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Bruhn D, Povlsen P, Gardner A, Mercado LM. Instantaneous Q 10 of night-time leaf respiratory CO 2 efflux - measurement and analytical protocol considerations. THE NEW PHYTOLOGIST 2024; 243:23-28. [PMID: 38600045 DOI: 10.1111/nph.19753] [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: 02/24/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
The temperature sensitivity (e.g. Q10) of night-time leaf respiratory CO2 efflux (RCO2) is a fundamental aspect of leaf physiology. The Q10 typically exhibits a dependence on measurement temperature, and it is speculated that this is due to temperature-dependent shifts in the relative control of leaf RCO2. Two decades ago, a review hypothesized that this mechanistically caused change in values of Q10 is predictable across plant taxa and biomes. Here, we discuss the most appropriate measuring protocol among existing data and for future data collection, to form the foundation of a future mechanistic understanding of Q10 of leaf RCO2 at different temperature ranges. We do this primarily via a review of existing literature on Q10 of night-time RCO2 and only supplement this to a lesser degree with our own original data. Based on mechanistic considerations, we encourage that instantaneous Q10 of leaf RCO2 to represent night-time should be measured: only at night-time; only in response to short-term narrow temperature variation (e.g. max. 10°C) to represent a given midpoint temperature at a time; in response to as many temperatures as possible within the chosen temperature range; and on still attached leaves.
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Affiliation(s)
- Dan Bruhn
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, 9220, Denmark
| | - Peter Povlsen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, 9220, Denmark
| | - Anna Gardner
- Faculty of Environment, Science and Economy, University of Exeter, EX4 4QE, Exeter, UK
- School of Biosciences, University of Birmingham, Birmingham, B14 2TT, UK
| | - Lina M Mercado
- Faculty of Environment, Science and Economy, University of Exeter, EX4 4QE, Exeter, UK
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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.
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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
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Xu Y, Schmiege SC, Sharkey TD. The oxidative pentose phosphate pathway in photosynthesis: a tale of two shunts. THE NEW PHYTOLOGIST 2024; 242:2453-2463. [PMID: 38567702 DOI: 10.1111/nph.19730] [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: 12/07/2023] [Accepted: 03/17/2024] [Indexed: 05/24/2024]
Abstract
CO2 release in the light (RL) and its presumed source, oxidative pentose phosphate pathways, were found to be insensitive to CO2 concentration. The oxidative pentose phosphate pathways form glucose 6-phosphate (G6P) shunts that bypass the nonoxidative pentose phosphate reactions of the Calvin-Benson cycle. Using adenosine diphosphate glucose and uridine diphosphate glucose as proxies for labeling of G6P in the stroma and cytosol respectively, it was found that only the cytosolic shunt was active. Uridine diphosphate glucose, a proxy for cytosolic G6P, and 6-phosphogluconate (6PG) were significantly less labeled than Calvin-Benson cycle intermediates in the light. But ADP glucose, a proxy for stromal G6P, is labeled to the same degree as Calvin-Benson cycle intermediates and much greater than 6PG. A metabolically inert pool of sedoheptulose bisphosphate can slowly equilibrate keeping the label in sedoheptulose lower than in other stromal metabolites. Finally, phosphorylation of fructose 6-phosphate (F6P) in the cytosol can allow some unlabeled carbon in cytosolic F6P to dilute label in phosphenolpyruvate. The results clearly show that there is oxidative pentose phosphate pathway activity in the cytosol that provides a shunt around the nonoxidative pentose phosphate pathway reactions of the Calvin-Benson cycle and is not strongly CO2-sensitive.
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Affiliation(s)
- Yuan Xu
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Stephanie C Schmiege
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Thomas D Sharkey
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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Abadie C, Lalande J, Dourmap C, Limami AM, Tcherkez G. Leaf day respiration involves multiple carbon sources and depends on previous dark metabolism. PLANT, CELL & ENVIRONMENT 2024; 47:2146-2162. [PMID: 38444114 DOI: 10.1111/pce.14871] [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: 10/06/2023] [Revised: 02/06/2024] [Accepted: 02/20/2024] [Indexed: 03/07/2024]
Abstract
Day respiration (Rd) is the metabolic, nonphotorespiratory process by which illuminated leaves liberate CO2 during photosynthesis. Rd is used routinely in photosynthetic models and is thus critical for calculations. However, metabolic details associated with Rd are poorly known, and this can be problematic to predict how Rd changes with environmental conditions and relates to night respiration. It is often assumed that day respiratory CO2 release just reflects 'ordinary' catabolism (glycolysis and Krebs 'cycle'). Here, we carried out a pulse-chase experiment, whereby a 13CO2 pulse in the light was followed by a chase period in darkness and then in the light. We took advantage of nontargeted, isotope-assisted metabolomics to determine non-'ordinary' metabolism, detect carbon remobilisation and compare light and dark 13C utilisation. We found that several concurrent metabolic pathways ('ordinary' catabolism, oxidative pentose phosphates pathway, amino acid production, nucleotide biosynthesis and secondary metabolism) took place in the light and participated in net CO2 efflux associated with day respiration. Flux reconstruction from metabolomics leads to an underestimation of Rd, further suggesting the contribution of a variety of CO2-evolving processes. Also, the cornerstone of the Krebs 'cycle', citrate, is synthetised de novo from photosynthates mostly in darkness, and remobilised or synthesised from stored material in the light. Collectively, our data provides direct evidence that leaf day respiration (i) involves several CO2-producing reactions and (ii) is fed by different carbon sources, including stored carbon disconnected from current photosynthates.
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Affiliation(s)
- Cyril Abadie
- Institut de recherche en horticulture et semences, INRAe, Université d'Angers, 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
| | - Julie Lalande
- Institut de recherche en horticulture et semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Corentin Dourmap
- Institut de recherche en horticulture et semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Anis M Limami
- Institut de recherche en horticulture et semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Guillaume Tcherkez
- Institut de recherche en horticulture et semences, INRAe, Université d'Angers, Beaucouzé, France
- Research School of Biology, ANU College of Science, Australian National University, Canberra, Australia
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Worthy FR, Schaefer DA, Wanasinghe D, Xu JC, Wang LS, Wang XY. Acquisition of green algal photobionts enables both chlorolichens and chloro-cyanolichens to activate photosynthesis at low humidity without liquid water. AOB PLANTS 2024; 16:plae025. [PMID: 38770101 PMCID: PMC11102867 DOI: 10.1093/aobpla/plae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 04/23/2024] [Indexed: 05/22/2024]
Abstract
Cyanobacteria require liquid water for photosynthesis, whereas green algae can photosynthesise with water vapour alone. We discovered that several Lobaria spp. which normally have cyanobacteria as the sole photobiont, in some regions of the trans-Himalayas also harboured green algae. We tested whether green algal acquisition was: limited to high elevations; obtained from neighbouring chloro-Lobaria species; enabled photosynthesis at low humidity. Lobaria spp. were collected from 2000 to 4000 m elevation. Spectrophotometry quantified green algal abundance by measuring chlorophyll b (absent in cyanobacteria). Thalli cross-sections visually confirmed green algal presence. We sequenced gene regions: Lobaria (ITS-EF-1α-RPB2), green algae (18S-RBC-L) and Nostoc (16S). Phylogenetic analysis determined myco-photobiont associations. We used a custom closed-circuit gas exchange system with an infrared gas analyser to measure CO2 exchange rates for desiccated specimens at 33%, 76%, 86% and 98% humidity. Cross-sections revealed that the photobiont layers in putative cyano-Lobaria contained both cyanobacteria and green algae, indicating that they should be considered chloro-cyanolichens. Chloro-Lobaria had no visible cephalodia nor cyanobacteria in the photobiont layer. Chloro-Lobaria and chloro-cyano-Lobaria had comparable levels of chlorophyll b. Chloro-Lobaria usually contained Symbiochloris. Chloro-cyano-Lobaria mainly associated with Parachloroidium and Nostoc; infrequently with Symbiochloris, Apatococcus, Chloroidium, Pseudochlorella, Trebouxia. Sequences from two green algal genera were obtained from within some thalli. Desiccated specimens of every Lobaria species could attain net photosynthesis with light exposure and 33% humidity. CO2 exchange dynamics over a five-day period differed between species. At all elevations, chloro-cyano-Lobaria spp. had abundant green algae in the photobiont layer, but green algal strains mostly differed to those of chloro-Lobaria spp. Both chloro-Lobaria and chloro-cyano-Lobaria were capable of conducting photosynthesis without liquid water. The data strongly suggest that they attained positive net photosynthesis.
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Affiliation(s)
- Fiona Ruth Worthy
- Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
- Honghe Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
| | - Douglas Allen Schaefer
- Honghe Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
| | - Dhanushka Wanasinghe
- Honghe Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
- Department of Soil Science, College of Food and Agriculture Sciences, King Saud University, Riyadh 11362, Saudi Arabia
| | - Jian Chu Xu
- Honghe Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
| | - Li Song Wang
- Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
| | - Xin Yu Wang
- Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan 650201, China
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Sharkey TD. The end game(s) of photosynthetic carbon metabolism. PLANT PHYSIOLOGY 2024; 195:67-78. [PMID: 38163636 PMCID: PMC11060661 DOI: 10.1093/plphys/kiad601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/27/2023] [Indexed: 01/03/2024]
Abstract
The year 2024 marks 70 years since the general outline of the carbon pathway in photosynthesis was published. Although several alternative pathways are now known, it is remarkable how many organisms use the reaction sequence described 70 yrs ago, which is now known as the Calvin-Benson cycle or variants such as the Calvin-Benson-Bassham cycle or Benson-Calvin cycle. However, once the carbon has entered the Calvin-Benson cycle and is converted to a 3-carbon sugar, it has many potential fates. This review will examine the last stages of photosynthetic metabolism in leaves. In land plants, this process mostly involves the production of sucrose provided by an endosymbiont (the chloroplast) to its host for use and transport to the rest of the plant. Photosynthetic metabolism also usually involves the synthesis of starch, which helps maintain respiration in the dark and enables the symbiont to supply sugars during both the day and night. Other end products made in the chloroplast are closely tied to photosynthetic CO2 assimilation. These include serine from photorespiration and various amino acids, fatty acids, isoprenoids, and shikimate pathway products. I also describe 2 pathways that can short circuit parts of the Calvin-Benson cycle. These final processes of photosynthetic metabolism play many important roles in plants.
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Affiliation(s)
- Thomas D Sharkey
- MSU-DOE Plant Research Laboratory, Plant Resilience Institute, and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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7
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Yu YZ, Liu HT, Yang F, Li L, Schäufele R, Tcherkez G, Schnyder H, Gong XY. δ13C of bulk organic matter and cellulose reveal post-photosynthetic fractionation during ontogeny in C4 grass leaves. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1451-1464. [PMID: 37943576 DOI: 10.1093/jxb/erad445] [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: 06/30/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
The 13C isotope composition (δ13C) of leaf dry matter is a useful tool for physiological and ecological studies. However, how post-photosynthetic fractionation associated with respiration and carbon export influences δ13C remains uncertain. We investigated the effects of post-photosynthetic fractionation on δ13C of mature leaves of Cleistogenes squarrosa, a perennial C4 grass, in controlled experiments with different levels of vapour pressure deficit and nitrogen supply. With increasing leaf age class, the 12C/13C fractionation of leaf organic matter relative to the δ13C of atmosphere CO2 (ΔDM) increased while that of cellulose (Δcel) was almost constant. The divergence between ΔDM and Δcel increased with leaf age class, with a maximum value of 1.6‰, indicating the accumulation of post-photosynthetic fractionation. Applying a new mass balance model that accounts for respiration and export of photosynthates, we found an apparent 12C/13C fractionation associated with carbon export of -0.5‰ to -1.0‰. Different ΔDM among leaves, pseudostems, daughter tillers, and roots indicate that post-photosynthetic fractionation happens at the whole-plant level. Compared with ΔDM of old leaves, ΔDM of young leaves and Δcel are more reliable proxies for predicting physiological parameters due to the lower sensitivity to post-photosynthetic fractionation and the similar sensitivity in responses to environmental changes.
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Affiliation(s)
- Yong Zhi Yu
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Hai Tao Liu
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- College of Resources and Environment, Henan Agricultural University, Zhengzhou 450046, China
| | - Fang Yang
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- College of Resources and Environment, Jilin Agricultural University, Changchun 130117, China
| | - Lei Li
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Rudi Schäufele
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
| | - Guillaume Tcherkez
- Research School of Biology, ANU Joint College of Science, Australian National University, Canberra ACT 0200, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, 42 rue Georges Morel, 49070 Beaucouzé, France
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
| | - Xiao Ying Gong
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- Fujian Provincial Key Laboratory for Plant Eco-physiology, Fuzhou, China
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Busch FA, Ainsworth EA, Amtmann A, Cavanagh AP, Driever SM, Ferguson JN, Kromdijk J, Lawson T, Leakey ADB, Matthews JSA, Meacham-Hensold K, Vath RL, Vialet-Chabrand S, Walker BJ, Papanatsiou M. A guide to photosynthetic gas exchange measurements: Fundamental principles, best practice and potential pitfalls. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38321805 DOI: 10.1111/pce.14815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/31/2023] [Indexed: 02/08/2024]
Abstract
Gas exchange measurements enable mechanistic insights into the processes that underpin carbon and water fluxes in plant leaves which in turn inform understanding of related processes at a range of scales from individual cells to entire ecosytems. Given the importance of photosynthesis for the global climate discussion it is important to (a) foster a basic understanding of the fundamental principles underpinning the experimental methods used by the broad community, and (b) ensure best practice and correct data interpretation within the research community. In this review, we outline the biochemical and biophysical parameters of photosynthesis that can be investigated with gas exchange measurements and we provide step-by-step guidance on how to reliably measure them. We advise on best practices for using gas exchange equipment and highlight potential pitfalls in experimental design and data interpretation. The Supporting Information contains exemplary data sets, experimental protocols and data-modelling routines. This review is a community effort to equip both the experimental researcher and the data modeller with a solid understanding of the theoretical basis of gas-exchange measurements, the rationale behind different experimental protocols and the approaches to data interpretation.
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Affiliation(s)
- Florian A Busch
- School of Biosciences and Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK
- Research School of Biology, The Australian National University, Canberra, Australian Captial Territory, Australia
| | | | - Anna Amtmann
- School of Molecular Biosciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Amanda P Cavanagh
- School of Life Sciences, University of Essex, Colchester, UK
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
| | - Steven M Driever
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - John N Ferguson
- School of Life Sciences, University of Essex, Colchester, UK
| | - Johannes Kromdijk
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK
| | - Andrew D B Leakey
- Departments of Plant Biology and Crop Sciences, University of Illinois Urbana Champaign, Urbana, Illinois, USA
| | | | | | - Richard L Vath
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
- LI-COR Environmental, Lincoln, Nebraska, USA
| | - Silvere Vialet-Chabrand
- Department of Plant Sciences, Horticulture and Product Physiology, Wageningen, The Netherlands
| | - Berkley J Walker
- Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - Maria Papanatsiou
- School of Molecular Biosciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
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Li X, Chen X, Li J, Wu P, Hu D, Zhong Q, Cheng D. Respiration in light of evergreen and deciduous woody species and its links to the leaf economic spectrum. TREE PHYSIOLOGY 2024; 44:tpad129. [PMID: 37847610 DOI: 10.1093/treephys/tpad129] [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: 02/28/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/19/2023]
Abstract
Leaf respiration in the light (Rlight) is crucial for understanding the net CO2 exchange of individual plants and entire ecosystems. However, Rlight is poorly quantified and rarely discussed in the context of the leaf economic spectrum (LES), especially among woody species differing in plant functional types (PFTs) (e.g., evergreen vs. deciduous species). To address this gap in our knowledge, Rlight, respiration in the dark (Rdark), light-saturated photosynthetic rates (Asat), leaf dry mass per unit area (LMA), leaf nitrogen (N) and phosphorus (P) concentrations, and maximum carboxylation (Vcmax) and electron transport rates (Jmax) of 54 representative subtropical woody evergreen and deciduous species were measured. With the exception of LMA, the parameters quantified in this study were significantly higher in deciduous species than in evergreen species. The degree of light inhibition did not significantly differ between evergreen (52%) and deciduous (50%) species. Rlight was significantly correlated with LES traits such as Asat, Rdark, LMA, N and P. The Rlight vs. Rdark and N relationships shared common slopes between evergreen and deciduous species, but significantly differed in their y-intercepts, in which the rates of Rlight were slower or faster for any given Rdark or N in deciduous species, respectively. A model for Rlight based on three traits (i.e., Rdark, LMA and P) had an explanatory power of 84.9%. These results show that there is a link between Rlight and the LES, and highlight that PFTs is an important factor in affecting Rlight and the relationships of Rlight with Rdark and N. Thus, this study provides information that can improve the next generation of terrestrial biosphere models (TBMs).
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Affiliation(s)
- Xueqin Li
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Xiaoping Chen
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, No. 8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Jinlong Li
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Panpan Wu
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Dandan Hu
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Quanlin Zhong
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
| | - Dongliang Cheng
- Institute of Geography, Fujian Normal University, No.8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, No. 8 Shangsan Road, Cangshan District, Fuzhou, Fujian 350007, China
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10
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Zheng DM, Wang X, Liu Q, Sun YR, Ma WT, Li L, Yang Z, Tcherkez G, Adams MA, Yang Y, Gong XY. Temperature responses of leaf respiration in light and darkness are similar and modulated by leaf development. THE NEW PHYTOLOGIST 2024; 241:1435-1446. [PMID: 37997699 DOI: 10.1111/nph.19428] [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: 08/25/2023] [Accepted: 11/06/2023] [Indexed: 11/25/2023]
Abstract
Our ability to predict temperature responses of leaf respiration in light and darkness (RL and RDk ) is essential to models of global carbon dynamics. While many models rely on constant thermal sensitivity (characterized by Q10 ), uncertainty remains as to whether Q10 of RL and RDk are actually similar. We measured short-term temperature responses of RL and RDk in immature and mature leaves of two evergreen tree species, Castanopsis carlesii and Ormosia henry in an open field. RL was estimated by the Kok method, the Yin method and a newly developed Kok-iterCc method. When estimated by the Yin and Kok-iterCc methods, RL and RDk had similar Q10 (c. 2.5). The Kok method overestimated both Q10 and the light inhibition of respiration. RL /RDk was not affected by leaf temperature. Acclimation of respiration in summer was associated with a decline in basal respiration but not in Q10 in both species, which was related to changes in leaf nitrogen content between seasons. Q10 of RL and RDk in mature leaves were 40% higher than in immature leaves. Our results suggest similar Q10 values can be used to model RL and RDk while leaf development-associated changes in Q10 require special consideration in future respiration models.
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Affiliation(s)
- Ding Ming Zheng
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Xuming Wang
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, 365000, China
- Fujian Provincial Key Laboratory for Plant Eco-Physiology, Fuzhou, 350117, China
| | - Qi Liu
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Yan Ran Sun
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Wei Ting Ma
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Lei Li
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Zhijie Yang
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, 365000, China
| | - Guillaume Tcherkez
- Research School of Biology, ANU College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, 0200, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, 42 rue Georges Morel, 49070, Beaucouzé, France
| | - Mark A Adams
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, VIC, 3122, Australia
| | - Yusheng Yang
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, 365000, China
| | - Xiao Ying Gong
- Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350117, China
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, 365000, China
- Fujian Provincial Key Laboratory for Plant Eco-Physiology, Fuzhou, 350117, China
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11
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Schmiege SC, Walker BJ, Sharkey TD. Using Gas Exchange to Study CO 2 Release During Photosynthesis with Steady- and Nonsteady-State Approaches. Methods Mol Biol 2024; 2792:143-161. [PMID: 38861085 DOI: 10.1007/978-1-0716-3802-6_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Measures of respiration in the light and Ci* are crucial to the modeling of photorespiration and photosynthesis. This chapter provides background on the equations used to model C3 photosynthesis and the history of the incorporation of the effects of rubisco oxygenation into these models. It then describes three methods used to determine two key parameters necessary to incorporate photorespiratory effects into C3 photosynthesis models: respiration in the light (RL) and Ci*. These methods include the Laisk, Yin, and isotopic methods. For the Laisk method, we also introduce a new rapid measurement technique.
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Affiliation(s)
- Stephanie C Schmiege
- Plant Resilience Institute, Michigan State University, East Lansing, MI, USA.
- Department of Biology, Western University, London, ON, Canada.
| | - Berkley J Walker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Thomas D Sharkey
- Plant Resilience Institute, Michigan State University, East Lansing, MI, USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
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12
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Ren Y, Wang H, Harrison SP, Prentice IC, Atkin OK, Smith NG, Mengoli G, Stefanski A, Reich PB. Reduced global plant respiration due to the acclimation of leaf dark respiration coupled with photosynthesis. THE NEW PHYTOLOGIST 2024; 241:578-591. [PMID: 37897087 DOI: 10.1111/nph.19355] [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: 02/02/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023]
Abstract
Leaf dark respiration (Rd ) acclimates to environmental changes. However, the magnitude, controls and time scales of acclimation remain unclear and are inconsistently treated in ecosystem models. We hypothesized that Rd and Rubisco carboxylation capacity (Vcmax ) at 25°C (Rd,25 , Vcmax,25 ) are coordinated so that Rd,25 variations support Vcmax,25 at a level allowing full light use, with Vcmax,25 reflecting daytime conditions (for photosynthesis), and Rd,25 /Vcmax,25 reflecting night-time conditions (for starch degradation and sucrose export). We tested this hypothesis temporally using a 5-yr warming experiment, and spatially using an extensive field-measurement data set. We compared the results to three published alternatives: Rd,25 declines linearly with daily average prior temperature; Rd at average prior night temperatures tends towards a constant value; and Rd,25 /Vcmax,25 is constant. Our hypothesis accounted for more variation in observed Rd,25 over time (R2 = 0.74) and space (R2 = 0.68) than the alternatives. Night-time temperature dominated the seasonal time-course of Rd , with an apparent response time scale of c. 2 wk. Vcmax dominated the spatial patterns. Our acclimation hypothesis results in a smaller increase in global Rd in response to rising CO2 and warming than is projected by the two of three alternative hypotheses, and by current models.
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Affiliation(s)
- Yanghang Ren
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
| | - Han Wang
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
| | - Sandy P Harrison
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
- School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading, Reading, RG6 6AH, UK
| | - I Colin Prentice
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
| | - Nicholas G Smith
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Giulia Mengoli
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
- Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2753, Australia
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13
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Dellero Y, Berardocco S, Bouchereau A. U- 13C-glucose incorporation into source leaves of Brassica napus highlights light-dependent regulations of metabolic fluxes within central carbon metabolism. JOURNAL OF PLANT PHYSIOLOGY 2024; 292:154162. [PMID: 38103478 DOI: 10.1016/j.jplph.2023.154162] [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: 07/07/2023] [Revised: 11/07/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023]
Abstract
Plant central carbon metabolism comprises several important metabolic pathways acting together to support plant growth and yield establishment. Despite the emergence of 13C-based dynamic approaches, the regulation of metabolic fluxes between light and dark conditions has not yet received sufficient attention for agronomically relevant plants. Here, we investigated the impact of light/dark conditions on carbon allocation processes within central carbon metabolism of Brassica napus after U-13C-glucose incorporation into leaf discs. Leaf gas-exchanges and metabolite contents were weakly impacted by the leaf disc method and the incorporation of glucose. 13C-analysis by GC-MS showed that U-13C-glucose was converted to fructose for de novo biosynthesis of sucrose at similar rates in both light and dark conditions. However, light conditions led to a reduced commitment of glycolytic carbons towards respiratory substrates (pyruvate, alanine, malate) and TCA cycle intermediates compared to dark conditions. Analysis of 13C-enrichment at the isotopologue level and metabolic pathway isotopic tracing reconstructions identified the contribution of multiple pathways to serine biosynthesis in light and dark conditions. However, the direct contribution of the glucose-6-phosphate shunt to serine biosynthesis was not observed. Our results also provided isotopic evidences for an active metabolic connection between the TCA cycle, glycolysis and photorespiration in light conditions through a rapid reallocation of TCA cycle decarboxylations back to the TCA cycle through photorespiration and glycolysis. Altogether, these results suggest the active coordination of core metabolic pathways across multiple compartments to reorganize C-flux modes.
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Affiliation(s)
- Younès Dellero
- INRAE, Université Rennes, Institut Agro, IGEPP-UMR1349, P2M2-MetaboHUB, Le Rheu, 35653, France.
| | - Solenne Berardocco
- INRAE, Université Rennes, Institut Agro, IGEPP-UMR1349, P2M2-MetaboHUB, Le Rheu, 35653, France
| | - Alain Bouchereau
- INRAE, Université Rennes, Institut Agro, IGEPP-UMR1349, P2M2-MetaboHUB, Le Rheu, 35653, France
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14
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Yin X, Amthor JS. Estimating leaf day respiration from conventional gas exchange measurements. THE NEW PHYTOLOGIST 2024; 241:52-58. [PMID: 37858976 DOI: 10.1111/nph.19330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023]
Abstract
Leaf day respiration (Rd ) strongly influences carbon-use efficiencies of whole plants and the global terrestrial biosphere. It has long been thought that Rd is slower than respiration in the dark at a given temperature, but measuring Rd by gas exchange remains a challenge because leaves in the light are also photosynthesizing. The Kok method and the Laisk method are widely used to estimate Rd . We highlight theoretical limitations of these popular methods, and recent progress toward their improvement by using additional information from chlorophyll fluorescence and by accounting for the photosynthetic reassimilation of respired CO2 . The latest evidence for daytime CO2 and energy release from the oxidative pentose phosphate pathway in chloroplasts appears to be important to understanding Rd .
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Affiliation(s)
- Xinyou Yin
- Centre for Crop Systems Analysis, Department of Plant Sciences, Wageningen University & Research, PO Box 430, 6700 AK, Wageningen, the Netherlands
| | - Jeffrey S Amthor
- Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
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15
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Schmiege SC, Sharkey TD, Walker B, Hammer J, Way DA. Laisk measurements in the nonsteady state: Tests in plants exposed to warming and variable CO2 concentrations. PLANT PHYSIOLOGY 2023; 193:1045-1057. [PMID: 37232396 PMCID: PMC10517191 DOI: 10.1093/plphys/kiad305] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/27/2023]
Abstract
Light respiration (RL) is an important component of plant carbon balance and a key parameter in photosynthesis models. RL is often measured using the Laisk method, a gas exchange technique that is traditionally employed under steady-state conditions. However, a nonsteady-state dynamic assimilation technique (DAT) may allow for more rapid Laisk measurements. In 2 studies, we examined the efficacy of DAT for estimating RL and the parameter Ci* (the intercellular CO2 concentration where Rubisco's oxygenation velocity is twice its carboxylation velocity), which is also derived from the Laisk technique. In the first study, we compared DAT and steady-state RL and Ci* estimates in paper birch (Betula papyrifera) growing under control and elevated temperature and CO2 concentrations. In the second, we compared DAT-estimated RL and Ci* in hybrid poplar (Populus nigra L. × P. maximowiczii A. Henry "NM6") exposed to high or low CO2 concentration pre-treatments. The DAT and steady-state methods provided similar RL estimates in B. papyrifera, and we found little acclimation of RL to temperature or CO2; however, Ci* was higher when measured with DAT compared to steady-state methods. These Ci* differences were amplified by the high or low CO2 pre-treatments. We propose that changes in the export of glycine from photorespiration may explain these apparent differences in Ci*.
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Affiliation(s)
- Stephanie C Schmiege
- Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Thomas D Sharkey
- Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Berkley Walker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Julia Hammer
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Danielle A Way
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
- Nicholas School of the Environment, Duke University, Durham, NC 27710, USA
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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16
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Pang X, Nawrocki WJ, Cardol P, Zheng M, Jiang J, Fang Y, Yang W, Croce R, Tian L. Weak acids produced during anaerobic respiration suppress both photosynthesis and aerobic respiration. Nat Commun 2023; 14:4207. [PMID: 37452043 PMCID: PMC10349137 DOI: 10.1038/s41467-023-39898-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/02/2023] [Indexed: 07/18/2023] Open
Abstract
While photosynthesis transforms sunlight energy into sugar, aerobic and anaerobic respiration (fermentation) catabolizes sugars to fuel cellular activities. These processes take place within one cell across several compartments, however it remains largely unexplored how they interact with one another. Here we report that the weak acids produced during fermentation down-regulate both photosynthesis and aerobic respiration. This effect is mechanistically explained with an "ion trapping" model, in which the lipid bilayer selectively traps protons that effectively acidify subcellular compartments with smaller buffer capacities - such as the thylakoid lumen. Physiologically, we propose that under certain conditions, e.g., dim light at dawn, tuning down the photosynthetic light reaction could mitigate the pressure on its electron transport chains, while suppression of respiration could accelerate the net oxygen evolution, thus speeding up the recovery from hypoxia. Since we show that this effect is conserved across photosynthetic phyla, these results indicate that fermentation metabolites exert widespread feedback control over photosynthesis and aerobic respiration. This likely allows algae to better cope with changing environmental conditions.
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Affiliation(s)
- Xiaojie Pang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wojciech J Nawrocki
- Department of Physics and Astronomy and LaserLab Amsterdam Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR7141, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005, Paris, France
| | - Pierre Cardol
- Génétique et Physiologie des Microalgues, InBioS/Phytosystems, Institut de Botanique, Université de Liège, B22, 4000, Liège, Belgium
| | - Mengyuan Zheng
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jingjing Jiang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
| | - Yuan Fang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenqiang Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Roberta Croce
- Department of Physics and Astronomy and LaserLab Amsterdam Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
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17
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Cox AJF, Hartley IP, Meir P, Sitch S, Dusenge ME, Restrepo Z, González-Caro S, Villegas JC, Uddling J, Mercado LM. Acclimation of photosynthetic capacity and foliar respiration in Andean tree species to temperature change. THE NEW PHYTOLOGIST 2023; 238:2329-2344. [PMID: 36987979 DOI: 10.1111/nph.18900] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/13/2023] [Indexed: 05/19/2023]
Abstract
Climate warming is causing compositional changes in Andean tropical montane forests (TMFs). These shifts are hypothesised to result from differential responses to warming of cold- and warm-affiliated species, with the former experiencing mortality and the latter migrating upslope. The thermal acclimation potential of Andean TMFs remains unknown. Along a 2000 m Andean altitudinal gradient, we planted individuals of cold- and warm-affiliated species (under common soil and irrigation), exposing them to the hot and cold extremes of their thermal niches, respectively. We measured the response of net photosynthesis (Anet ), photosynthetic capacity and leaf dark respiration (Rdark ) to warming/cooling, 5 months after planting. In all species, Anet and photosynthetic capacity at 25°C were highest when growing at growth temperatures (Tg ) closest to their thermal means, declining with warming and cooling in cold-affiliated and warm-affiliated species, respectively. When expressed at Tg , photosynthetic capacity and Rdark remained unchanged in cold-affiliated species, but the latter decreased in warm-affiliated counterparts. Rdark at 25°C increased with temperature in all species, but remained unchanged when expressed at Tg . Both species groups acclimated to temperature, but only warm-affiliated species decreased Rdark to photosynthetic capacity ratio at Tg as temperature increased. This could confer them a competitive advantage under future warming.
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Affiliation(s)
- Andrew J F Cox
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Iain P Hartley
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JN, UK
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Stephen Sitch
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Mirindi Eric Dusenge
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Zorayda Restrepo
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
| | - Sebastian González-Caro
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
| | - Juan Camilo Villegas
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Lina M Mercado
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
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18
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Schmiege SC, Heskel M, Fan Y, Way DA. It's only natural: Plant respiration in unmanaged systems. PLANT PHYSIOLOGY 2023; 192:710-727. [PMID: 36943293 PMCID: PMC10231469 DOI: 10.1093/plphys/kiad167] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 06/01/2023]
Abstract
Respiration plays a key role in the terrestrial carbon cycle and is a fundamental metabolic process in all plant tissues and cells. We review respiration from the perspective of plants that grow in their natural habitat and how it is influenced by wide-ranging elements at different scales, from metabolic substrate availability to shifts in climate. Decades of field-based measurements have honed our understanding of the biological and environmental controls on leaf, root, stem, and whole-organism respiration. Despite this effort, there remain gaps in our knowledge within and across species and ecosystems, especially in more challenging-to-measure tissues like roots. Recent databases of respiration rates and associated leaf traits from species representing diverse biomes, plant functional types, and regional climates have allowed for a wider-lens view at modeling this important CO2 flux. We also re-analyze published data sets to show that maximum leaf respiration rates (Rmax) in species from around the globe are related both to leaf economic traits and environmental variables (precipitation and air temperature), but that root respiration does not follow the same latitudinal trends previously published for leaf data. We encourage the ecophysiological community to continue to expand their study of plant respiration in tissues that are difficult to measure and at the whole plant and ecosystem levels to address outstanding questions in the field.
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Affiliation(s)
- Stephanie C Schmiege
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biology, Western University, N6A 3K7, London, ON, Canada
| | - Mary Heskel
- Department of Biology, Macalester College, Saint Paul, MN, USA 55105
| | - Yuzhen Fan
- Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Danielle A Way
- Department of Biology, Western University, N6A 3K7, London, ON, Canada
- Research School of Biology, The Australian National University, Acton, ACT, Australia
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
- Nicholas School of the Environment, Duke University, Durham, NC, USA
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19
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Burgess AJ. Breath of green life: Reduction in plant day and night respiration under elevated CO2. PLANT PHYSIOLOGY 2023; 192:31-33. [PMID: 36787227 PMCID: PMC10152654 DOI: 10.1093/plphys/kiad087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 05/03/2023]
Affiliation(s)
- Alexandra J Burgess
- Assistant Features Editor, Plant Physiology, American Society of Plant Biologists, USA
- Agriculture and Environmental Sciences, School of Biosciences, University of Nottingham Sutton Bonington Campus, Loughborough LE12 5RD, UK
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20
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Korte P, Unzner A, Damm T, Berger S, Krischke M, Mueller MJ. High triacylglycerol turnover is required for efficient opening of stomata during heat stress in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023. [PMID: 36976526 DOI: 10.1111/tpj.16210] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/04/2023] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
Heat stress triggers the accumulation of triacylglycerols in Arabidopsis leaves, which increases basal thermotolerance. However, how triacylglycerol synthesis is linked to thermotolerance remains unclear and the mechanisms involved remain to be elucidated. It has been shown that triacylglycerol and starch degradation are required to provide energy for stomatal opening induced by blue light at dawn. To investigate whether triacylglycerol turnover is involved in heat-induced stomatal opening during the day, we performed feeding experiments with labeled fatty acids. Heat stress strongly induced both triacylglycerol synthesis and degradation to channel fatty acids destined for peroxisomal ß-oxidation through the triacylglycerol pool. Analysis of mutants defective in triacylglycerol synthesis or peroxisomal fatty acid uptake revealed that triacylglycerol turnover and fatty acid catabolism are required for heat-induced stomatal opening in illuminated leaves. We show that triacylglycerol turnover is continuous (1.2 mol% per min) in illuminated leaves even at 22°C. The ß-oxidation of triacylglycerol-derived fatty acids generates C2 carbon units that are channeled into the tricarboxylic acid pathway in the light. In addition, carbohydrate catabolism is required to provide oxaloacetate as an acceptor for peroxisomal acetyl-CoA and maintain the tricarboxylic acid pathway for energy and amino acid production during the day.
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Affiliation(s)
- Pamela Korte
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Amelie Unzner
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Theresa Damm
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Susanne Berger
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Markus Krischke
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Martin J Mueller
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
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21
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Wang L, Zheng J, Wang G, Dang QL. Combined effects of elevated CO2 and warmer temperature on limitations to photosynthesis and carbon sequestration in yellow birch. TREE PHYSIOLOGY 2023; 43:379-389. [PMID: 36322135 DOI: 10.1093/treephys/tpac128] [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: 08/04/2022] [Revised: 10/13/2022] [Accepted: 09/30/2022] [Indexed: 05/03/2023]
Abstract
Elevated CO2 and warmer temperature occur simultaneously under the current climate change. However, their combined effects on the photosynthetic traits in boreal trees are not well understood. This study investigated the morphological and photosynthetic responses of yellow birch (Betula alleghaniensis Britt.) to a combined treatment of CO2 and temperature (ambient, ACT (400 μmol mol-1 CO2 and current temperature) vs elevated, ECT (750 μmol mol-1 CO2 and current +4 °C temperature)). It was found that ECT significantly reduced leaf-area based photosynthetic rate (An), maximum Rubisco carboxylation rate (Vcmax), photosynthetic electron transport rate (Jmax), leaf nitrogen concentration, respiration and mesophyll conductance. There were two interesting findings: first, the primary mechanism of photosynthetic limitation shifted from Ribulose-1,5-bisphosphate (RuBP) carboxylation (related to Vcmax) to RuBP regeneration (related to Jmax) in response to ECT, leading to decreased transition point (Ci-t and An-t) from RuBP carboxylation to regeneration; second, the increase in total leaf area in response to ECT more than compensated for the downregulation of leaf-area based photosynthesis, leading to greater biomass in ECT than in ACT. We proposed a new protocol for evaluating photosynthetic limitations by comparing the relative relationship between the transition point (Ci-t and An-t) and the photosynthetic rate at growth CO2 (Ci-g and An-g). Furthermore, we found that Jmax (RuBP regeneration) was the primary limitation to An under ECT.
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Affiliation(s)
- Lei Wang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Department of Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003, China
| | - Jinping Zheng
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Forestry College, Beihua University, 3999 Binjiang East Road, Jilin, Jilin 132013, China
| | - Gerong Wang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Forestry College, Beihua University, 3999 Binjiang East Road, Jilin, Jilin 132013, China
| | - Qing-Lai Dang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
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22
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Ma WT, Yu YZ, Wang X, Gong XY. Estimation of intrinsic water-use efficiency from δ 13C signature of C 3 leaves: Assumptions and uncertainty. FRONTIERS IN PLANT SCIENCE 2023; 13:1037972. [PMID: 36714771 PMCID: PMC9877432 DOI: 10.3389/fpls.2022.1037972] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
Carbon isotope composition (δ13C) has been widely used to estimate the intrinsic water-use efficiency (iWUE) of plants in ecosystems around the world, providing an ultimate record of the functional response of plants to climate change. This approach relies on established relationships between leaf gas exchange and isotopic discrimination, which are reflected in different formulations of 13C-based iWUE models. In the current literature, most studies have utilized the simple, linear equation of photosynthetic discrimination to estimate iWUE. However, recent studies demonstrated that using this linear model for quantitative studies of iWUE could be problematic. Despite these advances, there is a scarcity of review papers that have comprehensively reviewed the theoretical basis, assumptions, and uncertainty of 13C-based iWUE models. Here, we 1) present the theoretical basis of 13C-based iWUE models: the classical model (iWUEsim), the comprehensive model (iWUEcom), and the model incorporating mesophyll conductance (iWUEmes); 2) discuss the limitations of the widely used iWUEsim model; 3) and make suggestions on the application of the iWUEmes model. Finally, we suggest that a mechanistic understanding of mesophyll conductance associated effects and post-photosynthetic fractionation are the bottlenecks for improving the 13C-based estimation of iWUE.
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Affiliation(s)
- Wei Ting Ma
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yong Zhi Yu
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Xuming Wang
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
| | - Xiao Ying Gong
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Fujian Provincial Key Laboratory for Plant Eco-physiology, Fuzhou, China
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23
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Fu X, Walker BJ. Dynamic response of photorespiration in fluctuating light environments. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:600-611. [PMID: 35962786 DOI: 10.1093/jxb/erac335] [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: 05/16/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Photorespiration is a dynamic process that is intimately linked to photosynthetic carbon assimilation. There is a growing interest in understanding carbon assimilation during dynamic conditions, but the role of photorespiration under such conditions is unclear. In this review, we discuss recent work relevant to the function of photorespiration under dynamic conditions, with a special focus on light transients. This work reveals that photorespiration is a fundamental component of the light induction of assimilation where variable diffusive processes limit CO2 exchange with the atmosphere. Additionally, metabolic interactions between photorespiration and the C3 cycle may help balance fluxes under dynamic light conditions. We further discuss how the energy demands of photorespiration present special challenges to energy balancing during dynamic conditions. We finish the review with an overview of why regulation of photorespiration may be important under dynamic conditions to maintain appropriate fluxes through metabolic pathways related to photorespiration such as nitrogen and one-carbon metabolism.
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Affiliation(s)
- Xinyu Fu
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Berkley J Walker
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
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24
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Fu X, Gregory LM, Weise SE, Walker BJ. Integrated flux and pool size analysis in plant central metabolism reveals unique roles of glycine and serine during photorespiration. NATURE PLANTS 2023; 9:169-178. [PMID: 36536013 DOI: 10.1038/s41477-022-01294-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Photorespiration is an essential process juxtaposed between plant carbon and nitrogen metabolism that responds to dynamic environments. Photorespiration recycles inhibitory intermediates arising from oxygenation reactions catalysed by Rubisco back into the C3 cycle, but it is unclear what proportions of its nitrogen-containing intermediates (glycine and serine) are exported into other metabolisms in vivo and how these pool sizes affect net CO2 gas exchange during photorespiratory transients. Here, to address this uncertainty, we measured rates of amino acid export from photorespiration using isotopically non-stationary metabolic flux analysis. This analysis revealed that ~23-41% of the photorespiratory carbon was exported from the pathway as serine under various photorespiratory conditions. Furthermore, we determined that the build-up and relaxation of glycine pools constrained a large portion of photosynthetic acclimation during photorespiratory transients. These results reveal the unique and important roles of glycine and serine in successfully maintaining various photorespiratory fluxes that occur under environmental fluctuations in nature and providing carbon and nitrogen for metabolism.
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Affiliation(s)
- Xinyu Fu
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Luke M Gregory
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Sean E Weise
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Berkley J Walker
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA.
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25
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Wang L, Zuo Q, zheng J, You J, Yang G, Leng S. Salt stress decreases seed yield and postpones growth process of canola (Brassica napus L.) by changing nitrogen and carbon characters. Sci Rep 2022; 12:17884. [PMID: 36284201 PMCID: PMC9596443 DOI: 10.1038/s41598-022-22815-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 10/19/2022] [Indexed: 01/20/2023] Open
Abstract
Salt stress is a major challenge for plant growth and yield achievement in canola (Brassica napus L.). Nitrogen (N) is considered as an essential nutrient involved in many physiological processes, and carbon (C) is the most component of plant biomass. N and C assimilations of canola plants are always inhibited by salt stress. However, the knowledge of how salt stress affects biomass and seed yield through changing N and C characters is limited. A field experiment was conducted to investigate the growth process, N and C characters, photosynthetic performance, biomass accumulation and seed yield under the low and high soil salt-ion concentration conditions (LSSC and HSSC). The results indicated that HSSC postponed the time of early flowering stage and maturity stage by 4 ~ 5 days and 6 ~ 8 days, respectively, as compared with LSSC. Besides, HSSC decreased the N and C accumulation and C/N at both growing stages, suggesting that salt stress break the balance between C assimilation and N assimilation, with stronger effect on C assimilation. Although the plant N content under HSSC was increased, the photosynthesis rate at early flowering stage was decreased. The leaf area index at early flowering stage was also reduced. In addition, HSSC decreased N translocation efficiency especially in stem, and N utilization efficiency. These adverse effects of HSSC together resulted in reduced biomass accumulation and seed yield. In conclusion, the high soil salt-ion concentration reduced biomass accumulation and seed yield in canola through changing N and C characters.
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Affiliation(s)
- Long Wang
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
| | - Qingsong Zuo
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
| | - Jingdong zheng
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
| | - Jingjing You
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
| | - Guang Yang
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
| | - Suohu Leng
- grid.268415.cJiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China ,grid.268415.cJiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou University, 48 Wenhui East Road, Yangzhou, 225009 Jiangsu China
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26
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Faber AH, Griffin KL, Tjoelker MG, Pagter M, Yang J, Bruhn D. Consistent diurnal pattern of leaf respiration in the light among contrasting species and climates. THE NEW PHYTOLOGIST 2022; 236:71-85. [PMID: 35727175 PMCID: PMC9544685 DOI: 10.1111/nph.18330] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/12/2022] [Indexed: 05/02/2023]
Abstract
Leaf daytime respiration (leaf respiration in the light, RL ) is often assumed to constitute a fixed fraction of leaf dark respiration (RD ) (i.e. a fixed light inhibition of respiration (RD )) and vary diurnally due to temperature fluctuations. These assumptions were tested by measuring RL , RD and the light inhibition of RD in the field at a constant temperature using the Kok method. Measurements were conducted diurnally on 21 different species: 13 deciduous, four evergreen and four herbaceous from humid continental and humid subtropical climates. RL and RD showed significant diurnal variations and the diurnal pattern differed in trajectory and magnitude between climates, but not between plant functional types (PFTs). The light inhibition of RD varied diurnally and differed between climates and in trajectory between PFTs. The results highlight the entrainment of leaf daytime respiration to the diurnal cycle and that time of day should be accounted for in studies seeking to examine the environmental and biological drivers of leaf daytime respiration.
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Affiliation(s)
- Andreas H. Faber
- Department of Chemistry and BioscienceAalborg UniversityFredrik Bajers Vej 7H9220AalborgDenmark
| | - Kevin L. Griffin
- Department of Earth and Environmental SciencesColumbia UniversityPalisadesNY10964USA
- Department of Ecology, Evolution and Environmental BiologyColumbia UniversityNew YorkNY10027USA
- Lamont‐Doherty Earth ObservatoryColumbia UniversityPalisadesNY10964USA
| | - Mark G. Tjoelker
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2750Australia
| | - Majken Pagter
- Department of Chemistry and BioscienceAalborg UniversityFredrik Bajers Vej 7H9220AalborgDenmark
| | - Jinyan Yang
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2750Australia
| | - Dan Bruhn
- Department of Chemistry and BioscienceAalborg UniversityFredrik Bajers Vej 7H9220AalborgDenmark
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27
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Bruhn D, Newman F, Hancock M, Povlsen P, Slot M, Sitch S, Drake J, Weedon GP, Clark DB, Pagter M, Ellis RJ, Tjoelker MG, Andersen KM, Correa ZR, McGuire PC, Mercado LM. Nocturnal plant respiration is under strong non-temperature control. Nat Commun 2022; 13:5650. [PMID: 36163192 PMCID: PMC9512894 DOI: 10.1038/s41467-022-33370-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/13/2022] [Indexed: 11/09/2022] Open
Abstract
Most biological rates depend on the rate of respiration. Temperature variation is typically considered the main driver of daily plant respiration rates, assuming a constant daily respiration rate at a set temperature. Here, we show empirical data from 31 species from temperate and tropical biomes to demonstrate that the rate of plant respiration at a constant temperature decreases monotonically with time through the night, on average by 25% after 8 h of darkness. Temperature controls less than half of the total nocturnal variation in respiration. A new universal formulation is developed to model and understand nocturnal plant respiration, combining the nocturnal decrease in the rate of plant respiration at constant temperature with the decrease in plant respiration according to the temperature sensitivity. Application of the new formulation shows a global reduction of 4.5 -6 % in plant respiration and an increase of 7-10% in net primary production for the present-day.
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Affiliation(s)
- Dan Bruhn
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
| | - Freya Newman
- Faculty of Environment, Science and Economy', University of Exeter, Exeter, United Kingdom
| | - Mathilda Hancock
- Faculty of Environment, Science and Economy', University of Exeter, Exeter, United Kingdom
| | - Peter Povlsen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Martijn Slot
- Smithsonian Tropical Research Institute, Balboa Ancon, Republic of Panama
| | - Stephen Sitch
- Faculty of Environment, Science and Economy', University of Exeter, Exeter, United Kingdom
| | - John Drake
- Department of Sustainable Resources Management, SUNY College of Environmental Science and Forestry, Syracuse, USA
| | | | - Douglas B Clark
- UK Centre for Ecology & Hydrology, Wallingford, United Kingdom
| | - Majken Pagter
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Richard J Ellis
- UK Centre for Ecology & Hydrology, Wallingford, United Kingdom
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, Australia
| | | | - Zorayda Restrepo Correa
- Grupo Servicios ecosistemicos y cambio climático (SECC), Corporación COL-TREE, Medellin, Colombia
| | - Patrick C McGuire
- University of Reading, Department of Meteorology and National Centre for Atmospheric Science, Reading, United Kingdom
| | - Lina M Mercado
- Faculty of Environment, Science and Economy', University of Exeter, Exeter, United Kingdom. .,UK Centre for Ecology & Hydrology, Wallingford, United Kingdom.
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28
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Bender ML, Zhu XG, Falkowski P, Ma F, Griffin K. On the rate of phytoplankton respiration in the light. PLANT PHYSIOLOGY 2022; 190:267-279. [PMID: 35652738 PMCID: PMC9434318 DOI: 10.1093/plphys/kiac254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
The rate of algal and cyanobacterial respiration in the light is an important ecophysiological term that remains to be completely characterized and quantified. To address this issue, we exploited process-specific decarboxylation rates from flux balance analysis and isotopically nonstationary metabolic flux analysis. Our study, based on published data, suggested that decarboxylation is about 22% of net CO2 assimilation when the tricarboxylic acid cycle is completely open (characterized by the commitment of alpha ketoglutarate to amino acid synthesis and very low rates of succinate formation). This estimate was supported by calculating the decarboxylation rates required to synthesize the major components of biomass (proteins, lipids, and carbohydrates) at their typical abundance. Of the 22 CO2 molecules produced by decarboxylation (normalized to net assimilation = 100), approximately 13 were from pyruvate and 3 were from isocitrate. The remaining six units of decarboxylation were in the amino acid synthesis pathways outside the tricarboxylic acid cycle. A small additional flux came from photorespiration, decarboxylations of six phosphogluconate in the oxidative pentose phosphate pathway, and decarboxylations in the syntheses of lower-abundance compounds, including pigments and ribonucleic acids. This general approach accounted for the high decarboxylation rates in algae and cyanobacteria compared to terrestrial plants. It prompts a simple speculation for the origin of the Kok effect and helps constrain the photoautotrophic respiration rate, in the light, in the euphotic zone of the ocean and lakes.
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Affiliation(s)
| | - Xin-Guang Zhu
- State Key Laboratory of Plant Molecular Genetics, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Paul Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA
| | - Fangfang Ma
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China
| | - Kevin Griffin
- Department of Earth and Environmental Sciences, Columbia University, Palisades, New York 10964, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, New York 10027, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA
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29
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Jardine KJ, Lei J, Som S, Souza D, Clendinen CS, Mehta H, Handakumbura P, Bill M, Young RP. Light-Dependence of Formate (C1) and Acetate (C2) Transport and Oxidation in Poplar Trees. PLANTS 2022; 11:plants11162080. [PMID: 36015384 PMCID: PMC9413118 DOI: 10.3390/plants11162080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022]
Abstract
Although apparent light inhibition of leaf day respiration is a widespread reported phenomenon, the mechanisms involved, including utilization of alternate respiratory pathways and substrates and light inhibition of TCA cycle enzymes are under active investigation. Recently, acetate fermentation was highlighted as a key drought survival strategy mediated through protein acetylation and jasmonate signaling. Here, we evaluate the light-dependence of acetate transport and assimilation in Populus trichocarpa trees using the dynamic xylem solution injection (DXSI) method developed here for continuous studies of C1 and C2 organic acid transport and light-dependent metabolism. Over 7 days, 1.0 L of [13C]formate and [13C2]acetate solutions were delivered to the stem base of 2-year old potted poplar trees, while continuous diurnal observations were made in the canopy of CO2, H2O, and isoprene gas exchange together with δ13CO2. Stem base injection of 10 mM [13C2]acetate induced an overall pattern of canopy branch headspace 13CO2 enrichment (δ13CO2 +27‰) with a diurnal structure in δ13CO2 reaching a mid-day minimum followed by a maximum shortly after darkening where δ13CO2 values rapidly increased up to +12‰. In contrast, 50 mM injections of [13C]formate were required to reach similar δ13CO2 enrichment levels in the canopy with δ13CO2 following diurnal patterns of transpiration. Illuminated leaves of detached poplar branches pretreated with 10 mM [13C2]acetate showed lower δ13CO2 (+20‰) compared to leaves treated with 10 mM [13C]formate (+320‰), the opposite pattern observed at the whole plant scale. Following dark/light cycles at the leaf-scale, rapid, strong, and reversible enhancements in headspace δ13CO2 by up to +60‰ were observed in [13C2]acetate-treated leaves which showed enhanced dihydrojasmonic acid and TCA cycle intermediate concentrations. The results are consistent with acetate in the transpiration stream as an effective activator of the jasmonate signaling pathway and respiratory substrate. The shorter lifetime of formate relative to acetate in the transpiration stream suggests rapid formate oxidation to CO2 during transport to the canopy. In contrast, acetate is efficiently transported to the canopy where an increased allocation towards mitochondrial dark respiration occurs at night. The results highlight the potential for an effective integration of acetate into glyoxylate and TCA cycles and the light-inhibition of citrate synthase as a potential regulatory mechanism controlling the diurnal allocation of acetate between anabolic and catabolic processes.
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Affiliation(s)
- Kolby J. Jardine
- Lawrence Berkeley National Laboratory, Climate and Ecosystem Science Division, Berkeley, CA 94720, USA
- Correspondence:
| | - Joseph Lei
- Lawrence Berkeley National Laboratory, Climate and Ecosystem Science Division, Berkeley, CA 94720, USA
| | - Suman Som
- Lawrence Berkeley National Laboratory, Climate and Ecosystem Science Division, Berkeley, CA 94720, USA
| | - Daisy Souza
- Forest Management Laboratory, National Institute for Amazon Research, Manaus 69067-375, Brazil
| | - Chaevien S. Clendinen
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Hardeep Mehta
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Pubudu Handakumbura
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Markus Bill
- Lawrence Berkeley National Laboratory, Climate and Ecosystem Science Division, Berkeley, CA 94720, USA
| | - Robert P. Young
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA
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30
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Fang L, Yin X, van der Putten PEL, Martre P, Struik PC. Drought exerts a greater influence than growth temperature on the temperature response of leaf day respiration in wheat (Triticum aestivum). PLANT, CELL & ENVIRONMENT 2022; 45:2062-2077. [PMID: 35357701 PMCID: PMC9324871 DOI: 10.1111/pce.14324] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/21/2022] [Accepted: 03/26/2022] [Indexed: 05/22/2023]
Abstract
We assessed how the temperature response of leaf day respiration (Rd ) in wheat responded to contrasting water regimes and growth temperatures. In Experiment 1, well-watered and drought-stressed conditions were imposed on two genotypes; in Experiment 2, the two water regimes combined with high (HT), medium (MT) and low (LT) growth temperatures were imposed on one of the genotypes. Rd was estimated from simultaneous gas exchange and chlorophyll fluorescence measurements at six leaf temperatures (Tleaf ) for each treatment, using the Yin method for nonphotorespiratory conditions and the nonrectangular hyperbolic fitting method for photorespiratory conditions. The two genotypes responded similarly to growth and measurement conditions. Estimates of Rd for nonphotorespiratory conditions were generally higher than those for photorespiratory conditions, but their responses to Tleaf were similar. Under well-watered conditions, Rd and its sensitivity to Tleaf slightly acclimated to LT, but did not acclimate to HT. Temperature sensitivities of Rd were considerably suppressed by drought, and the suppression varied among growth temperatures. Thus, it is necessary to quantify interactions between drought and growth temperature for reliably modelling Rd under climate change. Our study also demonstrated that the Kok method, one of the currently popular methods for estimating Rd , underestimated Rd significantly.
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Affiliation(s)
- Liang Fang
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Xinyou Yin
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Peter E. L. van der Putten
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Pierre Martre
- LEPSE, Institut Agro SupAgro, INRAE, Univ MontpellierMontpellierFrance
| | - Paul C. Struik
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
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31
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Reimport of carbon from cytosolic and vacuolar sugar pools into the Calvin-Benson cycle explains photosynthesis labeling anomalies. Proc Natl Acad Sci U S A 2022; 119:e2121531119. [PMID: 35259011 PMCID: PMC8931376 DOI: 10.1073/pnas.2121531119] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificancePhotosynthesis metabolites are quickly labeled when 13CO2 is fed to leaves, but the time course of labeling reveals additional contributing processes involved in the metabolic dynamics of photosynthesis. The existence of three such processes is demonstrated, and a metabolic flux model is developed to explore and characterize them. The model is consistent with a slow return of carbon from cytosolic and vacuolar sugars into the Calvin-Benson cycle through the oxidative pentose phosphate pathway. Our results provide insight into how carbon assimilation is integrated into the metabolic network of photosynthetic cells with implications for global carbon fluxes.
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Oh GGK, O’Leary BM, Signorelli S, Millar AH. Alternative oxidase (AOX) 1a and 1d limit proline-induced oxidative stress and aid salinity recovery in Arabidopsis. PLANT PHYSIOLOGY 2022; 188:1521-1536. [PMID: 34919733 PMCID: PMC8896607 DOI: 10.1093/plphys/kiab578] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 05/24/2023]
Abstract
Proline (Pro) catabolism and reactive oxygen species production have been linked in mammals and Caenorhabditis elegans, while increases in leaf respiration rate follow Pro exposure in plants. Here, we investigated how alternative oxidases (AOXs) of the mitochondrial electron transport chain accommodate the large, atypical flux resulting from Pro catabolism and limit oxidative stress during Pro breakdown in mature Arabidopsis (Arabidopsis thaliana) leaves. Following Pro treatment, AOX1a and AOX1d accumulate at transcript and protein levels, with AOX1d approaching the level of the typically dominant AOX1a isoform. We therefore sought to determine the function of both AOX isoforms under Pro respiring conditions. Oxygen consumption rate measurements in aox1a and aox1d leaves suggested these AOXs can functionally compensate for each other to establish enhanced AOX catalytic capacity in response to Pro. Generation of aox1a.aox1d lines showed complete loss of AOX proteins and activity upon Pro treatment, yet full respiratory induction in response to Pro remained possible via the cytochrome pathway. However, aox1a.aox1d leaves displayed symptoms of elevated oxidative stress and suffered increased oxidative damage during Pro metabolism compared to the wild-type (WT) or the single mutants. During recovery from salt stress, when relatively high rates of Pro catabolism occur naturally, photosynthetic rates in aox1a.aox1d recovered slower than in the WT or the single aox lines, showing that both AOX1a and AOX1d are beneficial for cellular metabolism during Pro drawdown following osmotic stress. This work provides physiological evidence of a beneficial role for AOX1a but also the less studied AOX1d isoform in allowing safe catabolism of alternative respiratory substrates like Pro.
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Affiliation(s)
- Glenda Guek Khim Oh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
| | - Brendan M O’Leary
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
- Saskatoon Research and Development Centre, Agriculture and Agri-food, Saskatoon, SK S7N 0X2, Canada
| | - Santiago Signorelli
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
- Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Uruguay
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
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Fan Y, Asao S, Furbank RT, von Caemmerer S, Day DA, Tcherkez G, Sage TL, Sage RF, Atkin OK. The crucial roles of mitochondria in supporting C 4 photosynthesis. THE NEW PHYTOLOGIST 2022; 233:1083-1096. [PMID: 34669188 DOI: 10.1111/nph.17818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
C4 photosynthesis involves a series of biochemical and anatomical traits that significantly improve plant productivity under conditions that reduce the efficiency of C3 photosynthesis. We explore how evolution of the three classical biochemical types of C4 photosynthesis (NADP-ME, NAD-ME and PCK types) has affected the functions and properties of mitochondria. Mitochondria in C4 NAD-ME and PCK types play a direct role in decarboxylation of metabolites for C4 photosynthesis. Mitochondria in C4 PCK type also provide ATP for C4 metabolism, although this role for ATP provision is not seen in NAD-ME type. Such involvement has increased mitochondrial abundance/size and associated enzymatic capacity, led to changes in mitochondrial location and ultrastructure, and altered the role of mitochondria in cellular carbon metabolism in the NAD-ME and PCK types. By contrast, these changes in mitochondrial properties are absent in the C4 NADP-ME type and C3 leaves, where mitochondria play no direct role in photosynthesis. From an eco-physiological perspective, rates of leaf respiration in darkness vary considerably among C4 species but does not differ systematically among the three C4 types. This review outlines further mitochondrial research in key areas central to the engineering of the C4 pathway into C3 plants and to the understanding of variation in rates of C4 dark respiration.
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Affiliation(s)
- Yuzhen Fan
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Shinichi Asao
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Robert T Furbank
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Susanne von Caemmerer
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - David A Day
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Guillaume Tcherkez
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Institut de Recherche en Horticulture et Semences, INRA and University of Angers, Beaucouzé, 49070, France
| | - Tammy L Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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Li Y, Zhang X, Shao Q, Fan J, Chen Z, Dong J, Hu Z, Zhan Y. Community Composition and Structure Affect Ecosystem and Canopy Water Use Efficiency Across Three Typical Alpine Ecosystems. FRONTIERS IN PLANT SCIENCE 2022; 12:771424. [PMID: 35126410 PMCID: PMC8810523 DOI: 10.3389/fpls.2021.771424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Unique ecosystems distributed in alpine areas of the Qinghai-Tibetan Plateau play important roles in climate change mitigation, local food supply, and conservation of species diversity. To understand the water use efficiency (WUE) of this fragile and sensitive region, this study combined observed data from the eddy covariance system and the Shuttleworth-Wallace (S-W) model to measure the continuous mass exchange, including gross primary productivity (GPP), evapotranspiration (ET), and canopy transpiration (T) throughout 2 or 3 years (2016-2018) in three common alpine ecosystems (i.e., alpine steppe, alpine meadow, and alpine swamp). These ecosystems represent a water availability gradient and thus provide the opportunity to quantify environmental and biological controls on WUE at various spatiotemporal scales. We analyzed the ecosystem WUE (WUEe; defined as the ratio of GPP to ET) and canopy WUE (WUEc; defined as the ratio of GPP and canopy T). It was found that the yearly WUEe was 1.40, 1.63, and 2.16 g C kg-1 H2O, and the yearly WUEc was 8.93, 2.46, and 5.19 g C kg-1 H2O in the three typical ecosystems, respectively. The controlling factors of yearly WUE diverged between WUEe and WUEc. We found that plant functional group proportion (e.g., gramineous and Cyperaceae) highly explained the yearly WUEe variation across sites, and a good correlation was observed between community species diversity and WUEc. These findings suggest that community composition and trait change are critical in regulating WUEe and WUEc across different alpine ecosystems and that the regulation mechanisms may differ fundamentally between WUEe and WUEc.
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Affiliation(s)
- Yuzhe Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Xinyuan Zhang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
| | - Quanqin Shao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jiangwen Fan
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Zhi Chen
- Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jinwei Dong
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Zhongmin Hu
- School of Geography, South China Normal University, Guangzhou, China
| | - Yue Zhan
- College of Forestry, Nanjing Forestry University, Nanjing, China
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Shameer S, Wang Y, Bota P, Ratcliffe RG, Long SP, Sweetlove LJ. A hybrid kinetic and constraint-based model of leaf metabolism allows predictions of metabolic fluxes in different environments. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:295-313. [PMID: 34699645 DOI: 10.1111/tpj.15551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 10/08/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
While flux balance analysis (FBA) provides a framework for predicting steady-state leaf metabolic network fluxes, it does not readily capture the response to environmental variables without being coupled to other modelling formulations. To address this, we coupled an FBA model of 903 reactions of soybean (Glycine max) leaf metabolism with e-photosynthesis, a dynamic model that captures the kinetics of 126 reactions of photosynthesis and associated chloroplast carbon metabolism. Successful coupling was achieved in an iterative formulation in which fluxes from e-photosynthesis were used to constrain the FBA model and then, in turn, fluxes computed from the FBA model used to update parameters in e-photosynthesis. This process was repeated until common fluxes in the two models converged. Coupling did not hamper the ability of the kinetic module to accurately predict the carbon assimilation rate, photosystem II electron flux, and starch accumulation of field-grown soybean at two CO2 concentrations. The coupled model also allowed accurate predictions of additional parameters such as nocturnal respiration, as well as analysis of the effect of light intensity and elevated CO2 on leaf metabolism. Predictions included an unexpected decrease in the rate of export of sucrose from the leaf at high light, due to altered starch-sucrose partitioning, and altered daytime flux modes in the tricarboxylic acid cycle at elevated CO2 . Mitochondrial fluxes were notably different between growing and mature leaves, with greater anaplerotic, tricarboxylic acid cycle and mitochondrial ATP synthase fluxes predicted in the former, primarily to provide carbon skeletons and energy for protein synthesis.
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Affiliation(s)
- Sanu Shameer
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Yu Wang
- Carl R Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Pedro Bota
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - R George Ratcliffe
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Stephen P Long
- Carl R Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Lee J Sweetlove
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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O'Leary BM, Oh GGK, Millar AH. High-Throughput Oxygen Consumption Measurements in Leaf Tissue Using Oxygen Sensitive Fluorophores. Methods Mol Biol 2022; 2363:63-75. [PMID: 34545486 DOI: 10.1007/978-1-0716-1653-6_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Respiratory rate measurements are crucial assays to understand mitochondrial biochemistry as well as metabolic regulation within tissues. Several technologies currently exist that can measure plant respiratory oxygen consumption or carbon dioxide evolution rates over short durations by either isolated mitochondria or plant tissues. Here we describe recently developed alternative methods for measuring tissue oxygen consumption rates (OCRs) using systems reliant on oxygen sensitive fluorophores. The methods described have distinct experimental advantages: they can allow high-throughput and long-duration measurements; and they are particularly suited to investigating the metabolic regulation of respiration by comparing OCRs among treatments or genotypes.
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Affiliation(s)
- Brendan M O'Leary
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, WA, Australia.
| | - Glenda Guek Khim Oh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, WA, Australia
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, WA, Australia
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Krämer K, Kepp G, Brock J, Stutz S, Heyer AG. Acclimation to elevated CO 2 affects the C/N balance by reducing de novo N-assimilation. PHYSIOLOGIA PLANTARUM 2022; 174:e13615. [PMID: 35014037 DOI: 10.1111/ppl.13615] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Plants exposed to elevated atmospheric CO2 concentrations show an increased photosynthetic activity. However, after prolonged exposure, the activity declines. This acclimation to elevated CO2 is accompanied by a rise in the carbon-to-nitrogen ratio of the biomass. Hence, increased sugar accumulation and sequential downregulation of photosynthetic genes, as well as nitrogen depletion and reduced protein content, have been hypothesized as the cause of low photosynthetic performance. However, the reason for reduced nitrogen content in plants at high CO2 is unclear. Here, we show that reduced photorespiration at increased CO2 -to-O2 ratio leads to reduced de novo assimilation of nitrate, thus shifting the C/N balance. Metabolic modeling of acclimated and non-acclimated plants revealed the photorespiratory pathway to function as a sink for already assimilated nitrogen during the light period, providing carbon skeletons for de novo assimilation. At high CO2 , low photorespiratory activity resulted in diminished nitrogen assimilation and eventually resulted in reduced carbon assimilation. For the hpr1-1 mutant, defective in reduction of hydroxy-pyruvate, metabolic simulations show that turnover of photorespiratory metabolites is expanded into the night. Comparison of simulations for hpr1-1 with those for the wild type allowed investigating the effect of a perturbed photorespiration on N-assimilation.
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Affiliation(s)
- Konrad Krämer
- Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Gabi Kepp
- Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Judith Brock
- Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Simon Stutz
- Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Arnd G Heyer
- Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, University of Stuttgart, Stuttgart, Germany
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Dellero Y, Berardocco S, Berges C, Filangi O, Bouchereau A. Validation of carbon isotopologue distribution measurements by GC-MS and application to 13C-metabolic flux analysis of the tricarboxylic acid cycle in Brassica napus leaves. FRONTIERS IN PLANT SCIENCE 2022; 13:885051. [PMID: 36704152 PMCID: PMC9871494 DOI: 10.3389/fpls.2022.885051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 11/28/2022] [Indexed: 05/14/2023]
Abstract
The estimation of metabolic fluxes in photosynthetic organisms represents an important challenge that has gained interest over the last decade with the development of 13C-Metabolic Flux Analysis at isotopically non-stationary steady-state. This approach requires a high level of accuracy for the measurement of Carbon Isotopologue Distribution in plant metabolites. But this accuracy has still not been evaluated at the isotopologue level for GC-MS, leading to uncertainties for the metabolic fluxes calculated based on these fragments. Here, we developed a workflow to validate the measurements of CIDs from plant metabolites with GC-MS by producing tailor-made E. coli standard extracts harboring a predictable binomial CID for some organic and amino acids. Overall, most of our TMS-derivatives mass fragments were validated with these standards and at natural isotope abundance in plant matrices. Then, we applied this validated MS method to investigate the light/dark regulation of plant TCA cycle by incorporating U-13C-pyruvate to Brassica napus leaf discs. We took advantage of pathway-specific isotopologues/isotopomers observed between two and six hours of labeling to show that the TCA cycle can operate in a cyclic manner under both light and dark conditions. Interestingly, this forward cyclic flux mode has a nearly four-fold higher contribution for pyruvate-to-citrate and pyruvate-to-malate fluxes than the phosphoenolpyruvate carboxylase (PEPc) flux reassimilating carbon derived from some mitochondrial enzymes. The contribution of stored citrate to the mitochondrial TCA cycle activity was also questioned based on dynamics of 13C-enrichment in citrate, glutamate and succinate and variations of citrate total amounts under light and dark conditions. Interestingly, there was a light-dependent 13C-incorporation into glycine and serine showing that decarboxylations from pyruvate dehydrogenase complex and TCA cycle enzymes were actively reassimilated and could represent up to 5% to net photosynthesis.
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Affiliation(s)
- Younès Dellero
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Université Rennes, Institut Agro, Le Rheu, France
- Metabolic Profiling and Metabolomics platform (P2M2), Institute for Genetics, Environment and Plant Protection (IGEPP), Biopolymers Interactions Assemblies (BIA), Le Rheu, France
- MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
- *Correspondence: Younès Dellero,
| | - Solenne Berardocco
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Université Rennes, Institut Agro, Le Rheu, France
- Metabolic Profiling and Metabolomics platform (P2M2), Institute for Genetics, Environment and Plant Protection (IGEPP), Biopolymers Interactions Assemblies (BIA), Le Rheu, France
| | - Cécilia Berges
- MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
- Toulouse Biotechnology Institute, Université de Toulouse, National center for Scientific Research (CNRS), National Institute for Research for Agriculture, Food and Environment (INRAE), National Institute of Applied Sciences (INSA), Toulouse, France
| | - Olivier Filangi
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Université Rennes, Institut Agro, Le Rheu, France
- Metabolic Profiling and Metabolomics platform (P2M2), Institute for Genetics, Environment and Plant Protection (IGEPP), Biopolymers Interactions Assemblies (BIA), Le Rheu, France
- MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
| | - Alain Bouchereau
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Université Rennes, Institut Agro, Le Rheu, France
- Metabolic Profiling and Metabolomics platform (P2M2), Institute for Genetics, Environment and Plant Protection (IGEPP), Biopolymers Interactions Assemblies (BIA), Le Rheu, France
- MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
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Wang L, Dang QL. Growth and photosynthetic traits differ between shoots originated from axillary buds or from adventitious buds in Populus balsamifera L. cuttings. PHYSIOLOGIA PLANTARUM 2022; 174:e13599. [PMID: 34796965 DOI: 10.1111/ppl.13599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/07/2021] [Accepted: 11/14/2021] [Indexed: 06/13/2023]
Abstract
Bud development influences shoot branching and the plasticity and adaptability of plants. To explore the differences of post-embryonic development of different types of buds, shoots originated from adventitious buds and axillary buds of cuttings in two populations of balsam poplar (Populus balsamifera L.) were investigated for differences in leaf morphology, photosynthetic and growth characteristics, and the effects of a carbonic anhydrase (CA) inhibitor on CA activity, photosynthesis and mesophyll conductance (gm ). The results showed that axillary buds produced ovate first few leaves and longer shoots while adventitious buds produced lanceolate first few leaves with higher specific leaf area (SLA). There were no significant differences in leaf area-based photosynthetic rate (An ), maximum carboxylation rate (Vcmax ), and maximum electron transport rate (Jmax ) between shoots originated from the two bud types. Based on the principal component analysis, shoots of adventitious bud origin grouped on daytime respiration and SLA, while cuttings from axillary buds clustered toward the opposite direction of quantum yield and light saturation point. Shoots originated from different types of buds had different growth rates and biomass, but the direction of the differences varied with the population of the mother tree. The two populations differed in An , gm , and relationships between CA, An , and gm . There were differences in post-embryonic growth traits of shoots from axillary buds and those from adventitious buds, which may be an adaptive strategy for regeneration under different light conditions.
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Affiliation(s)
- Lei Wang
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, Ontario, Canada
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
| | - Qing-Lai Dang
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, Ontario, Canada
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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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Zhao HL, Chang TG, Xiao Y, Zhu XG. Potential metabolic mechanisms for inhibited chloroplast nitrogen assimilation under high CO2. PLANT PHYSIOLOGY 2021; 187:1812-1833. [PMID: 34618071 PMCID: PMC8566258 DOI: 10.1093/plphys/kiab345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 06/28/2021] [Indexed: 05/31/2023]
Abstract
Improving photosynthesis is considered a major and feasible option to dramatically increase crop yield potential. Increased atmospheric CO2 concentration often stimulates both photosynthesis and crop yield, but decreases protein content in the main C3 cereal crops. This decreased protein content in crops constrains the benefits of elevated CO2 on crop yield and affects their nutritional value for humans. To support studies of photosynthetic nitrogen assimilation and its complex interaction with photosynthetic carbon metabolism for crop improvement, we developed a dynamic systems model of plant primary metabolism, which includes the Calvin-Benson cycle, the photorespiration pathway, starch synthesis, glycolysis-gluconeogenesis, the tricarboxylic acid cycle, and chloroplastic nitrogen assimilation. This model successfully captures responses of net photosynthetic CO2 uptake rate (A), respiration rate, and nitrogen assimilation rate to different irradiance and CO2 levels. We then used this model to predict inhibition of nitrogen assimilation under elevated CO2. The potential mechanisms underlying inhibited nitrogen assimilation under elevated CO2 were further explored with this model. Simulations suggest that enhancing the supply of α-ketoglutarate is a potential strategy to maintain high rates of nitrogen assimilation under elevated CO2. This model can be used as a heuristic tool to support research on interactions between photosynthesis, respiration, and nitrogen assimilation. It also provides a basic framework to support the design and engineering of C3 plant primary metabolism for enhanced photosynthetic efficiency and nitrogen assimilation in the coming high-CO2 world.
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Affiliation(s)
- Hong-Long Zhao
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Tian-Gen Chang
- National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yi Xiao
- National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200031, China
- Department of Crop Sciences, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, USA
- Department of Plant Biology, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, USA
| | - Xin-Guang Zhu
- National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200031, China
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Condori-Apfata JA, Batista-Silva W, Medeiros DB, Vargas JR, Valente LML, Pérez-Díaz JL, Fernie AR, Araújo WL, Nunes-Nesi A. Downregulation of the E2 Subunit of 2-Oxoglutarate Dehydrogenase Modulates Plant Growth by Impacting Carbon-Nitrogen Metabolism in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2021; 62:798-814. [PMID: 33693904 PMCID: PMC8484937 DOI: 10.1093/pcp/pcab036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 02/28/2021] [Accepted: 04/16/2021] [Indexed: 05/04/2023]
Abstract
In Arabidopsis thaliana, two genes encode the E2 subunit of the 2-oxoglutarate dehydrogenase (2-OGDH), a multimeric complex composed of three subunits. To functionally characterize the isoforms of E2 subunit, we isolated Arabidopsis mutant lines for each gene encoding the E2 subunit and performed a detailed molecular and physiological characterization of the plants under controlled growth conditions. The functional lack of expression of E2 subunit isoforms of 2-OGDH increased plant growth, reduced dark respiration and altered carbohydrate metabolism without changes in the photosynthetic rate. Interestingly, plants from e2-ogdh lines also exhibited reduced seed weight without alterations in total seed number. We additionally observed that downregulation of 2-OGDH activity led to minor changes in the levels of tricarboxylic acid cycle intermediates without clear correlation with the reduced expression of specific E2-OGDH isoforms. Furthermore, the e2-ogdh mutant lines exhibited a reduction by up to 25% in the leaf total amino acids without consistent changes in the amino acid profile. Taken together, our results indicate that the two isoforms of E2 subunit play a similar role in carbon-nitrogen metabolism, in plant growth and in seed weight.
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Affiliation(s)
- Jorge A Condori-Apfata
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Willian Batista-Silva
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - David Barbosa Medeiros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam Golm 14476, Germany
| | - Jonas Rafael Vargas
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Luiz M Lopes Valente
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Jorge Luis Pérez-Díaz
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Alisdair R Fernie
- * Corresponding authors: Alisdair R. Fernie, E-mail, ; Adriano Nunes-Nesi, E-mail,
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Adriano Nunes-Nesi
- * Corresponding authors: Alisdair R. Fernie, E-mail, ; Adriano Nunes-Nesi, E-mail,
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43
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Yin X, Busch FA, Struik PC, Sharkey TD. Evolution of a biochemical model of steady-state photosynthesis. PLANT, CELL & ENVIRONMENT 2021; 44:2811-2837. [PMID: 33872407 PMCID: PMC8453732 DOI: 10.1111/pce.14070] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/10/2021] [Accepted: 04/12/2021] [Indexed: 05/29/2023]
Abstract
On the occasion of the 40th anniversary of the publication of the landmark model by Farquhar, von Caemmerer & Berry on steady-state C3 photosynthesis (known as the "FvCB model"), we review three major further developments of the model. These include: (1) limitation by triose phosphate utilization, (2) alternative electron transport pathways, and (3) photorespiration-associated nitrogen and C1 metabolisms. We discussed the relation of the third extension with the two other extensions, and some equivalent extensions to model C4 photosynthesis. In addition, the FvCB model has been coupled with CO2 -diffusion models. We review how these extensions and integration have broadened the use of the FvCB model in understanding photosynthesis, especially with regard to bioenergetic stoichiometries associated with photosynthetic quantum yields. Based on the new insights, we present caveats in applying the FvCB model. Further research needs are highlighted.
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Affiliation(s)
- Xinyou Yin
- Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Florian A. Busch
- School of Biosciences and Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
| | - Paul C. Struik
- Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Thomas D. Sharkey
- MSU‐DOE Plant Research Laboratory, Plant Resilience InstituteMichigan State UniversityEast LansingMichiganUSA
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44
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Sagun JV, Badger MR, Chow WS, Ghannoum O. Mehler reaction plays a role in C 3 and C 4 photosynthesis under shade and low CO 2. PHOTOSYNTHESIS RESEARCH 2021; 149:171-185. [PMID: 33534052 DOI: 10.1007/s11120-021-00819-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
Alternative electron fluxes such as the cyclic electron flux (CEF) around photosystem I (PSI) and Mehler reaction (Me) are essential for efficient photosynthesis because they generate additional ATP and protect both photosystems against photoinhibition. The capacity for Me can be estimated by measuring O2 exchange rate under varying irradiance and CO2 concentration. In this study, mass spectrometric measurements of O2 exchange were made using leaves of representative species of C3 and C4 grasses grown under natural light (control; PAR ~ 800 µmol quanta m-2 s-1) and shade (~ 300 µmol quanta m-2 s-1), and in representative species of gymnosperm, liverwort and fern grown under natural light. For all control grown plants measured at high CO2, O2 uptake rates were similar between the light and dark, and the ratio of Rubisco oxygenation to carboxylation (Vo/Vc) was low, which suggests little potential for Me, and that O2 uptake was mainly due to photorespiration or mitochondrial respiration under these conditions. Low CO2 stimulated O2 uptake in the light, Vo/Vc and Me in all species. The C3 species had similar Vo/Vc, but Me was highest in the grass and lowest in the fern. Among the C4 grasses, shade increased O2 uptake in the light, Vo/Vc and the assimilation quotient (AQ), particularly at low CO2, whilst Me was only substantial at low CO2 where it may contribute 20-50% of maximum electron flow under high light.
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Affiliation(s)
- Julius Ver Sagun
- ARC Centre of Excellence for Translational Photosynthesis, Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Murray R Badger
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - Wah Soon Chow
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - Oula Ghannoum
- ARC Centre of Excellence for Translational Photosynthesis, Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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45
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Scafaro AP, Fan Y, Posch BC, Garcia A, Coast O, Atkin OK. Responses of leaf respiration to heatwaves. PLANT, CELL & ENVIRONMENT 2021; 44:2090-2101. [PMID: 33534189 DOI: 10.1111/pce.14018] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
Mitochondrial respiration (R) is central to plant physiology and responds dynamically to daily short-term temperature changes. In the longer-term, changes in energy demand and membrane fluidity can decrease leaf R at a common temperature and increase the temperature at which leaf R peaks (Tmax ). However, leaf R functionality is more susceptible to short-term heatwaves. Catalysis increases with rising leaf temperature, driving faster metabolism and leaf R demand, despite declines in photosynthesis restricting assimilate supply and growth. Proteins denature as temperatures increase further, adding to maintenance costs. Excessive heat also inactivates respiratory enzymes, with a concomitant limitation on the capacity of the R system. These competing push-and-pull factors are responsible for the diminishing acceleration in leaf R rate as temperature rises. Under extreme heat, membranes become overly fluid, and enzymes such as the cytochrome c oxidase are impaired. Such changes can lead to over-reduction of the energy system culminating in reactive oxygen species production. This ultimately leads to the total breakdown of leaf R, setting the limit of leaf survival. Understanding the heat stress responses of leaf R is imperative, given the continued rise in frequency and intensity of heatwaves and the importance of R for plant fitness and survival.
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Affiliation(s)
- Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yuzhen Fan
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Andres Garcia
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Onoriode Coast
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- Natural Resources Institute, Agriculture, Health and Environment Department, University of Greenwich, Kent, UK
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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46
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Xu Y, Fu X, Sharkey TD, Shachar-Hill Y, Walker ABJ. The metabolic origins of non-photorespiratory CO2 release during photosynthesis: a metabolic flux analysis. PLANT PHYSIOLOGY 2021; 186:297-314. [PMID: 33591309 PMCID: PMC8154043 DOI: 10.1093/plphys/kiab076] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/16/2021] [Indexed: 05/02/2023]
Abstract
Respiration in the light (RL) releases CO2 in photosynthesizing leaves and is a phenomenon that occurs independently from photorespiration. Since RL lowers net carbon fixation, understanding RL could help improve plant carbon-use efficiency and models of crop photosynthesis. Although RL was identified more than 75 years ago, its biochemical mechanisms remain unclear. To identify reactions contributing to RL, we mapped metabolic fluxes in photosynthesizing source leaves of the oilseed crop and model plant camelina (Camelina sativa). We performed a flux analysis using isotopic labeling patterns of central metabolites during 13CO2 labeling time course, gas exchange, and carbohydrate production rate experiments. To quantify the contributions of multiple potential CO2 sources with statistical and biological confidence, we increased the number of metabolites measured and reduced biological and technical heterogeneity by using single mature source leaves and quickly quenching metabolism by directly injecting liquid N2; we then compared the goodness-of-fit between these data and data from models with alternative metabolic network structures and constraints. Our analysis predicted that RL releases 5.2 μmol CO2 g-1 FW h-1 of CO2, which is relatively consistent with a value of 9.3 μmol CO2 g-1 FW h-1 measured by CO2 gas exchange. The results indicated that ≤10% of RL results from TCA cycle reactions, which are widely considered to dominate RL. Further analysis of the results indicated that oxidation of glucose-6-phosphate to pentose phosphate via 6-phosphogluconate (the G6P/OPP shunt) can account for >93% of CO2 released by RL.
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Affiliation(s)
- Yuan Xu
- Department of Plant Biology, Michigan State University, Michigan 48824, USA
| | - Xinyu Fu
- Department of Plant Biology, Michigan State University, Michigan 48824, USA
- Department of Energy-Plant Research Laboratory, Michigan State University, Michigan 48824, USA
| | - Thomas D Sharkey
- Department of Energy-Plant Research Laboratory, Michigan State University, Michigan 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, Michigan 48824, USA
| | - Yair Shachar-Hill
- Department of Plant Biology, Michigan State University, Michigan 48824, USA
| | - and Berkley J Walker
- Department of Plant Biology, Michigan State University, Michigan 48824, USA
- Department of Energy-Plant Research Laboratory, Michigan State University, Michigan 48824, USA
- Author for communication:
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47
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Dellero Y, Jossier M, Bouchereau A, Hodges M, Leport L. Leaf Phenological Stages of Winter Oilseed Rape ( Brassica napus L.) Have Conserved Photosynthetic Efficiencies but Contrasted Intrinsic Water Use Efficiencies at High Light Intensities. FRONTIERS IN PLANT SCIENCE 2021; 12:659439. [PMID: 33936148 PMCID: PMC8083057 DOI: 10.3389/fpls.2021.659439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Leaf senescence in source leaves leads to the active degradation of chloroplast components [photosystems, chlorophylls, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)] and plays a key role in the efficient remobilization of nutrients toward sink tissues. However, the progression of leaf senescence can differentially modify the photosynthetic properties of source leaves depending on plant species. In this study, the photosynthetic and respiratory properties of four leaf ranks of oilseed rape describing leaf phenological stages having different sink-source activities were analyzed. To achieve this, photosynthetic pigments, total soluble proteins, Rubisco amounts, and the light response of chlorophyll fluorescence parameters coupled to leaf gas exchanges and leaf water content were measured. Photosynthetic CO2 assimilation and electron transfer rates, Rubisco and chlorophyll levels per leaf area were gradually decreased between young, mature and senescent leaves but they remained highly correlated at saturating light intensities. However, senescent leaves of oilseed rape had a lower intrinsic water use efficiency compared to young and mature leaves at saturating light intensities that was mainly due to higher stomatal conductance and transpiration rate with respect to stomatal density and net CO2 assimilation. The results are in favor of a concerted degradation of chloroplast components but a contrasted regulation of water status between leaves of different phenological stages of winter oilseed rape.
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Affiliation(s)
- Younès Dellero
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Institut Agro, Université Rennes, Le Rheu, France
| | - Mathieu Jossier
- Université Paris-Saclay, NAtional Committee of Scientific Research (CNRS), National Research Institute for Agriculture, Food and Environment (INRAE), Université Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, France
| | - Alain Bouchereau
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Institut Agro, Université Rennes, Le Rheu, France
| | - Michael Hodges
- Université Paris-Saclay, NAtional Committee of Scientific Research (CNRS), National Research Institute for Agriculture, Food and Environment (INRAE), Université Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, France
| | - Laurent Leport
- Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Institut Agro, Université Rennes, Le Rheu, France
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48
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Tcherkez G, Atkin OK. Unravelling mechanisms and impacts of day respiration in plant leaves: an introduction to a Virtual Issue. THE NEW PHYTOLOGIST 2021; 230:5-10. [PMID: 33650185 DOI: 10.1111/nph.17164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Affiliation(s)
- Guillaume Tcherkez
- Division of Plant Sciences, Research School of Biology, ANU College of Science, Australian National University, Canberra, ACT, 2601, Australia
| | - Owen K Atkin
- Division of Plant Sciences, Research School of Biology, ANU College of Science, Australian National University, Canberra, ACT, 2601, Australia
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49
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Bergman ME, González-Cabanelas D, Wright LP, Walker BJ, Phillips MA. Isotope ratio-based quantification of carbon assimilation highlights the role of plastidial isoprenoid precursor availability in photosynthesis. PLANT METHODS 2021; 17:32. [PMID: 33781281 PMCID: PMC8008545 DOI: 10.1186/s13007-021-00731-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/13/2021] [Indexed: 05/22/2023]
Abstract
BACKGROUND We report a method to estimate carbon assimilation based on isotope ratio-mass spectrometry (IRMS) of 13CO2 labeled plant tissue. Photosynthetic carbon assimilation is the principal experimental observable which integrates important aspects of primary plant metabolism. It is traditionally measured through gas exchange. Despite its centrality in plant research, gas exchange performs poorly with rosette growth habits typical of Arabidopsis thaliana, mutant lines with limited biomass, and accounts poorly for leaf shading. RESULTS IRMS-based carbon assimilation values from plants labeled at different light intensities were compared to those obtained by gas exchange, and the two methods yielded similar values. Using this method, we observed a strong correlation between 13C content and labeling time (R2 = 0.999) for 158 wild-type plants labeled for 6 to 42 min. Plants cultivated under different light regimes showed a linear response with respect to carbon assimilation, varying from 7.38 nmol 13C mg-1 leaf tissue min-1 at 80 PAR to 19.27 nmol 13C mg-1 leaf tissue min-1 at 500 PAR. We applied this method to examine the link between inhibition of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway and suppression of photosynthesis. A significant decrease in carbon assimilation was observed when metabolic activity in the MEP pathway was compromised by mutation or herbicides targeting the MEP pathway. Mutants affected in MEP pathway genes 1-DEOXY-D-XYLULOSE 5-PHOSPHATE SYNTHASE (DXS) or 1-HYDROXY-2-METHYL-2-(E)-BUTENYL 4-DIPHOSPHATE SYNTHASE (HDS) showed assimilation rates 36% and 61% lower than wild type. Similarly, wild type plants treated with the MEP pathway inhibitors clomazone or fosmidomycin showed reductions of 52% and 43%, respectively, while inhibition of the analogous mevalonic acid pathway, which supplies the same isoprenoid intermediates in the cytosol, did not, suggesting inhibition of photosynthesis was specific to disruption of the MEP pathway. CONCLUSIONS This method provides an alternative to gas exchange that offers several advantages: resilience to differences in leaf overlap, measurements based on tissue mass rather than leaf surface area, and compatibility with mutant Arabidopsis lines which are not amenable to gas exchange measurements due to low biomass and limited leaf surface area. It is suitable for screening large numbers of replicates simultaneously as well as post-hoc analysis of previously labeled plant tissue and is complementary to downstream detection of isotopic label in targeted metabolite pools.
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Affiliation(s)
- Matthew E Bergman
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 3G5, Canada
| | | | - Louwrance P Wright
- Zeiselhof Research Farm, Menlo Park, P.O. Box 35984, Pretoria, 0102, South Africa
| | - Berkley J Walker
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Michael A Phillips
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 3G5, Canada.
- Department of Biology, University of Toronto-Mississauga, Mississauga, ON, L5L 1C6, Canada.
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50
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Weitz KK, Smith ML, Hixson KK, Hill EA, Jansson JK, Hofmockel KS, Lipton MS. Real-Time Mass Spectrometry Measurements of Respiration Rates in Biological Systems. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:648-652. [PMID: 33258588 DOI: 10.1021/jasms.0c00251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Many organisms process carbon and other nutrients to generate energy through aerobic respiration where organic carbon compounds are broken down and oxygen is consumed, producing carbon dioxide and water. Respiration is indicative of active metabolism, and respiration rates are proportional to the amount of living biomass in an ecosystem. Although there are many methods for measuring respiration rates in the laboratory, current systems, such as infrared gas analyzers, are limited in their ability to independently resolve isotopomer fluxes across a range of relevant gases including both CO2 and O2 in real-time. Therefore, monitoring of biological respiration in real time under controlled laboratory conditions would enable better understanding of cellular physiology. To address this challenge, we developed a real time mass spectrometry (RTMS) manifold that simultaneously measures production and consumption of multiple gases and their isotopologues in seconds with the speed and sensitivity necessary to characterize rapidly changing respiration events as they occur. This universal manifold can be fitted to a variety of instruments and affords the same analytical precision and accuracy of the instrument while allowing for the real time measurements. Here, we paired the manifold to a single quad MS with an electron impact (EI) source operated in scan mode to detect extracted target gases by their respective masses (e.g., 12CO2 at mass 44, 13CO2 at 45). We demonstrated applicability of the RTMS instrument to different biological ecosystems (bacterial cultures, plants, and soil), and in all cases, we were able to detect simultaneous and rapid measurements of multiple gases in real time, providing novel insights into complex respiratory metabolism and the influence of biological and environmental factors.
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Affiliation(s)
- Karl K Weitz
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Montana L Smith
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kim K Hixson
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Eric A Hill
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Janet K Jansson
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kirsten S Hofmockel
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Mary S Lipton
- Environmental and Biological Sciences Division Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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