1
|
Johnson JE, Berry JA. The role of Cytochrome b 6f in the control of steady-state photosynthesis: a conceptual and quantitative model. PHOTOSYNTHESIS RESEARCH 2021; 148:101-136. [PMID: 33999328 PMCID: PMC8292351 DOI: 10.1007/s11120-021-00840-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 04/26/2021] [Indexed: 05/06/2023]
Abstract
Here, we present a conceptual and quantitative model to describe the role of the Cytochrome [Formula: see text] complex in controlling steady-state electron transport in [Formula: see text] leaves. The model is based on new experimental methods to diagnose the maximum activity of Cyt [Formula: see text] in vivo, and to identify conditions under which photosynthetic control of Cyt [Formula: see text] is active or relaxed. With these approaches, we demonstrate that Cyt [Formula: see text] controls the trade-off between the speed and efficiency of electron transport under limiting light, and functions as a metabolic switch that transfers control to carbon metabolism under saturating light. We also present evidence that the onset of photosynthetic control of Cyt [Formula: see text] occurs within milliseconds of exposure to saturating light, much more quickly than the induction of non-photochemical quenching. We propose that photosynthetic control is the primary means of photoprotection and functions to manage excitation pressure, whereas non-photochemical quenching functions to manage excitation balance. We use these findings to extend the Farquhar et al. (Planta 149:78-90, 1980) model of [Formula: see text] photosynthesis to include a mechanistic description of the electron transport system. This framework relates the light captured by PS I and PS II to the energy and mass fluxes linking the photoacts with Cyt [Formula: see text], the ATP synthase, and Rubisco. It enables quantitative interpretation of pulse-amplitude modulated fluorometry and gas-exchange measurements, providing a new basis for analyzing how the electron transport system coordinates the supply of Fd, NADPH, and ATP with the dynamic demands of carbon metabolism, how efficient use of light is achieved under limiting light, and how photoprotection is achieved under saturating light. The model is designed to support forward as well as inverse applications. It can either be used in a stand-alone mode at the leaf-level or coupled to other models that resolve finer-scale or coarser-scale phenomena.
Collapse
Affiliation(s)
- J E Johnson
- Dept. Global Ecology, Carnegie Institution, Stanford, CA, 94305, USA.
| | - J A Berry
- Dept. Global Ecology, Carnegie Institution, Stanford, CA, 94305, USA
| |
Collapse
|
2
|
Du B, Kruse J, Winkler JB, Alfarray S, Schnitzler JP, Ache P, Hedrich R, Rennenberg H. Climate and development modulate the metabolome and antioxidative system of date palm leaves. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5959-5969. [PMID: 31375818 PMCID: PMC6812712 DOI: 10.1093/jxb/erz361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Date palms are remarkably tolerant to environmental stresses, but the mechanisms involved remain poorly characterized. Leaf metabolome profiling was therefore performed on mature (ML) and young (YL) leaves of 2-year-old date palm seedlings that had been grown in climate chambers that simulate summer and winter conditions in eastern Saudi Arabia. Cultivation under high temperature (summer climate) resulted in higher YL H2O2 leaf levels despite increases in dehydroascorbate reductase (DHAR) activities. The levels of raffinose and galactinol, tricarboxylic acid cycle intermediates, and total amino acids were higher under these conditions, particularly in YL. The accumulation of unsaturated fatty acids, 9,12-octadecadienoic acid and 9,12,15-octadecatrienoic acid, was lower in ML. In contrast, the amounts of saturated tetradecanoic acid and heptadecanoic acid were increased in YL under summer climate conditions. The accumulation of phenolic compounds was favored under summer conditions, while flavonoids accumulated under lower temperature (winter climate) conditions. YL displayed stronger hydration, lower H2O2 levels, and more negative δ 13C values, indicating effective reactive oxygen species scavenging. These findings, which demonstrate the substantial metabolic adjustments that facilitate tolerance to the high temperatures in YL and ML, suggest that YL may be more responsive to climate change.
Collapse
Affiliation(s)
- Baoguo Du
- College of Life Science and Biotechnology, Mianyang Normal University, Mianyang, China
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universitat Freiburg, Freiburg, Germany
| | - Joerg Kruse
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universitat Freiburg, Freiburg, Germany
| | - Jana Barbro Winkler
- Helmholtz Zentrum München, Research Unit Environmental Simulation (EUS), Institute of Biochemical Plant Pathology, Neuherberg, Germany
| | | | - Joerg-Peter Schnitzler
- Helmholtz Zentrum München, Research Unit Environmental Simulation (EUS), Institute of Biochemical Plant Pathology, Neuherberg, Germany
| | - Peter Ache
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Heinz Rennenberg
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universitat Freiburg, Freiburg, Germany
- King Saud University, Riyadh, Saudi Arabia
| |
Collapse
|
3
|
Kruse J, Adams M, Winkler B, Ghirardo A, Alfarraj S, Kreuzwieser J, Hedrich R, Schnitzler JP, Rennenberg H. Optimization of photosynthesis and stomatal conductance in the date palm Phoenix dactylifera during acclimation to heat and drought. THE NEW PHYTOLOGIST 2019; 223:1973-1988. [PMID: 31093986 DOI: 10.1111/nph.15923] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 05/01/2019] [Indexed: 05/25/2023]
Abstract
We studied acclimation of leaf gas exchange to differing seasonal climate and soil water availability in slow-growing date palm (Phoenix dactylifera) seedlings. We used an extended Arrhenius equation to describe instantaneous temperature responses of leaf net photosynthesis (A) and stomatal conductance (G), and derived physiological parameters suitable for characterization of acclimation (Topt , Aopt and Tequ ). Optimum temperature of A (Topt ) ranged between 20-33°C in winter and 28-45°C in summer. Growth temperature (Tgrowth ) explained c. 50% of the variation in Topt , which additionally depended on leaf water status at the time of measurement. During water stress, light-saturated rates of A at Topt (i.e. Aopt ) were reduced to 30-80% of control levels, albeit not limited by CO2 supply per se. Equilibrium temperature (Tequ ), around which A/G and substomatal [CO2 ] are constant, remained tightly coupled with Topt . Our results suggest that acclimatory shifts in Topt and Aopt reflect a balance between maximization of photosynthesis and minimization of the risk of metabolic perturbations caused by imbalances in cellular [CO2 ]. This novel perspective on acclimation of leaf gas exchange is compatible with optimization theory, and might help to elucidate other acclimation and growth strategies in species adapted to differing climates.
Collapse
Affiliation(s)
- Jörg Kruse
- Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Köhler-Allee 53/54, Freiburg, 79110, Germany
- Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia
| | - Mark Adams
- Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia
- Swinburne University of Technology, John St., Hawthorn, Vic., 3122, Australia
| | - Barbro Winkler
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Andrea Ghirardo
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Saleh Alfarraj
- College of Sciences, King Saud University, PO Box 2455, Riyadh, 11451, Saudi Arabia
| | - Jürgen Kreuzwieser
- Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Köhler-Allee 53/54, Freiburg, 79110, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, Würzburg, 97082, Germany
| | - Jörg-Peter Schnitzler
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, 85764, Germany
| | - Heinz Rennenberg
- Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Köhler-Allee 53/54, Freiburg, 79110, Germany
- College of Sciences, King Saud University, PO Box 2455, Riyadh, 11451, Saudi Arabia
| |
Collapse
|
4
|
Vico G, Way DA, Hurry V, Manzoni S. Can leaf net photosynthesis acclimate to rising and more variable temperatures? PLANT, CELL & ENVIRONMENT 2019; 42:1913-1928. [PMID: 30706948 DOI: 10.1111/pce.13525] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 01/19/2019] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
Under future climates, leaf temperature (Tl ) will be higher and more variable. This will affect plant carbon (C) balance because photosynthesis and respiration both respond to short-term (subdaily) fluctuations in Tl and acclimate in the longer term (days to months). This study asks the question: To what extent can the potential and speed of photosynthetic acclimation buffer leaf C gain from rising and increasing variable Tl ? We quantified how increases in the mean and variability of growth temperature affect leaf performance (mean net CO2 assimilation rates, Anet ; its variability; and time under near-optimal photosynthetic conditions), as mediated by thermal acclimation. To this aim, the probability distribution of Anet was obtained by combining a probabilistic description of short- and long-term changes in Tl with data on Anet responses to these changes, encompassing 75 genera and 111 species, including both C3 and C4 species. Our results show that (a) expected increases in Tl variability will decrease mean Anet and increase its variability, whereas the effects of higher mean Tl depend on species and initial Tl , and (b) acclimation reduces the effects of leaf warming, maintaining Anet at >80% of its maximum under most thermal regimes.
Collapse
Affiliation(s)
- Giulia Vico
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, 750 07, Sweden
| | - Danielle A Way
- Department of Biology, University of Western Ontario, London, N6A 5B7, Ontario, Canada
- Nicholas School of the Environment, Duke University, Durham, 27708, North Carolina, USA
| | - Vaughan Hurry
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, 901 83, Sweden
| | - Stefano Manzoni
- Department of Physical Geography, Stockholm University, Stockholm, 106 91, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, 106 91, Sweden
| |
Collapse
|
5
|
Kruse J, Rennenberg H, Adams MA. Three physiological parameters capture variation in leaf respiration of Eucalyptus grandis, as elicited by short-term changes in ambient temperature, and differing nitrogen supply. PLANT, CELL & ENVIRONMENT 2018; 41:1369-1382. [PMID: 29424929 DOI: 10.1111/pce.13162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 06/08/2023]
Abstract
We used instantaneous temperature responses of CO2 -respiration to explore temperature acclimation dynamics for Eucalyptus grandis grown with differing nitrogen supply. A reduction in ambient temperature from 23 to 19 °C reduced light-saturated photosynthesis by 25% but increased respiratory capacity by 30%. Changes in respiratory capacity were not reversed after temperatures were subsequently increased to 27 °C. Temperature sensitivity of respiration measured at prevalent ambient temperature varied little between temperature treatments but was significantly reduced from ~105 kJ mol-1 when supply of N was weak, to ~70 kJ mol-1 when it was strong. Temperature sensitivity of respiration measured across a broader temperature range (20-40 °C) could be fully described by 2 exponent parameters of an Arrhenius-type model (i.e., activation energy of respiration at low reference temperature and a parameter describing the temperature dependence of activation energy). These 2 parameters were strongly correlated, statistically explaining 74% of observed variation. Residual variation was linked to treatment-induced changes in respiration at low reference temperature or respiratory capacity. Leaf contents of starch and soluble sugars suggest that respiratory capacity varies with source-sink imbalances in carbohydrate utilization, which in combination with shifts in carbon-flux mode, serve to maintain homeostasis of respiratory temperature sensitivity at prevalent growth temperature.
Collapse
Affiliation(s)
- Jörg Kruse
- Institute of Forest Sciences, Chair of Tree Physiology, Georges-Köhler-Allee 53/54, 79110, Freiburg, Germany
| | - Heinz Rennenberg
- Institute of Forest Sciences, Chair of Tree Physiology, Georges-Köhler-Allee 53/54, 79110, Freiburg, Germany
| | - Mark A Adams
- Centre for Carbon Water and Food, The University of Sydney, Sydney, NSW, 2006, Australia
- Swiunburne University of Technology, John Street, Hawthorn, 3122, Victoria, Australia
| |
Collapse
|
6
|
Atkin OK, Bahar NHA, Bloomfield KJ, Griffin KL, Heskel MA, Huntingford C, de la Torre AM, Turnbull MH. Leaf Respiration in Terrestrial Biosphere Models. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2017. [DOI: 10.1007/978-3-319-68703-2_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|