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Li M, Svoboda V, Davis G, Kramer D, Kunz HH, Kirchhoff H. Impact of ion fluxes across thylakoid membranes on photosynthetic electron transport and photoprotection. NATURE PLANTS 2021; 7:979-988. [PMID: 34140667 DOI: 10.1038/s41477-021-00947-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/18/2021] [Indexed: 05/06/2023]
Abstract
In photosynthetic thylakoid membranes the proton motive force (pmf) not only drives ATP synthesis, in addition it is central to controlling and regulating energy conversion. As a consequence, dynamic fine-tuning of the two pmf components, electrical (Δψ) and chemical (ΔpH), is an essential element for adjusting photosynthetic light reactions to changing environmental conditions. Good evidence exists that the Δψ/ΔpH partitioning is controlled by thylakoid potassium and chloride ion transporters and channels. However, a detailed mechanistic understanding of how these thylakoid ion transporter/channels control pmf partitioning is lacking. Here, we combined functional measurements on potassium and chloride ion transporter and channel loss-of-function mutants with extended mathematical simulations of photosynthetic light reactions in thylakoid membranes to obtain detailed kinetic insights into the complex interrelationship between membrane energization and ion fluxes across thylakoid membranes. The data reveal that potassium and chloride fluxes in the thylakoid lumen determined by the K+/H+ antiporter KEA3 and the voltage-gated Cl- channel VCCN1/Best1 have distinct kinetic responses that lead to characteristic and light-intensity-dependent Δψ/ΔpH oscillations. These oscillations fine-tune photoprotective mechanisms and electron transport which are particularly important during the first minutes of illumination and under fluctuating light conditions. By employing the predictive power of the model, we unravelled the functional consequences of changes in KEA3 and VCCN1 abundance and regulatory/enzymatic parameters on membrane energization and photoprotection.
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Affiliation(s)
- Meng Li
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Vaclav Svoboda
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Geoffry Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - David Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry, Michigan State University, East Lansing, MI, USA
| | - Hans-Henning Kunz
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA.
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Wu L, Wu M, Liu H, Gao Y, Chen F, Xiang Y. Identification and characterisation of monovalent cation/proton antiporters (CPAs) in Phyllostachys edulis and the functional analysis of PheNHX2 in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 164:205-221. [PMID: 34004558 DOI: 10.1016/j.plaphy.2021.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/03/2021] [Indexed: 05/16/2023]
Abstract
Plant monovalent cation/proton antiporters (CPAs), types of transmembrane transporters, play important roles in resistance to salt stress. In this study, 37 CPA genes from moso bamboo (Phyllostachys edulis) were identified and characterised. The expression profiles of 10 CPA1 genes (PheNHXs) of moso bamboo were detected by qRT-PCR, which showed that they were specifically expressed in six tissues. In addition, the expression of 10 PheNHXs in leaves and roots changed significantly under 150/200 mM NaCl and 100 μM ABA treatments. In particular, the expression of PheNHX2 in leaves and roots was significantly upregulated under NaCl treatment, thus, we cloned PheNHX2 and analysed its function. Subcellular localisation analysis showed that PheNHX2 was located on the vacuolar membrane. Overexpression of PheNHX2 reduced seed germination and root growth of Arabidopsis thaliana under salt stress, as well as severely affecting cellular Na+ and K+ content, which in turn reduced the salt tolerance of transgenic Arabidopsis. Measurements of physiological indicators, including chlorophyll content, malondialdehyde content, peroxidase and catalase enzyme activities and relative electrical conductivity, all supported this conclusion. Under salt stress, PheNHX2 also inhibited the expression of some stress-related and ion transport-related genes in transgenic Arabidopsis. Overall, these results indicate that overexpression of PheNHX2 reduces the salt tolerance of transgenic Arabidopsis. This investigation establishes a foundation for subsequent functional studies of moso bamboo CPA genes, and it provides a deeper understanding of PheNHX2 regulation in relation to the salt tolerance of moso bamboo.
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Affiliation(s)
- Lin Wu
- Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, China.
| | - Min Wu
- Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, China.
| | - Huanlong Liu
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Yameng Gao
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Feng Chen
- Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, China.
| | - Yan Xiang
- Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, China.
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Different Strategies for Photosynthetic Regulation under Fluctuating Light in Two Sympatric Paphiopedilum Species. Cells 2021; 10:cells10061451. [PMID: 34200524 PMCID: PMC8229141 DOI: 10.3390/cells10061451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/30/2021] [Accepted: 06/02/2021] [Indexed: 01/10/2023] Open
Abstract
Fluctuating light can cause selective photoinhibition of photosystem I (PSI) in angiosperms. Cyclic electron flow (CEF) around PSI and electron flux from water via the electron transport chain to oxygen (the water-water cycle) play important roles in coping with fluctuating light in angiosperms. However, it is unclear whether plant species in the same genus employ the same strategy to cope with fluctuating light. To answer this question, we measured P700 redox kinetics and chlorophyll fluorescence under fluctuating light in two Paphiopedilum (P.) Pftzer (Orchidaceae) species, P. dianthum and P. micranthum. After transition from dark to high light, P. dianthum displayed a rapid re-oxidation of P700, while P. micranthum displayed an over-reduction of P700. Furthermore, the rapid re-oxidation of P700 in P. dianthum was not observed when measured under anaerobic conditions. These results indicated that photo-reduction of O2 mediated by the water-water cycle was functional in P. dianthum but not in P. micranthum. Within the first few seconds after an abrupt transition from low to high light, PSI was highly oxidized in P. dianthum but was highly reduced in P. micranthum, indicating that the different responses of PSI to fluctuating light between P. micranthum and P. dianthum was attributed to the water-water cycle. In P. micranthum, the lack of the water-water cycle was partially compensated for by an enhancement of CEF. Taken together, P. dianthum and P. micranthum employed different strategies to cope with the abrupt change of light intensity, indicating the diversity of strategies for photosynthetic acclimation to fluctuating light in these two closely related orchid species.
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Höhner R, Day PM, Zimmermann SE, Lopez LS, Krämer M, Giavalisco P, Correa Galvis V, Armbruster U, Schöttler MA, Jahns P, Krueger S, Kunz HH. Stromal NADH supplied by PHOSPHOGLYCERATE DEHYDROGENASE3 is crucial for photosynthetic performance. PLANT PHYSIOLOGY 2021; 186:142-167. [PMID: 33779763 PMCID: PMC8154072 DOI: 10.1093/plphys/kiaa117] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/17/2020] [Indexed: 05/22/2023]
Abstract
During photosynthesis, electrons travel from light-excited chlorophyll molecules along the electron transport chain to the final electron acceptor nicotinamide adenine dinucleotide phosphate (NADP) to form NADPH, which fuels the Calvin-Benson-Bassham cycle (CBBC). To allow photosynthetic reactions to occur flawlessly, a constant resupply of the acceptor NADP is mandatory. Several known stromal mechanisms aid in balancing the redox poise, but none of them utilizes the structurally highly similar coenzyme NAD(H). Using Arabidopsis (Arabidopsis thaliana) as a C3-model, we describe a pathway that employs the stromal enzyme PHOSPHOGLYCERATE DEHYDROGENASE 3 (PGDH3). We showed that PGDH3 exerts high NAD(H)-specificity and is active in photosynthesizing chloroplasts. PGDH3 withdrew its substrate 3-PGA directly from the CBBC. As a result, electrons become diverted from NADPH via the CBBC into the separate NADH redox pool. pgdh3 loss-of-function mutants revealed an overreduced NADP(H) redox pool but a more oxidized plastid NAD(H) pool compared to wild-type plants. As a result, photosystem I acceptor side limitation increased in pgdh3. Furthermore, pgdh3 plants displayed delayed CBBC activation, changes in nonphotochemical quenching, and altered proton motive force partitioning. Our fluctuating light-stress phenotyping data showed progressing photosystem II damage in pgdh3 mutants, emphasizing the significance of PGDH3 for plant performance under natural light environments. In summary, this study reveals an NAD(H)-specific mechanism in the stroma that aids in balancing the chloroplast redox poise. Consequently, the stromal NAD(H) pool may provide a promising target to manipulate plant photosynthesis.
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Affiliation(s)
- Ricarda Höhner
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Philip M Day
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Sandra E Zimmermann
- Biocenter University of Cologne, Institute for Plant Science, Cologne 50674, Germany
| | - Laura S Lopez
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Moritz Krämer
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | | | - Viviana Correa Galvis
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Mark Aurel Schöttler
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Peter Jahns
- Plant Biochemistry, Heinrich-Heine-University Düsseldorf, Düsseldorf D-40225, Germany
| | - Stephan Krueger
- Biocenter University of Cologne, Institute for Plant Science, Cologne 50674, Germany
| | - Hans-Henning Kunz
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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Thioredoxin h2 and o1 Show Different Subcellular Localizations and Redox-Active Functions, and Are Extrachloroplastic Factors Influencing Photosynthetic Performance in Fluctuating Light. Antioxidants (Basel) 2021; 10:antiox10050705. [PMID: 33946819 PMCID: PMC8147087 DOI: 10.3390/antiox10050705] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 11/24/2022] Open
Abstract
Arabidopsis contains eight different h-type thioredoxins (Trx) being distributed in different cell organelles. Although Trx h2 is deemed to be confined to mitochondria, its subcellular localization and function are discussed controversially. Here, cell fractionation studies were used to clarify this question, showing Trx h2 protein to be exclusively localized in microsomes rather than mitochondria. Furthermore, Arabidopsis trxo1, trxh2 and trxo1h2 mutants were analyzed to compare the role of Trx h2 with mitochondrial Trx o1. Under medium light, trxo1 and trxo1h2 showed impaired growth, while trxh2 was similar to wild type. In line with this, trxo1 and trxo1h2 clustered differently from wild type with respect to nocturnal metabolite profiles, revealing a decrease in ascorbate and glutathione redox states. Under fluctuating light, these genotypic differences were attenuated. Instead, the trxo1h2 double mutant showed an improved NADPH redox balance, compared to wild type, accompanied by increased photosynthetic efficiency, specifically in the high-light phases. Conclusively, Trx h2 and Trx o1 are differentially localized in microsomes and mitochondria, respectively, which is associated with different redox-active functions and effects on plant growth in constant light, while there is a joint role of both Trxs in regulating NADPH redox balance and photosynthetic performance in fluctuating light.
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Buchert F, Bailleul B, Joliot P. Disentangling chloroplast ATP synthase regulation by proton motive force and thiol modulation in Arabidopsis leaves. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148434. [PMID: 33932368 DOI: 10.1016/j.bbabio.2021.148434] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/06/2021] [Accepted: 04/20/2021] [Indexed: 11/29/2022]
Abstract
The chloroplast ATP synthase (CF1Fo) contains a specific feature to the green lineage: a γ-subunit redox domain that contains a cysteine couple which interacts with the torque-transmitting βDELSEED-loop. This thiol modulation equips CF1Fo with an important environmental fine-tuning mechanism. In vitro, disulfide formation in the γ-redox domain slows down the activity of the CF1Fo at low transmembrane electrochemical proton gradient ( [Formula: see text] ), which agrees with its proposed role as chock based on recently solved structure. The γ-dithiol formation at the onset of light is crucial to maximize photosynthetic efficiency since it lowers the [Formula: see text] activation level for ATP synthesis in vitro. Here, we validate these findings in vivo by utilizing absorption spectroscopy in Arabidopsis thaliana. To do so, we monitored the [Formula: see text] present in darkness and identified its mitochondrial sources. By following the fate and components of light-induced extra [Formula: see text] , we estimated the ATP lifetime that lasted up to tens of minutes after long illuminations. Based on the relationship between [Formula: see text] and CF1Fo activity, we conclude that the dithiol configuration in vivo facilitates photosynthesis by driving the same ATP synthesis rate at a significative lower [Formula: see text] than in the γ-disulfide state. The presented in vivo findings are an additional proof of the importance of CF1Fo thiol modulation, reconciling biochemical in vitro studies and structural insights.
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Affiliation(s)
- Felix Buchert
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany.
| | - Benjamin Bailleul
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France
| | - Pierre Joliot
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France
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Gjindali A, Herrmann HA, Schwartz JM, Johnson GN, Calzadilla PI. A Holistic Approach to Study Photosynthetic Acclimation Responses of Plants to Fluctuating Light. FRONTIERS IN PLANT SCIENCE 2021; 12:668512. [PMID: 33936157 PMCID: PMC8079764 DOI: 10.3389/fpls.2021.668512] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/23/2021] [Indexed: 05/10/2023]
Abstract
Plants in natural environments receive light through sunflecks, the duration and distribution of these being highly variable across the day. Consequently, plants need to adjust their photosynthetic processes to avoid photoinhibition and maximize yield. Changes in the composition of the photosynthetic apparatus in response to sustained changes in the environment are referred to as photosynthetic acclimation, a process that involves changes in protein content and composition. Considering this definition, acclimation differs from regulation, which involves processes that alter the activity of individual proteins over short-time periods, without changing the abundance of those proteins. The interconnection and overlapping of the short- and long-term photosynthetic responses, which can occur simultaneously or/and sequentially over time, make the study of long-term acclimation to fluctuating light in plants challenging. In this review we identify short-term responses of plants to fluctuating light that could act as sensors and signals for acclimation responses, with the aim of understanding how plants integrate environmental fluctuations over time and tailor their responses accordingly. Mathematical modeling has the potential to integrate physiological processes over different timescales and to help disentangle short-term regulatory responses from long-term acclimation responses. We review existing mathematical modeling techniques for studying photosynthetic responses to fluctuating light and propose new methods for addressing the topic from a holistic point of view.
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Affiliation(s)
- Armida Gjindali
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Helena A. Herrmann
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jean-Marc Schwartz
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Giles N. Johnson
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Pablo I. Calzadilla
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
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Zou W, Liu K, Gao X, Yu C, Wang X, Shi J, Chao Y, Yu Q, Zhou G, Ge L. Diurnal variation of transitory starch metabolism is regulated by plastid proteins WXR1/WXR3 in Arabidopsis young seedlings. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3074-3090. [PMID: 33571997 DOI: 10.1093/jxb/erab056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Transitory starch is the portion of starch that is synthesized during the day in the chloroplast and usually used for plant growth overnight. Here, we report altered metabolism of transitory starch in the wxr1/wxr3 (weak auxin response 1/3) mutants of Arabidopsis. WXR1/WXR3 were previously reported to regulate root growth of young seedlings and affect the auxin response mediated by auxin polar transport in Arabidopsis. In this study the wxr1/wxr3 mutants accumulated transitory starch in cotyledon, young leaf, and hypocotyl at the end of night. WXR1/WXR3 expression showed diurnal variation. Grafting experiments indicated that the WXRs in root were necessary for proper starch metabolism and plant growth. We also found that photosynthesis was inhibited and the transcription level of DIN1/DIN6 (Dark-Inducible 1/6) was reduced in wxr1/wxr3. The mutants also showed a defect in the ionic equilibrium of Na+ and K+, consistent with our bioinformatics data that genes related to ionic equilibrium were misregulated in wxr1. Loss of function of WXR1 also resulted in abnormal trafficking of membrane lipids and proteins. This study reveals that the plastid proteins WXR1/WXR3 play important roles in promoting transitory starch degradation for plant growth over night, possibly through regulating ionic equilibrium in the root.
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Affiliation(s)
- Wenjiao Zou
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Kui Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Xueping Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Changjiang Yu
- Center for Crop Panomics, College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Xiaofei Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Junjie Shi
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yanru Chao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Qian Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
- Center for Crop Panomics, College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Gongke Zhou
- Center for Crop Panomics, College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Lei Ge
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
- Center for Crop Panomics, College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
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Liu H, Li Y, Hu Y, Yang Y, Zhang W, He M, Li X, Zhang C, Kong F, Liu X, Hou X. EDS1-interacting J protein 1 is an essential negative regulator of plant innate immunity in Arabidopsis. THE PLANT CELL 2021; 33:153-171. [PMID: 33751092 PMCID: PMC8136891 DOI: 10.1093/plcell/koaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 10/23/2020] [Indexed: 05/13/2023]
Abstract
Plants have evolved precise mechanisms to optimize immune responses against pathogens. ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) plays a vital role in plant innate immunity by regulating basal resistance and effector-triggered immunity. Nucleocytoplasmic trafficking of EDS1 is required for resistance reinforcement, but the molecular mechanism remains elusive. Here, we show that EDS1-INTERACTING J PROTEIN1 (EIJ1), which acts as a DnaJ protein-like chaperone in response to pathogen infection, functions as an essential negative regulator of plant immunity by interacting with EDS1. The loss-of-function mutation of EIJ1 did not affect plant growth but significantly enhanced pathogen resistance. Upon pathogen infection, EIJ1 relocalized from the chloroplast to the cytoplasm, where it interacted with EDS1, thereby restricting pathogen-triggered trafficking of EDS1 to the nucleus and compromising resistance at an early infection stage. During disease development, EIJ1 was gradually degraded, allowing the nuclear accumulation of EDS1 for transcriptional resistance reinforcement. The avirulent strain Pst DC3000 (AvrRps4) abolished the repressive action of EIJ1 by rapidly inducing its degradation in the effector-triggered immunity response. Thus, our findings show that EIJ1 is an essential EDS1-dependent negative regulator of innate plant immunity and provide a mechanistic understanding of how the nuclear versus cytoplasmic distribution of EDS1 is regulated during the immune response.
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Affiliation(s)
- Hailun Liu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yuge Li
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yilong Hu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yuhua Yang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Wenbin Zhang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ming He
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoming Li
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Chunyu Zhang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Fanjiang Kong
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Xu Liu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Xingliang Hou
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- Author for communication:
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60
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Sánchez-McSweeney A, González-Gordo S, Aranda-Sicilia MN, Rodríguez-Rosales MP, Venema K, Palma JM, Corpas FJ. Loss of function of the chloroplast membrane K +/H + antiporters AtKEA1 and AtKEA2 alters the ROS and NO metabolism but promotes drought stress resilience. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 160:106-119. [PMID: 33485149 DOI: 10.1016/j.plaphy.2021.01.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/08/2021] [Indexed: 05/28/2023]
Abstract
Potassium (K+) exerts key physiological functions such as osmoregulation, stomatal movement, membrane transport, protein synthesis and photosynthesis among others. Previously, it was demonstrated in Arabidopsis thaliana that the loss of function of the chloroplast K+Efflux Antiporters KEA1 and KEA2, located in the inner envelope membrane, provokes inefficient photosynthesis. Therefore, the main goal of this study was to evaluate the potential impact of the loss of function of those cation transport systems in the metabolism of reactive oxygen and nitrogen species (ROS and RNS). Using 14-day-old seedlings from Arabidopsis double knock-out kea1kea2 mutants, ROS metabolism and NO content in roots and green cotyledons were studied at the biochemical level. The loss of function of AtKEA1 and AtKEA2 did not cause oxidative stress but it provoked an alteration of the ROS homeostasis affecting some ROS-generating enzymes. These included glycolate oxidase (GOX) and NADPH-dependent superoxide generation activity, enzymatic and non-enzymatic antioxidants and both NADP-isocitrate dehydrogenase and NADP-malic enzyme activities. NO content, analyzed by confocal laser scanning microscopy (CLSM), was negatively affected in both photosynthetic and non-photosynthetic organs in kea1kea2 mutant seedlings. Furthermore, the S-nitrosoglutathione reductase (GSNOR) protein expression and activity were downregulated in kea1kea2 mutants, whereas the tyrosine nitrated protein profile, analyzed by immunoblot, was unaffected but the relative expression of each immunoreactive band changed. Moreover, kea1kea2 mutants showed an increased photorespiratory pathway and stomata closure, thus promoting a higher resilience to drought stress. Data suggest that the chloroplast osmotic balance and integrity maintained by AtKEA1 and AtKEA2 are necessary to keep the balance of ROS/RNS metabolism. Moreover, these data open new questions about how endogenous NO generation might be affected by the K+/H+ transport located in the chloroplasts.
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Affiliation(s)
| | - Salvador González-Gordo
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Spain
| | - María Nieves Aranda-Sicilia
- Group of Ion Homeostasis, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental Del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008, Granada, Spain
| | - María Pilar Rodríguez-Rosales
- Group of Ion Homeostasis, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental Del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008, Granada, Spain
| | - Kees Venema
- Group of Ion Homeostasis, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental Del Zaidín, CSIC, C/ Profesor Albareda, 1, 18008, Granada, Spain
| | - José M Palma
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Spain
| | - Francisco J Corpas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Spain.
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Aranda Sicilia MN, Sánchez Romero ME, Rodríguez Rosales MP, Venema K. Plastidial transporters KEA1 and KEA2 at the inner envelope membrane adjust stromal pH in the dark. THE NEW PHYTOLOGIST 2021; 229:2080-2090. [PMID: 33111995 DOI: 10.1111/nph.17042] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/10/2020] [Indexed: 05/08/2023]
Abstract
Photosynthesis and carbon fixation depend critically on the regulation of pH in chloroplast compartments in the daylight and at night. While it is established that an alkaline stroma is required for carbon fixation, it is not known how alkaline stromal pH is formed, maintained or regulated. We tested whether two envelope transporters, AtKEA1 and AtKEA2, directly affected stromal pH in isolated Arabidopsis chloroplasts using the fluorescent probe 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). External K+ -induced alkalinization of the stroma was observed in chloroplasts from wild-type (WT) plants but not from kea1kea2 mutants, suggesting that KEA1 and KEA2 mediate K+ uptake/H+ loss to modulate stromal pH. While light-stimulated alkalinization of the stroma was independent of KEA1 and KEA2, the rate of decay to neutral pH in the dark is delayed in kea1kea2 mutants. However, the dark-induced loss of a pH gradient across the thylakoid membrane was similar in WT and mutant chloroplasts. This indicates that proton influx from the cytosol mediated by envelope K+ /H+ antiporters contributes to adjustment of stromal pH upon light to dark transitions.
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Affiliation(s)
- María Nieves Aranda Sicilia
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - María Elena Sánchez Romero
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - María Pilar Rodríguez Rosales
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - Kees Venema
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
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62
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Wang Y, Chen YF, Wu WH. Potassium and phosphorus transport and signaling in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:34-52. [PMID: 33325114 DOI: 10.1111/jipb.13053] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/10/2020] [Indexed: 05/26/2023]
Abstract
Nitrogen (N), potassium (K), and phosphorus (P) are essential macronutrients for plant growth and development, and their availability affects crop yield. Compared with N, the relatively low availability of K and P in soils limits crop production and thus threatens food security and agricultural sustainability. Improvement of plant nutrient utilization efficiency provides a potential route to overcome the effects of K and P deficiencies. Investigation of the molecular mechanisms underlying how plants sense, absorb, transport, and use K and P is an important prerequisite to improve crop nutrient utilization efficiency. In this review, we summarize current understanding of K and P transport and signaling in plants, mainly taking Arabidopsis thaliana and rice (Oryza sativa) as examples. We also discuss the mechanisms coordinating transport of N and K, as well as P and N.
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Affiliation(s)
- Yi Wang
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yi-Fang Chen
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wei-Hua Wu
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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63
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Flannery SE, Hepworth C, Wood WHJ, Pastorelli F, Hunter CN, Dickman MJ, Jackson PJ, Johnson MP. Developmental acclimation of the thylakoid proteome to light intensity in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:223-244. [PMID: 33118270 PMCID: PMC7898487 DOI: 10.1111/tpj.15053] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/13/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
Photosynthetic acclimation, the ability to adjust the composition of the thylakoid membrane to optimise the efficiency of electron transfer to the prevailing light conditions, is crucial to plant fitness in the field. While much is known about photosynthetic acclimation in Arabidopsis, to date there has been no study that combines both quantitative label-free proteomics and photosynthetic analysis by gas exchange, chlorophyll fluorescence and P700 absorption spectroscopy. Using these methods we investigated how the levels of 402 thylakoid proteins, including many regulatory proteins not previously quantified, varied upon long-term (weeks) acclimation of Arabidopsis to low (LL), moderate (ML) and high (HL) growth light intensity and correlated these with key photosynthetic parameters. We show that changes in the relative abundance of cytb6 f, ATP synthase, FNR2, TIC62 and PGR6 positively correlate with changes in estimated PSII electron transfer rate and CO2 assimilation. Improved photosynthetic capacity in HL grown plants is paralleled by increased cyclic electron transport, which positively correlated with NDH, PGRL1, FNR1, FNR2 and TIC62, although not PGR5 abundance. The photoprotective acclimation strategy was also contrasting, with LL plants favouring slowly reversible non-photochemical quenching (qI), which positively correlated with LCNP, while HL plants favoured rapidly reversible quenching (qE), which positively correlated with PSBS. The long-term adjustment of thylakoid membrane grana diameter positively correlated with LHCII levels, while grana stacking negatively correlated with CURT1 and RIQ protein abundance. The data provide insights into how Arabidopsis tunes photosynthetic electron transfer and its regulation during developmental acclimation to light intensity.
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Affiliation(s)
- Sarah E. Flannery
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Christopher Hepworth
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - William H. J. Wood
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Federica Pastorelli
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Christopher N. Hunter
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Mark J. Dickman
- Department of Chemical and Biological EngineeringChELSI InstituteUniversity of SheffieldSheffieldUK
| | - Philip J. Jackson
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
- Department of Chemical and Biological EngineeringChELSI InstituteUniversity of SheffieldSheffieldUK
| | - Matthew P. Johnson
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
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64
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Theune ML, Hildebrandt S, Steffen-Heins A, Bilger W, Gutekunst K, Appel J. In-vivo quantification of electron flow through photosystem I - Cyclic electron transport makes up about 35% in a cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148353. [PMID: 33346012 DOI: 10.1016/j.bbabio.2020.148353] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/23/2020] [Accepted: 12/08/2020] [Indexed: 12/15/2022]
Abstract
Photosynthetic electron flow, driven by photosystem I and II, provides chemical energy for carbon fixation. In addition to a linear mode a second cyclic route exists, which only involves photosystem I. The exact contributions of linear and cyclic transport are still a matter of debate. Here, we describe the development of a method that allows quantification of electron flow in absolute terms through photosystem I in a photosynthetic organism for the first time. Specific in-vivo protocols allowed to discern the redox states of plastocyanin, P700 and the FeS-clusters including ferredoxin at the acceptor site of PSI in the cyanobacterium Synechocystis sp. PCC 6803 with the near-infrared spectrometer Dual-KLAS/NIR. P700 absorbance changes determined with the Dual-KLAS/NIR correlated linearly with direct determinations of PSI concentrations using EPR. Dark-interval relaxation kinetics measurements (DIRKPSI) were applied to determine electron flow through PSI. Counting electrons from hydrogen oxidation as electron donor to photosystem I in parallel to DIRKPSI measurements confirmed the validity of the method. Electron flow determination by classical PSI yield measurements overestimates electron flow at low light intensities and saturates earlier compared to DIRKPSI. Combination of DIRKPSI with oxygen evolution measurements yielded a proportion of 35% of surplus electrons passing PSI compared to PSII. We attribute these electrons to cyclic electron transport, which is twice as high as assumed for plants. Counting electrons flowing through the photosystems allowed determination of the number of quanta required for photosynthesis to 11 per oxygen produced, which is close to published values.
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Affiliation(s)
- Marius L Theune
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Sarah Hildebrandt
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Anja Steffen-Heins
- Division of Food Technology, Institute of Human Nutrition and Food Science, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Wolfgang Bilger
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Kirstin Gutekunst
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Jens Appel
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany.
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65
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Basso L, Yamori W, Szabo I, Shikanai T. Collaboration between NDH and KEA3 Allows Maximally Efficient Photosynthesis after a Long Dark Adaptation. PLANT PHYSIOLOGY 2020; 184:2078-2090. [PMID: 32978277 PMCID: PMC7723091 DOI: 10.1104/pp.20.01069] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/16/2020] [Indexed: 05/10/2023]
Abstract
In angiosperms, the NADH dehydrogenase-like (NDH) complex mediates cyclic electron transport around PSI (CET). K+ Efflux Antiporter3 (KEA3) is a putative thylakoid H+/K+ antiporter and allows an increase in membrane potential at the expense of the ∆pH component of the proton motive force. In this study, we discovered that the chlororespiratory reduction2-1 (crr2-1) mutation, which abolished NDH-dependent CET, enhanced the kea3-1 mutant phenotypes in Arabidopsis (Arabidopsis thaliana). The NDH complex pumps protons during CET, further enhancing ∆pH, but its physiological function has not been fully clarified. The observed effect only took place upon exposure to light of 110 µmol photons m-2 s-1 after overnight dark adaptation. We propose two distinct modes of NDH action. In the initial phase, within 1 min after the onset of actinic light, the NDH-dependent CET engages with KEA3 to enhance electron transport efficiency. In the subsequent phase, in which the ∆pH-dependent down-regulation of the electron transport is relaxed, the NDH complex engages with KEA3 to relax the large ∆pH formed during the initial phase. We observed a similar impact of the crr2-1 mutation in the genetic background of the PROTON GRADIENT REGULATION5 overexpression line, in which the size of ∆pH was enhanced. When photosynthesis was induced at 300 µmol photons m-2 s-1, the contribution of KEA3 was negligible in the initial phase and the ∆pH-dependent down-regulation was not relaxed in the second phase. In the crr2-1 kea3-1 double mutant, the induction of CO2 fixation was delayed after overnight dark adaptation.
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Affiliation(s)
- Leonardo Basso
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502 Japan
| | - Wataru Yamori
- Institute for Sustainable Agro-Ecosystem Services, Graduate School of Agriculture and Life Science, University of Tokyo, Tokyo 188-0002 Japan
| | - Ildiko Szabo
- Department of Biology, University of Padova, 606-8502 Padova, Italy
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502 Japan
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66
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Meng Q, Runkle ES. Growth Responses of Red-Leaf Lettuce to Temporal Spectral Changes. FRONTIERS IN PLANT SCIENCE 2020; 11:571788. [PMID: 33193506 PMCID: PMC7641902 DOI: 10.3389/fpls.2020.571788] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/30/2020] [Indexed: 05/28/2023]
Abstract
Lighting is typically static for indoor production of leafy greens. However, temporal spectrum differentiation for distinct growth phases can potentially control age-specific desirable traits. Spectral effects can be persistent yet dynamic as plants mature, necessitating characterization of time-dependent responses. We grew red-leaf lettuce (Lactuca sativa L.) "Rouxai" in a growth room at 23°C and under a 20-h photoperiod created by warm-white (WW), blue (B; peak = 449 nm), green (G; peak = 526 nm), red (R; peak = 664 nm), and/or far-red (FR; peak = 733 nm) light-emitting diodes. From day 0 to 11, plants received six static lighting treatments with the same total photon flux density (400-800 nm): WW180, R180, B20R160, B20G60R100, B20R100FR60, or B180 (subscripts denote photon flux densities in μmol⋅m-2⋅s-1). On day 11, plants grown under each of the six treatments were transferred to all treatments, which created 36 temporal spectrum alternations. Plant growth, morphology, and coloration were measured on days 11 and 25. Increasing B radiation from 0 to 100% in static treatments decreased shoot fresh and dry weights and increased foliage redness of seedlings and mature plants. Compared to B20R160, B20R100FR60 increased shoot fresh weight, but not dry weight, on both days. However, other phenotypic responses under static treatments changed over time. For example, leaf length under B180 was 35% lower on day 11 but similar on day 25 compared to that under R180. In the B20 background, substituting G60 for R radiation did not influence shoot weight on day 11 but decreased it by 19% on day 25. When plants were switched from one treatment to another on day 11, the treatments applied before day 11 influenced final shoot weight and, to a lesser extent, leaf length and foliage coloration on day 25. In comparison, effects of the treatments applied after day 11 were more pronounced. We conclude some phenotypic responses to light quality depend on time and sequential light quality treatments had cumulative effects on lettuce growth. The temporal complexity of spectral responses is critical in photobiological research and creates opportunities for time-specific spectrum delivery to optimize crop characteristics.
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67
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Babla MH, Tissue DT, Cazzonelli CI, Chen ZH. Effect of high light on canopy-level photosynthesis and leaf mesophyll ion flux in tomato. PLANTA 2020; 252:80. [PMID: 33037481 DOI: 10.1007/s00425-020-03493-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
This study highlights the potential link between high light-induced canopy-level photosynthesis and mesophyll cell K+, Cl-, Ca2+, and H+ homeostasis in tomato. Light is a primary energy source for photosynthesis and a vital regulator of mineral nutrient uptake and distribution in plants. Plants need to optimize photosynthesis and nutrient balance in leaves for performance in fluctuating light conditions that are partially regulated by light-induced ion homeostatsis in the mesophyll cells. It is still elusive whether high light-induced leaf mesophyll ion fluxes affect leaf photosynthesis at different canopy levels in Solanum lycopersicum L. Leaf gas exchange and microelectrode ion flux (MIFE) measurements were employed to study the effects of prolonged light-induced canopy-level leaf physiological responses of tomato plants. High light resulted in a significant lowering in photosynthesis in the fully-exposed top canopy leaves of tomato, but not to mid- or low-canopy leaves. Leaf mesophyll K+ effluxes of all canopies were significantly decreased after three weeks of high light treatment. However, high light-induced leaf mesophyll Ca2+ effluxes were significantly enhanced only in the top and mid canopies. Moreover, we found that photosynthetic parameters were significantly correlated with leaf mesophyll ion fluxes. We thus propose that canopy-level significant Ca2+ efflux and K+ efflux of leaf mesophyll may serve as early indicators for light-induced regulation on photosynthesis. We conclude that light-induced differential photosynthetic performance and ion fluxes in leaves may implicate a requirement of more uniform light irradiance and spectra at different canopy levels of tall greenhouse tomato plants. This can be achieved through new innovative greenhouse lighting technologies and covering materials towards the enhancement of crop photosynthesis and yield.
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Affiliation(s)
| | - David Thomas Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia
| | | | - Zhong-Hua Chen
- School of Science, Western Sydney University, Penrith, NSW, 2751, Australia.
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia.
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68
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Isayenkov SV, Dabravolski SA, Pan T, Shabala S. Phylogenetic Diversity and Physiological Roles of Plant Monovalent Cation/H + Antiporters. FRONTIERS IN PLANT SCIENCE 2020; 11:573564. [PMID: 33123183 PMCID: PMC7573149 DOI: 10.3389/fpls.2020.573564] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/02/2020] [Indexed: 05/23/2023]
Abstract
The processes of plant nutrition, stress tolerance, plant growth, and development are strongly dependent on transport of mineral nutrients across cellular membranes. Plant membrane transporters are key components of these processes. Among various membrane transport proteins, the monovalent cation proton antiporter (CPA) superfamily mediates a broad range of physiological and developmental processes such as ion and pH homeostasis, development of reproductive organs, chloroplast operation, and plant adaptation to drought and salt stresses. CPA family includes plasma membrane-bound Na+/H+ exchanger (NhaP) and intracellular Na+/H+ exchanger NHE (NHX), K+ efflux antiporter (KEA), and cation/H+ exchanger (CHX) family proteins. In this review, we have completed the phylogenetic inventory of CPA transporters and undertaken a comprehensive evolutionary analysis of their development. Compared with previous studies, we have significantly extended the range of plant species, including green and red algae and Acrogymnospermae into phylogenetic analysis. Our data suggest that the multiplication and complexation of CPA isoforms during evolution is related to land colonisation by higher plants and associated with an increase of different tissue types and development of reproductive organs. The new data extended the number of clades for all groups of CPAs, including those for NhaP/SOS, NHE/NHX, KEA, and CHX. We also critically evaluate the latest findings on the biological role, physiological functions and regulation of CPA transporters in relation to their structure and phylogenetic position. In addition, the role of CPA members in plant tolerance to various abiotic stresses is summarized, and the future priority directions for CPA studies in plants are discussed.
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Affiliation(s)
- Stanislav V. Isayenkov
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China
- Department of Plant Food Products and Biofortification, Institute of Food Biotechnology and Genomics NAS of Ukraine, Kyiv, Ukraine
| | - Siarhei A. Dabravolski
- Department of Clinical Diagnostics, Vitebsk State Academy of Veterinary Medicine [UO VGAVM], Vitebsk, Belarus
| | - Ting Pan
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China
| | - Sergey Shabala
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS, Australia
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69
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Müller-Schüssele SJ, Wang R, Gütle DD, Romer J, Rodriguez-Franco M, Scholz M, Buchert F, Lüth VM, Kopriva S, Dörmann P, Schwarzländer M, Reski R, Hippler M, Meyer AJ. Chloroplasts require glutathione reductase to balance reactive oxygen species and maintain efficient photosynthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1140-1154. [PMID: 32365245 DOI: 10.1111/tpj.14791] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 05/27/2023]
Abstract
Thiol-based redox-regulation is vital for coordinating chloroplast functions depending on illumination and has been throroughly investigated for thioredoxin-dependent processes. In parallel, glutathione reductase (GR) maintains a highly reduced glutathione pool, enabling glutathione-mediated redox buffering. Yet, how the redox cascades of the thioredoxin and glutathione redox machineries integrate metabolic regulation and detoxification of reactive oxygen species remains largely unresolved because null mutants of plastid/mitochondrial GR are embryo-lethal in Arabidopsis thaliana. To investigate whether maintaining a highly reducing stromal glutathione redox potential (EGSH ) via GR is necessary for functional photosynthesis and plant growth, we created knockout lines of the homologous enzyme in the model moss Physcomitrella patens. In these viable mutant lines, we found decreasing photosynthetic performance and plant growth with increasing light intensities, whereas ascorbate and zeaxanthin/antheraxanthin levels were elevated. By in vivo monitoring stromal EGSH dynamics, we show that stromal EGSH is highly reducing in wild-type and clearly responsive to light, whereas an absence of GR leads to a partial glutathione oxidation, which is not rescued by light. By metabolic labelling, we reveal changing protein abundances in the GR knockout plants, pinpointing the adjustment of chloroplast proteostasis and the induction of plastid protein repair and degradation machineries. Our results indicate that the plastid thioredoxin system is not a functional backup for the plastid glutathione redox systems, whereas GR plays a critical role in maintaining efficient photosynthesis.
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Affiliation(s)
- Stefanie J Müller-Schüssele
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, Bonn, 53113, Germany
| | - Ren Wang
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany
| | - Desirée D Gütle
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany
| | - Jill Romer
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, 53115, Germany
| | - Marta Rodriguez-Franco
- Cell Biology, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, 79104, Germany
| | - Martin Scholz
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany
| | - Volker M Lüth
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany
| | - Stanislav Kopriva
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, 50674, Germany
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, 53115, Germany
| | - Markus Schwarzländer
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestrasse18, Freiburg, 79104, Germany
| | - Michael Hippler
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, Bonn, 53113, Germany
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70
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Treves H, Siemiatkowska B, Luzarowska U, Murik O, Fernandez-Pozo N, Moraes TA, Erban A, Armbruster U, Brotman Y, Kopka J, Rensing SA, Szymanski J, Stitt M. Multi-omics reveals mechanisms of total resistance to extreme illumination of a desert alga. NATURE PLANTS 2020; 6:1031-1043. [PMID: 32719473 DOI: 10.1038/s41477-020-0729-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 06/24/2020] [Indexed: 05/25/2023]
Abstract
The unparalleled performance of Chlorella ohadii under irradiances of twice full sunlight underlines the gaps in our understanding of how the photosynthetic machinery operates, and what sets its upper functional limit. Rather than succumbing to photodamage under extreme irradiance, unique features of photosystem II function allow C. ohadii to maintain high rates of photosynthesis and growth, accompanied by major changes in composition and cellular structure. This remarkable resilience allowed us to investigate the systems response of photosynthesis and growth to extreme illumination in a metabolically active cell. Using redox proteomics, transcriptomics, metabolomics and lipidomics, we explored the cellular mechanisms that promote dissipation of excess redox energy, protein S-glutathionylation, inorganic carbon concentration, lipid and starch accumulation, and thylakoid stacking. C. ohadii possesses a readily available capacity to utilize a sudden excess of reducing power and carbon for growth and reserve formation, and post-translational redox regulation plays a pivotal role in this rapid response. Frequently the response in C. ohadii deviated from that of model species, reflecting its life history in desert sand crusts. Comparative global and case-specific analyses provided insights into the potential evolutionary role of effective reductant utilization in this extreme resistance of C. ohadii to extreme irradiation.
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Affiliation(s)
- Haim Treves
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany.
| | | | | | - Omer Murik
- Department of Plant & Environmental Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Noe Fernandez-Pozo
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | | | - Alexander Erban
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Ute Armbruster
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Yariv Brotman
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Joachim Kopka
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Stefan Andreas Rensing
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Jedrzej Szymanski
- Department of Network Analysis and Modelling, IPK, Gatersleben, Germany
| | - Mark Stitt
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
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71
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Li YT, Li Y, Li YN, Liang Y, Sun Q, Li G, Liu P, Zhang ZS, Gao HY. Dynamic light caused less photosynthetic suppression, rather than more, under nitrogen deficit conditions than under sufficient nitrogen supply conditions in soybean. BMC PLANT BIOLOGY 2020; 20:339. [PMID: 32680459 PMCID: PMC7368695 DOI: 10.1186/s12870-020-02516-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 06/23/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Plants are always exposed to dynamic light. The photosynthetic light use efficiency of leaves is lower in dynamic light than in uniform irradiance. Research on the influence of environmental factors on dynamic photosynthesis is very limited. Nitrogen is critical for plants, especially for photosynthesis. Low nitrogen (LN) decreases ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and thus limits photosynthesis. The decrease in Rubisco also delays photosynthetic induction in LN leaves; therefore, we hypothesized that the difference of photosynthetic CO2 fixation between uniform and dynamic light will be greater in LN leaves compared to leaves with sufficient nitrogen supply. RESULTS To test this hypothesis, soybean plants were grown under low or high nitrogen (HN), and the photosynthetic gas exchange, enzyme activity and protein amount in leaves were measured under uniform and dynamic light. Unexpectedly, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves. The underlying mechanism was also clarified. Short low-light (LL) intervals did not affect Rubisco activity but clearly deactivated fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase), indicating that photosynthetic induction after a LL interval depends on the reactivation of FBPase and SBPase rather than Rubisco. In LN leaves, the amount of Rubisco decreased more than FBPase and SBPase, so FBPase and SBPase were present in relative excess. A lower fraction of FBPase and SBPase needs to be activated in LN leaves for photosynthesis recovery during the high-light phase of dynamic light. Therefore, photosynthetic recovery is faster in LN leaves than in HN leaves, which relieves the photosynthetic suppression caused by dynamic light in LN leaves. CONCLUSIONS Contrary to our expectations, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves of soybean. This is the first report of a stress condition alleviating the photosynthetic suppression caused by dynamic light.
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Affiliation(s)
- Yu-Ting Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Yue-Nan Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Liang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Qiang Sun
- Tai'an Testing Center For Food And Drug Control, Tai'an, Shandong Province, China
| | - Geng Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Peng Liu
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Zi-Shan Zhang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Hui-Yuan Gao
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
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72
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Efficient photosynthesis in dynamic light environments: a chloroplast's perspective. Biochem J 2020; 476:2725-2741. [PMID: 31654058 PMCID: PMC6792033 DOI: 10.1042/bcj20190134] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/23/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022]
Abstract
In nature, light availability for photosynthesis can undergo massive changes on a very short timescale. Photosynthesis in such dynamic light environments requires that plants can respond swiftly. Expanding our knowledge of the rapid responses that underlie dynamic photosynthesis is an important endeavor: it provides insights into nature's design of a highly dynamic energy conversion system and hereby can open up new strategies for improving photosynthesis in the field. The present review focuses on three processes that have previously been identified as promising engineering targets for enhancing crop yield by accelerating dynamic photosynthesis, all three of them involving or being linked to processes in the chloroplast, i.e. relaxation of non-photochemical quenching, Calvin–Benson–Bassham cycle enzyme activation/deactivation and dynamics of stomatal conductance. We dissect these three processes on the functional and molecular level to reveal gaps in our understanding and critically discuss current strategies to improve photosynthesis in the field.
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73
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Bölter B, Mitterreiter MJ, Schwenkert S, Finkemeier I, Kunz HH. The topology of plastid inner envelope potassium cation efflux antiporter KEA1 provides new insights into its regulatory features. PHOTOSYNTHESIS RESEARCH 2020; 145:43-54. [PMID: 31865509 DOI: 10.1007/s11120-019-00700-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 12/11/2019] [Indexed: 05/25/2023]
Abstract
The plastid potassium cation efflux antiporters (KEAs) are important for chloroplast function, development, and photosynthesis. To understand their regulation at the protein level is therefore of fundamental importance. Prior studies have focused on the regulatory K+ transport and NAD-binding (KTN) domain in the C-terminus of the thylakoid carrier KEA3 but the localization of this domain remains unclear. While all three plastid KEA members are highly conserved in their transmembrane region and the C-terminal KTN domain, only the inner envelope KEA family members KEA1 and KEA2 carry a long soluble N-terminus. Interestingly, this region is acetylated at lysine 168 by the stromal acetyltransferase enzyme NSI. If an odd number of transmembrane domains existed for inner envelope KEAs, as it was suggested for all three plastid KEA carriers, regulatory domains and consequently protein regulation would occur on opposing sides of the inner envelope. In this study we therefore set out to investigate the topology of inner envelope KEA proteins. Using a newly designed antibody specific to the envelope KEA1 N-terminus and transgenic Arabidopsis plants expressing a C-terminal KEA1-YFP fusion protein, we show that both, the N-terminal and C-terminal, regulatory domains of KEA1 reside in the chloroplast stroma and not in the intermembrane space. Considering the high homology between KEA1 and KEA2, we therefore reason that envelope KEAs must consist of an even number of transmembrane domains.
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Affiliation(s)
- Bettina Bölter
- Dept. I, Plant Biochemistry, Ludwig Maximilians University Munich, Großhadernerstr. 2-4, 82152, Planegg-Martinsried, Germany
| | - Melanie J Mitterreiter
- Dept. I, Plant Biochemistry, Ludwig Maximilians University Munich, Großhadernerstr. 2-4, 82152, Planegg-Martinsried, Germany
| | - Serena Schwenkert
- Dept. I, Plant Biochemistry, Ludwig Maximilians University Munich, Großhadernerstr. 2-4, 82152, Planegg-Martinsried, Germany
| | - Iris Finkemeier
- Plant Physiology, Institute of Biology and Biotechnology of Plants, University of Muenster, Schlossplatz 7, 48149, Muenster, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA, 99164-4236, USA.
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74
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Diverse Physiological Functions of Cation Proton Antiporters across Bacteria and Plant Cells. Int J Mol Sci 2020; 21:ijms21124566. [PMID: 32604959 PMCID: PMC7349511 DOI: 10.3390/ijms21124566] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022] Open
Abstract
Membrane intrinsic transport systems play an important role in maintaining ion and pH homeostasis and forming the proton motive force in the cytoplasm and cell organelles. In most organisms, cation/proton antiporters (CPAs) mediate the exchange of K+, Na+ and Ca2+ for H+ across the membrane in response to a variety of environmental stimuli. The tertiary structure of the ion selective filter and the regulatory domains of Escherichia coli CPAs have been determined and a molecular mechanism of cation exchange has been proposed. Due to symbiogenesis, CPAs localized in mitochondria and chloroplasts of eukaryotic cells resemble prokaryotic CPAs. CPAs primarily contribute to keeping cytoplasmic Na+ concentrations low and controlling pH, which promotes the detoxification of electrophiles and formation of proton motive force across the membrane. CPAs in cyanobacteria and chloroplasts are regulators of photosynthesis and are essential for adaptation to high light or osmotic stress. CPAs in organellar membranes and in the plasma membrane also participate in various intracellular signal transduction pathways. This review discusses recent advances in our understanding of the role of CPAs in cyanobacteria and plant cells.
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75
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Tan SL, Yang YJ, Huang W. Moderate heat stress accelerates photoinhibition of photosystem I under fluctuating light in tobacco young leaves. PHOTOSYNTHESIS RESEARCH 2020; 144:373-382. [PMID: 32333230 DOI: 10.1007/s11120-020-00754-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
Moderate heat stress and fluctuating light are typical conditions in summer in tropical and subtropical regions. This type of stress can cause photodamage to photosystems I and II (PSI and PSII). However, photosynthetic responses to the combination of heat and fluctuating light in young leaves are little known. In this study, we investigated chlorophyll fluorescence and P700 redox state under fluctuating light at 25 °C and 42 °C in young leaves of tobacco. Our results indicated that fluctuating light caused selective photodamage to PSI in the young leaves at 25 °C and 42 °C. Furthermore, the moderate heat stress significantly accelerated photoinhibition of PSI under fluctuating light. Within the first 10 s after transition from low to high light, cyclic electron flow (CEF) around PSI was highly stimulated at 25 °C but was slightly activated at 42 °C. Such depression of CEF activation at moderate heat stress were unable to maintain energy balance under high light. As a result, electron flow from PSI to NADP+ was restricted, leading to the over-reduction of PSI electron carriers. These results indicated that moderate heat stress altered the CEF performance under fluctuating light and thus accelerated PSI photoinhibition in tobacco young leaves.
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Affiliation(s)
- Shun-Ling Tan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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76
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Correa Galvis V, Strand DD, Messer M, Thiele W, Bethmann S, Hübner D, Uflewski M, Kaiser E, Siemiatkowska B, Morris BA, Tóth SZ, Watanabe M, Brückner F, Höfgen R, Jahns P, Schöttler MA, Armbruster U. H + Transport by K + EXCHANGE ANTIPORTER3 Promotes Photosynthesis and Growth in Chloroplast ATP Synthase Mutants. PLANT PHYSIOLOGY 2020; 182:2126-2142. [PMID: 32041909 PMCID: PMC7140953 DOI: 10.1104/pp.19.01561] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/27/2020] [Indexed: 05/21/2023]
Abstract
The composition of the thylakoid proton motive force (pmf) is regulated by thylakoid ion transport. Passive ion channels in the thylakoid membrane dissipate the membrane potential (Δψ) component to allow for a higher fraction of pmf stored as a proton concentration gradient (ΔpH). K+/H+ antiport across the thylakoid membrane via K+ EXCHANGE ANTIPORTER3 (KEA3) instead reduces the ΔpH fraction of the pmf. Thereby, KEA3 decreases nonphotochemical quenching (NPQ), thus allowing for higher light use efficiency, which is particularly important during transitions from high to low light. Here, we show that in the background of the Arabidopsis (Arabidopsis thaliana) chloroplast (cp)ATP synthase assembly mutant cgl160, with decreased cpATP synthase activity and increased pmf amplitude, KEA3 plays an important role for photosynthesis and plant growth under steady-state conditions. By comparing cgl160 single with cgl160 kea3 double mutants, we demonstrate that in the cgl160 background loss of KEA3 causes a strong growth penalty. This is due to a reduced photosynthetic capacity of cgl160 kea3 mutants, as these plants have a lower lumenal pH than cgl160 mutants, and thus show substantially increased pH-dependent NPQ and decreased electron transport through the cytochrome b 6 f complex. Overexpression of KEA3 in the cgl160 background reduces pH-dependent NPQ and increases photosystem II efficiency. Taken together, our data provide evidence that under conditions where cpATP synthase activity is low, a KEA3-dependent reduction of ΔpH benefits photosynthesis and growth.
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Affiliation(s)
- Viviana Correa Galvis
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Deserah D Strand
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Michaela Messer
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Wolfram Thiele
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Stephanie Bethmann
- Institute of Plant Biochemistry, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Dennis Hübner
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Michal Uflewski
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Elias Kaiser
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Beata Siemiatkowska
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Bethan A Morris
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt 62, H-6726 Szeged, Hungary
| | - Mutsumi Watanabe
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Franziska Brückner
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Rainer Höfgen
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Peter Jahns
- Institute of Plant Biochemistry, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Mark Aurel Schöttler
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
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77
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Yang YJ, Zhang SB, Wang JH, Huang W. The decline in photosynthetic rate upon transfer from high to low light is linked to the slow kinetics of chloroplast ATP synthase in Bletilla striata. PHOTOSYNTHESIS RESEARCH 2020; 144:13-21. [PMID: 32166520 DOI: 10.1007/s11120-020-00725-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Upon a sudden transition from high to low light, the rate of CO2 assimilation (AN) in some plants first decreases to a low level before gradually becoming stable. However, the underlying mechanisms remain controversial. The activity of chloroplast ATP synthase (gH+) is usually depressed under high light when compared with low light. Therefore, we hypothesize that upon a sudden transfer from high to low light, the relatively low gH+ restricts ATP synthesis and thus causes a reduction in AN. To test this hypothesis, we measured gas exchange, chlorophyll fluorescence, P700 redox state, and electrochromic shift signals in Bletilla striata (Orchidaceae). After the transition from saturating to lower irradiance, AN and ETRII decreased first to a low level and then gradually increased to a stable value. Within the first seconds after transfer from high to low light, gH+ was maintained at low levels. During further exposure to low light, gH+ gradually increased to a stable value. Interestingly, a tight positive relationship was found between gH+ and ETRII. These results suggested that upon a sudden transition from high to low light, AN was restricted by gH+ at the step of ATP synthesis. Taken together, we propose that the decline in AN upon sudden transfer from high to low light is linked to the slow kinetics of chloroplast ATP synthase.
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Affiliation(s)
- Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Ji-Hua Wang
- Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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78
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Kaiser E, Walther D, Armbruster U. Growth under Fluctuating Light Reveals Large Trait Variation in a Panel of Arabidopsis Accessions. PLANTS (BASEL, SWITZERLAND) 2020; 9:E316. [PMID: 32138234 PMCID: PMC7154909 DOI: 10.3390/plants9030316] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/13/2020] [Accepted: 02/18/2020] [Indexed: 12/03/2022]
Abstract
The capacity of photoautotrophs to fix carbon depends on the efficiency of the conversion of light energy into chemical potential by photosynthesis. In nature, light input into photosynthesis can change very rapidly and dramatically. To analyze how genetic variation in Arabidopsis thaliana affects photosynthesis and growth under dynamic light conditions, 36 randomly chosen natural accessions were grown under uniform and fluctuating light intensities. After 14 days of growth under uniform or fluctuating light regimes, maximum photosystem II quantum efficiency (Fv/Fm) was determined, photosystem II operating efficiency (ΦPSII) and non-photochemical quenching (NPQ) were measured in low light, and projected leaf area (PLA) as well as the number of visible leaves were estimated. Our data show that ΦPSII and PLA were decreased and NPQ was increased, while Fv/Fm and number of visible leaves were unaffected, in most accessions grown under fluctuating compared to uniform light. There were large changes between accessions for most of these parameters, which, however, were not correlated with genomic variation. Fast growing accessions under uniform light showed the largest growth reductions under fluctuating light, which correlated strongly with a reduction in ΦPSII, suggesting that, under fluctuating light, photosynthesis controls growth and not vice versa.
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Affiliation(s)
- Elias Kaiser
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany;
- Horticulture and Product Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Dirk Walther
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany;
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany;
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79
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Górecka M, Lewandowska M, Dąbrowska-Bronk J, Białasek M, Barczak-Brzyżek A, Kulasek M, Mielecki J, Kozłowska-Makulska A, Gawroński P, Karpiński S. Photosystem II 22kDa protein level - a prerequisite for excess light-inducible memory, cross-tolerance to UV-C and regulation of electrical signalling. PLANT, CELL & ENVIRONMENT 2020; 43:649-661. [PMID: 31760664 DOI: 10.1111/pce.13686] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 05/20/2023]
Abstract
It is well known that PsbS is a key protein for the proper management of excessive energy in plants. Plants without PsbS cannot trigger non-photochemical quenching, which is crucial for optimal photosynthesis under variable conditions. Our studies showed wild-type plants had enhanced tolerance to UV-C-induced cell death (CD) upon induction of light memory by a blue or red light. However, npq4-1 plants, which lack PsbS, as well as plants overexpressing this protein (oePsbS), responded differently. Untreated oePsbS appeared more tolerant to UV-C exposure, whereas npq4-1 was unable to adequately induce cross-tolerance to UV-C. Similarly, light memory induced by episodic blue or red light was differently deregulated in npq-4 and oePsbS, as indicated by transcriptomic analyses, measurements of the trans-thylakoid pH gradient, chlorophyll a fluorescence parameters, and measurements of foliar surface electrical potential. The mechanism of the foliar CD development seemed to be unaffected in the analysed plants and is associated with chloroplast breakdown. Our results suggest a novel, substantial role for PsbS as a regulator of chloroplast retrograde signalling for light memory, light acclimation, CD, and cross-tolerance to UV radiation.
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Affiliation(s)
- Magdalena Górecka
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- Laboratory of Plant Pathogenesis, Institute of Biochemistry and Biophysics PAS, Warsaw, Poland
| | - Maria Lewandowska
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Joanna Dąbrowska-Bronk
- Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Maciej Białasek
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Anna Barczak-Brzyżek
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Milena Kulasek
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Poland
| | - Jakub Mielecki
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Anna Kozłowska-Makulska
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Piotr Gawroński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
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80
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Pohland AC, Schneider D. Mg2+ homeostasis and transport in cyanobacteria - at the crossroads of bacterial and chloroplast Mg2+ import. Biol Chem 2020; 400:1289-1301. [PMID: 30913030 DOI: 10.1515/hsz-2018-0476] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/19/2019] [Indexed: 12/29/2022]
Abstract
Magnesium cation (Mg2+) is the most abundant divalent cation in living cells, where it is required for various intracellular functions. In chloroplasts and cyanobacteria, established photosynthetic model systems, Mg2+ is the central ion in chlorophylls, and Mg2+ flux across the thylakoid membrane is required for counterbalancing the light-induced generation of a ΔpH across the thylakoid membrane. Yet, not much is known about Mg2+ homoeostasis, transport and distribution within cyanobacteria. However, Mg2+ transport across membranes has been studied in non-photosynthetic bacteria, and first observations and findings are reported for chloroplasts. Cyanobacterial cytoplasmic membranes appear to contain the well-characterized Mg2+ channels CorA and/or MgtE, which both facilitate transmembrane Mg2+ flux down the electrochemical gradient. Both Mg2+ channels are typical for non-photosynthetic bacteria. Furthermore, Mg2+ transporters of the MgtA/B family are also present in the cytoplasmic membrane to mediate active Mg2+ import into the bacterial cell. While the cytoplasmic membrane of cyanobacteria resembles a 'classical' bacterial membrane, essentially nothing is known about Mg2+ channels and/or transporters in thylakoid membranes of cyanobacteria or chloroplasts. As discussed here, at least one Mg2+ channelling protein must be localized within thylakoid membranes. Thus, either one of the 'typical' bacterial Mg2+ channels has a dual localization in the cytoplasmic plus the thylakoid membrane, or another, yet unidentified channel is present in cyanobacterial thylakoid membranes.
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Affiliation(s)
- Anne-Christin Pohland
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 30, D-55128 Mainz, Germany
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 30, D-55128 Mainz, Germany
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81
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Bettini PP, Lazzara L, Massi L, Fani F, Mauro ML. Effect of far-red light exposure on photosynthesis and photoprotection in tomato plants transgenic for the Agrobacterium rhizogenes rolB gene. JOURNAL OF PLANT PHYSIOLOGY 2020; 245:153095. [PMID: 31877472 DOI: 10.1016/j.jplph.2019.153095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 08/21/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Previous work showed in tomato plants harbouring the Agrobacterium rhizogenes rolB gene overexpression of genes involved in chloroplast function and stress response, significant increase in non-photochemical quenching and chlorophyll a and b content, and reduced chlorophyll a/b ratio. The latter condition being typical of plant shade where far-red is dominant, suggested a role for rolB in improving photosynthesis in such condition. To gain a better insight into these results, the photosynthetic performance of transgenic and control plants was compared by means of variable fluorescence kinetics with a WATER-PAM chlorophyll fluorometer, after 6 days-exposure to white light and to a far-red-enriched light source. Photosynthetic parameters analysed were quantum yield of photosystem II photochemistry Y(II); qL, corresponding to the fraction of open PSII reaction centers in a "lake" model of photosystem II; non-photochemical quenching and Y(NO), describing, respectively, regulated and non-regulated pathways for dissipation of excess energy. Chlorophyll a and b content was also analysed by HPLC. Finally, real-time PCR was performed to quantify the expression level of some of the chloroplast-related genes already shown to be overexpressed in transgenic plants. Quantum yield of photosystem II photochemistry decreased with increasing light intensity, showing no significant differences in both plant genotypes and light regimen. qL, on the other hand, was significantly higher at low PAR intensities, in particular in FR-treated transgenic plants. Fate of remaining light energy, channelled into regulated or non-regulated dissipation pathways, was different in transgenic and control plants, indicating a higher capability for protection from photodamage in rolB plants, particularly after exposure to far-red-enriched light. Chlorophyll a/b ratio was also decreased in transgenic plants under far-red-enriched light with respect to white light. Finally, qPCR showed that the expression of genes encoding small heat shock protein, chlorophyll a/b binding protein and carbonic anhydrase was significantly induced by far-red-enriched condition. Taken together, these data suggest the involvement of rolB in photosynthesis modulation under far-red-rich light in tomato.
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Affiliation(s)
- Priscilla P Bettini
- Dipartimento di Biologia, Università degli Studi di Firenze, via Madonna del Piano 6, 50019, Sesto f.no (FI), Italy.
| | - Luigi Lazzara
- Dipartimento di Biologia, Università degli Studi di Firenze, via Micheli 1, 50121, Firenze, Italy.
| | - Luca Massi
- Dipartimento di Biologia, Università degli Studi di Firenze, via Micheli 1, 50121, Firenze, Italy.
| | - Fabiola Fani
- Agenzia Regionale per la Protezione Ambientale della Toscana (ARPAT), Area Vasta Costa, Settore Mare, Sede di Piombino, via Adige 12, 57025, Piombino (LI), Italy.
| | - Maria Luisa Mauro
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, P.le A. Moro 5, 00185, Roma, Italy.
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82
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Davis GA, Kramer DM. Optimization of ATP Synthase c-Rings for Oxygenic Photosynthesis. FRONTIERS IN PLANT SCIENCE 2020; 10:1778. [PMID: 32082344 PMCID: PMC7003800 DOI: 10.3389/fpls.2019.01778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [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
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83
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Babla M, Cai S, Chen G, Tissue DT, Cazzonelli CI, Chen ZH. Molecular Evolution and Interaction of Membrane Transport and Photoreception in Plants. Front Genet 2019; 10:956. [PMID: 31681411 PMCID: PMC6797626 DOI: 10.3389/fgene.2019.00956] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Light is a vital regulator that controls physiological and cellular responses to regulate plant growth, development, yield, and quality. Light is the driving force for electron and ion transport in the thylakoid membrane and other membranes of plant cells. In different plant species and cell types, light activates photoreceptors, thereby modulating plasma membrane transport. Plants maximize their growth and photosynthesis by facilitating the coordinated regulation of ion channels, pumps, and co-transporters across membranes to fine-tune nutrient uptake. The signal-transducing functions associated with membrane transporters, pumps, and channels impart a complex array of mechanisms to regulate plant responses to light. The identification of light responsive membrane transport components and understanding of their potential interaction with photoreceptors will elucidate how light-activated signaling pathways optimize plant growth, production, and nutrition to the prevailing environmental changes. This review summarizes the mechanisms underlying the physiological and molecular regulations of light-induced membrane transport and their potential interaction with photoreceptors in a plant evolutionary and nutrition context. It will shed new light on plant ecological conservation as well as agricultural production and crop quality, bringing potential nutrition and health benefits to humans and animals.
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Affiliation(s)
- Mohammad Babla
- School of Science and Health, Western Sydney University, Penrith, NSW, Australia
| | - Shengguan Cai
- School of Science and Health, Western Sydney University, Penrith, NSW, Australia
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Guang Chen
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | - Zhong-Hua Chen
- School of Science and Health, Western Sydney University, Penrith, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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84
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Wang C, Shikanai T. Modification of Activity of the Thylakoid H +/K + Antiporter KEA3 Disturbs ∆pH-Dependent Regulation of Photosynthesis. PLANT PHYSIOLOGY 2019; 181:762-773. [PMID: 31427465 PMCID: PMC6776848 DOI: 10.1104/pp.19.00766] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 08/07/2019] [Indexed: 05/19/2023]
Abstract
The thylakoid K+ efflux antiporter 3 (KEA3) is required for regulating components of the proton motive force (pmf), proton concentration gradient (ΔpH), and membrane potential (Δψ). The Arabidopsis (Arabidopsis thaliana) disturbed proton gradient regulation mutant (dpgr) is a dominant allele of KEA3, conferring disturbed transport activity. Here, we show that overexpressing the DPGR-type KEA3 (DPGRox) retarded plant growth, whereas overexpressing the wild-type KEA3 (KEA3ox) did not. In KEA3ox lines, the contribution of Δψ to pmf was enhanced, but in DPGRox lines, the size of pmf was reduced. In DPGRox plants, proton conductivity of the thylakoid membrane (g H +) was elevated under high light, implying disturbed stoichiometry of H+/K+ antiport through DPGR-type KEA3 rather than simply enhanced activity. The ΔpH-dependent regulation consisting of thermal dissipation of excessively absorbed light energy and downregulation of cytochrome b 6 f complex activity was severely and mildly affected in DPGRox and KEA3ox plants, respectively. Consequently, photosystem I was sensitive to fluctuating light in both transgenic plants. Both photosystems were sensitive to constant high light and were slightly photodamaged even at standard growth light intensity in DPGRox plants. KEA3 regulates the components of pmf and optimizes the operation of ∆pH-dependent regulation of electron transport.
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Affiliation(s)
- Caijuan Wang
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
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85
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Zulfugarov IS, Wu G, Tovuu A, Lee CH. Effect of oxygen on the non-photochemical quenching of vascular plants and potential oxygen deficiency in the stroma of PsbS-knock-out rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 286:1-6. [PMID: 31300135 DOI: 10.1016/j.plantsci.2019.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/25/2019] [Accepted: 05/18/2019] [Indexed: 06/10/2023]
Abstract
The excessive and harmful light energy absorbed by the photosystem (PS) II of higher plants is dissipated as heat through a protective mechanism termed non-photochemical quenching (NPQ) of chlorophyll fluorescence. PsbS-knock-out (KO) mutants lack the trans-thylakoid proton gradient (ΔpH)-dependent part of NPQ. To elucidate the molecular mechanism of NPQ, we investigated its dependency on oxygen. The development of NPQ in wild-type (WT) rice under low-oxygen (LO) conditions was reduced to more than 50% of its original value. However, under high-oxygen (HO) conditions, the NPQ of both WT and PsbS-KO mutants recovered. Moreover, WT and PsbS-KO mutant leaves infiltrated with the ΔpH dissipating uncoupler nigericin showed increased NPQ values under HO conditions. The experiments using intact chloroplasts and protoplasts of Arabidopsis thaliana supported that the LO effects observed in rice leaves were not due to carbon dioxide deficiency. There was a noticeable 90% reduction in the half-time of P700 oxidation rate in LO-treated leaves compared with that of WT control leaves, but the HO treatment did not significantly change the half-time of P700 oxidation rate. Overall, the results obtained here indicate that the stroma of the PsbS-KO plants could be potentially under O2 deficiency. Because the functions of PsbS in rice leaves are likely to be similar to those in other higher plants, our findings offer novel insights into the role of oxygen in the development of NPQ.
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Affiliation(s)
- Ismayil S Zulfugarov
- Department of Integrated Biological Science and Department of Molecular Biology, Pusan National University, Busan 46241, Republic of Korea; Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, Baku AZ 1073, Azerbaijan; Department of Biology, North-Eastern Federal University, 58 Belinsky Str., Yakutsk 677-027, Republic of Sakha (Yakutia), Russian Federation
| | - Guangxi Wu
- Department of Integrated Biological Science and Department of Molecular Biology, Pusan National University, Busan 46241, Republic of Korea
| | - Altanzaya Tovuu
- Department of Integrated Biological Science and Department of Molecular Biology, Pusan National University, Busan 46241, Republic of Korea
| | - Choon-Hwan Lee
- Department of Integrated Biological Science and Department of Molecular Biology, Pusan National University, Busan 46241, Republic of Korea.
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86
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Kaňa R, Kotabová E, Šedivá B, Kuthanová Trsková E. Photoprotective strategies in the motile cryptophyte alga Rhodomonas salina-role of non-photochemical quenching, ions, photoinhibition, and cell motility. Folia Microbiol (Praha) 2019; 64:691-703. [PMID: 31352667 DOI: 10.1007/s12223-019-00742-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022]
Abstract
We explored photoprotective strategies in a cryptophyte alga Rhodomonas salina. This cryptophytic alga represents phototrophs where chlorophyll a/c antennas in thylakoids are combined with additional light-harvesting system formed by phycobiliproteins in the chloroplast lumen. The fastest response to excessive irradiation is induction of non-photochemical quenching (NPQ). The maximal NPQ appears already after 20 s of excessive irradiation. This initial phase of NPQ is sensitive to Ca2+ channel inhibitor (diltiazem) and disappears, also, in the presence of non-actin, an ionophore for monovalent cations. The prolonged exposure to high light of R. salina cells causes photoinhibition of photosystem II (PSII) that can be further enhanced when Ca2+ fluxes are inhibited by diltiazem. The light-induced reduction in PSII photochemical activity is smaller when compared with immotile diatom Phaeodactylum tricornutum. We explain this as a result of their different photoprotective strategies. Besides the protective role of NPQ, the motile R. salina also minimizes high light exposure by increased cell velocity by almost 25% percent (25% from 82 to 104 μm/s). We suggest that motility of algal cells might have a photoprotective role at high light because algal cell rotation around longitudinal axes changes continual irradiation to periodically fluctuating light.
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Affiliation(s)
- Radek Kaňa
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.
| | - Eva Kotabová
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Barbora Šedivá
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Eliška Kuthanová Trsková
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.,Student of Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, Ceske Budejovice, Czech Republic
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87
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Tsujii M, Kera K, Hamamoto S, Kuromori T, Shikanai T, Uozumi N. Evidence for potassium transport activity of Arabidopsis KEA1-KEA6. Sci Rep 2019; 9:10040. [PMID: 31296940 PMCID: PMC6624313 DOI: 10.1038/s41598-019-46463-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/24/2019] [Indexed: 12/12/2022] Open
Abstract
Arabidopsis thaliana contains the putative K+ efflux transporters KEA1-KEA6, similar to KefB and KefC of Escherichia coli. KEA1-KEA3 are involved in the regulation of photosynthetic electron transport and chloroplast development. KEA4-KEA6 mediate pH regulation of the endomembrane network during salinity stress. However, the ion transport activities of KEA1-KEA6 have not been directly characterized. In this study, we used an E. coli expression system to examine KEA activity. KEA1-KEA3 and KEA5 showed bi-directional K+ transport activity, whereas KEA4 and KEA6 functioned as a K+ uptake system. The thylakoid membrane-localized Na+/H+ antiporter NhaS3 from the model cyanobacterium Synechocystis is the closest homolog of KEA3. Changing the putative Na+/H+ selective site of KEA3 (Gln-Asp) to that of NhaS3 (Asp-Asp) did not alter the ion selectivity without loss of K+ transport activity. The first residue in the conserved motif was not a determinant for K+ or Na+ selectivity. Deletion of the possible nucleotide-binding KTN domain from KEA3 lowered K+ transport activity, indicating that the KTN domain was important for this function. The KEA3-G422R mutation discovered in the Arabidopsis dpgr mutant increased K+ transport activity, consistent with the mutant phenotype. These results indicate that Arabidopsis KEA1-KEA6 act as K+ transport systems, and support the interpretation that KEA3 promotes dissipation of ΔpH in the thylakoid membrane.
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Affiliation(s)
- Masaru Tsujii
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai, 980-8579, Japan
| | - Kota Kera
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai, 980-8579, Japan
| | - Shin Hamamoto
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai, 980-8579, Japan
| | - Takashi Kuromori
- RIKEN Center for Sustainable Resource Science, Wako, Saitama, 351-0198, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Nobuyuki Uozumi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai, 980-8579, Japan.
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88
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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 PHYSIOLOGY 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] [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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89
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Bouchnak I, Brugière S, Moyet L, Le Gall S, Salvi D, Kuntz M, Tardif M, Rolland N. Unraveling Hidden Components of the Chloroplast Envelope Proteome: Opportunities and Limits of Better MS Sensitivity. Mol Cell Proteomics 2019; 18:1285-1306. [PMID: 30962257 PMCID: PMC6601204 DOI: 10.1074/mcp.ra118.000988] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 04/03/2019] [Indexed: 12/31/2022] Open
Abstract
The chloroplast is a major plant cell organelle that fulfills essential metabolic and biosynthetic functions. Located at the interface between the chloroplast and other cell compartments, the chloroplast envelope system is a strategic barrier controlling the exchange of ions, metabolites and proteins, thus regulating essential metabolic functions (synthesis of hormones precursors, amino acids, pigments, sugars, vitamins, lipids, nucleotides etc.) of the plant cell. However, unraveling the contents of the chloroplast envelope proteome remains a difficult challenge; many proteins constituting this functional double membrane system remain to be identified. Indeed, the envelope contains only 1% of the chloroplast proteins (i.e. 0.4% of the whole cell proteome). In other words, most envelope proteins are so rare at the cell, chloroplast, or even envelope level, that they remained undetectable using targeted MS studies. Cross-contamination of chloroplast subcompartments by each other and by other cell compartments during cell fractionation, impedes accurate localization of many envelope proteins. The aim of the present study was to take advantage of technologically improved MS sensitivity to better define the proteome of the chloroplast envelope (differentiate genuine envelope proteins from contaminants). This MS-based analysis relied on an enrichment factor that was calculated for each protein identified in purified envelope fractions as compared with the value obtained for the same protein in crude cell extracts. Using this approach, a total of 1269 proteins were detected in purified envelope fractions, of which, 462 could be assigned an envelope localization by combining MS-based spectral count analyses with manual annotation using data from the literature and prediction tools. Many of such proteins being previously unknown envelope components, these data constitute a new resource of significant value to the broader plant science community aiming to define principles and molecular mechanisms controlling fundamental aspects of plastid biogenesis and functions.
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Affiliation(s)
- Imen Bouchnak
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France
| | - Sabine Brugière
- §University Grenoble Alpes, CEA, Inserm, IRIG-BGE, 38000 Grenoble, France
| | - Lucas Moyet
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France
| | - Sophie Le Gall
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France
| | - Daniel Salvi
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France
| | - Marcel Kuntz
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France
| | - Marianne Tardif
- §University Grenoble Alpes, CEA, Inserm, IRIG-BGE, 38000 Grenoble, France
| | - Norbert Rolland
- From the ‡University Grenoble Alpes, INRA, CNRS, CEA, IRIG-LPCV, 38000 Grenoble, France;.
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90
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K + and Cl - channels/transporters independently fine-tune photosynthesis in plants. Sci Rep 2019; 9:8639. [PMID: 31201341 PMCID: PMC6570773 DOI: 10.1038/s41598-019-44972-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 05/29/2019] [Indexed: 12/14/2022] Open
Abstract
In variable light environments, plants adjust light use in photosynthetic electron transport and photoprotective dissipation in the thylakoid membrane. In this respect, roles of the K+/H+ antiporter KEA3, the Cl- channel/transporter CLCe and the voltage-dependent Cl- channel VCCN1 have been unraveled in Arabidopsis thaliana. Here we report that they independently adjust photosynthesis on the basis of analyses using single and higher order loss-of-function mutants. In short experiments of photosynthetic response on transition from dark to low light, we reveal a sequential functioning of VCCN1 and CLCe in the activation of photoprotection and of KEA3 in its downregulation to a low steady state while adjusting the electron transport. On transition from low to high light, VCCN1 accelerates the activation of photoprotection, whereas KEA3 slows it down on transition from high to low light. Based on parallel electrochromic band shift measurements, the mechanism behind is that VCCN1 builds up a pH gradient across the thylakoid membrane, whereas KEA3 dissipates this gradient, which affects photoprotection. CLCe regulates photosynthesis by a pH-independent mechanism likely involving Cl- homeostasis. Nevertheless, all genotypes grow well in alternating high and low light. Taken together, the three studied ion channels/transporters function independently in adjusting photosynthesis to the light environment.
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91
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Tanaka Y, Adachi S, Yamori W. Natural genetic variation of the photosynthetic induction response to fluctuating light environment. CURRENT OPINION IN PLANT BIOLOGY 2019; 49:52-59. [PMID: 31202005 DOI: 10.1016/j.pbi.2019.04.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 04/13/2019] [Accepted: 04/25/2019] [Indexed: 05/08/2023]
Abstract
Field-grown plants experience fluctuating light intensity for periods extending from seconds to hours because of cloud movements and self-shading. When full light intensity returns after shading, the net CO2 assimilation rate in leaves does not reach its maximum value immediately, but rises gradually over several minutes to approach a new steady state. This phenomenon has been termed photosynthetic induction, which substantially affects the efficiency of carbon fixation, and thus crop production. The significant natural variation of the speed of induction response exists among not only interspecies but also intraspecies. Recent advances in molecular analysis and high-throughput measurement techniques have revealed the genetic and eco-physiological basis of observed genetic variations in photosynthetic induction response. Here, we review the current understanding of the physiological and genetic mechanisms behind photosynthetic induction, and discusses routes to further advances.
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Affiliation(s)
- Yu Tanaka
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan; Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Japan.
| | - Shunsuke Adachi
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Wataru Yamori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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92
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Sukhov VS, Gromova EN, Sukhova EM, Surova LM, Nerush VN, Vodeneev VA. Analysis of Correlations between the Indexes of Light-Dependent Reactions of Photosynthesis and the Photochemical Reflectance Index (PRI) in Pea Leaves under Short-Term Illumination. BIOCHEMISTRY (MOSCOW), SUPPLEMENT SERIES A: MEMBRANE AND CELL BIOLOGY 2019. [DOI: 10.1134/s1990747818040128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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93
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Shimakawa G, Miyake C. What Quantity of Photosystem I Is Optimum for Safe Photosynthesis? PLANT PHYSIOLOGY 2019; 179:1479-1485. [PMID: 30670604 PMCID: PMC6446780 DOI: 10.1104/pp.18.01493] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/15/2019] [Indexed: 05/05/2023]
Abstract
PSI has the potential to generate reactive oxygen species and be oxidatively inactivated by the reactive oxygen species. The photo-oxidative damage of PSI (also called PSI photoinhibition) causes the inhibition of the plant growth and is a lethal event for plants. It has been reported that PSI photoinhibition does not occur as long as the reaction-center chlorophyll (P700) remains oxidized, even in excess light conditions. This process is termed P700 oxidation and is supported by various regulatory mechanisms and likely also by the stoichiometric quantities of photosynthetic apparatus. In this study, we assessed how decreased photochemically active PSI in Arabidopsis (Arabidopsis thaliana) affected a variety of photosynthetic parameters, including P700 oxidation. Inactivation of PSI was rapidly and selectively induced by repetitive short-pulse illumination. PSI photoinhibition correlated linearly with decreases in effective quantum yield of PSII and nonphotochemical quenching; however, the photosynthetic CO2 assimilation rate was less affected, as exemplified by ∼50% of the normal CO2 assimilation rate maintained with an 80% loss in PSI photochemical activity. In contrast, effective quantum yield of PSI was enhanced following PSI photoinhibition, mainly owing to a decrease in the electron donor-side limitation of PSI. Based on these results, we propose that the stoichiometric quantity of PSI is optimized to induce P700 oxidation for dissipating excess light energy in PSI, thus avoiding inhibition of photosynthetic CO2 assimilation caused by PSI photoinhibition.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Nada, Kobe 657-8501, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Nada, Kobe 657-8501, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Tokyo 102-0076, Japan
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94
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Schneider T, Bolger A, Zeier J, Preiskowski S, Benes V, Trenkamp S, Usadel B, Farré EM, Matsubara S. Fluctuating Light Interacts with Time of Day and Leaf Development Stage to Reprogram Gene Expression. PLANT PHYSIOLOGY 2019; 179:1632-1657. [PMID: 30718349 PMCID: PMC6446761 DOI: 10.1104/pp.18.01443] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/23/2019] [Indexed: 05/20/2023]
Abstract
Natural light environments are highly variable. Flexible adjustment between light energy utilization and photoprotection is therefore of vital importance for plant performance and fitness in the field. Short-term reactions to changing light intensity are triggered inside chloroplasts and leaves within seconds to minutes, whereas long-term adjustments proceed over hours and days, integrating multiple signals. While the mechanisms of long-term acclimation to light intensity have been studied by changing constant growth light intensity during the day, responses to fluctuating growth light intensity have rarely been inspected in detail. We performed transcriptome profiling in Arabidopsis (Arabidopsis thaliana) leaves to investigate long-term gene expression responses to fluctuating light (FL). In particular, we examined whether responses differ between young and mature leaves or between morning and the end of the day. Our results highlight global reprogramming of gene expression under FL, including that of genes related to photoprotection, photosynthesis, and photorespiration and to pigment, prenylquinone, and vitamin metabolism. The FL-induced changes in gene expression varied between young and mature leaves at the same time point and between the same leaves in the morning and at the end of the day, indicating interactions of FL acclimation with leaf development stage and time of day. Only 46 genes were up- or down-regulated in both young and mature leaves at both time points. Combined analyses of gene coexpression and cis-elements pointed to a role of the circadian clock and light in coordinating the acclimatory responses of functionally related genes. Our results also suggest a possible cross talk between FL acclimation and systemic acquired resistance-like gene expression in young leaves.
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Affiliation(s)
- Trang Schneider
- IBG-2: Plant Sciences, Forschungszentrum Jülich, D-52425 Juelich, Germany
- Heinrich Heine University, D-40225 Duesseldorf, Germany
| | - Anthony Bolger
- Institute for Biology I: Institute for Botany and Molecular Genetics, RWTH Aachen University, D-52074 Aachen, Germany
| | - Jürgen Zeier
- Heinrich Heine University, D-40225 Duesseldorf, Germany
| | - Sabine Preiskowski
- IBG-2: Plant Sciences, Forschungszentrum Jülich, D-52425 Juelich, Germany
| | - Vladimir Benes
- Genomics Core Facility, EMBL Heidelberg, D-69117 Heidelberg, Germany
| | | | - Björn Usadel
- IBG-2: Plant Sciences, Forschungszentrum Jülich, D-52425 Juelich, Germany
- Institute for Biology I: Institute for Botany and Molecular Genetics, RWTH Aachen University, D-52074 Aachen, Germany
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Shizue Matsubara
- IBG-2: Plant Sciences, Forschungszentrum Jülich, D-52425 Juelich, Germany
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95
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Sharma H, Taneja M, Upadhyay SK. Identification, characterization and expression profiling of cation-proton antiporter superfamily in Triticum aestivum L. and functional analysis of TaNHX4-B. Genomics 2019; 112:356-370. [PMID: 30818061 DOI: 10.1016/j.ygeno.2019.02.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/18/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022]
Abstract
The monovalent cation proton antiporter (CPA) superfamily comprises Na+/H+ exchanger (NHX), K+ efflux antiporter (KEA), and cation/H+ exchanger (CHX) family proteins, which play vital functions in plants. A total of 107 TaCPA proteins were identified in Triticum aestivum, and phylogenetically classified into 35 TaNHX, 24 TaKEA and 48 TaCHX proteins. These families had representatives derived from all three sub-genomes. TaKEA genes consisted of higher number of exons, followed by TaNHXs and TaCHXs. The occurrence of about 10 transmembrane regions and higher composition of helices and coils support their membrane-bound and hydrophobic nature. Diverse expression in various tissues and modulated expression under stress conditions suggested their role in development and in response to stress. Co-expression analyses revealed their complex interaction networks. Expression of TaNHX4-B.1 and TaNHX4-B.4 facilitated differential abiotic stress tolerance to Escherichia coli. Our study provides comprehensive information about CPA genes, which would be useful in their future functional characterization.
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Affiliation(s)
- Himanshu Sharma
- Department of Botany, Panjab University, Sector 14, Chandigarh 160014, India
| | - Mehak Taneja
- Department of Botany, Panjab University, Sector 14, Chandigarh 160014, India
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96
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Wang Y, Tang RJ, Yang X, Zheng X, Shao Q, Tang QL, Fu A, Luan S. Golgi-localized cation/proton exchangers regulate ionic homeostasis and skotomorphogenesis in Arabidopsis. PLANT, CELL & ENVIRONMENT 2019; 42:673-687. [PMID: 30255504 DOI: 10.1111/pce.13452] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/14/2018] [Accepted: 09/22/2018] [Indexed: 05/24/2023]
Abstract
Multiple transporters and channels mediate cation transport across the plasma membrane and tonoplast to regulate ionic homeostasis in plant cells. However, much less is known about the molecular function of transporters that facilitate cation transport in other organelles such as Golgi. We report here that Arabidopsis KEA4, KEA5, and KEA6, members of cation/proton antiporters-2 (CPA2) superfamily were colocalized with the known Golgi marker, SYP32-mCherry. Although single kea4,5,6 mutants showed similar phenotype as the wild type under various conditions, kea4/5/6 triple mutants showed hypersensitivity to low pH, high K+ , and high Na+ and displayed growth defects in darkness, suggesting that these three KEA-type transporters function redundantly in controlling etiolated seedling growth and ion homeostasis. Detailed analysis indicated that the kea4/5/6 triple mutant exhibited cell wall biosynthesis defect during the rapid etiolated seedling growth and under high K+ /Na+ condition. The cell wall-derived pectin homogalacturonan (GalA)3 partially suppressed the growth defects and ionic toxicity in the kea4/5/6 triple mutants when grown in the dark but not in the light conditions. Together, these data support the hypothesis that the Golgi-localized KEAs play key roles in the maintenance of ionic and pH homeostasis, thereby facilitating Golgi function in cell wall biosynthesis during rapid etiolated seedling growth and in coping with high K+ /Na+ stress.
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Affiliation(s)
- Yuan Wang
- College of Life Sciences, Northwest University, Xi'an, China
- Department of Plant and Microbial Biology, University of California, Berkeley, California
| | - Ren-Jie Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, California
| | - Xiyan Yang
- Department of Plant and Microbial Biology, University of California, Berkeley, California
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Xiaojiang Zheng
- College of Life Sciences, Northwest University, Xi'an, China
- Department of Plant and Microbial Biology, University of California, Berkeley, California
| | - Qiaolin Shao
- Department of Plant and Microbial Biology, University of California, Berkeley, California
- The State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Qing-Lin Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, California
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Southwest University, Chongqing, China
| | - Aigen Fu
- College of Life Sciences, Northwest University, Xi'an, China
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, California
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97
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Liu J, Lu Y, Hua W, Last RL. A New Light on Photosystem II Maintenance in Oxygenic Photosynthesis. FRONTIERS IN PLANT SCIENCE 2019; 10:975. [PMID: 31417592 PMCID: PMC6685048 DOI: 10.3389/fpls.2019.00975] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 07/11/2019] [Indexed: 05/19/2023]
Abstract
Life on earth is sustained by oxygenic photosynthesis, a process that converts solar energy, carbon dioxide, and water into chemical energy and biomass. Sunlight is essential for growth and productivity of photosynthetic organisms. However, exposure to an excessive amount of light adversely affects fitness due to photooxidative damage to the photosynthetic machinery, primarily to the reaction center of the oxygen-evolving photosystem II (PSII). Photosynthetic organisms have evolved diverse photoprotective and adaptive strategies to avoid, alleviate, and repair PSII damage caused by high-irradiance or fluctuating light. Rapid and harmless dissipation of excess absorbed light within antenna as heat, which is measured by chlorophyll fluorescence as non-photochemical quenching (NPQ), constitutes one of the most efficient protective strategies. In parallel, an elaborate repair system represents another efficient strategy to maintain PSII reaction centers in active states. This article reviews both the reaction center-based strategy for robust repair of photodamaged PSII and the antenna-based strategy for swift control of PSII light-harvesting (NPQ). We discuss evolutionarily and mechanistically diverse strategies used by photosynthetic organisms to maintain PSII function for growth and productivity under static high-irradiance light or fluctuating light environments. Knowledge of mechanisms underlying PSII maintenance would facilitate bioengineering photosynthesis to enhance agricultural productivity and sustainability to feed a growing world population amidst climate change.
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Affiliation(s)
- Jun Liu
- Department of Functional Genomics and Molecular Biology, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Jun Liu,
| | - Yan Lu
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
| | - Wei Hua
- Department of Functional Genomics and Molecular Biology, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Wei Hua
| | - Robert L. Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
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98
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Shimadzu S, Seo M, Terashima I, Yamori W. Whole Irradiated Plant Leaves Showed Faster Photosynthetic Induction Than Individually Irradiated Leaves via Improved Stomatal Opening. FRONTIERS IN PLANT SCIENCE 2019; 10:1512. [PMID: 31850018 PMCID: PMC6892984 DOI: 10.3389/fpls.2019.01512] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 10/31/2019] [Indexed: 05/03/2023]
Abstract
Rapid photosynthetic induction is crucial for plants under fluctuating light conditions in a crop canopy as well as in an understory. Most previous studies have focused on photosynthetic induction responses in a single leaf, whereas the systemic responses of the whole plant have not been considered. In a natural environment, however, both single leaves and whole plants are exposed to sunlight, since the light environment is not uniform even within a given plant. In the present study, we examined whether there is any difference between the photosynthetic induction response of a leaf of a whole irradiated plant and an individually irradiated leaf in Arabidopsis thaliana to consider photosynthetic induction as the response of a whole plant. We used two methods, the visualization of photosynthesis and direct measurements of gas-exchange and Chl fluorescence, to demonstrate that whole irradiated plant promoted its photosynthetic induction via improved stomatal opening compared with individually irradiated leaf. Furthermore, using two Arabidopsis knockout mutants of abscisic acid transporter, abcg25 and abcg40, the present study suggests that abscisic acid could be involved in this systemic response for stomatal opening, allowing plants to optimize the use of light energy at minimal cost in plants in a dynamic light environment.
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Affiliation(s)
- Shunji Shimadzu
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Wataru Yamori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Institute for Sustainable Agro-Ecosystem Services, The University of Tokyo, Nishitokyo, Japan
- *Correspondence: Wataru Yamori,
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99
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Schneider D, Lopez LS, Li M, Crawford JD, Kirchhoff H, Kunz HH. Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM. PLANT METHODS 2019; 15:156. [PMID: 31889980 PMCID: PMC6927185 DOI: 10.1186/s13007-019-0546-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/09/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Over the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field. RESULTS We show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup. CONCLUSIONS With material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.
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Affiliation(s)
- Dominik Schneider
- Compact Plants Phenomics Center, Washington State University, PO Box 646340, Pullman, WA 99164-6340 USA
- Institute of Biological Chemistry, Washington State University, PO Box 646340, Pullman, WA 99164-6340 USA
| | - Laura S. Lopez
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236 USA
| | - Meng Li
- Institute of Biological Chemistry, Washington State University, PO Box 646340, Pullman, WA 99164-6340 USA
| | - Joseph D. Crawford
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236 USA
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, PO Box 646340, Pullman, WA 99164-6340 USA
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236 USA
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100
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Frank J, Happeck R, Meier B, Hoang MTT, Stribny J, Hause G, Ding H, Morsomme P, Baginsky S, Peiter E. Chloroplast-localized BICAT proteins shape stromal calcium signals and are required for efficient photosynthesis. THE NEW PHYTOLOGIST 2019; 221:866-880. [PMID: 30169890 DOI: 10.1111/nph.15407] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/17/2018] [Indexed: 05/18/2023]
Abstract
The photosynthetic machinery of plants must be regulated to maximize the efficiency of light reactions and CO2 fixation. Changes in free Ca2+ in the stroma of chloroplasts have been observed at the transition between light and darkness, and also in response to stress stimuli. Such Ca2+ dynamics have been proposed to regulate photosynthetic capacity. However, the molecular mechanisms of Ca2+ fluxes in the chloroplasts have been unknown. By employing a Ca2+ reporter-based approach, we identified two chloroplast-localized Ca2+ transporters in Arabidopsis thaliana, BICAT1 and BICAT2, that determine the amplitude of the darkness-induced Ca2+ signal in the chloroplast stroma. BICAT2 mediated Ca2+ uptake across the chloroplast envelope, and its knockout mutation strongly dampened the dark-induced [Ca2+ ]stroma signal. Conversely, this Ca2+ transient was increased in knockout mutants of BICAT1, which transports Ca2+ into the thylakoid lumen. Knockout mutation of BICAT2 caused severe defects in chloroplast morphology, pigmentation and photosynthetic light reactions, rendering bicat2 mutants barely viable under autotrophic growth conditions, while bicat1 mutants were less affected. These results show that BICAT transporters play a role in chloroplast Ca2+ homeostasis. They are also involved in the regulation of photosynthesis and plant productivity. Further work will be required to reveal whether the effect on photosynthesis is a direct result of their role as Ca2+ transporters.
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Affiliation(s)
- Julia Frank
- Institute for Biochemistry and Biotechnology, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Ricardo Happeck
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Bastian Meier
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Minh Thi Thanh Hoang
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Jiri Stribny
- Louvain Institute of Biomolecular Science and Technology (LIBST), Université Catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium
| | - Gerd Hause
- Biocenter, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Haidong Ding
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, China
| | - Pierre Morsomme
- Louvain Institute of Biomolecular Science and Technology (LIBST), Université Catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium
| | - Sacha Baginsky
- Institute for Biochemistry and Biotechnology, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
| | - Edgar Peiter
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, D-06120, Halle (Saale), Germany
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