1
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Raju AS, Kramer DM, Versaw WK. Genetically manipulated chloroplast stromal phosphate levels alter photosynthetic efficiency. Plant Physiol 2024:kiae241. [PMID: 38701198 DOI: 10.1093/plphys/kiae241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024]
Abstract
The concentration of inorganic phosphate (Pi) in the chloroplast stroma must be maintained within narrow limits to sustain photosynthesis and to direct the partitioning of fixed carbon. However, it is unknown if these limits or the underlying contributions of different chloroplastic Pi transporters vary throughout the photoperiod or between chloroplasts in different leaf tissues. To address these questions, we applied live Pi imaging to Arabidopsis (Arabidopsis thaliana) wild-type plants and two loss-of-function transporter mutants: triose phosphate/phosphate translocator (tpt), phosphate transporter 2; 1 (pht2; 1), and tpt pht2; 1. Our analyses revealed that stromal Pi varies spatially and temporally, and that TPT and PHT2; 1 contribute to Pi import with overlapping tissue specificities. Further, the series of progressively diminished steady-state stromal Pi levels in these mutants provided the means to examine the effects of Pi on photosynthetic efficiency without imposing nutritional deprivation. ΦPSII and nonphotochemical quenching (NPQ) correlated with stromal Pi levels. However, the proton efflux activity of the ATP synthase (gH+) and the thylakoid proton motive force (pmf) were unaltered under growth conditions, but were suppressed transiently after a dark to light transition with return to wild-type levels within 2 minutes. These results argue against a simple substrate-level limitation of ATP synthase by depletion of stromal Pi, favoring more integrated regulatory models, which include rapid acclimation of thylakoid ATP synthase activity to reduced Pi levels.
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Affiliation(s)
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Jan IngenHousz Institute
| | - Wayne K Versaw
- Department of Biology, Texas A&M University, College Station, Texas, USA
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2
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Cook R, Froehlich JE, Yang Y, Korkmaz I, Kramer DM, Benning C. Chloroplast phosphatases LPPγ and LPPε1 facilitate conversion of extraplastidic phospholipids to galactolipids. Plant Physiol 2024:kiae100. [PMID: 38401529 DOI: 10.1093/plphys/kiae100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/08/2024] [Accepted: 01/25/2024] [Indexed: 02/26/2024]
Abstract
Galactolipids comprise the majority of chloroplast membranes in plants, and their biosynthesis requires dephosphorylation of phosphatidic acid at the chloroplast envelope membranes. In Arabidopsis (Arabidopsis thaliana), the lipid phosphate phosphatases LPPγ, LPPε1, and LPPε2 have been previously implicated in chloroplast lipid assembly, with LPPγ being essential, as null mutants were reported to exhibit embryo lethality. Here, we show that lppγ mutants are in fact viable and that LPPγ, LPPε1, and LPPε2 do not appear to have central roles in the plastid pathway of membrane lipid biosynthesis. Redundant LPPγ and LPPε1 activity at the outer envelope membrane is important for plant development, and the respective lppγ lppε1 double mutant exhibits reduced flux through the ER pathway of galactolipid synthesis. While LPPε2 is imported and associated with interior chloroplast membranes, its role remains elusive and does not include basal nor phosphate limitation-induced biosynthesis of glycolipids. The specific physiological roles of LPPγ, LPPε1, and LPPε2 are yet to be uncovered, as does the identity of the phosphatidic acid phosphatase required for plastid galactolipid biosynthesis.
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Affiliation(s)
- Ron Cook
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
| | - John E Froehlich
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - Yang Yang
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
| | - Ilayda Korkmaz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - David M Kramer
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - Christoph Benning
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824
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3
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Parson WW, Huang J, Kulke M, Vermaas JV, Kramer DM. Electron transfer in a crystalline cytochrome with four hemes. J Chem Phys 2024; 160:065101. [PMID: 38341797 DOI: 10.1063/5.0186958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/18/2024] [Indexed: 02/13/2024] Open
Abstract
Diffusion of electrons over distances on the order of 100 μm has been observed in crystals of a small tetraheme cytochrome (STC) from Shewanella oneidensis [J. Huang et al. J. Am. Chem. Soc. 142, 10459-10467 (2020)]. Electron transfer between hemes in adjacent subunits of the crystal is slower and more strongly dependent on temperature than had been expected based on semiclassical electron-transfer theory. We here explore explanations for these findings by molecular-dynamics simulations of crystalline and monomeric STC. New procedures are developed for including time-dependent quantum mechanical energy differences in the gap between the energies of the reactant and product states and for evaluating fluctuations of the electronic-interaction matrix element that couples the two hemes. Rate constants for electron transfer are calculated from the time- and temperature-dependent energy gaps, coupling factors, and Franck-Condon-weighted densities of states using an expression with no freely adjustable parameters. Back reactions are considered, as are the effects of various protonation states of the carboxyl groups on the heme side chains. Interactions with water are found to dominate the fluctuations of the energy gap between the reactant and product states. The calculated rate constant for electron transfer from heme IV to heme Ib in a neighboring subunit at 300 K agrees well with the measured value. However, the calculated activation energy of the reaction in the crystal is considerably smaller than observed. We suggest two possible explanations for this discrepancy. The calculated rate constant for transfer from heme I to II within the same subunit of the crystal is about one-third that for monomeric STC in solution.
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Affiliation(s)
- William W Parson
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Jingcheng Huang
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Martin Kulke
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Josh V Vermaas
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - David M Kramer
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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4
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Smith K, Strand DD, Kramer DM, Walker BJ. The role of photorespiration in preventing feedback regulation via ATP synthase in Nicotiana tabacum. Plant Cell Environ 2024; 47:416-428. [PMID: 37937663 PMCID: PMC10842328 DOI: 10.1111/pce.14759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 10/17/2023] [Accepted: 10/23/2023] [Indexed: 11/09/2023]
Abstract
Photorespiration consumes substantial amounts of energy in the forms of adenosine triphosphate (ATP) and reductant making the pathway an important component in leaf energetics. Because of this high reductant demand, photorespiration is proposed to act as a photoprotective electron sink. However, photorespiration consumes more ATP relative to reductant than the C3 cycle meaning increased flux disproportionally increases ATP demand relative to reductant. Here we explore how energetic consumption from photorespiration impacts the flexibility of the light reactions in nicotiana tabacum. Specifically, we demonstrate that decreased photosynthetic efficiency (ϕII ) at low photorespiratory flux was related to feedback regulation at the chloroplast ATP synthase. Additionally, decreased ϕII at high photorespiratory flux resulted in the accumulation of photoinhibition at photosystem II centers. These results are contrary to the proposed role of photorespiration as a photoprotective electron sink. Instead, our results suggest a novel role of ATP consumption from photorespiration in maintaining ATP synthase activity, with implications for maintaining energy balance and preventing photodamage that will be critical for plant engineering strategies.
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Affiliation(s)
- Kaila Smith
- 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
- Plant Biotechnology for Health and Sustainability Program, Michigan State University, East Lansing, MI 48824, USA
| | - Deserah D Strand
- 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
| | - David M. Kramer
- Department of Energy-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 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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5
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Hoh D, Froehlich JE, Kramer DM. Redox regulation in chloroplast thylakoid lumen: The pmf changes everything, again. Plant Cell Environ 2023. [PMID: 38111217 DOI: 10.1111/pce.14789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/28/2023] [Accepted: 12/05/2023] [Indexed: 12/20/2023]
Abstract
Photosynthesis is the foundation of life on Earth. However, if not well regulated, it can also generate excessive reactive oxygen species (ROS), which can cause photodamage. Regulation of photosynthesis is highly dynamic, responding to both environmental and metabolic cues, and occurs at many levels, from light capture to energy storage and metabolic processes. One general mechanism of regulation involves the reversible oxidation and reduction of protein thiol groups, which can affect the activity of enzymes and the stability of proteins. Such redox regulation has been well studied in stromal enzymes, but more recently, evidence has emerged of redox control of thylakoid lumenal enzymes. This review/hypothesis paper summarizes the latest research and discusses several open questions and challenges to achieving effective redox control in the lumen, focusing on the distinct environments and regulatory components of the thylakoid lumen, including the need to transport electrons across the thylakoid membrane, the effects of pH changes by the proton motive force (pmf) in the stromal and lumenal compartments, and the observed differences in redox states. These constraints suggest that activated oxygen species are likely to be major regulatory contributors to lumenal thiol redox regulation, with key components and processes yet to be discovered.
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Affiliation(s)
- Donghee Hoh
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
| | - John E Froehlich
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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Kulke M, Olson DM, Huang J, Kramer DM, Vermaas JV. Long-Range Electron Transport Rates Depend on Wire Dimensions in Cytochrome Nanowires. Small 2023; 19:e2304013. [PMID: 37653599 DOI: 10.1002/smll.202304013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/18/2023] [Indexed: 09/02/2023]
Abstract
The ability to redirect electron transport to new reactions in living systems opens possibilities to store energy, generate new products, or probe physiological processes. Recent work by Huang et al. showed that 3D crystals of small tetraheme cytochromes (STC) can transport electrons over nanoscopic to mesoscopic distances by an electron hopping mechanism, making them promising materials for nanowires. However, fluctuations at room temperature may distort the nanostructure, hindering efficient electron transport. Classical molecular dynamics simulations of these fluctuations at the nano- and mesoscopic scales allowed us to develop a graph network representation to estimate maximum electron flow that can be driven through STC wires. In longer nanowires, transient structural fluctuations at protein-protein interfaces tended to obstruct efficient electron transfer, but these blockages are ameliorated in thicker crystals where alternative electron transfer pathways become more efficient. The model implies that more flexible proteinprotein interfaces limit the required minimum diameter to carry currents commensurate with conventional electronics.
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Affiliation(s)
- Martin Kulke
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Dayna M Olson
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Jingcheng Huang
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - David M Kramer
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Josh V Vermaas
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
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Hamabwe SM, Otieno NA, Soler-Garzón A, Miklas PN, Parker T, Kramer DM, Chattopadhyay A, Cheelo P, Kuwabo K, Kamfwa K. Identification of quantitative trait loci for drought tolerance in Bukoba/Kijivu Andean mapping population of common bean. Theor Appl Genet 2023; 136:222. [PMID: 37823979 DOI: 10.1007/s00122-023-04463-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
KEY MESSAGE Quantitative Trait Loci "hotspots" for drought tolerance were identified on chromosomes Pv06, Pv07 and Pv10 of common bean. Drought is a major production constraint of common bean (Phaseolus vulgaris L.) worldwide. The objective of this study was to identify the Quantitative Trait Loci (QTL) for drought tolerance in an Andean population of Recombinant Inbred Lines (RILs). A total of 155 F5:7 RILs derived from a cross between Kijivu (drought tolerant) and Bukoba (drought susceptible) were evaluated for drought tolerance in field and pot experiments. Four field experiments were conducted at three locations in Zambia in 2020 and 2021. All field trials were conducted in the dry season under irrigation. The 155 RILs were genotyped with 11,292 SNPs, and composite interval mapping was conducted to identify QTL for drought tolerance. Seed yield for Kijivu under drought stress was consistently higher than for Bukoba across all four field trials. A total of 60 QTL were identified for morphological, agronomic, and physiological traits under drought stress and non-stress conditions. However, the majority of these QTL were specific to drought stress. QTL "hotspots" for drought tolerance were identified on chromosomes Pv06, Pv07, and Pv10. Extensive co-localizations for agronomic and morpho-physiological traits under drought stress were observed at the three drought-tolerance QTL hotspots. Additionally, these three QTL hotspots overlapped with previously identified QTL for drought tolerance, while several others identified QTL are novel. The three identified QTL hotspots could be used in future marker-assisted selection for drought tolerance in common bean.
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Affiliation(s)
- Swivia M Hamabwe
- Department of Biology, School of Science and Technology, University of Nairobi, Nairobi, Kenya
- Department of Plant Science, University of Zambia, Great East Road, Lusaka, Zambia
| | - Nicholas Amimo Otieno
- Department of Biology, School of Science and Technology, University of Nairobi, Nairobi, Kenya
| | - Alvaro Soler-Garzón
- Grain Legume Genetics and Physiology Research Unit, United States Department of Agriculture-Agricultural Research Service, Prosser, WA, USA
| | - Phillip N Miklas
- Grain Legume Genetics and Physiology Research Unit, United States Department of Agriculture-Agricultural Research Service, Prosser, WA, USA
| | - Travis Parker
- Department of Plant Sciences/MS1, Section of Crop and Ecosystem Sciences, University of California, 1 Shields Avenue, Davis, CA, 95616-8780, USA
| | - David M Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, 48824, USA
| | | | - Pride Cheelo
- Department of Plant Science, University of Zambia, Great East Road, Lusaka, Zambia
| | - Kuwabo Kuwabo
- Department of Plant Science, University of Zambia, Great East Road, Lusaka, Zambia
| | - Kelvin Kamfwa
- Department of Plant Science, University of Zambia, Great East Road, Lusaka, Zambia.
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Niu Y, Lazár D, Holzwarth AR, Kramer DM, Matsubara S, Fiorani F, Poorter H, Schrey SD, Nedbal L. Plants cope with fluctuating light by frequency-dependent nonphotochemical quenching and cyclic electron transport. New Phytol 2023. [PMID: 37429324 DOI: 10.1111/nph.19083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/16/2023] [Indexed: 07/12/2023]
Abstract
In natural environments, plants are exposed to rapidly changing light. Maintaining photosynthetic efficiency while avoiding photodamage requires equally rapid regulation of photoprotective mechanisms. We asked what the operation frequency range of regulation is in which plants can efficiently respond to varying light. Chlorophyll fluorescence, P700, plastocyanin, and ferredoxin responses of wild-types Arabidopsis thaliana were measured in oscillating light of various frequencies. We also investigated the npq1 mutant lacking violaxanthin de-epoxidase, the npq4 mutant lacking PsbS protein, and the mutants crr2-2, and pgrl1ab impaired in different pathways of the cyclic electron transport. The fastest was the PsbS-regulation responding to oscillation periods longer than 10 s. Processes involving violaxanthin de-epoxidase dampened changes in chlorophyll fluorescence in oscillation periods of 2 min or longer. Knocking out the PGR5/PGRL1 pathway strongly reduced variations of all monitored parameters, probably due to congestion in the electron transport. Incapacitating the NDH-like pathway only slightly changed the photosynthetic dynamics. Our observations are consistent with the hypothesis that nonphotochemical quenching in slow light oscillations involves violaxanthin de-epoxidase to produce, presumably, a largely stationary level of zeaxanthin. We interpret the observed dynamics of photosystem I components as being formed in slow light oscillations partially by thylakoid remodeling that modulates the redox rates.
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Affiliation(s)
- Yuxi Niu
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Dušan Lazár
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Alfred R Holzwarth
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1105, NL-1081 HV, Amsterdam, the Netherlands
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Shizue Matsubara
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Fabio Fiorani
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Hendrik Poorter
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Silvia D Schrey
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Ladislav Nedbal
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
- PASTEUR, Department of Chemistry, École Normale Supérieure, Université PSL, Sorbonne Université, CNRS, 24, rue Lhomond, 75005, Paris, France
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Sharma N, Froehlich JE, Rillema R, Raba DA, Chambers T, Kerfeld CA, Kramer DM, Walker B, Brandizzi F. Arabidopsis stromal carbonic anhydrases exhibit non-overlapping roles in photosynthetic efficiency and development. Plant J 2023. [PMID: 37010739 DOI: 10.1111/tpj.16231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Carbonic anhydrases (CAs) are ubiquitous enzymes that accelerate the reversible conversion of CO2 to HCO3 - . The Arabidopsis genome encodes members of the α-, β- and γ-CA families, and it has been hypothesized that βCA activity has a role in photosynthesis. In this work, we tested this hypothesis by characterizing the two plastidial βCAs, βCA1 and βCA5, in physiological conditions of growth. We conclusively established that both proteins are localized in the chloroplast stroma and that the loss of βCA5 induced the expression of βCA1, supporting the existence of regulatory mechanisms to control the expression of stromal βCAs. We also established that βCA1 and βCA5 have markedly different enzymatic kinetics and physiological relevance. Specifically, we found that βCA5 had a first-order rate constant ~10-fold lower than βCA1, and that the loss of βCA5 is detrimental to growth and could be rescued by high CO2 . Furthermore, we established that, while a βCA1 mutation showed near wild-type growth and no significant impact on photosynthetic efficiency, the loss of βCA5 markedly disrupted photosynthetic efficiency and light-harvesting capacity at ambient CO2 . Therefore, we conclude that in physiological autotrophic growth, the loss of the more highly expressed βCA1 does not compensate for the loss of a less active βCA5, which in turn is involved in growth and photosynthesis at ambient CO2 levels. These results lend support to the hypothesis that, in Arabidopsis,βCAs have non-overlapping roles in photosynthesis and identify a critical activity of stromal βCA5 and a dispensable role for βCA1.
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Affiliation(s)
- Naveen Sharma
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
| | - John E Froehlich
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
- Biochemistry and Molecular Biology Department, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Rees Rillema
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Daniel A Raba
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Taylor Chambers
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
- Biochemistry and Molecular Biology Department, Michigan State University, East Lansing, Michigan, 48824, USA
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
- Biochemistry and Molecular Biology Department, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Berkley Walker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Federica Brandizzi
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- DOE-Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
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10
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Strand DD, Karcher D, Ruf S, Schadach A, Schöttler MA, Sandoval-Ibañez O, Hall D, Kramer DM, Bock R. Characterization of mutants deficient in N-terminal phosphorylation of the chloroplast ATP synthase subunit β. Plant Physiol 2023; 191:1818-1835. [PMID: 36635853 PMCID: PMC10022623 DOI: 10.1093/plphys/kiad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Understanding the regulation of photosynthetic light harvesting and electron transfer is of great importance to efforts to improve the ability of the electron transport chain to supply downstream metabolism. A central regulator of the electron transport chain is ATP synthase, the molecular motor that harnesses the chemiosmotic potential generated from proton-coupled electron transport to synthesize ATP. ATP synthase is regulated both thermodynamically and post-translationally, with proposed phosphorylation sites on multiple subunits. In this study we focused on two N-terminal serines on the catalytic subunit β in tobacco (Nicotiana tabacum), previously proposed to be important for dark inactivation of the complex to avoid ATP hydrolysis at night. Here we show that there is no clear role for phosphorylation in the dark inactivation of ATP synthase. Instead, mutation of one of the two phosphorylated serine residues to aspartate to mimic constitutive phosphorylation strongly decreased ATP synthase abundance. We propose that the loss of N-terminal phosphorylation of ATPβ may be involved in proper ATP synthase accumulation during complex assembly.
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Affiliation(s)
| | - Daniel Karcher
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Anne Schadach
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mark A Schöttler
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Omar Sandoval-Ibañez
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - David Hall
- DOE Plant Research Laboratory, Michigan State University, 612 Wilson Rd 106, East Lansing, Michigan, 48824, USA
| | - David M Kramer
- DOE Plant Research Laboratory, Michigan State University, 612 Wilson Rd 106, East Lansing, Michigan, 48824, USA
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11
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McClain AM, Cruz JA, Kramer DM, Sharkey TD. The time course of acclimation to the stress of triose phosphate use limitation. Plant Cell Environ 2023; 46:64-75. [PMID: 36305484 PMCID: PMC10100259 DOI: 10.1111/pce.14476] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Triose phosphate utilisation (TPU) limits the maximum rate at which plants can photosynthesise. However, TPU is almost never found to be limiting photosynthesis under ambient conditions for plants. This, along with previous results showing adaptability of TPU at low temperature, suggest that TPU capacity is regulated to be just above the photosynthetic rate achievable under the prevailing conditions. A set of experiments were performed to study the adaptability of TPU capacity when plants are acclimated to elevated CO2 concentrations. Plants held at 1500 ppm CO2 were initially TPU limited. After 30 h they no longer exhibited TPU limitations but they did not elevate their TPU capacity. Instead, the maximum rates of carboxylation and electron transport declined. A timecourse of regulatory responses was established. A step increase of CO2 first caused PSI to be oxidised but after 40 s both PSI and PSII had excess electrons as a result of acceptor-side limitations. Electron flow to PSI slowed and the proton motive force increased. Eventually, non-photochemical quenching reduced electron flow sufficiently to balance the TPU limitation. Over several minutes rubisco deactivated contributing to regulation of metabolism to overcome the TPU limitation.
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Affiliation(s)
- Alan M. McClain
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Biotechnology for Health and SustainabilityMichigan State UniversityEast LansingMichiganUSA
| | - Jeffrey A. Cruz
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
| | - David M. Kramer
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Thomas D. Sharkey
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Resilience InstituteMichigan State UniversityEast LansingMichiganUSA
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12
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von Bismarck T, Korkmaz K, Ruß J, Skurk K, Kaiser E, Correa Galvis V, Cruz JA, Strand DD, Köhl K, Eirich J, Finkemeier I, Jahns P, Kramer DM, Armbruster U. Light acclimation interacts with thylakoid ion transport to govern the dynamics of photosynthesis in Arabidopsis. New Phytol 2023; 237:160-176. [PMID: 36378135 DOI: 10.1111/nph.18534] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Understanding photosynthesis in natural, dynamic light environments requires knowledge of long-term acclimation, short-term responses, and their mechanistic interactions. To approach the latter, we systematically determined and characterized light-environmental effects on thylakoid ion transport-mediated short-term responses during light fluctuations. For this, Arabidopsis thaliana wild-type and mutants of the Cl- channel VCCN1 and the K+ exchange antiporter KEA3 were grown under eight different light environments and characterized for photosynthesis-associated parameters and factors in steady state and during light fluctuations. For a detailed characterization of selected light conditions, we monitored ion flux dynamics at unprecedented high temporal resolution by a modified spectroscopy approach. Our analyses reveal that daily light intensity sculpts photosynthetic capacity as a main acclimatory driver with positive and negative effects on the function of KEA3 and VCCN1 during high-light phases, respectively. Fluctuations in light intensity boost the accumulation of the photoprotective pigment zeaxanthin (Zx). We show that KEA3 suppresses Zx accumulation during the day, which together with its direct proton transport activity accelerates photosynthetic transition to lower light intensities. In summary, both light-environment factors, intensity and variability, modulate the function of thylakoid ion transport in dynamic photosynthesis with distinct effects on lumen pH, Zx accumulation, photoprotection, and photosynthetic efficiency.
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Affiliation(s)
| | - Kübra Korkmaz
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Jeremy Ruß
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Kira Skurk
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Elias Kaiser
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | | | - Jeffrey A Cruz
- 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
| | - Deserah D Strand
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Karin Köhl
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Jürgen Eirich
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, 48149, Münster, Germany
| | - Iris Finkemeier
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, 48149, Münster, Germany
| | - Peter Jahns
- Plant Biochemistry, Heinrich-Heine-University Düsseldorf, 40225, Düsseldorf, Germany
| | - David M Kramer
- 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
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
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13
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Lopez LS, Völkner C, Day PM, Lewis CM, Lewis CL, Schneider D, Correa Galvis V, Cruz JA, Armbruster U, Kramer DM, Kunz H. The Arabidopsis T-DNA mutant SALK_008491 carries a 14-kb deletion on chromosome 3 that provides rare insights into the plant response to dynamic light stress. Plant Direct 2022; 6:e429. [PMID: 35875836 PMCID: PMC9300446 DOI: 10.1002/pld3.429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/25/2022] [Accepted: 07/01/2022] [Indexed: 05/14/2023]
Abstract
In nature, plants experience rapid changes in light intensity and quality throughout the day. To maximize growth, they have established molecular mechanisms to optimize photosynthetic output while protecting components of the light-dependent reaction and CO2 fixation pathways. Plant phenotyping of mutant collections has become a powerful tool to unveil the genetic loci involved in environmental acclimation. Here, we describe the phenotyping of the transfer-DNA (T-DNA) insertion mutant line SALK_008491, previously known as nhd1-1. Growth in a fluctuating light regime caused a loss in growth rate accompanied by a spike in photosystem (PS) II damage and increased non-photochemical quenching (NPQ). Interestingly, an independent nhd1 null allele did not recapitulate the NPQ phenotype. Through bulk sequencing of a backcrossed segregating F2 pool, we identified an ~14-kb large deletion on chromosome 3 (Chr3) in SALK_008491 affecting five genes upstream of NHD1. Besides NHD1, which encodes for a putative plastid Na+/H+ antiporter, the stromal NAD-dependent D-3-phosphoglycerate dehydrogenase 3 (PGDH3) locus was eradicated. Although some changes in the SALK_008491 mutant's photosynthesis can be assigned to the loss of PGDH3, our follow-up studies employing respective single mutants and complementation with overlapping transformation-competent artificial chromosome (TAC) vectors reveal that the exacerbated fluctuating light sensitivity in SALK_008491 mutants result from the simultaneous loss of PGDH3 and NHD1. Altogether, the data obtained from this large deletion-carrying mutant provide new and unintuitive insights into the molecular mechanisms that function to protect the photosynthetic machinery. Moreover, our study renews calls for caution when setting up reverse genetic studies using T-DNA lines. Although second-site insertions, indels, and SNPs have been reported before, large deletion surrounding the insertion site causes yet another problem. Nevertheless, as shown through this research, such unpredictable genetic events following T-DNA mutagenesis can provide unintuitive insights that allow for understanding complex phenomena such as the plant acclimation to dynamic high light stress.
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Affiliation(s)
- Laura S. Lopez
- School of Biological SciencesWashington State UniversityPullmanWashington
| | - Carsten Völkner
- School of Biological SciencesWashington State UniversityPullmanWashington
- Department of Plant BiochemistryLMU MunichPlanegg‐MartinsriedGermany
| | - Philip M. Day
- School of Biological SciencesWashington State UniversityPullmanWashington
| | - Chance M. Lewis
- School of Biological SciencesWashington State UniversityPullmanWashington
| | - Chase L. Lewis
- School of Biological SciencesWashington State UniversityPullmanWashington
| | - Dominik Schneider
- Compact Plants Phenomics CenterWashington State UniversityPullmanWashingtonUSA
| | | | - Jeffrey A. Cruz
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant PhysiologyPotsdamGermany
| | - David M. Kramer
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
| | - Hans‐Henning Kunz
- School of Biological SciencesWashington State UniversityPullmanWashington
- Department of Plant BiochemistryLMU MunichPlanegg‐MartinsriedGermany
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14
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Hoh D, Horn PJ, Kanazawa A, Froehilch J, Cruz J, Tessmer OL, Hall D, Yin L, Benning C, Kramer DM. Genetically-determined variations in photosynthesis indicate roles for specific fatty acid species in chilling responses. Plant Cell Environ 2022; 45:1682-1697. [PMID: 35297062 DOI: 10.1111/pce.14313] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
Using a population of recombinant inbred lines (RILs) cowpea (Vigna unguiculata. L. Walp), we tested for co-linkages between lipid contents and chilling responses of photosynthesis. Under low-temperature conditions (19°C/13°C, day/night), we observed co-linkages between quantitative trait loci intervals for photosynthetic light reactions and specific fatty acids, most strikingly, the thylakoid-specific fatty acid 16:1Δ3trans found exclusively in phosphatidylglycerol (PG 16:1t). By contrast, we did not observe co-associations with bulk polyunsaturated fatty acids or high-melting-point-PG (sum of PG 16:0, PG 18:0 and PG 16:1t) previously thought to be involved in chilling sensitivity. These results suggest that in cowpea, chilling sensitivity is modulated by specific lipid interactions rather than bulk properties. We were able to recapitulate the predicted impact of PG 16:1t levels on photosynthetic responses at low temperature using mutants and transgenic Arabidopsis lines. Because PG 16:1t synthesis requires the activity of peroxiredoxin-Q, which is activated by H2 O2 and known to be involved in redox signalling, we hypothesise that the accumulation of PG 16:1t occurs as a result of upstream effects on photosynthesis that alter redox status and production of reactive oxygen species.
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Affiliation(s)
- Donghee Hoh
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
- Cell & Molecular Biology Program, Michigan State University, East Lansing, Michigan, USA
| | - Patrick J Horn
- Department of Biology, East Carolina University, Greenville, North Carolina, USA
| | - Atsuko Kanazawa
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - John Froehilch
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
| | - Jeffrey Cruz
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
| | | | - David Hall
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
| | - Lina Yin
- State Key Laboratory of Soil Erosion and Dryland Farming in the Loess Plateau, Northwest A&F University, Yangling, China
| | - Christoph Benning
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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15
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Kulke M, Olson DM, Parson WW, Huang J, Ducat DC, Kramer DM, Vermaas JV. Measuring heme-hopping electron transfer through a biological nanowire. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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16
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Neofotis P, Temple J, Tessmer OL, Bibik J, Norris N, Pollner E, Lucker B, Weraduwage SM, Withrow A, Sears B, Mogos G, Frame M, Hall D, Weissman J, Kramer DM. The induction of pyrenoid synthesis by hyperoxia and its implications for the natural diversity of photosynthetic responses in Chlamydomonas. eLife 2021; 10:67565. [PMID: 34936552 PMCID: PMC8694700 DOI: 10.7554/elife.67565] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 11/13/2021] [Indexed: 12/31/2022] Open
Abstract
In algae, it is well established that the pyrenoid, a component of the carbon-concentrating mechanism (CCM), is essential for efficient photosynthesis at low CO2. However, the signal that triggers the formation of the pyrenoid has remained elusive. Here, we show that, in Chlamydomonas reinhardtii, the pyrenoid is strongly induced by hyperoxia, even at high CO2 or bicarbonate levels. These results suggest that the pyrenoid can be induced by a common product of photosynthesis specific to low CO2 or hyperoxia. Consistent with this view, the photorespiratory by-product, H2O2, induced the pyrenoid, suggesting that it acts as a signal. Finally, we show evidence for linkages between genetic variations in hyperoxia tolerance, H2O2 signaling, and pyrenoid morphologies.
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Affiliation(s)
- Peter Neofotis
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joshua Temple
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Plant Biology, Michigan State University, East Lansing, United States
| | - Oliver L Tessmer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Jacob Bibik
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Nicole Norris
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Eric Pollner
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Ben Lucker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Sarathi M Weraduwage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, United States
| | - Alecia Withrow
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - Barbara Sears
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Greg Mogos
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Melinda Frame
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - David Hall
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joseph Weissman
- Corporate Strategic Research, ExxonMobil, Annandale, United States
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
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17
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Kanazawa A, Chattopadhyay A, Kuhlgert S, Tuitupou H, Maiti T, Kramer DM. Light potentials of photosynthetic energy storage in the field: what limits the ability to use or dissipate rapidly increased light energy? R Soc Open Sci 2021; 8:211102. [PMID: 34925868 PMCID: PMC8672073 DOI: 10.1098/rsos.211102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
The responses of plant photosynthesis to rapid fluctuations in environmental conditions are critical for efficient conversion of light energy. These responses are not well-seen laboratory conditions and are difficult to probe in field environments. We demonstrate an open science approach to this problem that combines multifaceted measurements of photosynthesis and environmental conditions, and an unsupervised statistical clustering approach. In a selected set of data on mint (Mentha sp.), we show that 'light potentials' for linear electron flow and non-photochemical quenching (NPQ) upon rapid light increases are strongly suppressed in leaves previously exposed to low ambient photosynthetically active radiation (PAR) or low leaf temperatures, factors that can act both independently and cooperatively. Further analyses allowed us to test specific mechanisms. With decreasing leaf temperature or PAR, limitations to photosynthesis during high light fluctuations shifted from rapidly induced NPQ to photosynthetic control of electron flow at the cytochrome b6f complex. At low temperatures, high light induced lumen acidification, but did not induce NPQ, leading to accumulation of reduced electron transfer intermediates, probably inducing photodamage, revealing a potential target for improving the efficiency and robustness of photosynthesis. We discuss the implications of the approach for open science efforts to understand and improve crop productivity.
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Affiliation(s)
- Atsuko Kanazawa
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Abhijnan Chattopadhyay
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA
| | - Sebastian Kuhlgert
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
| | - Hainite Tuitupou
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
| | - Tapabrata Maiti
- Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA
| | - David M. Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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18
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Mellon M, Storti M, Vera-Vives AM, Kramer DM, Alboresi A, Morosinotto T. Inactivation of mitochondrial complex I stimulates chloroplast ATPase in Physcomitrium patens. Plant Physiol 2021; 187:931-946. [PMID: 34608952 PMCID: PMC8491079 DOI: 10.1093/plphys/kiab276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 05/18/2021] [Indexed: 06/11/2023]
Abstract
Light is the ultimate source of energy for photosynthetic organisms, but respiration is fundamental for supporting metabolism during the night or in heterotrophic tissues. In this work, we isolated Physcomitrella (Physcomitrium patens) plants with altered respiration by inactivating Complex I (CI) of the mitochondrial electron transport chain by independently targeting on two essential subunits. Inactivation of CI caused a strong growth impairment even in fully autotrophic conditions in tissues where all cells are photosynthetically active, demonstrating that respiration is essential for photosynthesis. CI mutants showed alterations in the stoichiometry of respiratory complexes while the composition of photosynthetic apparatus was substantially unaffected. CI mutants showed altered photosynthesis with high activity of both Photosystems I and II, likely the result of high chloroplast ATPase activity that led to smaller ΔpH formation across thylakoid membranes, decreasing photosynthetic control on cytochrome b6f in CI mutants. These results demonstrate that alteration of respiratory activity directly impacts photosynthesis in P. patens and that metabolic interaction between organelles is essential in their ability to use light energy for growth.
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Affiliation(s)
- Marco Mellon
- Department of Biology, University of Padova, 35121 Padova, Italy
| | - Mattia Storti
- Department of Biology, University of Padova, 35121 Padova, Italy
| | | | - David M. Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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19
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Gregory LM, McClain AM, Kramer DM, Pardo JD, Smith KE, Tessmer OL, Walker BJ, Ziccardi LG, Sharkey TD. The triose phosphate utilization limitation of photosynthetic rate: Out of global models but important for leaf models. Plant Cell Environ 2021; 44:3223-3226. [PMID: 34278582 PMCID: PMC9291784 DOI: 10.1111/pce.14153] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/13/2021] [Indexed: 05/29/2023]
Abstract
The effect of including triose phosphate utilization (TPU) on parameterization of the Farquhar, von Caemmerer, Berry model of photosynthetic gas exchange measurements is explored. Better fits to data are found even though TPU rarely limits photosynthesis under physiological conditions.
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Affiliation(s)
- Luke M. Gregory
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Alan M. McClain
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Biotechnology for Health and Sustainability ProgramMichigan State UniversityEast LansingMichiganUSA
| | - David M. Kramer
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Jeremy D. Pardo
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Biotechnology for Health and Sustainability ProgramMichigan State UniversityEast LansingMichiganUSA
| | - Kaila E. Smith
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Biotechnology for Health and Sustainability ProgramMichigan State UniversityEast LansingMichiganUSA
| | - Oliver L. Tessmer
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
| | - Berkley J. Walker
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | | | - Thomas D. Sharkey
- MSU‐DOE Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
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20
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Osei-Bonsu I, McClain AM, Walker BJ, Sharkey TD, Kramer DM. The roles of photorespiration and alternative electron acceptors in the responses of photosynthesis to elevated temperatures in cowpea. Plant Cell Environ 2021; 44:2290-2307. [PMID: 33555066 DOI: 10.1111/pce.14026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 05/02/2023]
Abstract
We explored the effects, on photosynthesis in cowpea (Vigna unguiculata) seedlings, of high temperature and light-environmental stresses that often co-occur under field conditions and can have greater impact on photosynthesis than either by itself. We observed contrasting responses in the light and carbon assimilatory reactions, whereby in high temperature, the light reactions were stimulated while CO2 assimilation was substantially reduced. There were two striking observations. Firstly, the primary quinone acceptor (QA ), a measure of the regulatory balance of the light reactions, became more oxidized with increasing temperature, suggesting increased electron sink capacity, despite the reduced CO2 fixation. Secondly, a strong, O2 -dependent inactivation of assimilation capacity, consistent with down-regulation of rubisco under these conditions. The dependence of these effects on CO2 , O2 and light led us to conclude that both photorespiration and an alternative electron acceptor supported increased electron flow, and thus provided photoprotection under these conditions. Further experiments showed that the increased electron flow was maintained by rapid rates of PSII repair, particularly at combined high light and temperature. Overall, the results suggest that photodamage to the light reactions can be avoided under high light and temperatures by increasing electron sink strength, even when assimilation is strongly suppressed.
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Affiliation(s)
- Isaac Osei-Bonsu
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Horticulture Division, CSIR-Crops Research Institute, Kumasi, Ghana
| | - Alan M McClain
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Berkley J Walker
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
| | - Thomas D Sharkey
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - David M Kramer
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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21
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Peng J, Lu J, Hoh D, Dina AS, Shang X, Kramer DM, Chen J. Identifying emerging phenomenon in long temporal phenotyping experiments. Bioinformatics 2020; 36:568-577. [PMID: 31304958 DOI: 10.1093/bioinformatics/btz559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 07/07/2019] [Accepted: 07/12/2019] [Indexed: 01/26/2023] Open
Abstract
MOTIVATION The rapid improvement of phenotyping capability, accuracy and throughput have greatly increased the volume and diversity of phenomics data. A remaining challenge is an efficient way to identify phenotypic patterns to improve our understanding of the quantitative variation of complex phenotypes, and to attribute gene functions. To address this challenge, we developed a new algorithm to identify emerging phenomena from large-scale temporal plant phenotyping experiments. An emerging phenomenon is defined as a group of genotypes who exhibit a coherent phenotype pattern during a relatively short time. Emerging phenomena are highly transient and diverse, and are dependent in complex ways on both environmental conditions and development. Identifying emerging phenomena may help biologists to examine potential relationships among phenotypes and genotypes in a genetically diverse population and to associate such relationships with the change of environments or development. RESULTS We present an emerging phenomenon identification tool called Temporal Emerging Phenomenon Finder (TEP-Finder). Using large-scale longitudinal phenomics data as input, TEP-Finder first encodes the complicated phenotypic patterns into a dynamic phenotype network. Then, emerging phenomena in different temporal scales are identified from dynamic phenotype network using a maximal clique based approach. Meanwhile, a directed acyclic network of emerging phenomena is composed to model the relationships among the emerging phenomena. The experiment that compares TEP-Finder with two state-of-art algorithms shows that the emerging phenomena identified by TEP-Finder are more functionally specific, robust and biologically significant. AVAILABILITY AND IMPLEMENTATION The source code, manual and sample data of TEP-Finder are all available at: http://phenomics.uky.edu/TEP-Finder/. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Jiajie Peng
- School of Computer Science, Northwestern Polytechnical University, Xi'an 710072, China
| | - Junya Lu
- School of Computer Science, Northwestern Polytechnical University, Xi'an 710072, China
| | - Donghee Hoh
- Department of Energy Plant Research Lab.,Cell and Molecular Biology Program, Michigan State University, East Lansing, MI, 48824, USA
| | | | - Xuequn Shang
- School of Computer Science, Northwestern Polytechnical University, Xi'an 710072, China
| | | | - Jin Chen
- Institute for Biomedical Informatics, University of Kentucky, Lexington, KY 40536, USA
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22
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Major IT, Guo Q, Zhai J, Kapali G, Kramer DM, Howe GA. A Phytochrome B-Independent Pathway Restricts Growth at High Levels of Jasmonate Defense. Plant Physiol 2020; 183:733-749. [PMID: 32245790 PMCID: PMC7271779 DOI: 10.1104/pp.19.01335] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/25/2020] [Indexed: 05/20/2023]
Abstract
The plant hormone jasmonate (JA) promotes resistance to biotic stress by stimulating the degradation of JASMONATE ZIM-DOMAIN (JAZ) proteins, which relieves repression on MYC transcription factors that execute defense programs. JA-triggered depletion of JAZ proteins in Arabidopsis (Arabidopsis thaliana) is also associated with reduced growth and seed production, but the mechanisms underlying these pleiotropic growth effects remain unclear. Here, we investigated this question using an Arabidopsis JAZ-deficient mutant (jazD; jaz1-jaz7, jaz9, jaz10, and jaz 13) that exhibits high levels of defense and strong growth inhibition. Genetic suppressor screens for mutations that uncouple growth-defense tradeoffs in the jazD mutant identified nine independent causal mutations in the red-light receptor phytochrome B (phyB). Unlike the ability of the phyB mutations to completely uncouple the mild growth-defense phenotypes in a jaz mutant (jazQ) defective in JAZ1, JAZ3, JAZ4, JAZ9, and JAZ10, phyB null alleles only weakly alleviated the growth and reproductive defects in the jazD mutant. phyB-independent growth restriction of the jazD mutant was tightly correlated with upregulation of the Trp biosynthetic pathway but not with changes in central carbon metabolism. Interestingly, jazD and jazD phyB plants were insensitive to a chemical inhibitor of Trp biosynthesis, which is a phenotype previously observed in plants expressing hyperactive MYC transcription factors that cannot bind JAZ repressors. These data provide evidence that the mechanisms underlying JA-mediated growth-defense balance depend on the level of defense, and they further establish an association between growth inhibition at high levels of defense and dysregulation of Trp biosynthesis.
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Affiliation(s)
- Ian T Major
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Qiang Guo
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Jinling Zhai
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - George Kapali
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 42284
| | - David M Kramer
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Gregg A Howe
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 42284
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23
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Huang J, Zarzycki J, Gunner MR, Parson WW, Kern JF, Yano J, Ducat DC, Kramer DM. Mesoscopic to Macroscopic Electron Transfer by Hopping in a Crystal Network of Cytochromes. J Am Chem Soc 2020; 142:10459-10467. [DOI: 10.1021/jacs.0c02729] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jingcheng Huang
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jan Zarzycki
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - M. R. Gunner
- Department of Physics, City College of New York, New York, New York 10031, United States
| | - William W. Parson
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Jan F. Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel C. Ducat
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - David M. Kramer
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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24
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Walker BJ, Kramer DM, Fisher N, Fu X. Flexibility in the Energy Balancing Network of Photosynthesis Enables Safe Operation under Changing Environmental Conditions. Plants (Basel) 2020; 9:E301. [PMID: 32121540 PMCID: PMC7154899 DOI: 10.3390/plants9030301] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 12/11/2022]
Abstract
Given their ability to harness chemical energy from the sun and generate the organic compounds necessary for life, photosynthetic organisms have the unique capacity to act simultaneously as their own power and manufacturing plant. This dual capacity presents many unique challenges, chiefly that energy supply must be perfectly balanced with energy demand to prevent photodamage and allow for optimal growth. From this perspective, we discuss the energy balancing network using recent studies and a quantitative framework for calculating metabolic ATP and NAD(P)H demand using measured leaf gas exchange and assumptions of metabolic demand. We focus on exploring how the energy balancing network itself is structured to allow safe and flexible energy supply. We discuss when the energy balancing network appears to operate optimally and when it favors high capacity instead. We also present the hypothesis that the energy balancing network itself can adapt over longer time scales to a given metabolic demand and how metabolism itself may participate in this energy balancing.
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Affiliation(s)
- Berkley J. Walker
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823, USA
| | - David M. Kramer
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA
| | - Nicholas Fisher
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
| | - Xinyu Fu
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
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25
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Huang J, Ferlez BH, Young EJ, Kerfeld CA, Kramer DM, Ducat DC. Functionalization of Bacterial Microcompartment Shell Proteins With Covalently Attached Heme. Front Bioeng Biotechnol 2020; 7:432. [PMID: 31993414 PMCID: PMC6962350 DOI: 10.3389/fbioe.2019.00432] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/05/2019] [Indexed: 12/26/2022] Open
Abstract
Heme is a versatile redox cofactor that has considerable potential for synthetic biology and bioelectronic applications. The capacity to functionalize non-heme-binding proteins with covalently bound heme moieties in vivo could expand the variety of bioelectronic materials, particularly if hemes could be attached at defined locations so as to facilitate position-sensitive processes like electron transfer. In this study, we utilized the cytochrome maturation system I to develop a simple approach that enables incorporation of hemes into the backbone of target proteins in vivo. We tested our methodology by targeting the self-assembling bacterial microcompartment shell proteins, and inserting functional hemes at multiple locations in the protein backbone. We found substitution of three amino acids on the target proteins promoted heme attachment with high occupancy. Spectroscopic measurements suggested these modified proteins covalently bind low-spin hemes, with relative low redox midpoint potentials (about -210 mV vs. SHE). Heme-modified shell proteins partially retained their self-assembly properties, including the capacity to hexamerize, and form inter-hexamer attachments. Heme-bound shell proteins demonstrated the capacity to integrate into higher-order shell assemblies, however, the structural features of these macromolecular complexes was sometimes altered. Altogether, we report a versatile strategy for generating electron-conductive cytochromes from structurally-defined proteins, and provide design considerations on how heme incorporation may interface with native assembly properties in engineered proteins.
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Affiliation(s)
- Jingcheng Huang
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Bryan H. Ferlez
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Eric J. Young
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Cheryl A. Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - David M. Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Daniel C. Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
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26
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Flood PJ, Theeuwen TPJM, Schneeberger K, Keizer P, Kruijer W, Severing E, Kouklas E, Hageman JA, Wijfjes R, Calvo-Baltanas V, Becker FFM, Schnabel SK, Willems LAJ, Ligterink W, van Arkel J, Mumm R, Gualberto JM, Savage L, Kramer DM, Keurentjes JJB, van Eeuwijk F, Koornneef M, Harbinson J, Aarts MGM, Wijnker E. Reciprocal cybrids reveal how organellar genomes affect plant phenotypes. Nat Plants 2020; 6:13-21. [PMID: 31932677 DOI: 10.1038/s41477-019-0575-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/25/2019] [Indexed: 05/21/2023]
Abstract
Assessment of the impact of variation in chloroplast and mitochondrial DNA (collectively termed the plasmotype) on plant phenotypes is challenging due to the difficulty in separating their effect from nuclear-derived variation (the nucleotype). Haploid-inducer lines can be used as efficient plasmotype donors to generate new plasmotype-nucleotype combinations (cybrids)1. We generated a panel comprising all possible cybrids of seven Arabidopsis thaliana accessions and extensively phenotyped these lines for 1,859 phenotypes under both stable and fluctuating conditions. We show that natural variation in the plasmotype results in both additive and epistatic effects across all phenotypic categories. Plasmotypes that induce more additive phenotypic changes also cause more epistatic effects, suggesting a possible common basis for both additive and epistatic effects. On average, epistatic interactions explained twice as much of the variance in phenotypes as additive plasmotype effects. The impact of plasmotypic variation was also more pronounced under fluctuating and stressful environmental conditions. Thus, the phenotypic impact of variation in plasmotypes is the outcome of multi-level nucleotype-plasmotype-environment interactions and, as such, the plasmotype is likely to serve as a reservoir of variation that is predominantly exposed under certain conditions. The production of cybrids using haploid inducers is a rapid and precise method for assessment of the phenotypic effects of natural variation in organellar genomes. It will facilitate efficient screening of unique nucleotype-plasmotype combinations to both improve our understanding of natural variation in these combinations and identify favourable combinations to enhance plant performance.
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Affiliation(s)
- Pádraic J Flood
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands.
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, the Netherlands.
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
| | - Tom P J M Theeuwen
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands.
| | - Korbinian Schneeberger
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Paul Keizer
- Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Willem Kruijer
- Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Edouard Severing
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Evangelos Kouklas
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Jos A Hageman
- Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Raúl Wijfjes
- Bioinformatics Group, Wageningen, the Netherlands
| | - Vanesa Calvo-Baltanas
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Frank F M Becker
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Sabine K Schnabel
- Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Leo A J Willems
- Laboratory of Plant Physiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Wilco Ligterink
- Laboratory of Plant Physiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Jeroen van Arkel
- Bioscience, Wageningen University & Research, Wageningen, the Netherlands
| | - Roland Mumm
- Bioscience, Wageningen University & Research, Wageningen, the Netherlands
| | - José M Gualberto
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Linda Savage
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, USA
| | - David M Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, USA
| | - Joost J B Keurentjes
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Fred van Eeuwijk
- Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Maarten Koornneef
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jeremy Harbinson
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Mark G M Aarts
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Erik Wijnker
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands.
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27
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Lightfoot N, MacEwan L, Tufford L, Holness DL, Mayer C, Kramer DM. Who cares? The impact on caregivers of suspected mining-related lung cancer. ACTA ACUST UNITED AC 2019; 26:e494-e502. [PMID: 31548817 DOI: 10.3747/co.26.4635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Background In the present study, we investigated the emotional, physical, financial, occupational, practical, and quality-of-life impacts on caregivers of patients with mining-related lung cancer. Methods This concurrent, embedded, mixed-methods study used individual in-depth qualitative interviews and the 36-item Short Form Health Survey (version 2: RAND Corporation, Santa Monica, CA, U.S.A.) quality-of-life measure with 8 caregivers of patients with suspected mining-related lung cancer who had worked in Sudbury or Elliot Lake (or both), and sometimes elsewhere. Individuals who assist workers in filing compensation claims were also interviewed in Sudbury and Elliot Lake. Interviews (n = 11) were transcribed and analyzed thematically. Results Caregiver themes focused on the long time to, and the shock of, diagnosis and dealing with lung cancer; not much of a life for caregivers; strong views about potential cancer causes; concerns about financial impacts; compensation experiences and long time to compensation; and suggestions for additional support. Quality-of-life scores were below the norm for most measures. Individuals who assist workers in preparing claims were passionate about challenges in the compensation journey; the requirement for more and better family support; the need to focus on compensation compared with cost control; the need for better exposure monitoring, controls, resources, and research; and job challenges, barriers, and satisfaction. Conclusions Caregivers expressed a need for more education about the compensation process and for greater support. Worker representatives required persistence, additional workplace monitoring and controls, additional research, and a focus on compensation compared with cost control. They also emphasized the need for more family support.
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Affiliation(s)
- N Lightfoot
- School of Rural and Northern Health, Laurentian University, Sudbury, ON
| | - L MacEwan
- School of Social Work, Laurentian University, Sudbury, ON
| | - L Tufford
- School of Social Work, Laurentian University, Sudbury, ON
| | - D L Holness
- Dalla Lana School of Public Health and Department of Medicine, University of Toronto, and Division of Occupational Medicine and Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON
| | - C Mayer
- Supportive Care Oncology Research Unit, Health Sciences North, Sudbury, ON
| | - D M Kramer
- School of Occupational and Public Health, Ryerson University, Toronto, ON
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28
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Höhner R, Galvis VC, Strand DD, Völkner C, Krämer M, Messer M, Dinc F, Sjuts I, Bölter B, Kramer DM, Armbruster U, Kunz HH. Photosynthesis in Arabidopsis Is Unaffected by the Function of the Vacuolar K + Channel TPK3. Plant Physiol 2019; 180:1322-1335. [PMID: 31053658 PMCID: PMC6752931 DOI: 10.1104/pp.19.00255] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 04/25/2019] [Indexed: 05/21/2023]
Abstract
Photosynthesis is limited by the slow relaxation of nonphotochemical quenching, which primarily dissipates excess absorbed light energy as heat. Because the heat dissipation process is proportional to light-driven thylakoid lumen acidification, manipulating thylakoid ion and proton flux via transport proteins could improve photosynthesis. However, an important aspect of the current understanding of the thylakoid ion transportome is inaccurate. Using fluorescent protein fusions, we show that the Arabidopsis (Arabidopsis thaliana) two-pore K+ channel TPK3, which had been reported to mediate thylakoid K+ flux, localizes to the tonoplast, not the thylakoid. The localization of TPK3 outside of the thylakoids is further supported by the absence of TPK3 in isolated thylakoids as well as the inability of isolated chloroplasts to import TPK3 protein. In line with the subcellular localization of TPK3 in the vacuole, we observed that photosynthesis in the Arabidopsis null mutant tpk3-1, which carries a transfer DNA insertion in the first exon, remains unaffected. To gain a comprehensive understanding of how thylakoid ion flux impacts photosynthetic efficiency under dynamic growth light regimes, we performed long-term photosynthesis imaging of established and newly isolated transthylakoid K+- and Cl--flux mutants. Our results underpin the importance of the thylakoid ion transport proteins potassium cation efflux antiporter KEA3 and voltage-dependent chloride channel VCCN1 and suggest that the activity of yet unknown K+ channel(s), but not TPK3, is critical for optimal photosynthesis in dynamic light environments.
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Affiliation(s)
- Ricarda Höhner
- Plant Physiology, School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236
| | - Viviana Correa Galvis
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476 Potsdam, Germany
| | - Deserah D Strand
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476 Potsdam, Germany
| | - Carsten Völkner
- Plant Physiology, School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236
| | - Moritz Krämer
- Plant Physiology, School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236
| | - Michaela Messer
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476 Potsdam, Germany
| | - Firdevs Dinc
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476 Potsdam, Germany
| | - Inga Sjuts
- Ludwig Maximilian University Munich, Department I, Plant Biochemistry, 82152 Planegg-Martinsried, Germany
| | - Bettina Bölter
- Ludwig Maximilian University Munich, Department I, Plant Biochemistry, 82152 Planegg-Martinsried, Germany
| | - David M Kramer
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476 Potsdam, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236
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29
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Li J, Weraduwage SM, Preiser AL, Tietz S, Weise SE, Strand DD, Froehlich JE, Kramer DM, Hu J, Sharkey TD. A Cytosolic Bypass and G6P Shunt in Plants Lacking Peroxisomal Hydroxypyruvate Reductase. Plant Physiol 2019; 180:783-792. [PMID: 30886114 PMCID: PMC6548278 DOI: 10.1104/pp.19.00256] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 03/11/2019] [Indexed: 05/18/2023]
Abstract
The oxygenation of ribulose 1,5-bisphosphate by Rubisco is the first step in photorespiration and reduces the efficiency of photosynthesis in C3 plants. Our recent data indicate that mutants in photorespiration have increased rates of photosynthetic cyclic electron flow around photosystem I. We investigated mutant lines lacking peroxisomal hydroxypyruvate reductase to determine if there are connections between 2-phosphoglycolate accumulation and cyclic electron flow in Arabidopsis (Arabidopsis thaliana). We found that 2-phosphoglycolate is a competitive inhibitor of triose phosphate isomerase, an enzyme in the Calvin-Benson cycle that converts glyceraldehyde 3-phosphate to dihydroxyacetone phosphate. This block in metabolism could be overcome if glyceraldehyde 3-phosphate is exported to the cytosol, where cytosolic triose phosphate isomerase could convert it to dihydroxyacetone phosphate. We found evidence that carbon is reimported as glucose-6-phosphate, forming a cytosolic bypass around the block of stromal triose phosphate isomerase. However, this also stimulates a glucose-6-phosphate shunt, which consumes ATP, which can be compensated by higher rates of cyclic electron flow.
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Affiliation(s)
- Jiying Li
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Sarathi M Weraduwage
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Alyssa L Preiser
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Stefanie Tietz
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Sean E Weise
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Deserah D Strand
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - John E Froehlich
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - David M Kramer
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Jianping Hu
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Thomas D Sharkey
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824
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30
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Li J, Tietz S, Cruz JA, Strand DD, Xu Y, Chen J, Kramer DM, Hu J. Photometric screens identified Arabidopsis peroxisome proteins that impact photosynthesis under dynamic light conditions. Plant J 2019; 97:460-474. [PMID: 30350901 DOI: 10.1111/tpj.14134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/14/2018] [Accepted: 10/17/2018] [Indexed: 05/02/2023]
Abstract
Plant peroxisomes function collaboratively with other subcellular organelles, such as chloroplasts and mitochondria, in several metabolic processes. To comprehensively investigate the impact of peroxisomal function on photosynthesis, especially under conditions that are more relevant to natural environments, a systematic screen of over 150 Arabidopsis mutants of genes encoding peroxisomal proteins was conducted using the automated Dynamic Environment Photosynthesis Imager (DEPI). Dynamic and high-light (HL) conditions triggered significant photosynthetic defects in a subset of the mutants, including those of photorespiration (PR) and other peroxisomal processes, some of which may also be related to PR. Further analysis of the PR mutants revealed activation of cyclic electron flow (CEF) around photosystem I and higher accumulation of hydrogen peroxide (H2 O2 ) under HL conditions. We hypothesize that impaired PR disturbs the balance of ATP and NADPH, leading to the accumulation of H2 O2 that activates CEF to produce ATP to compensate for the imbalance of reducing equivalents. The identification of peroxisomal mutants involved in PR and other peroxisomal functions in the photometric screen will enable further investigation of regulatory links between photosynthesis and PR and interorganellar interaction at the mechanistic level.
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Affiliation(s)
- Jiying Li
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Jeffrey A Cruz
- Department of Energy 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
| | - Deserah D Strand
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Ye Xu
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Jin Chen
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Computer Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - David M Kramer
- Department of Energy 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
| | - Jianping Hu
- 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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Davis GA, Kramer DM. Optimization of ATP Synthase c-Rings for Oxygenic Photosynthesis. Front Plant Sci 2019; 10:1778. [PMID: 32082344 PMCID: PMC7003800 DOI: 10.3389/fpls.2019.01778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/20/2019] [Indexed: 05/10/2023]
Abstract
The conversion of sunlight into useable cellular energy occurs via the proton-coupled electron transfer reactions of photosynthesis. Light is absorbed by photosynthetic pigments and transferred to photochemical reaction centers to initiate electron and proton transfer reactions to store energy in a redox gradient and an electrochemical proton gradient (proton motive force, pmf), composed of a concentration gradient (ΔpH) and an electric field (Δψ), which drives the synthesis of ATP through the thylakoid FoF1-ATP synthase. Although ATP synthase structure and function are conserved across biological kingdoms, the number of membrane-embedded ion-binding c subunits varies between organisms, ranging from 8 to 17, theoretically altering the H+/ATP ratio for different ATP synthase complexes, with profound implications for the bioenergetic processes of cellular metabolism. Of the known c-ring stoichiometries, photosynthetic c-rings are among the largest identified stoichiometries, and it has been proposed that decreasing the c-stoichiometry could increase the energy conversion efficiency of photosynthesis. Indeed, there is strong evidence that the high H+/ATP of the chloroplast ATP synthase results in a low ATP/nicotinamide adenine dinucleotide phosphate (NADPH) ratio produced by photosynthetic linear electron flow, requiring secondary processes such as cyclic electron flow to support downstream metabolism. We hypothesize that the larger c subunit stoichiometry observed in photosynthetic ATP synthases was selected for because it allows the thylakoid to maintain pmf in a range where ATP synthesis is supported, but avoids excess Δψ and ΔpH, both of which can lead to production of reactive oxygen species and subsequent photodamage. Numerical kinetic simulations of the energetics of chloroplast photosynthetic reactions with altered c-ring size predicts the energy storage of pmf and its effects on the photochemical reaction centers strongly support this hypothesis, suggesting that, despite the low efficiency and suboptimal ATP/NADPH ratio, a high H+/ATP is favored to avoid photodamage. This has important implications for the evolution and regulation of photosynthesis as well as for synthetic biology efforts to alter photosynthetic efficiency by engineering the ATP synthase.
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Affiliation(s)
- Geoffry A. Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - David M. Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
- *Correspondence: David M. Kramer,
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Cruz JA, Savage LJ, Zegarac R, Hall CC, Satoh-Cruz M, Davis GA, Kovac WK, Chen J, Kramer DM. Dynamic Environmental Photosynthetic Imaging Reveals Emergent Phenotypes. Cell Syst 2018; 2:365-77. [PMID: 27336966 DOI: 10.1016/j.cels.2016.06.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/29/2016] [Accepted: 06/01/2016] [Indexed: 10/21/2022]
Abstract
Understanding and improving the productivity and robustness of plant photosynthesis requires high-throughput phenotyping under environmental conditions that are relevant to the field. Here we demonstrate the dynamic environmental photosynthesis imager (DEPI), an experimental platform for integrated, continuous, and high-throughput measurements of photosynthetic parameters during plant growth under reproducible yet dynamic environmental conditions. Using parallel imagers obviates the need to move plants or sensors, reducing artifacts and allowing simultaneous measurement on large numbers of plants. As a result, DEPI can reveal phenotypes that are not evident under standard laboratory conditions but emerge under progressively more dynamic illumination. We show examples in mutants of Arabidopsis of such "emergent phenotypes" that are highly transient and heterogeneous, appearing in different leaves under different conditions and depending in complex ways on both environmental conditions and plant developmental age. These emergent phenotypes appear to be caused by a range of phenomena, suggesting that such previously unseen processes are critical for plant responses to dynamic environments.
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Affiliation(s)
- Jeffrey A Cruz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Linda J Savage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Robert Zegarac
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Christopher C Hall
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Mio Satoh-Cruz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Geoffry A Davis
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Cell and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - William Kent Kovac
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Jin Chen
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Computer Science and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
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Yin X, Liu X, Chen J, Kramer DM. Joint Multi-Leaf Segmentation, Alignment, and Tracking for Fluorescence Plant Videos. IEEE Trans Pattern Anal Mach Intell 2018; 40:1411-1423. [PMID: 28715326 DOI: 10.1109/tpami.2017.2728065] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This paper proposes a novel framework for fluorescence plant video processing. The plant research community is interested in the leaf-level photosynthetic analysis within a plant. A prerequisite for such analysis is to segment all leaves, estimate their structures, and track them over time. We identify this as a joint multi-leaf segmentation, alignment, and tracking problem. First, leaf segmentation and alignment are applied on the last frame of a plant video to find a number of well-aligned leaf candidates. Second, leaf tracking is applied on the remaining frames with leaf candidate transformation from the previous frame. We form two optimization problems with shared terms in their objective functions for leaf alignment and tracking respectively. A quantitative evaluation framework is formulated to evaluate the performance of our algorithm with four metrics. Two models are learned to predict the alignment accuracy and detect tracking failure respectively in order to provide guidance for subsequent plant biology analysis. The limitation of our algorithm is also studied. Experimental results show the effectiveness, efficiency, and robustness of the proposed method.
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Davis GA, Rutherford AW, Kramer DM. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δ ψ and ΔpH. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0381. [PMID: 28808100 DOI: 10.1098/rstb.2016.0381] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching (qE), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δψ) induce photosystem II recombination reactions that produce damaging singlet oxygen (1O2). Both qE and FRIP are directly linked to the thylakoid proton motive force (pmf), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δψ and formation of ΔpH. This would result in increased rates for the formation and decay of qE while resulting in a more rapid decline in the amplitudes of Δψ-spikes and decreasing 1O2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo, while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis researchers to further explore and test specific hypotheses.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | | | - David M Kramer
- Department of Energy 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
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Fristedt R, Hu C, Wheatley N, Roy LM, Wachter RM, Savage L, Harbinson J, Kramer DM, Merchant SS, Yeates T, Croce R. RAF2 is a RuBisCO assembly factor in Arabidopsis thaliana. Plant J 2018; 94:146-156. [PMID: 29396988 DOI: 10.1111/tpj.13849] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/22/2017] [Accepted: 01/08/2018] [Indexed: 06/07/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) catalyzes the reaction between gaseous carbon dioxide (CO2 ) and ribulose-1,5-bisphosphate. Although it is one of the most studied enzymes, the assembly mechanisms of the large hexadecameric RuBisCO is still emerging. In bacteria and in the C4 plant Zea mays, a protein with distant homology to pterin-4α-carbinolamine dehydratase (PCD) has recently been shown to be involved in RuBisCO assembly. However, studies of the homologous PCD-like protein (RAF2, RuBisCO assembly factor 2) in the C3 plant Arabidopsis thaliana (A. thaliana) have so far focused on its role in hormone and stress signaling. We investigated whether A. thalianaRAF2 is also involved in RuBisCO assembly. We localized RAF2 to the soluble chloroplast stroma and demonstrated that raf2 A. thaliana mutant plants display a severe pale green phenotype with reduced levels of stromal RuBisCO. We concluded that the RAF2 protein is probably involved in RuBisCO assembly in the C3 plant A. thaliana.
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Affiliation(s)
- Rikard Fristedt
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Chen Hu
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
| | - Nicole Wheatley
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Laura M Roy
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
| | - Rebekka M Wachter
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, AZ, USA
| | - Linda Savage
- Department of Energy Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Jeremy Harbinson
- Horticulture and Product Physiology Group, Wageningen University, Wageningen, The Netherlands
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Todd Yeates
- Department of Chemistry and Biochemistry and Institute for Genomics and Proteomics, UCLA, Los Angeles, CA, USA
| | - Roberta Croce
- Biophysics of Photosynthesis, VU University Amsterdam, Amsterdam, The Netherlands
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Du ZY, Lucker BF, Zienkiewicz K, Miller TE, Zienkiewicz A, Sears BB, Kramer DM, Benning C. Galactoglycerolipid Lipase PGD1 Is Involved in Thylakoid Membrane Remodeling in Response to Adverse Environmental Conditions in Chlamydomonas. Plant Cell 2018; 30:447-465. [PMID: 29437989 PMCID: PMC5868692 DOI: 10.1105/tpc.17.00446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 05/20/2023]
Abstract
Photosynthesis occurs in the thylakoid membrane, where the predominant lipid is monogalactosyldiacylglycerol (MGDG). As environmental conditions change, photosynthetic membranes have to adjust. In this study, we used a loss-of-function Chlamydomonas reinhardtii mutant deficient in the MGDG-specific lipase PGD1 (PLASTID GALACTOGLYCEROLIPID DEGRADATION1) to investigate the link between MGDG turnover, chloroplast ultrastructure, and the production of reactive oxygen species (ROS) in response to different adverse environmental conditions. The pgd1 mutant showed altered MGDG abundance and acyl composition and altered abundance of photosynthesis complexes, with an increased PSII/PSI ratio. Transmission electron microscopy showed hyperstacking of the thylakoid grana in the pgd1 mutant. The mutant also exhibited increased ROS production during N deprivation and high light exposure. Supplementation with bicarbonate or treatment with the photosynthetic electron transport blocker DCMU protected the cells against oxidative stress in the light and reverted chlorosis of pgd1 cells during N deprivation. Furthermore, exposure to stress conditions such as cold and high osmolarity induced the expression of PGD1, and loss of PGD1 in the mutant led to increased ROS production and inhibited cell growth. These findings suggest that PGD1 plays essential roles in maintaining appropriate thylakoid membrane composition and structure, thereby affecting growth and stress tolerance when cells are challenged under adverse conditions.
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Affiliation(s)
- Zhi-Yan Du
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Ben F Lucker
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Krzysztof Zienkiewicz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
| | - Tarryn E Miller
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Agnieszka Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
| | - Barbara B Sears
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - David M Kramer
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
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Morales A, Yin X, Harbinson J, Driever SM, Molenaar J, Kramer DM, Struik PC. In Silico Analysis of the Regulation of the Photosynthetic Electron Transport Chain in C3 Plants. Plant Physiol 2018; 176:1247-1261. [PMID: 28924017 PMCID: PMC5813522 DOI: 10.1104/pp.17.00779] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/13/2017] [Indexed: 05/18/2023]
Abstract
We present a new simulation model of the reactions in the photosynthetic electron transport chain of C3 species. We show that including recent insights about the regulation of the thylakoid proton motive force, ATP/NADPH balancing mechanisms (cyclic and noncyclic alternative electron transport), and regulation of Rubisco activity leads to emergent behaviors that may affect the operation and regulation of photosynthesis under different dynamic environmental conditions. The model was parameterized with experimental results in the literature, with a focus on Arabidopsis (Arabidopsis thaliana). A dataset was constructed from multiple sources, including measurements of steady-state and dynamic gas exchange, chlorophyll fluorescence, and absorbance spectroscopy under different light intensities and CO2, to test predictions of the model under different experimental conditions. Simulations suggested that there are strong interactions between cyclic and noncyclic alternative electron transport and that an excess capacity for alternative electron transport is required to ensure adequate redox state and lumen pH. Furthermore, the model predicted that, under specific conditions, reduction of ferredoxin by plastoquinol is possible after a rapid increase in light intensity. Further analysis also revealed that the relationship between ATP synthesis and proton motive force was highly regulated by the concentrations of ATP, ADP, and inorganic phosphate, and this facilitated an increase in nonphotochemical quenching and proton motive force under conditions where metabolism was limiting, such as low CO2, high light intensity, or combined high CO2 and high light intensity. The model may be used as an in silico platform for future research on the regulation of photosynthetic electron transport.
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Affiliation(s)
- Alejandro Morales
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK, Wageningen, The Netherlands
| | - Xinyou Yin
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK, Wageningen, The Netherlands
| | - Jeremy Harbinson
- Horticulture and Product Physiology, Wageningen University, 6700 AA, Wageningen, The Netherlands
| | - Steven M Driever
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK, Wageningen, The Netherlands
| | - Jaap Molenaar
- Biometris, Mathematical and Statistical Methods Group, Wageningen University, 6700 AA, Wageningen, The Netherlands
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823
| | - Paul C Struik
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK, Wageningen, The Netherlands
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Oh S, Strand DD, Kramer DM, Chen J, Montgomery BL. Transcriptome and phenotyping analyses support a role for chloroplast sigma factor 2 in red-light-dependent regulation of growth, stress, and photosynthesis. Plant Direct 2018; 2:e00043. [PMID: 31245709 PMCID: PMC6508532 DOI: 10.1002/pld3.43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 05/04/2023]
Abstract
Sigma factor (SIG) proteins contribute to promoter specificity of the plastid-encoded RNA polymerase during chloroplast genome transcription. All six members of the SIG family, that is, SIG1-SIG6, are nuclear-encoded proteins targeted to chloroplasts. Sigma factor 2 (SIG2) is a phytochrome-regulated protein important for stoichiometric control of the expression of plastid- and nuclear-encoded genes that impact plastid development and plant growth and development. Among SIG factors, SIG2 is required not only for transcription of chloroplast genes (i.e., anterograde signaling), but also impacts nuclear-encoded, photosynthesis-related, and light signaling-related genes (i.e., retrograde signaling) in response to plastid functional status. Although SIG2 is involved in photomorphogenesis in Arabidopsis, the molecular bases for its role in light signaling that impacts photomorphogenesis and aspects of photosynthesis have only recently begun to be investigated. Previously, we reported that SIG2 is necessary for phytochrome-mediated photomorphogenesis specifically under red (R) and far-red light, thereby suggesting a link between phytochromes and nuclear-encoded SIG2 in light signaling. To explore transcriptional roles of SIG2 in R-dependent growth and development, we performed RNA sequencing analysis to compare gene expression in sig2-2 mutant and Col-0 wild-type seedlings at two developmental stages (1- and 7-day). We identified a subset of misregulated genes involved in growth, hormonal cross talk, stress responses, and photosynthesis. To investigate the functional relevance of these gene expression analyses, we performed several comparative phenotyping tests. In these analyses, strong sig2 mutants showed insensitivity to bioactive GA 3, high intracellular levels of hydrogen peroxide (H2O2) indicative of a stress response, and specific defects in photosynthesis, including elevated levels of cyclic electron flow (CEF) and nonphotochemical quenching (NPQ). We demonstrated that SIG2 regulates a broader range of physiological responses at the molecular level than previously reported, with specific roles in red-light-mediated photomorphogenesis.
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Affiliation(s)
- Sookyung Oh
- Department of Energy – Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
| | - Deserah D. Strand
- Department of Energy – Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
- Present address:
Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdam‐GolmGermany
| | - David M. Kramer
- Department of Energy – Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMIUSA
| | - Jin Chen
- UK Medical Center MN 150University of Kentucky College of MedicineLexingtonKYUSA
| | - Beronda L. Montgomery
- Department of Energy – Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMIUSA
- Department of Microbiology & Molecular GeneticsMichigan State UniversityEast LansingMIUSA
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Oakley CG, Savage L, Lotz S, Larson GR, Thomashow MF, Kramer DM, Schemske DW. Genetic basis of photosynthetic responses to cold in two locally adapted populations of Arabidopsis thaliana. J Exp Bot 2018; 69:699-709. [PMID: 29300935 PMCID: PMC5853396 DOI: 10.1093/jxb/erx437] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 11/17/2017] [Indexed: 05/18/2023]
Abstract
Local adaptation is common, but the traits and genes involved are often unknown. Physiological responses to cold probably contribute to local adaptation in wide-ranging species, but the genetic basis underlying natural variation in these traits has rarely been studied. Using a recombinant inbred (495 lines) mapping population from locally adapted populations of Arabidopsis thaliana from Sweden and Italy, we grew plants at low temperature and mapped quantitative trait loci (QTLs) for traits related to photosynthesis: maximal quantum efficiency (Fv/Fm), rapidly reversible photoprotection (NPQfast), and photoinhibition of PSII (NPQslow) using high-throughput, whole-plant measures of chlorophyll fluorescence. In response to cold, the Swedish line had greater values for all traits, and for every trait, large effect QTLs contributed to parental differences. We found one major QTL affecting all traits, as well as unique major QTLs for each trait. Six trait QTLs overlapped with previously published locally adaptive QTLs based on fitness measured in the native environments over 3 years. Our results demonstrate that photosynthetic responses to cold can vary dramatically within a species, and may predominantly be caused by a few QTLs of large effect. Some photosynthesis traits and QTLs probably contribute to local adaptation in this system.
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Affiliation(s)
- Christopher G Oakley
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- Correspondence:
| | - Linda Savage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Samuel Lotz
- 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
| | - G Rudd Larson
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Genetics Graduate Program, Michigan State University, East Lansing, MI, USA
| | - Michael F Thomashow
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, USA
| | - David M Kramer
- Department of Plant Biology, 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
| | - Douglas W Schemske
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- W.K. Kellogg Biological Station, Michigan State University, East Lansing, MI, USA
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40
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Lucker B, Schwarz E, Kuhlgert S, Ostendorf E, Kramer DM. Spectroanalysis in native gels (SING): rapid spectral analysis of pigmented thylakoid membrane complexes separated by CN-PAGE. Plant J 2017; 92:744-756. [PMID: 28865165 DOI: 10.1111/tpj.13703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/22/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Photosynthetic organisms rapidly adjust the capture, transfer and utilization of light energy to optimize the efficiency of photosynthesis and avoid photodamage. These adjustments involve fine-tuning of expression levels and mutual interactions among electron/proton transfer components and their associated light-harvesting antenna. Detailed studies of these interactions and their dynamics have been hindered by the low throughput and resolution of currently available research tools, which involve laborious isolation, separation and characterization steps. To address these issues, we developed an approach that measured multiple spectroscopic properties of thylakoid preparations directly in native polyacrylamide gel electrophoresis gels, enabling unprecedented resolution of photosynthetic complexes, both in terms of the spectroscopic and functional details, as well as the ability to distinguish separate complexes and thus test their functional connections. As a demonstration, we explore the thylakoid membrane components of Chlamydomonas reinhardtii acclimated to high and low light, using a combination of room temperature absorption and 77K fluorescence emission to generate a multi-dimensional molecular and spectroscopic map of the photosynthetic apparatus. We show that low-light-acclimated cells accumulate a photosystem I-containing megacomplex that is absent in high-light-acclimated cells and contains distinct LhcII proteins that can be distinguished based on their spectral signatures.
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Affiliation(s)
- Ben Lucker
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Eliezer Schwarz
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Sebastian Kuhlgert
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Elisabeth Ostendorf
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - David M Kramer
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
- DOE-Plant Research Laboratory, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
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41
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Tietz S, Hall CC, Cruz JA, Kramer DM. NPQ (T) : a chlorophyll fluorescence parameter for rapid estimation and imaging of non-photochemical quenching of excitons in photosystem-II-associated antenna complexes. Plant Cell Environ 2017; 40:1243-1255. [PMID: 28699261 DOI: 10.1111/pce.12924] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 05/05/2023]
Abstract
In photosynthesis, light energy is absorbed by light-harvesting complexes and used to drive photochemistry. However, a fraction of absorbed light is lost to non-photochemical quenching (NPQ) that reflects several important photosynthetic processes to dissipate excess energy. Currently, estimates of NPQ and its individual components (qE , qI , qZ and qT ) are measured from pulse-amplitude-modulation (PAM) measurements of chlorophyll fluorescence yield and require measurements of the maximal yield of fluorescence in fully dark-adapted material (Fm ), when NPQ is assumed to be negligible. Unfortunately, this approach requires extensive dark acclimation, often precluding widespread or high-throughput use, particularly under field conditions or in imaging applications, while introducing artefacts when Fm is measured in the presence of residual photodamaged centres. To address these limitations, we derived and characterized a new set of parameters, NPQ(T) , and its components that can be (1) measured in a few seconds, allowing for high-throughput and field applications; (2) does not require full relaxation of quenching processes and thus can be applied to photoinhibited materials; (3) can distinguish between NPQ and chloroplast movements; and (4) can be used to image NPQ in plants with large leaf movements. We discuss the applications benefits and caveats of both approaches.
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Affiliation(s)
- Stefanie Tietz
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Christopher C Hall
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, 48824-1312, USA
- Plant Biology, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Jeffrey A Cruz
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, 48824-1312, USA
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - David M Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, 48824-1312, USA
- Plant Biology, Michigan State University, East Lansing, MI, 48824-1312, USA
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824-1312, USA
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42
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Dutta S, Cruz JA, Imran SM, Chen J, Kramer DM, Osteryoung KW. Variations in chloroplast movement and chlorophyll fluorescence among chloroplast division mutants under light stress. J Exp Bot 2017; 68:3541-3555. [PMID: 28645163 PMCID: PMC5853797 DOI: 10.1093/jxb/erx203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/25/2017] [Indexed: 05/18/2023]
Abstract
Chloroplasts divide to maintain consistent size, shape, and number in leaf mesophyll cells. Altered expression of chloroplast division proteins in Arabidopsis results in abnormal chloroplast morphology. To better understand the influence of chloroplast morphology on chloroplast movement and photosynthesis, we compared the chloroplast photorelocation and photosynthetic responses of a series of Arabidopsis chloroplast division mutants with a wide variety of chloroplast phenotypes. Chloroplast movement was monitored by red light reflectance imaging of whole plants under increasing intensities of white light. The accumulation and avoidance responses were differentially affected in different mutants and depended on both chloroplast number and morphological heterogeneity. Chlorophyll fluorescence measurements during 5 d light experiments demonstrated that mutants with large-chloroplast phenotypes generally exhibited greater PSII photodamage than those with intermediate phenotypes. No abnormalities in photorelocation efficiency or photosynthetic capacity were observed in plants with small-chloroplast phenotypes. Simultaneous measurement of chloroplast movement and chlorophyll fluorescence indicated that the energy-dependent (qE) and long-lived components of non-photochemical quenching that reflect photoinhibition are affected differentially in different division mutants exposed to high or fluctuating light intensities. We conclude that chloroplast division mutants with abnormal chloroplast morphologies differ markedly from the wild type in their light adaptation capabilities, which may decrease their relative fitness in nature.
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Affiliation(s)
- Siddhartha Dutta
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Jeffrey A Cruz
- 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
| | - Saif M Imran
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
| | - Jin Chen
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Computer Sciences and Engineering, Michigan State University, East Lansing, MI, USA
| | - David M Kramer
- 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
- Correspondence: or
| | - Katherine W Osteryoung
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- Correspondence: or
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43
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Strand DD, Fisher N, Kramer DM. The higher plant plastid NAD(P)H dehydrogenase-like complex (NDH) is a high efficiency proton pump that increases ATP production by cyclic electron flow. J Biol Chem 2017; 292:11850-11860. [PMID: 28559282 DOI: 10.1074/jbc.m116.770792] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/26/2017] [Indexed: 12/31/2022] Open
Abstract
Cyclic electron flow around photosystem I (CEF) is critical for balancing the photosynthetic energy budget of the chloroplast by generating ATP without net production of NADPH. We demonstrate that the chloroplast NADPH dehydrogenase complex, a homolog to respiratory Complex I, pumps approximately two protons from the chloroplast stroma to the lumen per electron transferred from ferredoxin to plastoquinone, effectively increasing the efficiency of ATP production via CEF by 2-fold compared with CEF pathways involving non-proton-pumping plastoquinone reductases. By virtue of this proton-pumping stoichiometry, we hypothesize that NADPH dehydrogenase not only efficiently contributes to ATP production but operates near thermodynamic reversibility, with potentially important consequences for remediating mismatches in the thylakoid energy budget.
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Affiliation(s)
- Deserah D Strand
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823
| | - Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48823.
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44
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Yang Y, Xu L, Feng Z, Cruz JA, Savage LJ, Kramer DM, Chen J. PhenoCurve: capturing dynamic phenotype-environment relationships using phenomics data. Bioinformatics 2017; 33:1370-1378. [PMID: 28453685 DOI: 10.1093/bioinformatics/btw673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 10/27/2016] [Indexed: 11/14/2022] Open
Abstract
Motivation Phenomics is essential for understanding the mechanisms that regulate or influence growth, fitness, and development. Techniques have been developed to conduct high-throughput large-scale phenotyping on animals, plants and humans, aiming to bridge the gap between genomics, gene functions and traits. Although new developments in phenotyping techniques are exciting, we are limited by the tools to analyze fully the massive phenotype data, especially the dynamic relationships between phenotypes and environments. Results We present a new algorithm called PhenoCurve, a knowledge-based curve fitting algorithm, aiming to identify the complex relationships between phenotypes and environments, thus studying both values and trends of phenomics data. The results on both real and simulated data showed that PhenoCurve has the best performance among all the six tested methods. Its application to photosynthesis hysteresis pattern identification reveals new functions of core genes that control photosynthetic efficiency in response to varying environmental conditions, which are critical for understanding plant energy storage and improving crop productivity. Availability and Implementation Software is available at phenomics.uky.edu/PhenoCurve. Contact chen.jin@uky.edu or kramerd8@cns.msu.edu. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Yifan Yang
- Department of Epidemiology and Biostatistics
| | - Lei Xu
- Department of Computer Science and Engineering.,Department of Energy Plant Research Laboratory
| | - Zheyun Feng
- Department of Computer Science and Engineering
| | | | | | - David M Kramer
- Department of Energy Plant Research Laboratory.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Jin Chen
- Institute of Biomedical Informatics, University of Kentucky, Lexington, KY 40536, USA
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45
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Kanazawa A, Ostendorf E, Kohzuma K, Hoh D, Strand DD, Sato-Cruz M, Savage L, Cruz JA, Fisher N, Froehlich JE, Kramer DM. Chloroplast ATP Synthase Modulation of the Thylakoid Proton Motive Force: Implications for Photosystem I and Photosystem II Photoprotection. Front Plant Sci 2017; 8:719. [PMID: 28515738 PMCID: PMC5413553 DOI: 10.3389/fpls.2017.00719] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 04/19/2017] [Indexed: 05/18/2023]
Abstract
In wild type plants, decreasing CO2 lowers the activity of the chloroplast ATP synthase, slowing proton efflux from the thylakoid lumen resulting in buildup of thylakoid proton motive force (pmf). The resulting acidification of the lumen regulates both light harvesting, via the qE mechanism, and photosynthetic electron transfer through the cytochrome b6f complex. Here, we show that the cfq mutant of Arabidopsis, harboring single point mutation in its γ-subunit of the chloroplast ATP synthase, increases the specific activity of the ATP synthase and disables its down-regulation under low CO2. The increased thylakoid proton conductivity (gH+) in cfq results in decreased pmf and lumen acidification, preventing full activation of qE and more rapid electron transfer through the b6f complex, particularly under low CO2 and fluctuating light. These conditions favor the accumulation of electrons on the acceptor side of PSI, and result in severe loss of PSI activity. Comparing the current results with previous work on the pgr5 mutant suggests a general mechanism where increased PSI photodamage in both mutants is caused by loss of pmf, rather than inhibition of CEF per se. Overall, our results support a critical role for ATP synthase regulation in maintaining photosynthetic control of electron transfer to prevent photodamage.
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Affiliation(s)
- Atsuko Kanazawa
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
- Chemistry, Michigan State University, East LansingMI, USA
| | | | - Kaori Kohzuma
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
| | - Donghee Hoh
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
- Cell and Molecular Biology, Michigan State University, East LansingMI, USA
| | - Deserah D. Strand
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
| | - Mio Sato-Cruz
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
| | - Linda Savage
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
| | - Jeffrey A. Cruz
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
- Biochemistry and Molecular Biology, Michigan State University, East LansingMI, USA
| | - Nicholas Fisher
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
| | - John E. Froehlich
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
- Biochemistry and Molecular Biology, Michigan State University, East LansingMI, USA
| | - David M. Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East LansingMI, USA
- Biochemistry and Molecular Biology, Michigan State University, East LansingMI, USA
- *Correspondence: David M. Kramer,
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46
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Kohzuma K, Froehlich JE, Davis GA, Temple JA, Minhas D, Dhingra A, Cruz JA, Kramer DM. The Role of Light-Dark Regulation of the Chloroplast ATP Synthase. Front Plant Sci 2017; 8:1248. [PMID: 28791032 PMCID: PMC5522872 DOI: 10.3389/fpls.2017.01248] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/03/2017] [Indexed: 05/18/2023]
Abstract
The chloroplast ATP synthase catalyzes the light-driven synthesis of ATP and is activated in the light and inactivated in the dark by redox-modulation through the thioredoxin system. It has been proposed that this down-regulation is important for preventing wasteful hydrolysis of ATP in the dark. To test this proposal, we compared the effects of extended dark exposure in Arabidopsis lines expressing the wild-type and mutant forms of ATP synthase that are redox regulated or constitutively active. In contrast to the predictions of the model, we observed that plants with wild-type redox regulation lost photosynthetic capacity rapidly in darkness, whereas those expressing redox-insensitive form were far more stable. To explain these results, we propose that in wild-type plants, down-regulation of ATP synthase inhibits ATP hydrolysis, leading to dissipation of thylakoid proton motive force (pmf) and subsequent inhibition of protein transport across the thylakoid through the twin arginine transporter (Tat)-dependent and Sec-dependent import pathways, resulting in the selective loss of specific protein complexes. By contrast, in mutants with a redox-insensitive ATP synthase, pmf is maintained by ATP hydrolysis, thus allowing protein transport to maintain photosynthetic activities for extended periods in the dark. Hence, a basal level of Tat-dependent, as well as, Sec-dependent import activity, in the dark helps replenishes certain components of the photosynthetic complexes and thereby aids in maintaining overall complex activity. However, the influence of a dark pmf on thylakoid protein import, by itself, could not explain all the effects we observed in this study. For example, we also observed in wild type plants a large transient buildup of thylakoid pmf and nonphotochemical exciton quenching upon sudden illumination of dark adapted plants. Therefore, we conclude that down-regulation of the ATP synthase is probably not related to preventing loss of ATP per se. Instead, ATP synthase redox regulation may be impacting a number of cellular processes such as (1) the accumulation of chloroplast proteins and/or ions or (2) the responses of photosynthesis to rapid changes in light intensity. A model highlighting the complex interplay between ATP synthase regulation and pmf in maintaining various chloroplast functions in the dark is presented. Significance Statement: We uncover an unexpected role for thioredoxin modulation of the chloroplast ATP synthase in regulating the dark-stability of the photosynthetic apparatus, most likely by controlling thylakoid membrane transport of proteins and ions.
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Affiliation(s)
- Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
| | - John E. Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East LansingMI, United States
- *Correspondence: John E. Froehlich,
| | - Geoffry A. Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
- Department of Cell and Molecular Biology, Michigan State University, East LansingMI, United States
| | - Joshua A. Temple
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
| | - Deepika Minhas
- Department of Horticulture and Landscape Architecture, Washington State University, WashingtonDC, United States
| | - Amit Dhingra
- Department of Horticulture and Landscape Architecture, Washington State University, WashingtonDC, United States
| | - Jeffrey A. Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East LansingMI, United States
| | - David M. Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East LansingMI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East LansingMI, United States
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47
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Abramson BW, Kachel B, Kramer DM, Ducat DC. Increased Photochemical Efficiency in Cyanobacteria via an Engineered Sucrose Sink. Plant Cell Physiol 2016; 57:2451-2460. [PMID: 27742883 DOI: 10.1093/pcp/pcw169] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
In plants, a limited capacity to utilize or export the end-products of the Calvin-Benson cycle (CB) from photosynthetically active source cells to non-photosynthetic sink cells can result in reduced carbon capture and photosynthetic electron transport (PET), and lowered photochemical efficiency. The down-regulation of photosynthesis caused by reduced capacity to utilize photosynthate has been termed 'sink limitation'. Recently, several cyanobacterial and algal strains engineered to overproduce target metabolites have exhibited increased photochemistry, suggesting that possible source-sink regulatory mechanisms may be involved. We directly examined photochemical properties following induction of a heterologous sucrose 'sink' in the unicellular cyanobacterium Synechococcus elongatus PCC 7942. We show that total photochemistry increases proportionally to the experimentally controlled rate of sucrose export. Importantly, the quantum yield of PSII (ΦII) increases in response to sucrose export while the PET chain becomes more oxidized from less PSI acceptor-side limitation, suggesting increased CB activity and a decrease in sink limitation. Enhanced photosynthetic activity and linear electron flow are detectable within hours of induction of the heterologous sink and are independent of pigmentation alterations or the ionic/osmotic effects of the induction system. These observations provide direct evidence that secretion of heterologous carbon bioproducts can be used as an alternative approach to improve photosynthetic efficiency, presumably by by-passing sink limitation. Our results also suggest that engineered microalgal production strains are valuable alternative models for examining photosynthetic sink limitation because they enable greater control and monitoring of metabolite fluxes relative to plants.
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Affiliation(s)
- Bradley W Abramson
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Cell and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Benjamin Kachel
- Department of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - David M Kramer
- 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
| | - Daniel C Ducat
- 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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48
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016. [PMID: 27697149 DOI: 10.7554/elife.16921.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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49
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016; 5. [PMID: 27697149 PMCID: PMC5050024 DOI: 10.7554/elife.16921] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/08/2016] [Indexed: 12/20/2022] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field. DOI:http://dx.doi.org/10.7554/eLife.16921.001
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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50
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Kuhlgert S, Austic G, Zegarac R, Osei-Bonsu I, Hoh D, Chilvers MI, Roth MG, Bi K, TerAvest D, Weebadde P, Kramer DM. MultispeQ Beta: a tool for large-scale plant phenotyping connected to the open PhotosynQ network. R Soc Open Sci 2016; 3:160592. [PMID: 27853580 PMCID: PMC5099005 DOI: 10.1098/rsos.160592] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 09/26/2016] [Indexed: 05/08/2023]
Abstract
Large-scale high-throughput plant phenotyping (sometimes called phenomics) is becoming increasingly important in plant biology and agriculture and is essential to cutting-edge plant breeding and management approaches needed to meet the food and fuel needs for the next century. Currently, the application of these approaches is severely limited by the availability of appropriate instrumentation and by the ability to communicate experimental protocols, results and analyses. To address these issues, we have developed a low-cost, yet sophisticated open-source scientific instrument designed to enable communities of researchers, plant breeders, educators, farmers and citizen scientists to collect high-quality field data on a large scale. The MultispeQ provides measurements in the field or laboratory of both, environmental conditions (light intensity and quality, temperature, humidity, CO2 levels, time and location) and useful plant phenotypes, including photosynthetic parameters-photosystem II quantum yield (ΦII), non-photochemical exciton quenching (NPQ), photosystem II photoinhibition, light-driven proton translocation and thylakoid proton motive force, regulation of the chloroplast ATP synthase and potentially many others-and leaf chlorophyll and other pigments. Plant phenotype data are transmitted from the MultispeQ to mobile devices, laptops or desktop computers together with key metadata that gets saved to the PhotosynQ platform (https://photosynq.org) and provides a suite of web-based tools for sharing, visualization, filtering, dissemination and analyses. We present validation experiments, comparing MultispeQ results with established platforms, and show that it can be usefully deployed in both laboratory and field settings. We present evidence that MultispeQ can be used by communities of researchers to rapidly measure, store and analyse multiple environmental and plant properties, allowing for deeper understanding of the complex interactions between plants and their environment.
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Affiliation(s)
- Sebastian Kuhlgert
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Greg Austic
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Robert Zegarac
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Isaac Osei-Bonsu
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Donghee Hoh
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Martin I. Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
- Genetics Graduate Program, Michigan State University, East Lansing, MI, USA
| | - Mitchell G. Roth
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
- Genetics Graduate Program, Michigan State University, East Lansing, MI, USA
| | - Kevin Bi
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Dan TerAvest
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | | | - David M. Kramer
- MSU-DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Author for correspondence: David M. Kramer e-mail:
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