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Hermann-Ene V, Vetter W. Stable Carbon Isotope Ratios (δ 13C Values [‰]) of Individual Sterols in the Oils of C 3, C 4, and CAM Plants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:8247-8256. [PMID: 38551065 DOI: 10.1021/acs.jafc.3c08324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The compound-specific determination of δ13C values [‰] by gas chromatography interfaced with isotope ratio mass spectrometry (GC-IRMS) is a powerful analytical method to indicate minute but relevant variations in the 13C/12C ratio of sample compounds. In this study, the δ13C values [‰] of individual sterols were measured in eleven different oils of C3, C4, and CAM plants (n = 33) by GC-IRMS. For this purpose, a suitable acetylation method was developed for sterols. Nine of the eleven phytosterols identified by GC with mass spectrometry (GC/MS) could be measured by GC-IRMS. The δ13C values [‰] of individual sterols and squalene of C3 plant oils were between 3‰ and >16‰ more negative (lighter in carbon) than in C4 and CAM oils. We also showed that the blending of C4 oils into C3 oils (exemplarily conducted with one olive and one corn oil) would be precisely determined by means of the δ13C value [‰] of β-sitosterol.
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Affiliation(s)
- Vanessa Hermann-Ene
- Institute of Food Chemistry (170b), University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany
| | - Walter Vetter
- Institute of Food Chemistry (170b), University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany
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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.
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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
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Baan J, Holloway-Phillips M, Nelson DB, Kahmen A. The metabolic sensitivity of hydrogen isotope fractionation differs between plant compounds. PHYTOCHEMISTRY 2023; 207:113563. [PMID: 36528118 DOI: 10.1016/j.phytochem.2022.113563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 12/10/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Hydrogen stable isotope analyses (δ2H) of plant derived organic compounds are a useful tool for ecological, environmental, and palaeoclimatological research. However, during organic compound synthesis, variable biosynthetic 2H-fractionation has been suggested to occur as a result of changes in plant carbon fluxes. So far, inference has been based on examining the δ2H patterns of plant compounds along environmental gradients, among plant species, and between plant organs. In an alternative approach, we used four plant species with four different types of mutations that cause impaired starch synthesis to assess whether variability in carbon metabolism affects the biosynthetic 2H-fractionation during cellulose, phytol, and acetogenic lipid synthesis. We found that mutants with impaired starch synthesis always had higher cellulose and phytol δ2H values compared to the wild type. By contrast, 2H-fractionation during acetogenic lipid biosynthesis generally did not show strong metabolic sensitivity. We rationalise these differences by considering the biosynthetic pathway of each compound and the likely source of the variable isotope fractionation. In different organic compounds, the sensitivity of variable biosynthetic 2H-fractionation to changes in C-metabolism depends on incorporation of specific H atoms from precursor molecules. As such, we determined that the similar increase in cellulose and phytol δ2H values as an effect of impaired starch synthesis most likely originates in triose-phosphates.
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Affiliation(s)
- Jochem Baan
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056, Basel, Switzerland.
| | - Meisha Holloway-Phillips
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056, Basel, Switzerland
| | - Daniel B Nelson
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056, Basel, Switzerland
| | - Ansgar Kahmen
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056, Basel, Switzerland
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Li X, Lan C, Li X, Hu Z, Jia B. A review on design-build-test-learn cycle to potentiate progress in isoprenoid engineering of photosynthetic microalgae. BIORESOURCE TECHNOLOGY 2022; 363:127981. [PMID: 36130687 DOI: 10.1016/j.biortech.2022.127981] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
Currently, the generation of isoprenoid factories in microalgae relies on two strategies: 1) enhanced production of endogenous isoprenoids; or 2) production of heterologous terpenes by metabolic engineering. Nevertheless, low titers and productivity are still a feature of isoprenoid biotechnology and need to be addressed. In this context, the mechanisms underlying isoprenoid biosynthesis in microalgae and its relationship with central carbon metabolism are reviewed. Developments in microalgal biotechnology are discussed, and a new approach of integrated "design-build-test-learn" cycle is advocated to the trends, challenges and prospects involved in isoprenoid engineering. The emerging and promising strategies and tools are discussed for microalgal engineering in the future. This review encourages a systematic engineering perspective aimed at potentiating progress in isoprenoid engineering of photosynthetic microalgae.
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Affiliation(s)
- Xiangyu Li
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Chengxiang Lan
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Xinyi Li
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Bin Jia
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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Wieloch T, Grabner M, Augusti A, Serk H, Ehlers I, Yu J, Schleucher J. Metabolism is a major driver of hydrogen isotope fractionation recorded in tree-ring glucose of Pinus nigra. THE NEW PHYTOLOGIST 2022; 234:449-461. [PMID: 35114006 PMCID: PMC9306475 DOI: 10.1111/nph.18014] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/24/2022] [Indexed: 05/13/2023]
Abstract
Stable isotope abundances convey valuable information about plant physiological processes and underlying environmental controls. Central gaps in our mechanistic understanding of hydrogen isotope abundances impede their widespread application within the plant and biogeosciences. To address these gaps, we analysed intramolecular deuterium abundances in glucose of Pinus nigra extracted from an annually resolved tree-ring series (1961-1995). We found fractionation signals (i.e. temporal variability in deuterium abundance) at glucose H1 and H2 introduced by closely related metabolic processes. Regression analysis indicates that these signals (and thus metabolism) respond to drought and atmospheric CO2 concentration beyond a response change point. They explain ≈ 60% of the whole-molecule deuterium variability. Altered metabolism is associated with below-average yet not exceptionally low growth. We propose the signals are introduced at the leaf level by changes in sucrose-to-starch carbon partitioning and anaplerotic carbon flux into the Calvin-Benson cycle. In conclusion, metabolism can be the main driver of hydrogen isotope variation in plant glucose.
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Affiliation(s)
- Thomas Wieloch
- Department of Medical Biochemistry and BiophysicsUmeå University901 87UmeåSweden
| | - Michael Grabner
- Institute of Wood Technology and Renewable MaterialsUniversity of Natural Resources and Life Sciences Vienna3430Tulln an der DonauAustria
| | - Angela Augusti
- Research Institute on Terrestrial EcosystemsNational Research CouncilPorano (TR)05010Italy
| | - Henrik Serk
- Department of Medical Biochemistry and BiophysicsUmeå University901 87UmeåSweden
| | - Ina Ehlers
- Department of Medical Biochemistry and BiophysicsUmeå University901 87UmeåSweden
| | - Jun Yu
- Department of Mathematics and Mathematical StatisticsUmeå University901 87UmeåSweden
| | - Jürgen Schleucher
- Department of Medical Biochemistry and BiophysicsUmeå University901 87UmeåSweden
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Kreuzwieser J, Meischner M, Grün M, Yáñez-Serrano AM, Fasbender L, Werner C. Drought affects carbon partitioning into volatile organic compound biosynthesis in Scots pine needles. THE NEW PHYTOLOGIST 2021; 232:1930-1943. [PMID: 34523149 DOI: 10.1111/nph.17736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
The effect of drought on the interplay of processes controlling carbon partitioning into plant primary and secondary metabolisms, such as respiratory CO2 release and volatile organic compound (VOC) biosynthesis, is not fully understood. To elucidate the effect of drought on the fate of cellular C sources into VOCs vs CO2 , we conducted tracer experiments with 13 CO2 and position-specific 13 C-labelled pyruvate, a key metabolite between primary and secondary metabolisms, in Scots pine seedlings. We determined the stable carbon isotope composition of leaf exchanged CO2 and VOC. Drought reduced the emission of the sesquiterpenes α-farnesene and β-farnesene but did not affect 13 C-incorporation from 13 C-pyruvate. The labelling patterns suggest that farnesene biosynthesis partially depends on isopentenyl diphosphate crosstalk between chloroplasts and cytosol, and that drought inhibits this process. Contrary to sesquiterpenes, drought did not affect emission of isoprene, monoterpenes and some oxygenated compounds. During the day, pyruvate was used in the TCA cycle to a minor degree but was mainly consumed in pathways of secondary metabolism. Drought partly inhibited such pathways, while allocation into the TCA cycle increased. Drought caused a re-direction of pyruvate consuming pathways, which contributed to maintenance of isoprene and monoterpene production despite strongly inhibited photosynthesis. This underlines the importance of these volatiles for stress tolerance.
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Affiliation(s)
- Jürgen Kreuzwieser
- Chair of Ecosystem Physiology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79110, Germany
| | - Mirjam Meischner
- Chair of Ecosystem Physiology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79110, Germany
| | - Michel Grün
- Chair of Ecosystem Physiology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79110, Germany
| | - Ana Maria Yáñez-Serrano
- Institute of Environmental Assessment and Water Research (IDAEA), Spanish Research Council (CSIC), Barcelona, 08034, Spain
- Center for Ecological Research and Forestry Applications (CREAF), Cerdanyola del Vallès, 08193, Spain
- Global Ecology Unit, CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Spain
| | - Lukas Fasbender
- Chair of Ecosystem Physiology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79110, Germany
| | - Christiane Werner
- Chair of Ecosystem Physiology, Albert-Ludwigs-Universität Freiburg, Freiburg, 79110, Germany
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