departement
Umweltgeowissenschaften, Universität
Basel, Bernoullistrasse
30, CH-4056 Basel, Switzerland
- Agroscope,
Climate and Agriculture Group, Reckenholzstrasse 191, CH-8046 Zurich, Switzerland
| | - Christine Alewell
- Departement
Umweltgeowissenschaften, Universität
Basel, Bernoullistrasse
30, CH-4056 Basel, Switzerland
| | - Jürgen Schleucher
- Department
of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
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Serk H, Nilsson MB, Bohlin E, Ehlers I, Wieloch T, Olid C, Grover S, Kalbitz K, Limpens J, Moore T, Münchberger W, Talbot J, Wang X, Knorr KH, Pancotto V, Schleucher J. Global CO 2 fertilization of Sphagnum peat mosses via suppression of photorespiration during the twentieth century. Sci Rep 2021; 11:24517. [PMID: 34972838 PMCID: PMC8720097 DOI: 10.1038/s41598-021-02953-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Natural peatlands contribute significantly to global carbon sequestration and storage of biomass, most of which derives from Sphagnum peat mosses. Atmospheric CO2 levels have increased dramatically during the twentieth century, from 280 to > 400 ppm, which has affected plant carbon dynamics. Net carbon assimilation is strongly reduced by photorespiration, a process that depends on the CO2 to O2 ratio. Here we investigate the response of the photorespiration to photosynthesis ratio in Sphagnum mosses to recent CO2 increases by comparing deuterium isotopomers of historical and contemporary Sphagnum tissues collected from 36 peat cores from five continents. Rising CO2 levels generally suppressed photorespiration relative to photosynthesis but the magnitude of suppression depended on the current water table depth. By estimating the changes in water table depth, temperature, and precipitation during the twentieth century, we excluded potential effects of these climate parameters on the observed isotopomer responses. Further, we showed that the photorespiration to photosynthesis ratio varied between Sphagnum subgenera, indicating differences in their photosynthetic capacity. The global suppression of photorespiration in Sphagnum suggests an increased net primary production potential in response to the ongoing rise in atmospheric CO2, in particular for mire structures with intermediate water table depths.
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Affiliation(s)
- Henrik Serk
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.,Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Mats B Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
| | - Elisabet Bohlin
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Ina Ehlers
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Thomas Wieloch
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Carolina Olid
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.,Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden
| | - Samantha Grover
- Department of Applied Chemistry and Environmental Science, RMIT University, Melbourne, Australia
| | - Karsten Kalbitz
- Institute of Soil Science and Site Ecology, Dresden University of Technology, Tharandt, Germany
| | - Juul Limpens
- Department of Environmental Sciences, Wageningen University, Wageningen, The Netherlands
| | - Tim Moore
- Department of Geography, McGill University, Montreal, Canada
| | | | - Julie Talbot
- Department of Geography, Université de Montréal, Montreal, Canada
| | - Xianwei Wang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, People's Republic of China
| | | | - Verónica Pancotto
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
| | - Jürgen Schleucher
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
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