1
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Schmal C. The seasons within: a theoretical perspective on photoperiodic entrainment and encoding. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:549-564. [PMID: 37659985 PMCID: PMC11226496 DOI: 10.1007/s00359-023-01669-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 09/04/2023]
Abstract
Circadian clocks are internal timing devices that have evolved as an adaption to the omnipresent natural 24 h rhythmicity of daylight intensity. Properties of the circadian system are photoperiod dependent. The phase of entrainment varies systematically with season. Plastic photoperiod-dependent re-arrangements in the mammalian circadian core pacemaker yield an internal representation of season. Output pathways of the circadian clock regulate photoperiodic responses such as flowering time in plants or hibernation in mammals. Here, we review the concepts of seasonal entrainment and photoperiodic encoding. We introduce conceptual phase oscillator models as their high level of abstraction, but, yet, intuitive interpretation of underlying parameters allows for a straightforward analysis of principles that determine entrainment characteristics. Results from this class of models are related and discussed in the context of more complex conceptual amplitude-phase oscillators as well as contextual molecular models that take into account organism, tissue, and cell-type-specific details.
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Affiliation(s)
- Christoph Schmal
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany.
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2
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Alexandre Moraes T, Mengin V, Peixoto B, Encke B, Krohn N, Höhne M, Krause U, Stitt M. The circadian clock mutant lhy cca1 elf3 paces starch mobilization to dawn despite severely disrupted circadian clock function. PLANT PHYSIOLOGY 2022; 189:2332-2356. [PMID: 35567528 PMCID: PMC9348821 DOI: 10.1093/plphys/kiac226] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Many plants, including Arabidopsis (Arabidopsis thaliana), accumulate starch in the daytime and remobilize it to support maintenance and growth at night. Starch accumulation is increased when carbon is in short supply, for example, in short photoperiods. Mobilization is paced to exhaust starch around dawn, as anticipated by the circadian clock. This diel pattern of turnover is largely robust against loss of day, dawn, dusk, or evening clock components. Here, we investigated diel starch turnover in the triple circadian clock mutant lhy cca1 elf3, which lacks the LATE ELONGATED HYPOCOTYL and the CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) dawn components and the EARLY FLOWERING3 (ELF3) evening components of the circadian clock. The diel oscillations of transcripts for the remaining clock components and related genes like REVEILLE and PHYTOCHROME-INTERACING FACTOR family members exhibited attenuated amplitudes and altered peak time, weakened dawn dominance, and decreased robustness against changes in the external light-dark cycle. The triple mutant was unable to increase starch accumulation in short photoperiods. However, it was still able to pace starch mobilization to around dawn in different photoperiods and growth irradiances and to around 24 h after the previous dawn in T17 and T28 cycles. The triple mutant was able to slow down starch mobilization after a sudden low-light day or a sudden early dusk, although in the latter case it did not fully compensate for the lengthened night. Overall, there was a slight trend to less linear mobilization of starch. Thus, starch mobilization can be paced rather robustly to dawn despite a major disruption of the transcriptional clock. It is proposed that temporal information can be delivered from clock components or a semi-autonomous oscillator.
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Affiliation(s)
| | - Virginie Mengin
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - Bruno Peixoto
- Instituto Gulbenkian de Ciência, Oeiras 2780-156,Portugal
- GREEN-IT Bioresources for Sustainability, ITQB NOVA, Oeiras 2780-157,Portugal
| | - Beatrice Encke
- Systematic Botany and Biodiversity, Humboldt University of Berlin, Berlin D-10115, Germany
| | - Nicole Krohn
- Abteilung für Parodontologie und Synoptische Zahnmedizin, Charité Universitätsmedizin, Berlin 14197, Germany
| | - Melanie Höhne
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany
| | - Ursula Krause
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany
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3
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Greenwood M, Tokuda IT, Locke JCW. A spatial model of the plant circadian clock reveals design principles for coordinated timing. Mol Syst Biol 2022; 18:e10140. [PMID: 35312157 PMCID: PMC8935279 DOI: 10.15252/msb.202010140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022] Open
Abstract
Individual plant cells possess a genetic network, the circadian clock, that times internal processes to the day‐night cycle. Mathematical models of the clock are typically either “whole‐plant” that ignore tissue or cell type‐specific clock behavior, or “phase‐only” that do not include molecular components. To address the complex spatial coordination observed in experiments, here we implemented a clock network model on a template of a seedling. In our model, the sensitivity to light varies across the plant, and cells communicate their timing via local or long‐distance sharing of clock components, causing their rhythms to couple. We found that both varied light sensitivity and long‐distance coupling could generate period differences between organs, while local coupling was required to generate the spatial waves of clock gene expression observed experimentally. We then examined our model under noisy light‐dark cycles and found that local coupling minimized timing errors caused by the noise while allowing each plant region to maintain a different clock phase. Thus, local sensitivity to environmental inputs combined with local coupling enables flexible yet robust circadian timing.
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Affiliation(s)
- Mark Greenwood
- Sainsbury Laboratory University of Cambridge Cambridge UK
- Department of Biochemistry University of Cambridge Cambridge UK
| | - Isao T Tokuda
- Department of Mechanical Engineering Ritsumeikan University Kusatsu Japan
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4
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Smith AM, Zeeman SC. Starch: A Flexible, Adaptable Carbon Store Coupled to Plant Growth. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:217-245. [PMID: 32075407 DOI: 10.1146/annurev-arplant-050718-100241] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Research in the past decade has uncovered new and surprising information about the pathways of starch synthesis and degradation. This includes the discovery of previously unsuspected protein families required both for processes and for the long-sought mechanism of initiation of starch granules. There is also growing recognition of the central role of leaf starch turnover in making carbon available for growth across the day-night cycle. Sophisticated systems-level control mechanisms involving the circadian clock set rates of nighttime starch mobilization that maintain a steady supply of carbon until dawn and modulate partitioning of photosynthate into starch in the light, optimizing the fraction of assimilated carbon that can be used for growth. These discoveries also uncover complexities: Results from experiments with Arabidopsis leaves in conventional controlled environments are not necessarily applicable to other organs or species or to growth in natural, fluctuating environments.
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Affiliation(s)
| | - Samuel C Zeeman
- Institute of Plant Molecular Biology, ETH Zürich, 8092 Zürich, Switzerland
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5
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Moraes TA, Mengin V, Annunziata MG, Encke B, Krohn N, Höhne M, Stitt M. Response of the Circadian Clock and Diel Starch Turnover to One Day of Low Light or Low CO 2. PLANT PHYSIOLOGY 2019; 179:1457-1478. [PMID: 30670603 PMCID: PMC6446786 DOI: 10.1104/pp.18.01418] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/09/2019] [Indexed: 05/18/2023]
Abstract
Diel starch turnover responds rapidly to changes in the light regime. We investigated if these responses require changes in the temporal dynamics of the circadian clock. Arabidopsis (Arabidopsis thaliana) was grown in a 12-h photoperiod for 19 d, shifted to three different reduced light levels or to low CO2 for one light period, and returned to growth conditions. The treatments produced widespread changes in clock transcript abundance. However, almost all of the changes were restricted to extreme treatments that led to carbon starvation and were small compared to the magnitude of the circadian oscillation. Changes included repression of EARLY FLOWERNG 4, slower decay of dusk components, and a slight phase delay at the next dawn, possibly due to abrogated Evening Complex function and sustained expression of PHYTOCHROME INTERACTING FACTORs and REVEILLEs during the night. Mobilization of starch in the night occurred in a linear manner and was paced to dawn, both in moderate treatments that did not alter clock transcripts and in extreme treatments that led to severe carbon starvation. We conclude that pacing of starch mobilization to dawn does not require retrograde carbon signaling to the transcriptional clock. On the following day, growth decreased, sugars rose, and starch accumulation was stimulated in low-light-treated plants compared to controls. This adaptive response was marked after moderate treatments and occurred independently of changes in the transcriptional clock. It is probably a time-delayed response to low-C signaling in the preceding 24-h cycle, possibly including changes in PHYTOCHROME INTERACTING FACTOR and REVEILLE expression.
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Affiliation(s)
- Thiago Alexandre Moraes
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Virginie Mengin
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Maria Grazia Annunziata
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Beatrice Encke
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Nicole Krohn
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Melanie Höhne
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Mark Stitt
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
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6
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Flis A, Mengin V, Ivakov AA, Mugford ST, Hubberten HM, Encke B, Krohn N, Höhne M, Feil R, Hoefgen R, Lunn JE, Millar AJ, Smith AM, Sulpice R, Stitt M. Multiple circadian clock outputs regulate diel turnover of carbon and nitrogen reserves. PLANT, CELL & ENVIRONMENT 2019; 42:549-573. [PMID: 30184255 DOI: 10.1111/pce.13440] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 08/27/2018] [Accepted: 08/31/2018] [Indexed: 05/09/2023]
Abstract
Plants accumulate reserves in the daytime to support growth at night. Circadian regulation of diel reserve turnover was investigated by profiling starch, sugars, glucose 6-phosphate, organic acids, and amino acids during a light-dark cycle and after transfer to continuous light in Arabidopsis wild types and in mutants lacking dawn (lhy cca1), morning (prr7 prr9), dusk (toc1, gi), or evening (elf3) clock components. The metabolite time series were integrated with published time series for circadian clock transcripts to identify circadian outputs that regulate central metabolism. (a) Starch accumulation was slower in elf3 and prr7 prr9. It is proposed that ELF3 positively regulates starch accumulation. (b) Reducing sugars were high early in the T-cycle in elf3, revealing that ELF3 negatively regulates sucrose recycling. (c) The pattern of starch mobilization was modified in all five mutants. A model is proposed in which dawn and dusk/evening components interact to pace degradation to anticipated dawn. (d) An endogenous oscillation of glucose 6-phosphate revealed that the clock buffers metabolism against the large influx of carbon from photosynthesis. (e) Low levels of organic and amino acids in lhy cca1 and high levels in prr7 prr9 provide evidence that the dawn components positively regulate the accumulation of amino acid reserves.
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Affiliation(s)
- Anna Flis
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Virginie Mengin
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Alexander A Ivakov
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Sam T Mugford
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | - Beatrice Encke
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Nicole Krohn
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Melanie Höhne
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Rainer Hoefgen
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Andrew J Millar
- SynthSys and School of Biological Sciences, C.H. Waddington Building, University of Edinburgh, Edinburgh, UK
| | | | - Ronan Sulpice
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Mark Stitt
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
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7
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Webb AAR, Seki M, Satake A, Caldana C. Continuous dynamic adjustment of the plant circadian oscillator. Nat Commun 2019; 10:550. [PMID: 30710080 PMCID: PMC6358598 DOI: 10.1038/s41467-019-08398-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/09/2019] [Indexed: 11/08/2022] Open
Abstract
The clockwork of plant circadian oscillators has been resolved through investigations in Arabidopsis thaliana. The circadian oscillator is an important regulator of much of plant physiology, though many of the mechanisms are unclear. New findings demonstrate that the oscillator adjusts phase and period in response to abiotic and biotic signals, providing insight in to how the plant circadian oscillator integrates with the biology of the cell and entrains to light, dark and temperature cycles. We propose that the plant circadian oscillator is dynamically plastic, in constant adjustment, rather than being an isolated clock impervious to cellular events.
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Affiliation(s)
- Alex A R Webb
- Department of Plant Sciences, Downing Street, Cambridge, CB3 0LJ, UK.
| | - Motohide Seki
- Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minamiku, Fukuoka, 815-8540, Japan
| | - Akiko Satake
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, 819-0395, Japan
| | - Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
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8
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Küstner L, Nägele T, Heyer AG. Mathematical modeling of diurnal patterns of carbon allocation to shoot and root in Arabidopsis thaliana. NPJ Syst Biol Appl 2019; 5:4. [PMID: 30701083 PMCID: PMC6346032 DOI: 10.1038/s41540-018-0080-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 12/07/2018] [Indexed: 12/23/2022] Open
Abstract
We developed a mathematical model to simulate dynamics of central carbon metabolism over complete diurnal cycles for leaves of Arabidopsis thaliana exposed to either normal (120 µmol m-2 s-1) or high light intensities (1200 µmol m- 2 s-1). The main objective was to obtain a high-resolution time series for metabolite dynamics as well as for shoot structural carbon formation (compounds with long residence time) and assimilate export of aerial organs to the sink tissue. Model development comprised a stepwise increment of complexity to finally approach the in vivo situation. The correct allocation of assimilates to either sink export or shoot structural carbon formation was a central goal of model development. Diurnal gain of structural carbon was calculated based on the daily increment in total photosynthetic carbon fixation, and this was the only parameter for structural carbon formation implemented in the model. Simulations of the dynamics of central metabolite pools revealed that shoot structural carbon formation occurred solely during the light phase but not during the night. The model allowed simulation of shoot structural carbon formation as a function of central leaf carbon metabolism under different environmental conditions without structural modifications. Model simulations were performed for the accession Landsberg erecta (Ler) and its hexokinase null-mutant gin2-1. This mutant displays a slow growth phenotype especially at increasing light intensities. Comparison of simulations revealed that the retarded shoot growth in the mutant resulted from an increased assimilate transport to sink organs. Due to its central function in sucrose cycling and sugar signaling, our findings suggest an important role of hexokinase-1 for carbon allocation to either shoot growth or assimilate export.
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Affiliation(s)
- Lisa Küstner
- University of Stuttgart, Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Thomas Nägele
- Ludwig-Maximilians-University Munich, Department Biology I, Plant Evolutionary Cell Biology, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Arnd G. Heyer
- University of Stuttgart, Institute of Biomaterials and Biomolecular Systems, Department of Plant Biotechnology, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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9
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Zakhartsev M. Using a Multi-compartmental Metabolic Model to Predict Carbon Allocation in Arabidopsis thaliana. Methods Mol Biol 2019; 2014:345-369. [PMID: 31197808 DOI: 10.1007/978-1-4939-9562-2_27] [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: 06/09/2023]
Abstract
The molecular mechanism of loading/unloading of sucrose into/from the phloem plays an important role in sucrose translocation among plant tissues. Perturbation of this mechanism results in growth phenotypes of a plant. In order to better understand the coupling of sucrose translocation with metabolic processes a multi-compartmental metabolic network of Arabidopsis thaliana was reconstructed and optimized with respect to biomass growth, both in light and in dark conditions. The model can be used to perform flux balance analysis of metabolic fluxes through the central carbon metabolism and catabolic and anabolic pathways. Balances and turnover of energy (ATP/ADP) and redox metabolites (NAD(P)H/NAD(P)) as well as proton concentrations in different compartments can be estimated. Importantly, the model can be used to quantify the translocation of sucrose from source to sink tissues through phloem in association with an integral balance of protons, which in turn is defined by the operational modes of the energy metabolism (light and dark conditions). This chapter describes how a multi-compartmental model to predict carbon allocation is constructed and used.
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Affiliation(s)
- Maksim Zakhartsev
- Centre for Integrative Genetics, Norwegian University of Life Sciences, Ås, Norway.
- Plant Systems Biology, University of Hohenheim, Stuttgart, Germany.
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10
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Rasmusson LM, Lauritano C, Procaccini G, Gullström M, Buapet P, Björk M. Respiratory oxygen consumption in the seagrass Zostera marina varies on a diel basis and is partly affected by light. MARINE BIOLOGY 2017; 164:140. [PMID: 28596620 PMCID: PMC5446554 DOI: 10.1007/s00227-017-3168-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 05/17/2017] [Indexed: 06/07/2023]
Abstract
The seagrass Zostera marina is an important marine ecosystem engineer, greatly influencing oxygen and carbon fluctuations in temperate coastal areas. Although photosynthetically driven gas fluxes are well studied, the impact of the plant's mitochondrial respiration on overall CO2 and O2 fluxes in marine vegetated areas is not yet understood. Likewise, the gene expression in relation to the respiratory pathway has not been well analyzed in seagrasses. This study uses a combined approach, studying respiratory oxygen consumption rates in darkness simultaneously with changes in gene expression, with the aim of examining how respiratory oxygen consumption fluctuates on a diel basis. Measurements were first made in a field study where samples were taken directly from the ocean to the laboratory for estimations of respiratory rates. This was followed by a laboratory study where measurements of respiration and expression of genes known to be involved in mitochondrial respiration were conducted for 5 days under light conditions mimicking natural summer light (i.e., 15 h of light and 9 h of darkness), followed by 3 days of constant darkness to detect the presence of a potential circadian clock. In the field study, there was a clear diel variation in respiratory oxygen consumption with the highest rates in the late evening and at night (0.766 and 0.869 µmol O2 m-2 s-1, respectively). These repetitive diel patterns were not seen in the laboratory, where water conditions (temperature, pH, and oxygen) showed minor fluctuations and only light varied. The gene expression analysis did not give clear evidence on drivers behind the respiratory fluxes; however, expression levels of the selected genes generally increased when the seagrass was kept in constant darkness. While light may influence mitochondrial respiratory fluxes, it appears that other environmental factors (e.g., temperature, pH, or oxygen) could be of significance too. As seagrasses substantially alter the proportions of both oxygen and inorganic carbon in the water column and respiration is a great driver of these alterations, we propose that acknowledging the presence of respiratory fluctuations in nature should be considered when estimating coastal carbon budgets. As dark respiration in field at midnight was approximately doubled from that of midday, great over-, or underestimations of the respiratory carbon dioxide release from seagrasses could be made if values are just obtained at one specific time point and considered constant.
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Affiliation(s)
- Lina M. Rasmusson
- Seagrass Ecology and Physiology Research Group, Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Chiara Lauritano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Gabriele Procaccini
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Martin Gullström
- Seagrass Ecology and Physiology Research Group, Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pimchanok Buapet
- Seagrass Ecology and Physiology Research Group, Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 Thailand
| | - Mats Björk
- Seagrass Ecology and Physiology Research Group, Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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11
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Mora-García S, de Leone MJ, Yanovsky M. Time to grow: circadian regulation of growth and metabolism in photosynthetic organisms. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:84-90. [PMID: 27912128 DOI: 10.1016/j.pbi.2016.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/10/2016] [Accepted: 11/11/2016] [Indexed: 05/21/2023]
Abstract
Circadian clocks are molecular devices that help adjust organisms to periodic environmental changes. Although formally described as self-sustaining oscillators that are synchronized by external cues and produce defined outputs, it is increasingly clear that physiological processes not only are regulated by, but also regulate the function of the clock. We discuss three recent examples of the intimate relationships between the function of the clock, growth and metabolism in photosynthetic organisms: the daily tracking of sun by sunflowers, the fine computations plants and cyanobacteria perform to manage carbon reserves and prevent starvation, and the changes in clock parameters that went along with domestication of tomato.
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Affiliation(s)
- Santiago Mora-García
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
| | - María José de Leone
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Marcelo Yanovsky
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
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12
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Zakhartsev M, Medvedeva I, Orlov Y, Akberdin I, Krebs O, Schulze WX. Metabolic model of central carbon and energy metabolisms of growing Arabidopsis thaliana in relation to sucrose translocation. BMC PLANT BIOLOGY 2016; 16:262. [PMID: 28031032 PMCID: PMC5192601 DOI: 10.1186/s12870-016-0868-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 08/05/2016] [Indexed: 05/12/2023]
Abstract
BACKGROUND Sucrose translocation between plant tissues is crucial for growth, development and reproduction of plants. Systemic analysis of these metabolic and underlying regulatory processes allow a detailed understanding of carbon distribution within the plant and the formation of associated phenotypic traits. Sucrose translocation from 'source' tissues (e.g. mesophyll) to 'sink' tissues (e.g. root) is tightly bound to the proton gradient across the membranes. The plant sucrose transporters are grouped into efflux exporters (SWEET family) and proton-symport importers (SUC, STP families). To better understand regulation of sucrose export from source tissues and sucrose import into sink tissues, there is a need for a metabolic model that takes in account the tissue organisation of Arabidopsis thaliana with corresponding metabolic specificities of respective tissues in terms of sucrose and proton production/utilization. An ability of the model to operate under different light modes ('light' and 'dark') and correspondingly in different energy producing modes is particularly important in understanding regulatory modules. RESULTS Here, we describe a multi-compartmental model consisting of a mesophyll cell with plastid and mitochondrion, a phloem cell, as well as a root cell with mitochondrion. In this model, the phloem was considered as a non-growing transport compartment, the mesophyll compartment was considered as both autotrophic (growing on CO2 under light) and heterotrophic (growing on starch in darkness), and the root was always considered as heterotrophic tissue dependent on sucrose supply from the mesophyll compartment. In total, the model includes 413 balanced compounds interconnected by 400 transformers. The structured metabolic model accounts for central carbon metabolism, photosynthesis, photorespiration, carbohydrate metabolism, energy and redox metabolisms, proton metabolism, biomass growth, nutrients uptake, proton gradient generation and sucrose translocation between tissues. Biochemical processes in the model were associated with gene-products (742 ORFs). Flux Balance Analysis (FBA) of the model resulted in balanced carbon, nitrogen, proton, energy and redox states under both light and dark conditions. The main H+-fluxes were reconstructed and their directions matched with proton-dependent sucrose translocation from 'source' to 'sink' under any light condition. CONCLUSIONS The model quantified the translocation of sucrose between plant tissues in association with an integral balance of protons, which in turn is defined by operational modes of the energy metabolism.
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Affiliation(s)
- Maksim Zakhartsev
- Department of Plant Systems Biology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Irina Medvedeva
- Novosibirsk State University, Pirogova 2, 630090 Novosibirsk, Russia
| | - Yury Orlov
- The Federal Research Center Institute of Cytology and Genetics, Russian Academy of Sciences, Lavrentyeva 10, 630090 Novosibirsk, Russia
| | - Ilya Akberdin
- The Federal Research Center Institute of Cytology and Genetics, Russian Academy of Sciences, Lavrentyeva 10, 630090 Novosibirsk, Russia
- Biology Department, San Diego State University, San Diego, CA 92182-4614 USA
| | - Olga Krebs
- Heidelberg Institute of Theoretical Sciences, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Waltraud X. Schulze
- Department of Plant Systems Biology, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
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13
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Larbat R, Robin C, Lillo C, Drengstig T, Ruoff P. Modeling the diversion of primary carbon flux into secondary metabolism under variable nitrate and light/dark conditions. J Theor Biol 2016; 402:144-57. [PMID: 27164436 DOI: 10.1016/j.jtbi.2016.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 02/01/2023]
Abstract
In plants, the partitioning of carbon resources between growth and defense is detrimental for their development. From a metabolic viewpoint, growth is mainly related to primary metabolism including protein, amino acid and lipid synthesis, whereas defense is based notably on the biosynthesis of a myriad of secondary metabolites. Environmental factors, such as nitrate fertilization, impact the partitioning of carbon resources between growth and defense. Indeed, experimental data showed that a shortage in the nitrate fertilization resulted in a reduction of the plant growth, whereas some secondary metabolites involved in plant defense, such as phenolic compounds, accumulated. Interestingly, sucrose, a key molecule involved in the transport and partitioning of carbon resources, appeared to be under homeostatic control. Based on the inflow/outflow properties of sucrose homeostatic regulation we propose a global model on how the diversion of the primary carbon flux into the secondary phenolic pathways occurs at low nitrate concentrations. The model can account for the accumulation of starch during the light phase and the sucrose remobilization by starch degradation during the night. Day-length sensing mechanisms for variable light-dark regimes are discussed, showing that growth is proportional to the length of the light phase. The model can describe the complete starch consumption during the night for plants adapted to a certain light/dark regime when grown on sufficient nitrate and can account for an increased accumulation of starch observed under nitrate limitation.
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Affiliation(s)
- Romain Larbat
- INRA UMR 1121, Agronomie & Environnement Nancy-Colmar, TSA 40602, 54518 Vandoeuvre Cedex, France; Université de Lorraine UMR 1121, Agronomie & Environnement Nancy-Colmar, TSA 40602, 54518 Vandoeuvre Cedex, France.
| | - Christophe Robin
- INRA UMR 1121, Agronomie & Environnement Nancy-Colmar, TSA 40602, 54518 Vandoeuvre Cedex, France; Université de Lorraine UMR 1121, Agronomie & Environnement Nancy-Colmar, TSA 40602, 54518 Vandoeuvre Cedex, France
| | - Cathrine Lillo
- Centre for Organelle Research, University of Stavanger, Stavanger Innovation Park, Måltidets Hus, 4021 Stavanger, Norway
| | - Tormod Drengstig
- Department of Computer Science and Electrical Engineering, University of Stavanger, 4036 Stavanger, Norway
| | - Peter Ruoff
- Centre for Organelle Research, University of Stavanger, Stavanger Innovation Park, Måltidets Hus, 4021 Stavanger, Norway.
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14
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Li H, Liang Z, Ding G, Shi L, Xu F, Cai H. A Natural Light/Dark Cycle Regulation of Carbon-Nitrogen Metabolism and Gene Expression in Rice Shoots. FRONTIERS IN PLANT SCIENCE 2016; 7:1318. [PMID: 27625675 PMCID: PMC5003941 DOI: 10.3389/fpls.2016.01318] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 08/17/2016] [Indexed: 05/23/2023]
Abstract
Light and temperature are two particularly important environmental cues for plant survival. Carbon and nitrogen are two essential macronutrients required for plant growth and development, and cellular carbon and nitrogen metabolism must be tightly coordinated. In order to understand how the natural light/dark cycle regulates carbon and nitrogen metabolism in rice plants, we analyzed the photosynthesis, key carbon-nitrogen metabolites, and enzyme activities, and differentially expressed genes and miRNAs involved in the carbon and nitrogen metabolic pathway in rice shoots at the following times: 2:00, 6:00, 10:00, 14:00, 18:00, and 22:00. Our results indicated that more CO2 was fixed into carbohydrates by a high net photosynthetic rate, respiratory rate, and stomatal conductance in the daytime. Although high levels of the nitrate reductase activity, free ammonium and carbohydrates were exhibited in the daytime, the protein synthesis was not significantly facilitated by the light and temperature. In mRNA sequencing, the carbon and nitrogen metabolism-related differentially expressed genes were obtained, which could be divided into eight groups: photosynthesis, TCA cycle, sugar transport, sugar metabolism, nitrogen transport, nitrogen reduction, amino acid metabolism, and nitrogen regulation. Additionally, a total of 78,306 alternative splicing events have been identified, which primarily belong to alternative 5' donor sites, alternative 3' acceptor sites, intron retention, and exon skipping. In sRNA sequencing, four carbon and nitrogen metabolism-related miRNAs (osa-miR1440b, osa-miR2876-5p, osa-miR1877 and osa-miR5799) were determined to be regulated by natural light/dark cycle. The expression level analysis showed that the four carbon and nitrogen metabolism-related miRNAs negatively regulated their target genes. These results may provide a good strategy to study how natural light/dark cycle regulates carbon and nitrogen metabolism to ensure plant growth and development.
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15
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Pokhilko A, Bou-Torrent J, Pulido P, Rodríguez-Concepción M, Ebenhöh O. Mathematical modelling of the diurnal regulation of the MEP pathway in Arabidopsis. THE NEW PHYTOLOGIST 2015; 206:1075-1085. [PMID: 25598499 DOI: 10.1111/nph.13258] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 11/30/2014] [Indexed: 05/23/2023]
Abstract
Isoprenoid molecules are essential elements of plant metabolism. Many important plant isoprenoids, such as chlorophylls, carotenoids, tocopherols, prenylated quinones and hormones are synthesised in chloroplasts via the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway. Here we develop a mathematical model of diurnal regulation of the MEP pathway in Arabidopsis thaliana. We used both experimental and theoretical approaches to integrate mechanisms potentially involved in the diurnal control of the pathway. Our data show that flux through the MEP pathway is accelerated in light due to the photosynthesis-dependent supply of metabolic substrates of the pathway and the transcriptional regulation of key biosynthetic genes by the circadian clock. We also demonstrate that feedback regulation of both the activity and the abundance of the first enzyme of the MEP pathway (1-deoxy-D-xylulose 5-phosphate synthase, DXS) by pathway products stabilizes the flux against changes in substrate supply and adjusts the flux according to product demand under normal growth conditions. These data illustrate the central relevance of photosynthesis, the circadian clock and feedback control of DXS for the diurnal regulation of the MEP pathway.
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Affiliation(s)
- Alexandra Pokhilko
- Institute for Complex Systems and Mathematical Biology, King's College, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK
| | - Jordi Bou-Torrent
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain
| | - Pablo Pulido
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain
| | - Manuel Rodríguez-Concepción
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain
| | - Oliver Ebenhöh
- Institute for Complex Systems and Mathematical Biology, King's College, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstraße 1, D-40225, Düsseldorf, Germany
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16
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Webb AAR, Satake A. Understanding circadian regulation of carbohydrate metabolism in Arabidopsis using mathematical models. PLANT & CELL PHYSIOLOGY 2015; 56:586-93. [PMID: 25745029 DOI: 10.1093/pcp/pcv033] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 02/23/2015] [Indexed: 05/28/2023]
Abstract
C3 plants assimilate carbon by photosynthesis only during the day, but carbon resources are also required for growth and maintenance at night. To avoid carbon starvation, many plants store a part of photosynthetic carbon in starch during the day, and degrade it to supply sugars for growth at night. In Arabidopsis, starch accumulation in the day and degradation at night occur almost linearly, with the shape of this diel starch profile adaptively changing to allow continuous supply of sugar even in long-night conditions. The anticipation of dawn required to ensure linear consumption of starch to almost zero at dawn presumably requires the circadian clock. We review the links between carbon metabolism and the circadian clock, and mathematical models aimed at explaining the diel starch profile. These models can be considered in two classes, those that assume the level of available starch is sensed and the system ensures linearity of starch availability, and those in which sugar sensing is assumed, yielding linearity of starch availability as an emergent property of sucrose homeostasis. In the second class of model the feedback from starch metabolism to the circadian clock is considered to be essential for adaptive response to diverse photoperiods, consistent with recent empirical data demonstrating entrainment of the circadian clock by photosynthesis. Knowledge concerning the mechanisms regulating the dynamics of starch metabolism and sugar homeostasis in plants is required to develop new theories about the limitations of growth and biomass accumulation.
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Affiliation(s)
- Alex A R Webb
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA UK
| | - Akiko Satake
- Faculty of Earth Environmental Science, Hokkaido University N10W5, Kita-ku, Sapporo, Hokkaido, 060-0810 Japan
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17
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Scialdone A, Howard M. How plants manage food reserves at night: quantitative models and open questions. FRONTIERS IN PLANT SCIENCE 2015; 6:204. [PMID: 25873925 PMCID: PMC4379750 DOI: 10.3389/fpls.2015.00204] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/14/2015] [Indexed: 05/18/2023]
Abstract
In order to cope with night-time darkness, plants during the day allocate part of their photosynthate for storage, often as starch. This stored reserve is then degraded at night to sustain metabolism and growth. However, night-time starch degradation must be tightly controlled, as over-rapid turnover results in premature depletion of starch before dawn, leading to starvation. Recent experiments in Arabidopsis have shown that starch degradation proceeds at a constant rate during the night and is set such that starch reserves are exhausted almost precisely at dawn. Intriguingly, this pattern is robust with the degradation rate being adjusted to compensate for unexpected changes in the time of darkness onset. While a fundamental role for the circadian clock is well-established, the underlying mechanisms controlling starch degradation remain poorly characterized. Here, we discuss recent quantitative models that have been proposed to explain how plants can compute the appropriate starch degradation rate, a process that requires an effective arithmetic division calculation. We review experimental confirmation of the models, and describe aspects that require further investigation. Overall, the process of night-time starch degradation necessitates a fundamental metabolic role for the circadian clock and, more generally, highlights how cells process information in order to optimally manage their resources.
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Affiliation(s)
- Antonio Scialdone
- Wellcome Trust Sanger Institute, Wellcome Trust Genome CampusHinxton, Cambridge, UK
- European Molecular Biology Laboratory-European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome CampusHinxton, Cambridge, UK
| | - Martin Howard
- Computational and Systems Biology, John Innes CentreNorwich, UK
- *Correspondence: Martin Howard, Computational and Systems Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK
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18
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Dodd AN, Belbin FE, Frank A, Webb AAR. Interactions between circadian clocks and photosynthesis for the temporal and spatial coordination of metabolism. FRONTIERS IN PLANT SCIENCE 2015; 6:245. [PMID: 25914715 PMCID: PMC4391236 DOI: 10.3389/fpls.2015.00245] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/26/2015] [Indexed: 05/05/2023]
Abstract
All plant productivity, including the food that we eat, arises from the capture of solar energy by plants. At most latitudes sunlight is available for only part of the 24 h day due to the rotation of the planet. This rhythmic and predictable alteration in the environment has driven the evolution of the circadian clock, which has an extremely pervasive influence upon plant molecular biology, physiology and phenology. A number of recent studies have demonstrated that the circadian clock is integrated very closely with photosynthesis and its metabolic products. We consider the coupling of the circadian oscillator with carbohydrate biochemistry and the connections between the nuclear-encoded circadian clock and processes within chloroplasts. We describe how this might provide adaptations to optimize plant performance in an environment that varies both predictably upon a daily and seasonal basis, and unpredictably due to the weather.
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Affiliation(s)
- Antony N. Dodd
- School of Biological Sciences, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
| | - Fiona E. Belbin
- School of Biological Sciences, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
| | - Alexander Frank
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Alex A. R. Webb
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
- *Correspondence: Alex A. R. Webb, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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19
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Chew YH, Wenden B, Flis A, Mengin V, Taylor J, Davey CL, Tindal C, Thomas H, Ougham HJ, de Reffye P, Stitt M, Williams M, Muetzelfeldt R, Halliday KJ, Millar AJ. Multiscale digital Arabidopsis predicts individual organ and whole-organism growth. Proc Natl Acad Sci U S A 2014; 111:E4127-36. [PMID: 25197087 PMCID: PMC4191812 DOI: 10.1073/pnas.1410238111] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Understanding how dynamic molecular networks affect whole-organism physiology, analogous to mapping genotype to phenotype, remains a key challenge in biology. Quantitative models that represent processes at multiple scales and link understanding from several research domains can help to tackle this problem. Such integrated models are more common in crop science and ecophysiology than in the research communities that elucidate molecular networks. Several laboratories have modeled particular aspects of growth in Arabidopsis thaliana, but it was unclear whether these existing models could productively be combined. We test this approach by constructing a multiscale model of Arabidopsis rosette growth. Four existing models were integrated with minimal parameter modification (leaf water content and one flowering parameter used measured data). The resulting framework model links genetic regulation and biochemical dynamics to events at the organ and whole-plant levels, helping to understand the combined effects of endogenous and environmental regulators on Arabidopsis growth. The framework model was validated and tested with metabolic, physiological, and biomass data from two laboratories, for five photoperiods, three accessions, and a transgenic line, highlighting the plasticity of plant growth strategies. The model was extended to include stochastic development. Model simulations gave insight into the developmental control of leaf production and provided a quantitative explanation for the pleiotropic developmental phenotype caused by overexpression of miR156, which was an open question. Modular, multiscale models, assembling knowledge from systems biology to ecophysiology, will help to understand and to engineer plant behavior from the genome to the field.
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Affiliation(s)
- Yin Hoon Chew
- SynthSys and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JD, United Kingdom
| | - Bénédicte Wenden
- Institut National de la Recherche Agronomique and Université Bordeaux, Unité Mixte de Recherche 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France
| | - Anna Flis
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Virginie Mengin
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | | | - Christopher L Davey
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 2FG, United Kingdom
| | - Christopher Tindal
- SynthSys and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JD, United Kingdom
| | - Howard Thomas
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 2FG, United Kingdom
| | - Helen J Ougham
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 2FG, United Kingdom
| | - Philippe de Reffye
- Cirad-Amis, Unité Mixte de Recherche, Association pour le Maintien d'une Agriculture Paysanne, F-34398 Montpellier Cedex 5, France; and
| | - Mark Stitt
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Mathew Williams
- School of GeoSciences, University of Edinburgh, Edinburgh EH9 3JN, United Kingdom
| | | | - Karen J Halliday
- SynthSys and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JD, United Kingdom
| | - Andrew J Millar
- SynthSys and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JD, United Kingdom;
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20
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Müller LM, von Korff M, Davis SJ. Connections between circadian clocks and carbon metabolism reveal species-specific effects on growth control. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2915-23. [PMID: 24706717 DOI: 10.1093/jxb/eru117] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The plant circadian system exists in a framework of rhythmic metabolism. Much has been learned about the transcriptional machinery that generates the clock rhythm. Interestingly, these components are largely conserved between monocots and dicots, but key differences in physiological and developmental output processes have been found. How the clock coordinates carbon metabolism to drive plant growth performance is described with a focus on starch breakdown in Arabidopsis. It is proposed that clock effects on plant growth and fitness are more complex than just matching internal with external rhythms. Interesting recent findings support that the products of photosynthesis, probably sucrose, in turn feeds back to the clock to set its rhythm. In this way, the clock both controls and is controlled by carbon fluxes. This has an interesting connection to stress signalling and water-use efficiency, and it is now known that the clock and abscisic acid pathways are reciprocally coordinated. These processes converge to drive growth in a species-specific context such that predictions from the Arabidopsis model to other species can be restricted. This has been seen from phenotypic growth studies that revealed that dicot shoot growth is rhythmic whereas monocot shoot growth is continuous. Taken together, emerging evidence suggests reciprocal interactions between metabolism, the circadian clock, and stress signalling to control growth and fitness in Arabidopsis, but transferability to other species is not always possible due to species-specific effects.
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Affiliation(s)
- Lukas M Müller
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne 50829, Germany
| | - Maria von Korff
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne 50829, Germany Institute of Plant Genetics, Heinrich-Heine-University, Düsseldorf 40225, Germany Cluster of Excellence on Plant Sciences, Düsseldorf 40225, Germany
| | - Seth J Davis
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne 50829, Germany Department of Biology, University of York, York, YO10 5DD, UK
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21
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Tomé F, Nägele T, Adamo M, Garg A, Marco-llorca C, Nukarinen E, Pedrotti L, Peviani A, Simeunovic A, Tatkiewicz A, Tomar M, Gamm M. The low energy signaling network. FRONTIERS IN PLANT SCIENCE 2014; 5:353. [PMID: 25101105 PMCID: PMC4102169 DOI: 10.3389/fpls.2014.00353] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/02/2014] [Indexed: 05/07/2023]
Abstract
Stress impacts negatively on plant growth and crop productivity, caicultural production worldwide. Throughout their life, plants are often confronted with multiple types of stress that affect overall cellular energy status and activate energy-saving responses. The resulting low energy syndrome (LES) includes transcriptional, translational, and metabolic reprogramming and is essential for stress adaptation. The conserved kinases sucrose-non-fermenting-1-related protein kinase-1 (SnRK1) and target of rapamycin (TOR) play central roles in the regulation of LES in response to stress conditions, affecting cellular processes and leading to growth arrest and metabolic reprogramming. We review the current understanding of how TOR and SnRK1 are involved in regulating the response of plants to low energy conditions. The central role in the regulation of cellular processes, the reprogramming of metabolism, and the phenotypic consequences of these two kinases will be discussed in light of current knowledge and potential future developments.
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Affiliation(s)
- Filipa Tomé
- Bayer CropScience NV, Innovation CenterGhent, Belgium
- *Correspondence: Filipa Tomé, Bayer CropScience NV, Innovation Center, Technologiepark 38, 9052 Zwijnaarde (Ghent), Belgium e-mail:
| | - Thomas Nägele
- Department of Ecogenomics and Systems Biology, University of ViennaVienna, Austria
| | | | - Abhroop Garg
- Zentrum für Molekularbiologie der Pflanzen, Eberhard Karls Universität TübingenTübingen, Germany
| | - Carles Marco-llorca
- Zentrum für Molekularbiologie der Pflanzen, Eberhard Karls Universität TübingenTübingen, Germany
| | - Ella Nukarinen
- Department of Ecogenomics and Systems Biology, University of ViennaVienna, Austria
| | - Lorenzo Pedrotti
- Julius-von-Sachs-Institut, Julius-Maximilians-Universität WürzburgWürzburg, Germany
| | - Alessia Peviani
- Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht UniversityUtrecht, Netherlands
| | - Andrea Simeunovic
- Department of Ecogenomics and Systems Biology, University of ViennaVienna, Austria
| | - Anna Tatkiewicz
- Universidad Politécnica de Madrid–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de MadridMadrid, Spain
| | - Monika Tomar
- Molecular Plant Physiology, Institute of Environmental Biology, Utrecht UniversityUtrecht, Netherlands
| | - Magdalena Gamm
- Molecular Plant Physiology, Institute of Environmental Biology, Utrecht UniversityUtrecht, Netherlands
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