1
|
Tcherkez G, Abadie C, Dourmap C, Lalande J, Limami AM. Leaf day respiration: More than just catabolic CO 2 production in the light. PLANT, CELL & ENVIRONMENT 2024; 47:2631-2639. [PMID: 38528759 DOI: 10.1111/pce.14904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/08/2024] [Accepted: 03/18/2024] [Indexed: 03/27/2024]
Abstract
Summary statementDay respiration is a net flux resulting from several CO2‐generating and CO2‐fixing reactions, not only related to catabolism but also to anabolism. We review pieces of evidence that decarboxylating reactions are partly fed by carbon sources disconnected from current photosynthesis and how they reflect various metabolic pathways.
Collapse
Affiliation(s)
- Guillaume Tcherkez
- Institut de recherche en horticulture et semences, Université d'Angers, INRAe, Beaucouzé, France
- Research school of biology, ANU College of Science, Australian National University, Canberra, Australia
| | - Cyril Abadie
- Institut de recherche en horticulture et semences, Université d'Angers, INRAe, Beaucouzé, France
- Ecophysiologie et génomique fonctionnelle de la vigne, Institut des Sciences de la Vigne et du Vin, INRAe, Université de Bordeaux, Villenave-d'Ornon, France
| | - Corentin Dourmap
- Institut de recherche en horticulture et semences, Université d'Angers, INRAe, Beaucouzé, France
| | - Julie Lalande
- Institut de recherche en horticulture et semences, Université d'Angers, INRAe, Beaucouzé, France
| | - Anis M Limami
- Institut de recherche en horticulture et semences, Université d'Angers, INRAe, Beaucouzé, France
| |
Collapse
|
2
|
Hildebrand GA, Honeker LK, Freire-Zapata V, Ayala-Ortiz C, Rajakaruna S, Fudyma J, Daber LE, AminiTabrizi R, Chu RL, Toyoda J, Flowers SE, Hoyt DW, Hamdan R, Gil-Loaiza J, Shi L, Dippold MA, Ladd SN, Werner C, Meredith LK, Tfaily MM. Uncovering the dominant role of root metabolism in shaping rhizosphere metabolome under drought in tropical rainforest plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165689. [PMID: 37481084 DOI: 10.1016/j.scitotenv.2023.165689] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/29/2023] [Accepted: 07/19/2023] [Indexed: 07/24/2023]
Abstract
Plant-soil-microbe interactions are crucial for driving rhizosphere processes that contribute to metabolite turnover and nutrient cycling. With the increasing frequency and severity of water scarcity due to climate warming, understanding how plant-mediated processes, such as root exudation, influence soil organic matter turnover in the rhizosphere is essential. In this study, we used 16S rRNA gene amplicon sequencing, rhizosphere metabolomics, and position-specific 13C-pyruvate labeling to examine the effects of three different plant species (Piper auritum, Hibiscus rosa sinensis, and Clitoria fairchildiana) and their associated microbial communities on soil organic carbon turnover in the rhizosphere. Our findings indicate that in these tropical plants, the rhizosphere metabolome is primarily shaped by the response of roots to drought rather than direct shifts in the rhizosphere bacterial community composition. Specifically, the reduced exudation of plant roots had a notable effect on the metabolome of the rhizosphere of P. auritum, with less reliance on neighboring microbes. Contrary to P. auritum, H. rosa sinensis and C. fairchildiana experienced changes in their exudate composition during drought, causing alterations to the bacterial communities in the rhizosphere. This, in turn, had a collective impact on the rhizosphere's metabolome. Furthermore, the exclusion of phylogenetically distant microbes from the rhizosphere led to shifts in its metabolome. Additionally, C. fairchildiana appeared to be associated with only a subset of symbiotic bacteria under drought conditions. These results indicate that plant species-specific microbial interactions systematically change with the root metabolome. As roots respond to drought, their associated microbial communities adapt, potentially reinforcing the drought tolerance strategies of plant roots. These findings have significant implications for maintaining plant health and preference during drought stress and improving plant performance under climate change.
Collapse
Affiliation(s)
- Gina A Hildebrand
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA
| | - Linnea K Honeker
- BIO5 Institute, The University of Arizona, 1657 E Helen St., Tucson, AZ 85719, USA; School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell St., Tucson, AZ 85721, USA
| | - Viviana Freire-Zapata
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA
| | - Christian Ayala-Ortiz
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA
| | - Sumudu Rajakaruna
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA
| | - Jane Fudyma
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA; Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA 95816, USA
| | - L Erik Daber
- Georges-Köhler-Allee 53/54, University of Freiburg, 79110 Freiburg, Germany
| | - Roya AminiTabrizi
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA
| | - Rosalie L Chu
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Jason Toyoda
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Sarah E Flowers
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - David W Hoyt
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Rasha Hamdan
- Department of Chemistry and Biochemistry, Lebanese University, Beirut, Lebanon
| | - Juliana Gil-Loaiza
- School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell St., Tucson, AZ 85721, USA
| | - Lingling Shi
- Geo-Biosphere Interactions, Department of Geosciences, University of Tuebingen, Schnarrenbergstrasse 94-96, 72076 Tuebingen, Germany
| | - Michaela A Dippold
- Geo-Biosphere Interactions, Department of Geosciences, University of Tuebingen, Schnarrenbergstrasse 94-96, 72076 Tuebingen, Germany
| | - S Nemiah Ladd
- Georges-Köhler-Allee 53/54, University of Freiburg, 79110 Freiburg, Germany; Department of Environmental Science, University of Basel, Bernoullistrasse 30/32, 4056 Basel, Switzerland
| | - Christiane Werner
- Georges-Köhler-Allee 53/54, University of Freiburg, 79110 Freiburg, Germany
| | - Laura K Meredith
- BIO5 Institute, The University of Arizona, 1657 E Helen St., Tucson, AZ 85719, USA; School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell St., Tucson, AZ 85721, USA; Biosphere 2, University of Arizona, 32540 S Biosphere Rd, Oracle, AZ 85739, USA
| | - Malak M Tfaily
- Department of Environmental Science, University of Arizona, 1177 E 4th St., AZ 85721, USA; BIO5 Institute, The University of Arizona, 1657 E Helen St., Tucson, AZ 85719, USA; Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA.
| |
Collapse
|
3
|
Ladd SN, Daber LE, Bamberger I, Kübert A, Kreuzwieser J, Purser G, Ingrisch J, Deleeuw J, van Haren J, Meredith LK, Werner C. Leaf-level metabolic changes in response to drought affect daytime CO2 emission and isoprenoid synthesis pathways. TREE PHYSIOLOGY 2023; 43:1917-1932. [PMID: 37552065 PMCID: PMC10643046 DOI: 10.1093/treephys/tpad094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/28/2023] [Accepted: 07/31/2023] [Indexed: 08/09/2023]
Abstract
In the near future, climate change will cause enhanced frequency and/or severity of droughts in terrestrial ecosystems, including tropical forests. Drought responses by tropical trees may affect their carbon use, including production of volatile organic compounds (VOCs), with implications for carbon cycling and atmospheric chemistry that are challenging to predict. It remains unclear how metabolic adjustments by mature tropical trees in response to drought will affect their carbon fluxes associated with daytime CO2 production and VOC emission. To address this gap, we used position-specific 13C-pyruvate labeling to investigate leaf CO2 and VOC fluxes from four tropical species before and during a controlled drought in the enclosed rainforest of Biosphere 2 (B2). Overall, plants that were more drought-sensitive had greater reductions in daytime CO2 production. Although daytime CO2 production was always dominated by non-mitochondrial processes, the relative contribution of CO2 from the tricarboxylic acid cycle tended to increase under drought. A notable exception was the legume tree Clitoria fairchildiana R.A. Howard, which had less anabolic CO2 production than the other species even under pre-drought conditions, perhaps due to more efficient refixation of CO2 and anaplerotic use for amino acid synthesis. The C. fairchildiana was also the only species to allocate detectable amounts of 13C label to VOCs and was a major source of VOCs in B2. In C. fairchildiana leaves, our data indicate that intermediates from the mevalonic acid (MVA) pathway are used to produce the volatile monoterpene trans-β-ocimene, but not isoprene. This apparent crosstalk between the MVA and methylerythritol phosphate pathways for monoterpene synthesis declined with drought. Finally, although trans-β-ocimene emissions increased under drought, it was increasingly sourced from stored intermediates and not de novo synthesis. Unique metabolic responses of legumes may play a disproportionate role in the overall changes in daytime CO2 and VOC fluxes in tropical forests experiencing drought.
Collapse
Affiliation(s)
- S Nemiah Ladd
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
- Department of Environmental Sciences, University of Basel, Bernoullistrasse 30, Basel 4056, Switzerland
| | - L Erik Daber
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
| | - Ines Bamberger
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
- Atmospheric Chemistry Group, University of Bayreuth (BayCEER), Dr–Hans–Frisch–Straße 1–3, Bayreuth 95448, Germany
| | - Angelika Kübert
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
- Institute for Atmospheric and Earth System Research, University of Helsinki, Pietari Kalmin katu 5, Helsinki 00014, Finland
| | - Jürgen Kreuzwieser
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
| | - Gemma Purser
- School of Chemistry, The University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK
- UK Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, UK
| | - Johannes Ingrisch
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
- Department of Ecology, University of Innsbruck, Sternwartestrasse 15, Innsbruck 6020, Austria
| | - Jason Deleeuw
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
| | - Joost van Haren
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
- Honors College, University of Arizona, 1101 E. Mabel Street, Tucson, AZ 85719, USA
| | - Laura K Meredith
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ, 85721, USA
| | - Christiane Werner
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University of Freiburg, Georges–Köhler–Allee 053/054, Freiburg 79110, Germany
| |
Collapse
|
4
|
Salomón RL, Rodríguez-Calcerrada J, De Roo L, Miranda JC, Bodé S, Boeckx P, Steppe K. Carbon isotope composition of respired CO2 in woody stems and leafy shoots of three tree species along the growing season: physiological drivers for respiratory fractionation. TREE PHYSIOLOGY 2023; 43:1731-1744. [PMID: 37471648 DOI: 10.1093/treephys/tpad091] [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: 05/30/2023] [Revised: 07/10/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
The carbon isotope composition of respired CO2 (δ13CR) and bulk organic matter (δ13CB) of various plant compartments informs about the isotopic fractionation and substrate of respiratory processes, which are crucial to advance the understanding of carbon allocation in plants. Nevertheless, the variation across organs, species and seasons remains poorly understood. Cavity Ring-Down Laser Spectroscopy was applied to measure δ13CR in leafy shoots and woody stems of maple (Acer platanoides L.), oak (Quercus robur L.) and cedar (Thuja occidentalis L.) trees during spring and late summer. Photosynthesis, respiration, growth and non-structural carbohydrates were measured in parallel to evaluate potential drivers for respiratory fractionation. The CO2 respired by maple and oak shoots was 13C-enriched relative to δ13CB during spring, but not late summer or in the stem. In cedar, δ13CR did not vary significantly throughout organs and seasons, with respired CO2 being 13C-depleted relative to δ13CB. Shoot δ13CR was positively related to leaf starch concentration in maple, while stem δ13CR was inversely related to stem growth. These relations were not significant for oak or cedar. The variability in δ13CR suggests (i) different contributions of respiratory pathways between organs and (ii) seasonality in the respiratory substrate and constitutive compounds for wood formation in deciduous species, less apparent in evergreen cedar, whose respiratory metabolism might be less variable.
Collapse
Affiliation(s)
- Roberto L Salomón
- Department of Plants and Crops, Faculty of Bioscience Engineering, Laboratory of Plant Ecology, Ghent University, Coupure links 653, Ghent 9000, Belgium
- Departamento de Sistemas y Recursos Naturales, Research Group FORESCENT, Universidad Politécnica de Madrid, Jose Antonio Novais 10, 28040, Madrid, Spain
| | - Jesús Rodríguez-Calcerrada
- Departamento de Sistemas y Recursos Naturales, Research Group FORESCENT, Universidad Politécnica de Madrid, Jose Antonio Novais 10, 28040, Madrid, Spain
| | - Linus De Roo
- Department of Plants and Crops, Faculty of Bioscience Engineering, Laboratory of Plant Ecology, Ghent University, Coupure links 653, Ghent 9000, Belgium
| | - José Carlos Miranda
- Departamento de Sistemas y Recursos Naturales, Research Group FORESCENT, Universidad Politécnica de Madrid, Jose Antonio Novais 10, 28040, Madrid, Spain
| | - Samuel Bodé
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Coupure links 653, Gent 9000, Belgium
| | - Pascal Boeckx
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Coupure links 653, Gent 9000, Belgium
| | - Kathy Steppe
- Department of Plants and Crops, Faculty of Bioscience Engineering, Laboratory of Plant Ecology, Ghent University, Coupure links 653, Ghent 9000, Belgium
| |
Collapse
|
5
|
Ladd SN, Nelson DB, Bamberger I, Daber LE, Kreuzwieser J, Kahmen A, Werner C. Metabolic exchange between pathways for isoprenoid synthesis and implications for biosynthetic hydrogen isotope fractionation. THE NEW PHYTOLOGIST 2021; 231:1708-1719. [PMID: 34028817 DOI: 10.1111/nph.17510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 05/16/2021] [Indexed: 06/12/2023]
Abstract
Hydrogen isotope ratios of plant lipids are used for paleoclimate reconstruction, but are influenced by both source water and biosynthetic processes. Measuring 2 H : 1 H ratios of multiple compounds produced by different pathways could allow these effects to be separated, but hydrogen isotope fractionations during isoprenoid biosynthesis remain poorly constrained. To investigate how hydrogen isotope fractionation during isoprenoid biosynthesis is influenced by molecular exchange between the cytosolic and plastidial production pathways, we paired position-specific 13 C-pyruvate labeling with hydrogen isotope measurements of lipids in Pachira aquatica saplings. We find that acetogenic compounds primarily incorporated carbon from 13 C2-pyruvate, whereas isoprenoids incorporated 13 C1- and 13 C2-pyruvate equally. This indicates that cytosolic pyruvate is primarily introduced into plastidial isoprenoids via glyceraldehyde 3-phosphate and that plastidial isoprenoid intermediates are incorporated into cytosolic isoprenoids. Probably as a result of the large differences in hydrogen isotope fractionation between plastidial and cytosolic isoprenoid pathways, sterols from P. aquatica are at least 50‰ less 2 H-enriched relative to phytol than sterols in other plants. These results provide the first experimental evidence that incorporation of plastidial intermediates reduces 2 H : 1 H ratios of sterols. This suggests that relative offsets between the 2 H : 1 H ratios of sterols and phytol can trace exchange between the two isoprenoid synthesis pathways.
Collapse
Affiliation(s)
- S Nemiah Ladd
- Chair of Ecosystem Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee 053/054, Freiburg, 79110, Germany
| | - Daniel B Nelson
- Plant Physiological Ecology, Department of Environmental Sciences, University of Basel, Schönbeinstrasse 6, Basel, 4056, Switzerland
| | - Ines Bamberger
- Chair of Ecosystem Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee 053/054, Freiburg, 79110, Germany
| | - L Erik Daber
- Chair of Ecosystem Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee 053/054, Freiburg, 79110, Germany
| | - Jürgen Kreuzwieser
- Chair of Ecosystem Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee 053/054, Freiburg, 79110, Germany
| | - Ansgar Kahmen
- Plant Physiological Ecology, Department of Environmental Sciences, University of Basel, Schönbeinstrasse 6, Basel, 4056, Switzerland
| | - Christiane Werner
- Chair of Ecosystem Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee 053/054, Freiburg, 79110, Germany
| |
Collapse
|
6
|
Werner C, Fasbender L, Romek KM, Yáñez-Serrano AM, Kreuzwieser J. Heat Waves Change Plant Carbon Allocation Among Primary and Secondary Metabolism Altering CO 2 Assimilation, Respiration, and VOC Emissions. FRONTIERS IN PLANT SCIENCE 2020; 11:1242. [PMID: 32922421 PMCID: PMC7456945 DOI: 10.3389/fpls.2020.01242] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 07/29/2020] [Indexed: 05/17/2023]
Abstract
Processes controlling plant carbon allocation among primary and secondary metabolism, i.e., carbon assimilation, respiration, and VOC synthesis are still poorly constrained, particularly regarding their response to stress. To investigate these processes, we simulated a 10-day 38°C heat wave, analysing real-time carbon allocation into primary and secondary metabolism in the Mediterranean shrub Halimium halimifolium L. We traced position-specific 13C-labeled pyruvate into daytime VOC and CO2 emissions and during light-dark transition. Net CO2 assimilation strongly declined under heat, due to three-fold higher respiration rates. Interestingly, day respiration also increased two-fold. Decarboxylation of the C1-atom of pyruvate was the main process driving daytime CO2 release, whereas the C2-moiety was not decarboxylated in the TCA cycle. Heat induced high emissions of methanol, methyl acetate, acetaldehyde as well as mono- and sesquiterpenes, particularly during the first two days. After 10-days of heat a substantial proportion of 13C-labeled pyruvate was allocated into de novo synthesis of VOCs. Thus, during extreme heat waves high respiratory losses and reduced assimilation can shift plants into a negative carbon balance. Still, plants enhanced their investment into de novo VOC synthesis despite associated metabolic CO2 losses. We conclude that heat stress re-directed the proportional flux of key metabolites into pathways of VOC biosynthesis most likely at the expense of reactions of plant primary metabolism, which might highlight their importance for stress protection.
Collapse
Affiliation(s)
- Christiane Werner
- Ecosystem Physiology, University of Freiburg, Freiburg, Germany
- *Correspondence: Christiane Werner,
| | - Lukas Fasbender
- Ecosystem Physiology, University of Freiburg, Freiburg, Germany
| | | | - Ana Maria Yáñez-Serrano
- Ecosystem Physiology, University of Freiburg, Freiburg, Germany
- Center of Ecological Research and Forest Applications (CREAF), Universitat Autònoma de Barcelona, Barcelona, Spain
- Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, Barcelona, Spain
| | | |
Collapse
|
7
|
Giuliani R, Karki S, Covshoff S, Lin HC, Coe RA, Koteyeva NK, Quick WP, Von Caemmerer S, Furbank RT, Hibberd JM, Edwards GE, Cousins AB. Knockdown of glycine decarboxylase complex alters photorespiratory carbon isotope fractionation in Oryza sativa leaves. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2773-2786. [PMID: 30840760 PMCID: PMC6506765 DOI: 10.1093/jxb/erz083] [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: 10/23/2018] [Accepted: 02/12/2019] [Indexed: 05/07/2023]
Abstract
The influence of reduced glycine decarboxylase complex (GDC) activity on leaf atmosphere CO2 and 13CO2 exchange was tested in transgenic Oryza sativa with the GDC H-subunit knocked down in leaf mesophyll cells. Leaf measurements on transgenic gdch knockdown and wild-type plants were carried out in the light under photorespiratory and low photorespiratory conditions (i.e. 18.4 kPa and 1.84 kPa atmospheric O2 partial pressure, respectively), and in the dark. Under approximately current ambient O2 partial pressure (18.4 kPa pO2), the gdch knockdown plants showed an expected photorespiratory-deficient phenotype, with lower leaf net CO2 assimilation rates (A) than the wild-type. Additionally, under these conditions, the gdch knockdown plants had greater leaf net discrimination against 13CO2 (Δo) than the wild-type. This difference in Δo was in part due to lower 13C photorespiratory fractionation (f) ascribed to alternative decarboxylation of photorespiratory intermediates. Furthermore, the leaf dark respiration rate (Rd) was enhanced and the 13CO2 composition of respired CO2 (δ13CRd) showed a tendency to be more depleted in the gdch knockdown plants. These changes in Rd and δ13CRd were due to the amount and carbon isotopic composition of substrates available for dark respiration. These results demonstrate that impairment of the photorespiratory pathway affects leaf 13CO2 exchange, particularly the 13C decarboxylation fractionation associated with photorespiration.
Collapse
Affiliation(s)
- Rita Giuliani
- School of Biological Sciences, Molecular Plant Sciences, Washington State University, Pullman, WA, USA
| | - Shanta Karki
- C4 Rice Center, International Rice Research Institute (IRRI), Los Baños, Philippines
| | - Sarah Covshoff
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Hsiang-Chun Lin
- C4 Rice Center, International Rice Research Institute (IRRI), Los Baños, Philippines
| | - Robert A Coe
- C4 Rice Center, International Rice Research Institute (IRRI), Los Baños, Philippines
| | - Nuria K Koteyeva
- Laboratory of Anatomy and Morphology, V.L. Komarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia
| | - W Paul Quick
- C4 Rice Center, International Rice Research Institute (IRRI), Los Baños, Philippines
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Susanne Von Caemmerer
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, Australia
| | - Robert T Furbank
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, Australia
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Gerald E Edwards
- School of Biological Sciences, Molecular Plant Sciences, Washington State University, Pullman, WA, USA
| | - Asaph B Cousins
- School of Biological Sciences, Molecular Plant Sciences, Washington State University, Pullman, WA, USA
| |
Collapse
|
8
|
Lehmann MM, Ghiasi S, George GM, Cormier MA, Gessler A, Saurer M, Werner RA. Influence of starch deficiency on photosynthetic and post-photosynthetic carbon isotope fractionations. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1829-1841. [PMID: 30785201 PMCID: PMC6436151 DOI: 10.1093/jxb/erz045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/21/2019] [Indexed: 05/27/2023]
Abstract
Carbon isotope (13C) fractionations occurring during and after photosynthetic CO2 fixation shape the carbon isotope composition (δ13C) of plant material and respired CO2. However, responses of 13C fractionations to diel variation in starch metabolism in the leaf are not fully understood. Here we measured δ13C of organic matter (δ13COM), concentrations and δ13C of potential respiratory substrates, δ13C of dark-respired CO2 (δ13CR), and gas exchange in leaves of starch-deficient plastidial phosphoglucomutase (pgm) mutants and wild-type plants of four species (Arabidopsis thaliana, Mesembryanthemum crystallinum, Nicotiana sylvestris, and Pisum sativum). The strongest δ13C response to the pgm-induced starch deficiency was observed in N. sylvestris, with more negative δ13COM, δ13CR, and δ13C values for assimilates (i.e. sugars and starch) and organic acids (i.e. malate and citrate) in pgm mutants than in wild-type plants during a diel cycle. The genotype differences in δ13C values could be largely explained by differences in leaf gas exchange. In contrast, the PGM-knockout effect on post-photosynthetic 13C fractionations via the plastidic fructose-1,6-bisphosphate aldolase reaction or during respiration was small. Taken together, our results show that the δ13C variations in starch-deficient mutants are primarily explained by photosynthetic 13C fractionations and that the combination of knockout mutants and isotope analyses allows additional insights into plant metabolism.
Collapse
Affiliation(s)
- Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse, Birmensdorf, Switzerland
| | - Shiva Ghiasi
- Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse, Zurich, Switzerland
| | - Gavin M George
- Institute of Molecular Plant Biology, ETH Zurich, Universitaetstrasse, Zurich, Switzerland
| | - Marc-André Cormier
- GFZ – German Research Centre for Geosciences, Geomorphology, Organic Surface Geochemistry Lab, Telegrafenberg, Wissenschaftspark Albert Einstein, Potsdam, Germany
- University of Oxford, Department of Earth Sciences, Ocean Biogeochemistry Group, South Parks Road, Oxford, UK
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse, Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, Universitaetstrasse, Zurich, Switzerland
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse, Birmensdorf, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse, Zurich, Switzerland
| |
Collapse
|
9
|
Fasbender L, Yáñez-Serrano AM, Kreuzwieser J, Dubbert D, Werner C. Real-time carbon allocation into biogenic volatile organic compounds (BVOCs) and respiratory carbon dioxide (CO2) traced by PTR-TOF-MS, 13CO2 laser spectroscopy and 13C-pyruvate labelling. PLoS One 2018; 13:e0204398. [PMID: 30252899 PMCID: PMC6155514 DOI: 10.1371/journal.pone.0204398] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 09/07/2018] [Indexed: 01/09/2023] Open
Abstract
Our understanding of biogenic volatile organic compound (BVOC) emissions improved substantially during the last years. Nevertheless, there are still large uncertainties of processes controlling plant carbon investment into BVOCs, of some biosynthetic pathways and their linkage to CO2 decarboxylation at central metabolic branching points. To shed more light on carbon partitioning during BVOC biosynthesis, we used an innovative approach combining δ13CO2 laser spectroscopy, high-sensitivity proton-transfer-reaction time-of-flight mass spectrometry and a multiple branch enclosure system in combination with position-specific 13C-metabolite labelling. Feeding experiments with position-specific 13C-labelled pyruvate, a central metabolite of BVOC synthesis, enabled online detection of carbon partitioning into 13C-BVOCs and respiratory 13CO2. Measurements of trace gas emissions of the Mediterranean shrub Halimium halimifolium revealed a broad range of emitted BVOCs. In general, [2-13C]-PYR was rapidly incorporated into emitted acetic acid, methyl acetate, toluene, cresol, trimethylbenzene, ethylphenol, monoterpenes and sesquiterpenes, indicating de novo BVOC biosynthesis of these compounds. In contrast, [1-13C]-pyruvate labelling substantially increased 13CO2 emissions in the light indicating C1-decarboxylation. Similar labelling patterns of methyl acetate and acetic acid suggested tightly connected biosynthetic pathways and, furthermore, there were hints of possible biosynthesis of benzenoids via the MEP-pathway. Overall, substantial CO2 emission from metabolic branching points during de novo BVOC biosynthesis indicated that decarboxylation of [1-13C]-pyruvate, as a non-mitochondrial source of CO2, seems to contribute considerably to daytime CO2 release from leaves. Our approach, combining synchronised BVOC and CO2 measurements in combination with position-specific labelling opens the door for real-time analysis tracing metabolic pathways and carbon turnover under different environmental conditions, which may enhance our understanding of regulatory mechanisms in plant carbon metabolism and BVOC biosynthesis.
Collapse
Affiliation(s)
- Lukas Fasbender
- Ecosystem Physiology, Institute of Forest Sciences, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Ana Maria Yáñez-Serrano
- Ecosystem Physiology, Institute of Forest Sciences, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Jürgen Kreuzwieser
- Ecosystem Physiology, Institute of Forest Sciences, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - David Dubbert
- Ecosystem Physiology, Institute of Forest Sciences, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Christiane Werner
- Ecosystem Physiology, Institute of Forest Sciences, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| |
Collapse
|
10
|
Zhong S, Chai H, Xu Y, Li Y, Ma JY, Sun W. Drought Sensitivity of the Carbon Isotope Composition of Leaf Dark-Respired CO 2 in C 3 ( Leymus chinensis) and C 4 ( Chloris virgata and Hemarthria altissima) Grasses in Northeast China. FRONTIERS IN PLANT SCIENCE 2017; 8:1996. [PMID: 29375587 PMCID: PMC5770615 DOI: 10.3389/fpls.2017.01996] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 11/07/2017] [Indexed: 05/13/2023]
Abstract
Whether photosynthetic pathway differences exist in the amplitude of nighttime variations in the carbon isotope composition of leaf dark-respired CO2 (δ13Cl) and respiratory apparent isotope fractionation relative to biomass (ΔR,biomass) in response to drought stress is unclear. These differences, if present, would be important for the partitioning of C3-C4 mixed ecosystem C fluxes. We measured δ13Cl, the δ13C of biomass and of potential respiratory substrates and leaf gas exchange in one C3 (Leymus chinensis) and two C4 (Chloris virgata and Hemarthria altissima) grasses during a manipulated drought period. For all studied grasses, δ13Cl decreased from 21:00 to 03:00 h. The magnitude of the nighttime shift in δ13Cl decreased with increasing drought stress. The δ13Cl values were correlated with the δ13C of respiratory substrates, whereas the magnitude of the nighttime shift in δ13Cl strongly depended on the daytime carbon assimilation rate and the range of nighttime variations in the respiratory substrate content. The ΔR,biomass in the C3 and C4 grasses varied in opposite directions with the intensification of the drought stress. The contribution of C4 plant-associated carbon flux is likely to be overestimated if carbon isotope signatures are used for the partitioning of ecosystem carbon exchange and the δ13C of biomass is used as a substitute for leaf dark-respired CO2. The detected drought sensitivities in δ13Cl and differences in respiratory apparent isotope fractionation between C3 and C4 grasses have marked implications for isotope partitioning studies at the ecosystem level.
Collapse
Affiliation(s)
- Shangzhi Zhong
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Hua Chai
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Yueqiao Xu
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Yan Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Jian-Ying Ma
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Wei Sun
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| |
Collapse
|
11
|
Lehmann MM, Wegener F, Werner RA, Werner C. Diel variations in carbon isotopic composition and concentration of organic acids and their impact on plant dark respiration in different species. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:776-84. [PMID: 27086877 DOI: 10.1111/plb.12464] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/13/2016] [Indexed: 05/19/2023]
Abstract
Leaf respiration in the dark and its C isotopic composition (δ(13) CR ) contain information about internal metabolic processes and respiratory substrates. δ(13) CR is known to be less negative compared to potential respiratory substrates, in particular shortly after darkening during light enhanced dark respiration (LEDR). This phenomenon might be driven by respiration of accumulated (13) C-enriched organic acids, however, studies simultaneously measuring δ(13) CR during LEDR and potential respiratory substrates are rare. We determined δ(13) CR and respiration rates (R) during LEDR, as well as δ(13) C and concentrations of potential respiratory substrates using compound-specific isotope analyses. The measurements were conducted throughout the diel cycle in several plant species under different environmental conditions. δ(13) CR and R patterns during LEDR were strongly species-specific and showed an initial peak, which was followed by a progressive decrease in both values. The species-specific differences in δ(13) CR and R during LEDR may be partially explained by the isotopic composition of organic acids (e.g., oxalate, isocitrate, quinate, shikimate, malate), which were (13) C-enriched compared to other respiratory substrates (e.g., sugars and amino acids). However, the diel variations in both δ(13) C and concentrations of the organic acids were generally low. Thus, additional factors such as the heterogeneous isotope distribution in organic acids and the relative contribution of the organic acids to respiration are required to explain the strong (13) C enrichment in leaf dark-respired CO2 .
Collapse
Affiliation(s)
- M M Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, Switzerland
- Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - F Wegener
- Ecosystem Physiology, University Freiburg, Freiburg, Germany
| | - R A Werner
- Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - C Werner
- Ecosystem Physiology, University Freiburg, Freiburg, Germany
| |
Collapse
|
12
|
Lehmann MM, Wegener F, Barthel M, Maurino VG, Siegwolf RTW, Buchmann N, Werner C, Werner RA. Metabolic Fate of the Carboxyl Groups of Malate and Pyruvate and their Influence on δ(13)C of Leaf-Respired CO2 during Light Enhanced Dark Respiration. FRONTIERS IN PLANT SCIENCE 2016; 7:739. [PMID: 27375626 PMCID: PMC4891945 DOI: 10.3389/fpls.2016.00739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/13/2016] [Indexed: 05/03/2023]
Abstract
The enhanced CO2 release of illuminated leaves transferred into darkness, termed "light enhanced dark respiration (LEDR)", is often associated with an increase in the carbon isotope ratio of the respired CO2 (δ(13)CLEDR). The latter has been hypothesized to result from different respiratory substrates and decarboxylation reactions in various metabolic pathways, which are poorly understood so far. To provide a better insight into the underlying metabolic processes of δ(13)CLEDR, we fed position-specific (13)C-labeled malate and pyruvate via the xylem stream to leaves of species with high and low δ(13)CLEDR values (Halimium halimifolium and Oxalis triangularis, respectively). During respective label application, we determined label-derived leaf (13)CO2 respiration using laser spectroscopy and the (13)C allocation to metabolic fractions during light-dark transitions. Our results clearly show that both carboxyl groups (C-1 and C-4 position) of malate similarly influence respiration and metabolic fractions in both species, indicating possible isotope randomization of the carboxyl groups of malate by the fumarase reaction. While C-2 position of pyruvate was only weakly respired, the species-specific difference in natural δ(13)CLEDR patterns were best reflected by the (13)CO2 respiration patterns of the C-1 position of pyruvate. Furthermore, (13)C label from malate and pyruvate were mainly allocated to amino and organic acid fractions in both species and only little to sugar and lipid fractions. In summary, our results suggest that respiration of both carboxyl groups of malate (via fumarase) by tricarboxylic acid cycle reactions or by NAD-malic enzyme influences δ(13)CLEDR. The latter supplies the pyruvate dehydrogenase reaction, which in turn determines natural δ(13)CLEDR pattern by releasing the C-1 position of pyruvate.
Collapse
Affiliation(s)
- Marco M. Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer InstituteVilligen, Switzerland
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | | | - Matti Barthel
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | - Veronica G. Maurino
- Plant Molecular Physiology and Biotechnology Group, Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University and Cluster of Excellence on Plant Sciences (CEPLAS)Düsseldorf, Germany
| | - Rolf T. W. Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer InstituteVilligen, Switzerland
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | | | - Roland A. Werner
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| |
Collapse
|
13
|
Ghashghaie J, Badeck FW, Girardin C, Huignard C, Aydinlis Z, Fonteny C, Priault P, Fresneau C, Lamothe-Sibold M, Streb P, Terwilliger VJ. Changes and their possible causes in δ13C of dark-respired CO2 and its putative bulk and soluble sources during maize ontogeny. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2603-15. [PMID: 26970389 DOI: 10.1093/jxb/erw075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The issues of whether, where, and to what extent carbon isotopic fractionations occur during respiration affect interpretations of plant functions that are important to many disciplines across the natural sciences. Studies of carbon isotopic fractionation during dark respiration in C3 plants have repeatedly shown respired CO2 to be (13)C enriched relative to its bulk leaf sources and (13)C depleted relative to its bulk root sources. Furthermore, two studies showed respired CO2 to become progressively (13)C enriched during leaf ontogeny and (13)C depleted during root ontogeny in C3 legumes. As such data on C4 plants are scarce and contradictory, we investigated apparent respiratory fractionations of carbon and their possible causes in different organs of maize plants during early ontogeny. As in the C3 plants, leaf-respired CO2 was (13)C enriched whereas root-respired CO2 was (13)C depleted relative to their putative sources. In contrast to the findings for C3 plants, however, not only root- but also leaf-respired CO2 became more (13)C depleted during ontogeny. Leaf-respired CO2 was highly (13)C enriched just after light-dark transition but the enrichment rapidly decreased over time in darkness. We conclude that (i) although carbon isotopic fractionations in C4 maize and leguminous C3 crop roots are similar, increasing phosphoenolpyruvate-carboxylase activity during maize ontogeny could have produced the contrast between the progressive (13)C depletion of maize leaf-respired CO2 and (13)C enrichment of C3 leaf-respired CO2 over time, and (ii) in both maize and C3 leaves, highly (13)C enriched leaf-respired CO2 at light-to-dark transition and its rapid decrease during darkness, together with the observed decrease in leaf malate content, may be the result of a transient effect of light-enhanced dark respiration.
Collapse
Affiliation(s)
- Jaleh Ghashghaie
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Franz W Badeck
- Genomics Research Centre, Council for Agricultural Research and Economics, 29017 Fiorenzuola d'Arda (PC), Italy
| | - Cyril Girardin
- UMR ECOSYS, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Christophe Huignard
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Zackarie Aydinlis
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Charlotte Fonteny
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Pierrick Priault
- Université de Lorraine, UMR Ecologie et Ecophysiologie Forestière, 54506 Vandoeuvre-lès-Nancy, France INRA, UMR Ecologie et Ecophysiologie Forestière, 54280 Champenoux, France
| | - Chantal Fresneau
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Marlène Lamothe-Sibold
- Institute of Plant Sciences Paris-Saclay, IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, 91405 Orsay, France
| | - Peter Streb
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Valery J Terwilliger
- Department of Geography, 1475 Jayhawk Drive, University of Kansas, Lawrence, KS 66045, USA School of Natural Sciences, 5200 North Lake Road, University of California, CA 95343, USA
| |
Collapse
|
14
|
Cui H, Wang Y, Jiang Q, Chen S, Ma JY, Sun W. Carbon Isotope Composition of Nighttime Leaf-Respired CO2 in the Agricultural-Pastoral Zone of the Songnen Plain, Northeast China. PLoS One 2015; 10:e0137575. [PMID: 26356083 PMCID: PMC4565631 DOI: 10.1371/journal.pone.0137575] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/18/2015] [Indexed: 11/23/2022] Open
Abstract
Variations in the carbon isotope signature of leaf dark-respired CO2 (δ13CR) within a single night is a widely observed phenomenon. However, it is unclear whether there are plant functional type differences with regard to the amplitude of the nighttime variation in δ13CR. These differences, if present, would be important for interpreting the short-term variations in the stable carbon signature of ecosystem respiration and the partitioning of carbon fluxes. To assess the plant functional type differences relating to the magnitude of the nighttime variation in δ13CR and the respiratory apparent fractionation, we measured the δ13CR, the leaf gas exchange, and the δ13C of the respiratory substrates of 22 species present in the agricultural-pastoral zone of the Songnen Plain, northeast China. The species studied were grouped into C3 and C4 plants, trees, grasses, and herbs. A significant nocturnal shift in δ13CR was detected in 20 of the studied species, with the magnitude of the shift ranging from 1‰ to 5.8‰. The magnitude of the nighttime variation in δ13CR was strongly correlated with the daytime cumulative carbon assimilation, which suggests that variation in δ13CR were influenced, to some extent, by changes in the contribution of malate decarboxylation to total respiratory CO2 flux. There were no differences in the magnitude of the nighttime variation in δ13CR between the C3 and C4 plants, as well as among the woody plants, herbs and graminoids. Leaf respired CO2 was enriched in 13C compared to biomass, soluble carbohydrates and lipids; however the magnitude of enrichment differed between 8 pm and 4 am, which were mainly caused by the changes in δ13CR. We also detected the plant functional type differences in respiratory apparent fractionation relative to biomass at 4 am, which suggests that caution should be exercised when using the δ13C of bulk leaf material as a proxy for the δ13C of leaf-respired CO2.
Collapse
Affiliation(s)
- Haiying Cui
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, Jilin Province, P. R. China, 130024
| | - Yunbo Wang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, Jilin Province, P. R. China, 130024
| | - Qi Jiang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, Jilin Province, P. R. China, 130024
| | - Shiping Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, P. R. China, 100093
| | - Jian-Ying Ma
- Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, P. R. China, 830011
| | - Wei Sun
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, Jilin Province, P. R. China, 130024
| |
Collapse
|
15
|
Lehmann MM, Rinne KT, Blessing C, Siegwolf RTW, Buchmann N, Werner RA. Malate as a key carbon source of leaf dark-respired CO2 across different environmental conditions in potato plants. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:5769-81. [PMID: 26139821 PMCID: PMC4566975 DOI: 10.1093/jxb/erv279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Dissimilation of carbon sources during plant respiration in support of metabolic processes results in the continuous release of CO2. The carbon isotopic composition of leaf dark-respired CO2 (i.e. δ (13) C R ) shows daily enrichments up to 14.8‰ under different environmental conditions. However, the reasons for this (13)C enrichment in leaf dark-respired CO2 are not fully understood, since daily changes in δ(13)C of putative leaf respiratory carbon sources (δ (13) C RS ) are not yet clear. Thus, we exposed potato plants (Solanum tuberosum) to different temperature and soil moisture treatments. We determined δ (13) C R with an in-tube incubation technique and δ (13) C RS with compound-specific isotope analysis during a daily cycle. The highest δ (13) C RS values were found in the organic acid malate under different environmental conditions, showing less negative values compared to δ (13) C R (up to 5.2‰) and compared to δ (13) C RS of soluble carbohydrates, citrate and starch (up to 8.8‰). Moreover, linear relationships between δ (13) C R and δ (13) C RS among different putative carbon sources were strongest for malate during daytime (r(2)=0.69, P≤0.001) and nighttime (r(2)=0.36, P≤0.001) under all environmental conditions. A multiple linear regression analysis revealed δ (13) C RS of malate as the most important carbon source influencing δ (13) C R . Thus, our results strongly indicate malate as a key carbon source of (13)C enriched dark-respired CO2 in potato plants, probably driven by an anapleurotic flux replenishing intermediates of the Krebs cycle.
Collapse
Affiliation(s)
- Marco M Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland Institute of Agricultural Sciences, ETH Zurich, Universitaetsstr. 2, CH-8092 Zurich, Switzerland
| | - Katja T Rinne
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Carola Blessing
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstr. 2, CH-8092 Zurich, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstr. 2, CH-8092 Zurich, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstr. 2, CH-8092 Zurich, Switzerland
| |
Collapse
|
16
|
Wegener F, Beyschlag W, Werner C. High intraspecific ability to adjust both carbon uptake and allocation under light and nutrient reduction in Halimium halimifolium L. FRONTIERS IN PLANT SCIENCE 2015; 6:609. [PMID: 26300906 PMCID: PMC4528176 DOI: 10.3389/fpls.2015.00609] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 07/23/2015] [Indexed: 05/28/2023]
Abstract
The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. In the present study, we investigated the regulation of C uptake and allocation and their adjustments during plant growth. We induced different allocation strategies in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analyzed allocation parameters as well as morphological and physiological traits for 15 months. Further, we conducted a (13)CO2 pulse-labeling and followed the way of recently assimilated carbon to eight different tissue classes and respiration for 13 days. The plant responses were remarkably distinct in our study, with mainly morphological/physiological adaptions in case of light reduction and adjustment of C allocation in case of nutrient reduction. The transport of recently assimilated C to the root system was enhanced in amount (c. 200%) and velocity under nutrient limited conditions compared to control plants. Despite the 57% light reduction the total biomass production was not affected in the Low L treatment. The plants probably compensated light reduction by an improvement of their ability to fix C. Thus, our results support the concept that photosynthesis is, at least in a medium term perspective, influenced by the C demand of the plant and not exclusively by environmental factors. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C reflux from storage and structural C pools and therefore enhance the fraction of recent assimilates allocated to respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a regulation mechanism for C translocation in plants.
Collapse
Affiliation(s)
- Frederik Wegener
- Ecosystem Physiology, University of FreiburgFreiburg, Germany
- AgroEcosystem Research, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of BayreuthBayreuth, Germany
| | - Wolfram Beyschlag
- Experimental and Systems Ecology, University of BielefeldBielefeld, Germany
| | - Christiane Werner
- Ecosystem Physiology, University of FreiburgFreiburg, Germany
- AgroEcosystem Research, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of BayreuthBayreuth, Germany
| |
Collapse
|
17
|
Wegener F, Beyschlag W, Werner C. Dynamic carbon allocation into source and sink tissues determine within-plant differences in carbon isotope ratios. FUNCTIONAL PLANT BIOLOGY : FPB 2015; 42:620-629. [PMID: 32480706 DOI: 10.1071/fp14152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 03/10/2015] [Indexed: 05/28/2023]
Abstract
Organs of C3 plants differ in their C isotopic signature (δ13C). In general, leaves are 13C-depleted relative to other organs. To investigate the development of spatial δ13C patterns, we induced different C allocation strategies by reducing light and nutrient availability for 12 months in the Mediterranean shrub Halimium halimifolium L. We measured morphological and physiological traits and the spatial δ13C variation among seven tissue classes during the experiment. A reduction of light (Low-L treatment) increased aboveground C allocation, plant height and specific leaf area. Reduced nutrient availability (Low-N treatment) enhanced C allocation into fine roots and reduced the spatial δ13C variation. In contrast, control and Low-L plants with high C allocation in new leaves showed a high δ13C variation within the plant (up to 2.5‰). The spatial δ13C variation was significantly correlated with the proportion of second-generation leaves from whole-plant biomass (R2=0.46). According to our results, isotope fractionation in dark respiration can influence the C isotope composition of plant tissues but cannot explain the entire spatial pattern seen. Our study indicates a foliar depletion in 13C during leaf development combined with export of relatively 13C-enriched C by mature source leaves as an important reason for the observed spatial δ13C pattern.
Collapse
Affiliation(s)
- Frederik Wegener
- AgroEcosystem Research, BAYCEER, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Wolfram Beyschlag
- Experimental and Systems Ecology, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Christiane Werner
- AgroEcosystem Research, BAYCEER, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| |
Collapse
|
18
|
Alexova R, Nelson CJ, Jacoby RP, Millar AH. Exposure of barley plants to low Pi leads to rapid changes in root respiration that correlate with specific alterations in amino acid substrates. THE NEW PHYTOLOGIST 2015; 206:696-708. [PMID: 25557489 DOI: 10.1111/nph.13245] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 11/18/2014] [Indexed: 05/28/2023]
Abstract
The majority of inorganic phosphate (Pi ) stress studies in plants have focused on the response after growth has been retarded. Evidence from transcript analysis, however, shows that a Pi -stress specific response is initiated within minutes of transfer to low Pi and in crop plants precedes the expression of Pi transporters and depletion of vacuolar Pi reserves by days. In order to investigate the physiological and metabolic events during early exposure to low Pi in grain crops, we monitored the response of whole barley plants during the first hours following Pi withdrawal. Lowering the concentration of Pi led to rapid changes in root respiration and leaf gas exchange throughout the early phase of the light course. Combining amino and organic acid analysis with (15) N labelling we show a root-specific effect on nitrogen metabolism linked to specific substrates of respiration as soon as 1 h following Pi withdrawal; this explains the respiratory responses observed and was confirmed by stimulation of respiration by exogenous addition of these respiratory substrates to roots. The rapid adjustment of substrates for respiration in roots during short-term Pi -stress is highlighted and this could help guide roots towards Pi -rich soil patches without compromising biomass accumulation of the plant.
Collapse
Affiliation(s)
- Ralitza Alexova
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia; Centre for Comparative Analysis of Biomolecular Networks, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | | | | | | |
Collapse
|
19
|
Schmidt HL, Robins RJ, Werner RA. Multi-factorial in vivo stable isotope fractionation: causes, correlations, consequences and applications. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2015; 51:155-199. [PMID: 25894429 DOI: 10.1080/10256016.2015.1014355] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many physical and chemical processes in living systems are accompanied by isotope fractionation on H, C, N, O and S. Although kinetic or thermodynamic isotope effects are always the basis, their in vivo manifestation is often modulated by secondary influences. These include metabolic branching events or metabolite channeling, metabolite pool sizes, reaction mechanisms, anatomical properties and compartmentation of plants and animals, and climatological or environmental conditions. In the present contribution, the fundamentals of isotope effects and their manifestation under in vivo conditions are outlined. The knowledge about and the understanding of these interferences provide a potent tool for the reconstruction of physiological events in plants and animals, their geographical origin, the history of bulk biomass and the biosynthesis of defined representatives. It allows the use of isotope characteristics of biomass for the elucidation of biochemical pathways and reaction mechanisms and for the reconstruction of climatic, physiological, ecological and environmental conditions during biosynthesis. Thus, it can be used for the origin and authenticity control of food, the study of ecosystems and animal physiology, the reconstruction of present and prehistoric nutrition chains and paleaoclimatological conditions. This is demonstrated by the outline of fundamental and application-orientated examples for all bio-elements. The aim of the review is to inform (advanced) students from various disciplines about the whole potential and the scope of stable isotope characteristics and fractionations and to provide them with a comprehensive introduction to the literature on fundamental aspects and applications.
Collapse
Affiliation(s)
- Hanns-Ludwig Schmidt
- a Lehrstuhl für Biologische Chemie , Technische Universität München , Freising-Weihenstephan, Germany
| | | | | |
Collapse
|
20
|
Nogués S, Aljazairi S, Arias C, Sánchez E, Aranjuelo I. Two distinct plant respiratory physiotypes might exist which correspond to fast-growing and slow-growing species. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:1157-1163. [PMID: 24973588 DOI: 10.1016/j.jplph.2014.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/04/2014] [Accepted: 03/19/2014] [Indexed: 06/03/2023]
Abstract
The origin of the carbon atoms in CO2 respired by leaves in the dark of several plant species has been studied using 13C/12C stable isotopes. This study was conducted using an open gas exchange system for isotope labeling that was coupled to an elemental analyzer and further linked to an isotope ratio mass spectrometer (EA-IRMS) or coupled to a gas chromatography-combustion-isotope ratio mass spectrometer (GC-C-IRMS). We demonstrate here that the carbon, which is recently assimilated during photosynthesis, accounts for nearly ca. 50% of the carbon in the CO2 lost through dark respiration (Rd) after illumination in fast-growing and cultivated plants and trees and, accounts for only ca. 10% in slow-growing plants. Moreover, our study shows that fast-growing plants, which had the largest percentages of newly fixed carbon of leaf-respired CO2, were also those with the largest shoot/root ratios, whereas slow-growing plants showed the lowest shoot/root values.
Collapse
Affiliation(s)
- Salvador Nogués
- Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Universitat de Barcelona, E-08028 Barcelona, Spain.
| | - Salvador Aljazairi
- Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Claudia Arias
- Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Elena Sánchez
- Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Iker Aranjuelo
- Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Universitat de Barcelona, E-08028 Barcelona, Spain
| |
Collapse
|
21
|
Jardine K, Wegener F, Abrell L, van Haren J, Werner C. Phytogenic biosynthesis and emission of methyl acetate. PLANT, CELL & ENVIRONMENT 2014; 37:414-24. [PMID: 23862653 DOI: 10.1111/pce.12164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/07/2013] [Accepted: 07/08/2013] [Indexed: 05/19/2023]
Abstract
Acetylation of plant metabolites fundamentally changes their volatility, solubility and activity as semiochemicals. Here we present a new technique termed dynamic (13) C-pulse chasing to track the fate of C1-3 carbon atoms of pyruvate into the biosynthesis and emission of methyl acetate (MA) and CO2 . (13) C-labelling of MA and CO2 branch emissions respond within minutes to changes in (13) C-positionally labelled pyruvate solutions fed through the transpiration stream. Strong (13) C-labelling of MA emissions occurred only under pyruvate-2-(13) C and pyruvate-2,3-(13) C feeding, but not pyruvate-1-(13) C feeding. In contrast, strong (13) CO2 emissions were only observed under pyruvate-1-(13) C feeding. These results demonstrate that MA (and other volatile and non-volatile metabolites) derive from the C2,3 atoms of pyruvate while the C1 atom undergoes decarboxylation. The latter is a non-mitochondrial source of CO2 in the light generally not considered in studies of CO2 sources and sinks. Within a tropical rainforest mesocosm, we also observed atmospheric concentrations of MA up to 0.6 ppbv that tracked light and temperature conditions. Moreover, signals partially attributed to MA were observed in ambient air within and above a tropical rainforest in the Amazon. Our study highlights the potential importance of acetyl coenzyme A (CoA) biosynthesis as a source of acetate esters and CO2 to the atmosphere.
Collapse
Affiliation(s)
- Kolby Jardine
- Climate Science Department, Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | | | | | | |
Collapse
|
22
|
Ghashghaie J, Badeck FW. Opposite carbon isotope discrimination during dark respiration in leaves versus roots - a review. THE NEW PHYTOLOGIST 2014; 201:751-769. [PMID: 24251924 DOI: 10.1111/nph.12563] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 09/15/2013] [Indexed: 05/13/2023]
Abstract
In general, leaves are (13) C-depleted compared with all other organs (e.g. roots, stem/trunk and fruits). Different hypotheses are formulated in the literature to explain this difference. One of these states that CO2 respired by leaves in the dark is (13) C-enriched compared with leaf organic matter, while it is (13) C-depleted in the case of root respiration. The opposite respiratory fractionation between leaves and roots was invoked as an explanation for the widespread between-organ isotopic differences. After summarizing the basics of photosynthetic and post-photosynthetic discrimination, we mainly review the recent findings on the isotopic composition of CO2 respired by leaves (autotrophic organs) and roots (heterotrophic organs) compared with respective plant material (i.e. apparent respiratory fractionation) as well as its metabolic origin. The potential impact of such fractionation on the isotopic signal of organic matter (OM) is discussed. Some perspectives for future studies are also proposed .
Collapse
Affiliation(s)
- Jaleh Ghashghaie
- Laboratoire d'Ecologie, Systématique et Evolution (ESE), CNRS UMR8079, Bâtiment 362, Université de Paris-Sud (XI), F-91405, Orsay Cedex, France
| | - Franz W Badeck
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, Genomics research centre (CRA - GPG), Via San Protaso, 302, 29017, Fiorenzuola d'Arda (PC), Italy
- Potsdam Institute for Climate Impact Research (PIK), PF 60 12 03, 14412, Potsdam, Germany
| |
Collapse
|
23
|
Nguyen Tu TT, Biron P, Maseyk K, Richard P, Zeller B, Quénéa K, Alexis M, Bardoux G, Vaury V, Girardin C, Pouteau V, Billiou D, Bariac T. Variability of 13C-labeling in plant leaves. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1961-1968. [PMID: 23939963 DOI: 10.1002/rcm.6650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/30/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Plant tissues artificially labeled with (13)C are increasingly used in environmental studies to unravel biogeochemical and ecophysiological processes. However, the variability of (13)C-content in labeled tissues has never been carefully investigated. Hence, this study aimed at documenting the variability of (13)C-content in artificially labeled leaves. METHODS European beech and Italian ryegrass were subjected to long-term (13)C-labeling in a controlled-environment growth chamber. The (13)C-content of the leaves obtained after several months labeling was determined by isotope ratio mass spectrometry. RESULTS The (13)C-content of the labeled leaves exhibited inter- and intra-leaf variability much higher than those naturally occurring in unlabeled plants, which do not exceed a few per mil. This variability was correlated with labeling intensity: the isotope composition of leaves varied in ranges of ca 60‰ and 90‰ for experiments that led to average leaf (13)C-content of ca +15‰ and +450‰, respectively. CONCLUSIONS The reported variability of isotope composition in (13)C-enriched leaves is critical, and should be taken into account in subsequent experimental investigations of environmental processes using (13)C-labeled plant tissues.
Collapse
Affiliation(s)
- Thanh Thuy Nguyen Tu
- UMR 7618 BioEMCo GOME, Université Pierre et Marie Curie, CC120, 4 Place Jussieu, 75 252, Paris cedex 05, France.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Dubbert M, Rascher KG, Werner C. Species-specific differences in temporal and spatial variation in δ(13)C of plant carbon pools and dark-respired CO (2) under changing environmental conditions. PHOTOSYNTHESIS RESEARCH 2012; 113:297-309. [PMID: 22618996 DOI: 10.1007/s11120-012-9748-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 05/09/2012] [Indexed: 05/19/2023]
Abstract
Stable carbon isotope signatures are often used as tracers for environmentally driven changes in photosynthetic δ(13)C discrimination. However, carbon isotope signatures downstream from carboxylation by Rubisco are altered within metabolic pathways, transport and respiratory processes, leading to differences in δ(13)C between carbon pools along the plant axis and in respired CO(2). Little is known about the within-plant variation in δ(13)C under different environmental conditions or between species. We analyzed spatial, diurnal, and environmental variations in δ(13)C of water soluble organic matter (δ(13)C(WSOM)) of leaves, phloem and roots, as well as dark-respired δ(13)CO(2) (δ(13)C(res)) in leaves and roots. We selected distinct light environments (forest understory and an open area), seasons (Mediterranean spring and summer drought) and three functionally distinct understory species (two native shrubs-Halimium halimifolium and Rosmarinus officinalis-and a woody invader-Acacia longifolia). Spatial patterns in δ(13)C(WSOM) along the plant vertical axis and between respired δ(13)CO(2) and its putative substrate were clearly species specific and the most δ(13)C-enriched and depleted values were found in δ(13)C of leaf dark-respired CO(2) and phloem sugars, ~-15 and ~-33 ‰, respectively. Comparisons between study sites and seasons revealed that spatial and diurnal patterns were influenced by environmental conditions. Within a species, phloem δ(13)C(WSOM) and δ(13)C(res) varied by up to 4 ‰ between seasons and sites. Thus, careful characterization of the magnitude and environmental dependence of apparent post-carboxylation fractionation is needed when using δ(13)C signatures to trace changes in photosynthetic discrimination.
Collapse
Affiliation(s)
- Maren Dubbert
- Experimental and System Ecology, University of Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany.
| | | | | |
Collapse
|
25
|
Mortazavi B, Conte MH, Chanton JP, Weber JC, Martin TA, Cropper WP. Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jg001867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
26
|
Sun W, Resco V, Williams DG. Environmental and physiological controls on the carbon isotope composition of CO2 respired by leaves and roots of a C3 woody legume (Prosopis velutina) and a C4 perennial grass (Sporobolus wrightii). PLANT, CELL & ENVIRONMENT 2012; 35:567-577. [PMID: 21955347 DOI: 10.1111/j.1365-3040.2011.02436.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Accurate estimates of the δ(13) C value of CO(2) respired from roots (δ(13) C(R_root) ) and leaves (δ(13) C(R_leaf) ) are important for tracing and understanding changes in C fluxes at the ecosystem scale. Yet the mechanisms underlying temporal variation in these isotopic signals are not fully resolved. We measured δ(13) C(R_leaf) , δ(13) C(R_root) , and the δ(13) C values and concentrations of glucose and sucrose in leaves and roots in the C(4) grass Sporobolus wrightii and the C(3) tree Prosopis velutina in a savanna ecosystem in southeastern Arizona, USA. Night-time variation in δ(13) C(R_leaf) of up to 4.6 ± 0.6‰ in S. wrightii and 3.0 ± 0.6‰ in P. velutina were correlated with shifts in leaf sucrose concentration, but not with changes in δ(13) C values of these respiratory substrates. Strong positive correlations between δ(13) C(R_root) and root glucose δ(13) C values in P. velutina suggest large diel changes in δ(13) C(R_root) (were up to 3.9‰) influenced by short-term changes in δ(13) C of leaf-derived phloem C. No diel variation in δ(13) C(R_root) was observed in S. wrightii. Our findings show that short-term changes in δ(13) C(R_leaf) and δ(13) C(R_root) were both related to substrate isotope composition and concentration. Changes in substrate limitation or demand for biosynthesis may largely control short-term variation in the δ(13) C of respired CO(2) in these species.
Collapse
Affiliation(s)
- Wei Sun
- Department of Renewable Resources Department of Botany Program in Ecology, University of Wyoming, Laramie, WY 82071, USA.
| | | | | |
Collapse
|
27
|
Werner RA, Buchmann N, Siegwolf RTW, Kornexl BE, Gessler A. Metabolic fluxes, carbon isotope fractionation and respiration--lessons to be learned from plant biochemistry. THE NEW PHYTOLOGIST 2011; 191:10-15. [PMID: 21521226 DOI: 10.1111/j.1469-8137.2011.03741.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Affiliation(s)
- Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
- (Author for correspondence: tel: +41 44 632 6754; email )
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
| | - Rolf T W Siegwolf
- Lab for Atmospheric Chemistry, Stable Isotopes and Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Barbara E Kornexl
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
| | - Arthur Gessler
- Institute for Landscape Biogeochemistry, Leibniz-Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany
- Professorship for Landscape Biogeochemistry, Humboldt-University at Berlin, Lentze-Allee 75, 14195 Berlin, Germany
| |
Collapse
|
28
|
Barbour MM, Hunt JE, Kodama N, Laubach J, McSeveny TM, Rogers GND, Tcherkez G, Wingate L. Rapid changes in δ¹³C of ecosystem-respired CO₂ after sunset are consistent with transient ¹³C enrichment of leaf respired CO₂. THE NEW PHYTOLOGIST 2011; 190:990-1002. [PMID: 21294737 DOI: 10.1111/j.1469-8137.2010.03635.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The CO₂ respired by darkened, light-adapted, leaves is enriched in ¹³C during the first minutes, and this effect may be related to rapid changes in leaf respiratory biochemistry upon darkening. We hypothesized that this effect would be evident at the ecosystem scale. High temporal resolution measurements of the carbon isotope composition of ecosystem respiration were made over 28 diel periods in an abandoned temperate pasture, and were compared with leaf-level measurements at differing levels of pre-illumination. At the leaf level, CO₂ respired by darkened leaves that had been preadapted to high light was strongly enriched in ¹³C, but such a ¹³C-enrichment rapidly declined over 60-100 min. The ¹³C-enrichment was less pronounced when leaves were preadapted to low light. These leaf-level responses were mirrored at the ecosystem scale; after sunset following clear, sunny days respired CO₂ was first ¹³C enriched, but the ¹³C-enrichment rapidly declined over 60-100 min. Further, this response was less pronounced following cloudy days. We conclude that the dynamics of leaf respiratory isotopic signal caused variations in ecosystem-scale ¹²CO₂/¹³) CO₂ exchange. Such rapid isotope kinetics should be considered when applying ¹³C-based techniques to elucidate ecosystem carbon cycling.
Collapse
Affiliation(s)
- Margaret M Barbour
- Landcare Research, PO Box 40, Lincoln 7640, New Zealand
- Faculty of Agriculture, Food and Natural Resources, The University of Sydney, Private Bag 4011, Narellan NSW 2567, Australia
| | - John E Hunt
- Landcare Research, PO Box 40, Lincoln 7640, New Zealand
| | - Naomi Kodama
- Landcare Research, PO Box 40, Lincoln 7640, New Zealand
- Agro-Meteorology Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba 305-8604, Japan
| | | | | | | | - Guillaume Tcherkez
- Institut de Biologie des Plantes, Université Paris Sud 11, CNRS UMR 8618, 91405 Orsay Cedex, France
| | - Lisa Wingate
- Department of Plant Sciences, The University of Cambridge, Cambridge, UK
| |
Collapse
|
29
|
Barbour MM, Tcherkez G, Bickford CP, Mauve C, Lamothe M, Sinton S, Brown H. δ(13) C of leaf-respired CO(2) reflects intrinsic water-use efficiency in barley. PLANT, CELL & ENVIRONMENT 2011; 34:792-799. [PMID: 21276010 DOI: 10.1111/j.1365-3040.2011.02282.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: 05/30/2023]
Abstract
Leaf intrinsic water-use efficiency (WUE), the ratio of photosynthetic rate to stomatal conductance (A/g(s) ), is a key plant trait linking terrestrial carbon and water cycles. A rapid, integrative proxy for A/g(s) is of benefit to crop breeding programmes aiming to improve WUE, but also for ecologists interested in plant carbon-water balance in natural systems. We hypothesize that the carbon isotope composition of leaf-respired CO(2) (δ(13) C(Rl) ), two hours after leaves are transferred to the dark, records photosynthetic carbon isotope discrimination and so provides a proxy for A/g(s) . To test this hypothesis, δ(13) C(Rl) was measured in four barley cultivars grown in the field at two levels of water availability and compared to leaf-level gas exchange (the ratio of leaf intercellular to ambient CO(2) partial pressure, C(i) /C(a) , and A/g(s) ). Leaf-respired CO(2) was more (13) C-depleted in plants grown at higher water availability, varied between days as environmental conditions changed, and was significantly different between cultivars. A strong relationship between δ(13) C(Rl) and δ(13) C of sucrose was observed. δ(13) C(Rl) was converted into apparent photosynthetic discrimination (Δ(13) C(Rl) ) revealing strong relationships between Δ(13) C(Rl) and C(i) /C(a) and A/g(s) during the vegetative stage of growth. We therefore conclude that δ(13) C(Rl) may provide a rapid, integrative proxy for A/g(s) in barley.
Collapse
Affiliation(s)
- Margaret M Barbour
- Faculty of Agriculture, Food and Natural Resources, The University of Sydney, Private Bag 4011, Narellan NSW 2567, Australia.
| | | | | | | | | | | | | |
Collapse
|
30
|
Ubierna N, Marshall JD. Vertical and seasonal variation in the δ¹³C of leaf-respired CO₂ in a mixed conifer forest. TREE PHYSIOLOGY 2011; 31:414-427. [PMID: 21551356 DOI: 10.1093/treephys/tpr026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The C-isotopic composition (δ¹³C) of leaf respiration (δ(LR)) has previously been shown to vary among functional groups, plant organs and times of day. We here investigated vertical and seasonal variation in δ(LR) through deep (~35 m) forest canopies. We measured δ(LR), δ¹³C of leaf bulk organic matter (δ(LB)), specific leaf area, net photosynthesis (A) and dark respiration in shade, middle and sun foliage in four conifer species from May to August. We used Keeling plots to estimate δ(LR); we developed a novel technique for ensuring that the respiratory substrate was not changing over the course of the measurement. Variables δ(LR) and δ(LB) displayed a vertical pattern in Abies grandis, Pseudotsuga menziesii and Thuja plicata, but were independent of canopy position in Larix occidentalis. Vertical gradients in δ(LB) (3.6‰) and δ(LR) (2.8‰) were similar. The respiratory enrichment (δ(LR)-δ(LB)) was smaller in expanding (3‰) than mature (4-8‰) foliage. There was a linear relationship between the respiratory enrichment and A. Our data support the hypothesis that δ(LR) values are related to patterns of C allocation among metabolic pathways. We demonstrated that considerable variation in δ(LR) occurs vertically through the canopy (3‰ gradient) and seasonally (3-7‰). Understanding sources of variation in respiratory signals is fundamental to comprehending C dynamics and for global model applications.
Collapse
Affiliation(s)
- Nerea Ubierna
- Department of Forest Resources, University of Idaho, PO Box 441133, Moscow, ID 83844-1133, USA.
| | | |
Collapse
|
31
|
Kuptz D, Matyssek R, Grams TEE. Seasonal dynamics in the stable carbon isotope composition δ¹³C from non-leafy branch, trunk and coarse root CO₂ efflux of adult deciduous (Fagus sylvatica) and evergreen (Picea abies) trees. PLANT, CELL & ENVIRONMENT 2011; 34:363-373. [PMID: 21054435 DOI: 10.1111/j.1365-3040.2010.02246.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Respiration is a substantial driver of carbon (C) flux in forest ecosystems and stable C isotopes provide an excellent tool for its investigation. We studied seasonal dynamics in δ¹³C of CO₂ efflux (δ¹³C(E)) from non-leafy branches, upper and lower trunks and coarse roots of adult trees, comparing deciduous Fagus sylvatica (European beech) with evergreen Picea abies (Norway spruce). In both species, we observed strong and similar seasonal dynamics in the δ¹³C(E) of above-ground plant components, whereas δ¹³C(E) of coarse roots was rather stable. During summer, δ¹³C(E) of trunks was about -28.2‰ (Beech) and -26.8‰ (Spruce). During winter dormancy, δ¹³C(E) increased by 5.6-9.1‰. The observed dynamics are likely related to a switch from growth to starch accumulation during fall and remobilization of starch, low TCA cycle activity and accumulation of malate by PEPc during winter. The seasonal δ¹³C(E) pattern of branches of Beech and upper trunks of Spruce was less variable, probably because these organs were additionally supplied by winter photosynthesis. In view of our results and pervious studies, we conclude that the pronounced increases in δ¹³C(E) of trunks during the winter results from interrupted access to recent photosynthates.
Collapse
Affiliation(s)
- Daniel Kuptz
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Life Science Center Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany.
| | | | | |
Collapse
|
32
|
Rascher KG, Máguas C, Werner C. On the use of phloem sap δ¹³C as an indicator of canopy carbon discrimination. TREE PHYSIOLOGY 2010; 30:1499-514. [PMID: 21071770 DOI: 10.1093/treephys/tpq092] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this study we measured δ¹³C in various carbon pools along the basipetal transport pathway in co-occurring Pinus pinaster and Acacia longifolia trees under Mediterranean climate conditions in the field. Overall, species differences in photosynthetic discrimination resulted in more enriched δ¹³C values in the water-conserving overstory P. pinaster relative to the water-spending understory invasive A. longifolia. Post-photosynthetic fractionation effects resulted in differences in δ¹³C of water-soluble organic matter pools along the plant axis with progressive depletion in δ¹³C from the canopy to the trunk (∼6.5‰ depletion in A. longifolia and ∼0.8‰ depletion in P. pinaster). Regardless of these fractionation effects, phloem sap δ¹³C in both terminal branches and the main stem correlated well with environmental parameters driving photosynthesis for both species, indicating that phloem sap δ¹³C has potential as an integrative tracer of changes in canopy carbon discrimination (Δ¹³C). Furthermore, we illustrate that a simple model based on sap flow estimated canopy stomatal conductance (G(S)) and phloem sap δ¹³C measurements has significant potential as a tool for estimating canopy-level carbon assimilation rates.
Collapse
Affiliation(s)
- Katherine G Rascher
- Exp. and Systems Ecology, University of Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
| | | | | |
Collapse
|
33
|
Phillips CL, Nickerson N, Risk D, Kayler ZE, Andersen C, Mix A, Bond BJ. Soil moisture effects on the carbon isotope composition of soil respiration. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:1271-1280. [PMID: 20391598 DOI: 10.1002/rcm.4511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The carbon isotopic composition (delta(13)C) of recently assimilated plant carbon is known to depend on water-stress, caused either by low soil moisture or by low atmospheric humidity. Air humidity has also been shown to correlate with the delta(13)C of soil respiration, which suggests indirectly that recently fixed photosynthates comprise a substantial component of substrates consumed by soil respiration. However, there are other reasons why the delta(13)CO(2) of soil efflux may change with moisture conditions, which have not received as much attention. Using a combination of greenhouse experiments and modeling, we examined whether moisture can cause changes in fractionation associated with (1) non-steady-state soil CO(2) transport, and (2) heterotrophic soil-respired delta(13)CO(2). In a first experiment, we examined the effects of soil moisture on total respired delta(13)CO(2) by growing Douglas fir seedlings under high and low soil moisture conditions. The measured delta(13)C of soil respiration was 4.7 per thousand more enriched in the low-moisture treatment; however, subsequent investigation with an isotopologue-based gas diffusion model suggested that this result was probably influenced by gas transport effects. A second experiment examined the heterotrophic component of soil respiration by incubating plant-free soils, and showed no change in microbial-respired delta(13)CO(2) across a large moisture range. Our results do not rule out the potential influence of recent photosynthates on soil-respired delta(13)CO(2), but they indicate that the expected impacts of photosynthetic discrimination may be similar in direction and magnitude to those from gas transport-related fractionation. Gas transport-related fractionation may operate as an alternative or an additional factor to photosynthetic discrimination to explain moisture-related variation in soil-respired delta(13)CO(2).
Collapse
Affiliation(s)
- Claire L Phillips
- Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331, USA.
| | | | | | | | | | | | | |
Collapse
|
34
|
Tcherkez G. Do metabolic fluxes matter for interpreting isotopic respiratory signals? THE NEW PHYTOLOGIST 2010; 186:566-571. [PMID: 20522163 DOI: 10.1111/j.1469-8137.2010.03178.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
|
35
|
Unger S, Máguas C, Pereira JS, Aires LM, David TS, Werner C. Disentangling drought-induced variation in ecosystem and soil respiration using stable carbon isotopes. Oecologia 2010; 163:1043-57. [PMID: 20217141 DOI: 10.1007/s00442-010-1576-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Accepted: 01/25/2010] [Indexed: 10/19/2022]
Abstract
Combining C flux measurements with information on their isotopic composition can yield a process-based understanding of ecosystem C dynamics. We studied the variations in both respiratory fluxes and their stable C isotopic compositions (delta(13)C) for all major components (trees, understory, roots and soil microorganisms) in a Mediterranean oak savannah during a period with increasing drought. We found large drought-induced and diurnal dynamics in isotopic compositions of soil, root and foliage respiration (delta(13)C(res)). Soil respiration was the largest contributor to ecosystem respiration (R (eco)), exhibiting a depleted isotopic signature and no marked variations with increasing drought, similar to ecosystem respired delta(13)CO(2), providing evidence for a stable C-source and minor influence of recent photosynthate from plants. Short-term and diurnal variations in delta(13)C(res) of foliage and roots (up to 8 and 4 per thousand, respectively) were in agreement with: (1) recent hypotheses on post-photosynthetic fractionation processes, (2) substrate changes with decreasing assimilation rates in combination with increased respiratory demand, and (3) decreased phosphoenolpyruvate carboxylase activity in drying roots, while altered photosynthetic discrimination was not responsible for the observed changes in delta(13)C(res). We applied a flux-based and an isotopic flux-based mass balance, yielding good agreement at the soil scale, while the isotopic mass balance at the ecosystem scale was not conserved. This was mainly caused by uncertainties in Keeling plot intercepts at the ecosystem scale due to small CO(2) gradients and large differences in delta(13)C(res) of the different component fluxes. Overall, stable isotopes provided valuable new insights into the drought-related variations of ecosystem C dynamics, encouraging future studies but also highlighting the need of improved methodology to disentangle short-term dynamics of isotopic composition of R (eco).
Collapse
Affiliation(s)
- Stephan Unger
- Department of Experimental and Systems Ecology, University of Bielefeld, Universitätsstrasse 25 W4-114, 33615 Bielefeld, Germany.
| | | | | | | | | | | |
Collapse
|