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Sekiguchi T, Yoshida K, Wakabayashi KI, Hisabori T. Proton gradient across the chloroplast thylakoid membrane governs the redox regulatory function of ATP synthase. J Biol Chem 2024; 300:107659. [PMID: 39128728 PMCID: PMC11406350 DOI: 10.1016/j.jbc.2024.107659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/23/2024] [Accepted: 08/01/2024] [Indexed: 08/13/2024] Open
Abstract
Chloroplast ATP synthase (CFoCF1) synthesizes ATP by using a proton electrochemical gradient across the thylakoid membrane, termed ΔμH+, as an energy source. This gradient is necessary not only for ATP synthesis but also for reductive activation of CFoCF1 by thioredoxin, using reducing equivalents produced by the photosynthetic electron transport chain. ΔμH+ comprises two thermodynamic components: pH differences across the membrane (ΔpH) and the transmembrane electrical potential (ΔΨ). In chloroplasts, the ratio of these two components in ΔμH+ is crucial for efficient solar energy utilization. However, the specific contribution of each component to the reductive activation of CFoCF1 remains unclear. In this study, an in vitro assay system for evaluating thioredoxin-mediated CFoCF1 reduction is established, allowing manipulation of ΔμH+ components in isolated thylakoid membranes using specific chemicals. Our biochemical analyses revealed that ΔpH formation is essential for thioredoxin-mediated CFoCF1 reduction on the thylakoid membrane, whereas ΔΨ formation is nonessential.
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Affiliation(s)
- Takatoshi Sekiguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Ken-Ichi Wakabayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan; International Research Frontiers Initiative, Tokyo Institute of Technology, Yokohama, Japan.
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2
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Rey P, Henri P, Alric J, Blanchard L, Viola S. Participation of the stress-responsive CDSP32 thioredoxin in the modulation of chloroplast ATP-synthase activity in Solanum tuberosum. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39189948 DOI: 10.1111/pce.15101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 08/06/2024] [Accepted: 08/09/2024] [Indexed: 08/28/2024]
Abstract
Plant thioredoxins (TRXs) are involved in numerous metabolic and signalling pathways, such as light-dependent regulation of photosynthesis. The atypical TRX CDSP32, chloroplastic drought-induced stress protein of 32 kDa, includes two TRX-fold domains and participates in responses to oxidative stress as an electron donor to other thiol reductases. Here, we further characterised potato lines modified for CDSP32 expression to clarify the physiological roles of the TRX. Upon high salt treatments, modified lines displayed changes in the abundance and redox status of CDSP32 antioxidant partners, and exhibited sensitivity to combined saline-alkaline stress. In non-stressed plants overexpressing CDSP32, a lower abundance of photosystem II subunits and ATP-synthase γ subunit was noticed. The CDSP32 co-suppressed line showed altered chlorophyll a fluorescence induction and impaired regulation of the transthylakoid membrane potential during dark/light and light/dark transitions. These data, in agreement with the previously reported interaction between CDSP32 and ATP-synthase γ subunit, suggest that CDSP32 affects the redox regulation of ATP-synthase activity. Consistently, modelling of protein complex 3-D structure indicates that CDSP32 could constitute a suitable partner of ATP-synthase γ subunit. We discuss the roles of the TRX in the regulation of both photosynthetic activity and enzymatic antioxidant network in relation with environmental conditions.
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Affiliation(s)
- Pascal Rey
- Aix Marseille University, CEA, CNRS, BIAM, Photosynthesis & Environment (P&E) Team, Saint Paul, France
| | - Patricia Henri
- Aix Marseille University, CEA, CNRS, BIAM, Photosynthesis & Environment (P&E) Team, Saint Paul, France
| | - Jean Alric
- Aix Marseille University, CEA, CNRS, BIAM, Photosynthesis & Environment (P&E) Team, Saint Paul, France
| | - Laurence Blanchard
- Aix Marseille University, CEA, CNRS, BIAM, Molecular and Environmental Microbiology (MEM) Team, Saint Paul, France
| | - Stefania Viola
- Aix Marseille University, CEA, CNRS, BIAM, Photosynthesis & Environment (P&E) Team, Saint Paul, France
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3
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Yoshida K, Hisabori T. Divergent Protein Redox Dynamics and Their Relationship with Electron Transport Efficiency during Photosynthesis Induction. PLANT & CELL PHYSIOLOGY 2024; 65:737-747. [PMID: 38305687 PMCID: PMC11138366 DOI: 10.1093/pcp/pcae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/08/2024] [Accepted: 01/31/2024] [Indexed: 02/03/2024]
Abstract
Various chloroplast proteins are activated/deactivated during the light/dark cycle via the redox regulation system. Although the photosynthetic electron transport chain provides reducing power to redox-sensitive proteins via the ferredoxin (Fd)/thioredoxin (Trx) pathway for their enzymatic activity control, how the redox states of individual proteins are linked to electron transport efficiency remains uncharacterized. Here we addressed this subject with a focus on the photosynthetic induction phase. We used Arabidopsis plants, in which the amount of Fd-Trx reductase (FTR), a core component in the Fd/Trx pathway, was genetically altered. Several chloroplast proteins showed different redox shift responses toward low- and high-light treatments. The light-dependent reduction of Calvin-Benson cycle enzymes fructose 1,6-bisphosphatase (FBPase) and sedoheptulose 1,7-bisphosphatase (SBPase) was partially impaired in the FTR-knockdown ftrb mutant. Simultaneous analyses of chlorophyll fluorescence and P700 absorbance change indicated that the induction of the electron transport reactions was delayed in the ftrb mutant. FTR overexpression also mildly affected the reduction patterns of FBPase and SBPase under high-light conditions, which were accompanied by the modification of electron transport properties. Accordingly, the redox states of FBPase and SBPase were linearly correlated with electron transport rates. In contrast, ATP synthase was highly reduced even when electron transport reactions were not fully induced. Furthermore, the redox response of proton gradient regulation 5-like photosynthetic phenotype1 (PGRL1; a protein involved in cyclic electron transport) did not correlate with electron transport rates. Our results provide insights into the working dynamics of the redox regulation system and their differential associations with photosynthetic electron transport efficiency.
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Affiliation(s)
- Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, 226-8501 Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, 226-8501 Japan
- Internantional Research Frontiers Initiative, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, 226-8501 Japan
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4
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Okegawa Y, Sato N, Nakakura R, Murai R, Sakamoto W, Motohashi K. x- and y-type thioredoxins maintain redox homeostasis on photosystem I acceptor side under fluctuating light. PLANT PHYSIOLOGY 2023; 193:2498-2512. [PMID: 37606239 PMCID: PMC10663110 DOI: 10.1093/plphys/kiad466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 08/07/2023] [Indexed: 08/23/2023]
Abstract
Plants cope with sudden increases in light intensity through various photoprotective mechanisms. Redox regulation by thioredoxin (Trx) systems also contributes to this process. Whereas the functions of f- and m-type Trxs in response to such fluctuating light conditions have been extensively investigated, those of x- and y-type Trxs are largely unknown. Here, we analyzed the trx x single, trx y1 trx y2 double, and trx x trx y1 trx y2 triple mutants in Arabidopsis (Arabidopsis thaliana). A detailed analysis of photosynthesis revealed changes in photosystem I (PSI) parameters under low light in trx x and trx x trx y1 trx y2. The electron acceptor side of PSI was more reduced in these mutants than in the wild type. This mutant phenotype was more pronounced under fluctuating light conditions. During both low- and high-light phases, the PSI acceptor side was largely limited in trx x and trx x trx y1 trx y2. After fluctuating light treatment, we observed more severe PSI photoinhibition in trx x and trx x trx y1 trx y2 than in the wild type. Furthermore, when grown under fluctuating light conditions, trx x and trx x trx y1 trx y2 plants showed impaired growth and decreased level of PSI subunits. These results suggest that Trx x and Trx y prevent redox imbalance on the PSI acceptor side, which is required to protect PSI from photoinhibition, especially under fluctuating light. We also propose that Trx x and Trx y contribute to maintaining the redox balance even under constant low-light conditions to prepare for sudden increases in light intensity.
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Affiliation(s)
- Yuki Okegawa
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Nozomi Sato
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
| | - Rino Nakakura
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
| | - Ryota Murai
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Ken Motohashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kyoto 603-8047, Japan
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5
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Li Y, Zhang L, Shen Y, Peng L, Gao F. CBSX2 is required for the efficient oxidation of chloroplast redox-regulated enzymes in darkness. PLANT DIRECT 2023; 7:e542. [PMID: 38028645 PMCID: PMC10643993 DOI: 10.1002/pld3.542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/10/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023]
Abstract
Thiol/disulfide-based redox regulation in plant chloroplasts is essential for controlling the activity of target proteins in response to light signals. One of the examples of such a role in chloroplasts is the activity of the chloroplast ATP synthase (CFoCF1), which is regulated by the redox state of the CF1γ subunit and involves two cysteines in its central domain. To investigate the mechanism underlying the oxidation of CF1γ and other chloroplast redox-regulated enzymes in the dark, we characterized the Arabidopsis cbsx2 mutant, which was isolated based on its altered NPQ (non-photochemical quenching) induction upon illumination. Whereas in dark-adapted WT plants CF1γ was completely oxidized, a small amount of CF1γ remained in the reduced state in cbsx2 under the same conditions. In this mutant, reduction of CF1γ was not affected in the light, but its oxidation was less efficient during a transition from light to darkness. The redox states of the Calvin cycle enzymes FBPase and SBPase in cbsx2 were similar to those of CF1γ during light/dark transitions. Affinity purification and subsequent analysis by mass spectrometry showed that the components of the ferredoxin-thioredoxin reductase/thioredoxin (FTR-Trx) and NADPH-dependent thioredoxin reductase (NTRC) systems as well as several 2-Cys peroxiredoxins (Prxs) can be co-purified with CBSX2. In addition to the thioredoxins, yeast two-hybrid analysis showed that CBSX2 also interacts with NTRC. Taken together, our results suggest that CBSX2 participates in the oxidation of the chloroplast redox-regulated enzymes in darkness, probably through regulation of the activity of chloroplast redox systems in vivo.
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Affiliation(s)
- Yonghong Li
- College of Biology and Brewing EngineeringTaiShan UniversityTaianChina
| | - Lin Zhang
- Shanghai Collaborative Innovation Center of Plant Germplasm Resources Development, College of Life SciencesShanghai Normal UniversityShanghaiChina
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life SciencesShanghai Normal UniversityShanghaiChina
| | - Yurou Shen
- Shanghai Collaborative Innovation Center of Plant Germplasm Resources Development, College of Life SciencesShanghai Normal UniversityShanghaiChina
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life SciencesShanghai Normal UniversityShanghaiChina
| | - Lianwei Peng
- Shanghai Collaborative Innovation Center of Plant Germplasm Resources Development, College of Life SciencesShanghai Normal UniversityShanghaiChina
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life SciencesShanghai Normal UniversityShanghaiChina
| | - Fudan Gao
- Shanghai Collaborative Innovation Center of Plant Germplasm Resources Development, College of Life SciencesShanghai Normal UniversityShanghaiChina
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life SciencesShanghai Normal UniversityShanghaiChina
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6
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Degen GE, Jackson PJ, Proctor MS, Zoulias N, Casson SA, Johnson MP. High cyclic electron transfer via the PGR5 pathway in the absence of photosynthetic control. PLANT PHYSIOLOGY 2023; 192:370-386. [PMID: 36774530 PMCID: PMC10152662 DOI: 10.1093/plphys/kiad084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 01/24/2023] [Indexed: 05/03/2023]
Abstract
The light reactions of photosynthesis couple electron and proton transfers across the thylakoid membrane, generating NADPH, and proton motive force (pmf) that powers the endergonic synthesis of ATP by ATP synthase. ATP and NADPH are required for CO2 fixation into carbohydrates by the Calvin-Benson-Bassham cycle. The dominant ΔpH component of the pmf also plays a photoprotective role in regulating photosystem II light harvesting efficiency through nonphotochemical quenching (NPQ) and photosynthetic control via electron transfer from cytochrome b6f (cytb6f) to photosystem I. ΔpH can be adjusted by increasing the proton influx into the thylakoid lumen via upregulation of cyclic electron transfer (CET) or decreasing proton efflux via downregulation of ATP synthase conductivity (gH+). The interplay and relative contributions of these two elements of ΔpH control to photoprotection are not well understood. Here, we showed that an Arabidopsis (Arabidopsis thaliana) ATP synthase mutant hunger for oxygen in photosynthetic transfer reaction 2 (hope2) with 40% higher proton efflux has supercharged CET. Double crosses of hope2 with the CET-deficient proton gradient regulation 5 and ndh-like photosynthetic complex I lines revealed that PROTON GRADIENT REGULATION 5 (PGR5)-dependent CET is the major pathway contributing to higher proton influx. PGR5-dependent CET allowed hope2 to maintain wild-type levels of ΔpH, CO2 fixation and NPQ, however photosynthetic control remained absent and PSI was prone to photoinhibition. Therefore, high CET in the absence of ATP synthase regulation is insufficient for PSI photoprotection.
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Affiliation(s)
- Gustaf E Degen
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Philip J Jackson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 4NL, UK
| | - Matthew S Proctor
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Nicholas Zoulias
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Stuart A Casson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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7
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The ferredoxin/thioredoxin pathway constitutes an indispensable redox-signaling cascade for light-dependent reduction of chloroplast stromal proteins. J Biol Chem 2022; 298:102650. [PMID: 36448836 PMCID: PMC9712825 DOI: 10.1016/j.jbc.2022.102650] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 12/02/2022] Open
Abstract
To ensure efficient photosynthesis, chloroplast proteins need to be flexibly regulated under fluctuating light conditions. Thiol-based redox regulation plays a key role in reductively activating several chloroplast proteins in a light-dependent manner. The ferredoxin (Fd)/thioredoxin (Trx) pathway has long been recognized as the machinery that transfers reducing power generated by photosynthetic electron transport reactions to redox-sensitive target proteins; however, its biological importance remains unclear, because the complete disruption of the Fd/Trx pathway in plants has been unsuccessful to date. Especially, recent identifications of multiple redox-related factors in chloroplasts, as represented by the NADPH-Trx reductase C, have raised a controversial proposal that other redox pathways work redundantly with the Fd/Trx pathway. To address these issues directly, we used CRISPR/Cas9 gene editing to create Arabidopsis mutant plants in which the activity of the Fd/Trx pathway was completely defective. The mutants generated showed severe growth inhibition. Importantly, these mutants almost entirely lost the ability to reduce several redox-sensitive proteins in chloroplast stroma, including four Calvin-Benson cycle enzymes, NADP-malate dehydrogenase, and Rubisco activase, under light conditions. These striking phenotypes were further accompanied by abnormally developed chloroplasts and a drastic decline in photosynthetic efficiency. These results indicate that the Fd/Trx pathway is indispensable for the light-responsive activation of diverse stromal proteins and photoautotrophic growth of plants. Our data also suggest that the ATP synthase is exceptionally reduced by other pathways in a redundant manner. This study provides an important insight into how the chloroplast redox-regulatory system operates in vivo.
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8
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Sekiguchi T, Yoshida K, Wakabayashi KI, Hisabori T. Dissipation of the proton electrochemical gradient in chloroplasts promotes the oxidation of ATP synthase by thioredoxin-like proteins. J Biol Chem 2022; 298:102541. [PMID: 36174673 PMCID: PMC9626944 DOI: 10.1016/j.jbc.2022.102541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/15/2022] [Accepted: 09/21/2022] [Indexed: 12/05/2022] Open
Abstract
Chloroplast FoF1-ATP synthase (CFoCF1) uses an electrochemical gradient of protons across the thylakoid membrane (ΔμH+) as an energy source in the ATP synthesis reaction. CFoCF1 activity is regulated by the redox state of a Cys pair on its central axis, that is, the γ subunit (CF1-γ). When the ΔμH+ is formed by the photosynthetic electron transfer chain under light conditions, CF1-γ is reduced by thioredoxin (Trx), and the entire CFoCF1 enzyme is activated. The redox regulation of CFoCF1 is a key mechanism underlying the control of ATP synthesis under light conditions. In contrast, the oxidative deactivation process involving CFoCF1 has not been clarified. In the present study, we analyzed the oxidation of CF1-γ by two physiological oxidants in the chloroplast, namely the proteins Trx-like 2 and atypical Cys-His-rich Trx. Using the thylakoid membrane containing the reduced form of CFoCF1, we were able to assess the CF1-γ oxidation ability of these Trx-like proteins. Our kinetic analysis indicated that these proteins oxidized CF1-γ with a higher efficiency than that achieved by a chemical oxidant and typical chloroplast Trxs. Additionally, the CF1-γ oxidation rate due to Trx-like proteins and the affinity between them were changed markedly when ΔμH+ formation across the thylakoid membrane was manipulated artificially. Collectively, these results indicate that the formation status of the ΔμH+ controls the redox regulation of CFoCF1 to prevent energetic disadvantages in plants.
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Affiliation(s)
- Takatoshi Sekiguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-Ku, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-Ku, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Ken-Ichi Wakabayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-Ku, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-Ku, Yokohama, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan.
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9
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Baudry K, Barbut F, Domenichini S, Guillaumot D, Thy MP, Vanacker H, Majeran W, Krieger-Liszkay A, Issakidis-Bourguet E, Lurin C. Adenylates regulate Arabidopsis plastidial thioredoxin activities through the binding of a CBS domain protein. PLANT PHYSIOLOGY 2022; 189:2298-2314. [PMID: 35736508 PMCID: PMC9342986 DOI: 10.1093/plphys/kiac199] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/29/2022] [Indexed: 06/15/2023]
Abstract
Cystathionine-β-synthase (CBS) domains are found in proteins of all living organisms and have been proposed to play a role as energy sensors regulating protein activities through their adenosyl ligand binding capacity. In plants, members of the CBSX protein family carry a stand-alone pair of CBS domains. In Arabidopsis (Arabidopsis thaliana), CBSX1 and CBSX2 are targeted to plastids where they have been proposed to regulate thioredoxins (TRXs). TRXs are ubiquitous cysteine thiol oxido-reductases involved in the redox-based regulation of numerous enzymatic activities as well as in the regeneration of thiol-dependent peroxidases. In Arabidopsis, 10 TRX isoforms have been identified in plastids and divided into five sub-types. Here, we show that CBSX2 specifically inhibits the activities of m-type TRXs toward two chloroplast TRX-related targets. By testing activation of NADP-malate dehydrogenase and reduction of 2-Cys peroxiredoxin, we found that TRXm1/2 inhibition by CBSX2 was alleviated in the presence of AMP or ATP. We also determined, by pull-down assays, a direct interaction of CBSX2 with reduced TRXm1 and m2 that was abolished in the presence of adenosyl ligands. In addition, we report that, compared with wild-type plants, the Arabidopsis T-DNA double mutant cbsx1 cbsx2 exhibits growth and chlorophyll accumulation defects in cold conditions, suggesting a function of plastidial CBSX proteins in plant stress adaptation. Together, our results show an energy-sensing regulation of plastid TRX m activities by CBSX, possibly allowing a feedback regulation of ATP homeostasis via activation of cyclic electron flow in the chloroplast, to maintain a high energy level for optimal growth.
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Affiliation(s)
- Kevin Baudry
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | - Félix Barbut
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | | | - Damien Guillaumot
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | - Mai Pham Thy
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | - Hélène Vanacker
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | - Wojciech Majeran
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
| | - Anja Krieger-Liszkay
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette 91198, France
| | | | - Claire Lurin
- CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, Gif sur Yvette 91190, France
- CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Cité, Gif sur Yvette 91190, France
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10
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Verification of the Relationship between Redox Regulation of Thioredoxin Target Proteins and Their Proximity to Thylakoid Membranes. Antioxidants (Basel) 2022; 11:antiox11040773. [PMID: 35453458 PMCID: PMC9032623 DOI: 10.3390/antiox11040773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 02/04/2023] Open
Abstract
Thioredoxin (Trx) is a key protein of the redox regulation system in chloroplasts, where it modulates various enzyme activities. Upon light irradiation, Trx reduces the disulfide bonds of Trx target proteins (thereby turning on their activities) using reducing equivalents obtained from the photosynthetic electron transport chain. This reduction process involves a differential response, i.e., some Trx target proteins in the stroma respond slowly to the change in redox condition caused by light/dark changes, while the ATP synthase γ subunit (CF1-γ) located on the surface of thylakoid membrane responds with high sensitivity. The factors that determine this difference in redox kinetics are not yet known, although here, we hypothesize that it is due to each protein’s localization in the chloroplast, i.e., the reducing equivalents generated under light conditions can be transferred more efficiently to the proteins on thylakoid membrane than to stromal proteins. To explore this possibility, we anchored SBPase, one of the stromal Trx target proteins, to the thylakoid membrane in Arabidopsis thaliana. Analyses of the redox behaviors of the anchored and unanchored proteins showed no significant difference in their reduction kinetics, implying that protein sensitivity to redox regulation is determined by other factors.
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11
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Okegawa Y, Tsuda N, Sakamoto W, Motohashi K. Maintaining the Chloroplast Redox Balance through the PGR5-Dependent Pathway and the Trx System Is Required for Light-Dependent Activation of Photosynthetic Reactions. PLANT & CELL PHYSIOLOGY 2022; 63:92-103. [PMID: 34623443 DOI: 10.1093/pcp/pcab148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/26/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
Light-dependent activation of chloroplast enzymes is required for the rapid induction of photosynthesis after a shift from dark to light. The thioredoxin (Trx) system plays a central role in this process. In chloroplasts, the Trx system consists of two pathways: the ferredoxin (Fd)/Trx pathway and the nicotinamide adenine dinucleotide phosphate (NADPH)-Trx reductase C (NTRC) pathway. In Arabidopsis (Arabidopsis thaliana) mutants defective in either pathway, the photoreduction of thiol enzymes was impaired, resulting in decreased carbon fixation. The close relationship between the Fd/Trx pathway and proton gradient regulation 5 (PGR5)-dependent photosystem I cyclic electron transport (PSI CET) in the induction of photosynthesis was recently elucidated. However, how the PGR5-dependent pathway is involved in the NTRC pathway is unclear, although NTRC has been suggested to physically interact with PGR5. In this study, we analyzed Arabidopsis mutants lacking either the PGR5 or the chloroplast NADH dehydrogenase-like complex (NDH)-dependent PSI CET pathway in the ntrc mutant background. The ntrc pgr5 double mutant suppressed both the growth defects and the high non-photochemical quenching phenotype of the ntrc mutant when grown under long-day conditions. By contrast, the inactivation of NDH activity with the chlororespiratory reduction 2-2 mutant failed to suppress either phenotype. We discovered that the phenotypic rescue of ntrc by pgr5 is caused by the partial restoration of Trx-dependent reduction of thiol enzymes. These results suggest that electron partitioning to the PGR5-dependent pathway and the Trx system needs to be properly regulated for the activation of the Calvin-Benson-Bassham cycle enzymes during the induction of photosynthesis.
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Affiliation(s)
- Yuki Okegawa
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama, 710-0046 Japan
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto, 603-8047 Japan
| | - Natsuki Tsuda
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto, 603-8047 Japan
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama, 710-0046 Japan
| | - Ken Motohashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto, 603-8047 Japan
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Current Knowledge on Mechanisms Preventing Photosynthesis Redox Imbalance in Plants. Antioxidants (Basel) 2021; 10:antiox10111789. [PMID: 34829660 PMCID: PMC8614926 DOI: 10.3390/antiox10111789] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/28/2021] [Accepted: 11/05/2021] [Indexed: 12/03/2022] Open
Abstract
Photosynthesis includes a set of redox reactions that are the source of reducing power and energy for the assimilation of inorganic carbon, nitrogen and sulphur, thus generating organic compounds, and oxygen, which supports life on Earth. As sessile organisms, plants have to face continuous changes in environmental conditions and need to adjust the photosynthetic electron transport to prevent the accumulation of damaging oxygen by-products. The balance between photosynthetic cyclic and linear electron flows allows for the maintenance of a proper NADPH/ATP ratio that is adapted to the plant’s needs. In addition, different mechanisms to dissipate excess energy operate in plants to protect and optimise photosynthesis under adverse conditions. Recent reports show an important role of redox-based dithiol–disulphide interchanges, mediated both by classical and atypical chloroplast thioredoxins (TRXs), in the control of these photoprotective mechanisms. Moreover, membrane-anchored TRX-like proteins, such as HCF164, which transfer electrons from stromal TRXs to the thylakoid lumen, play a key role in the regulation of lumenal targets depending on the stromal redox poise. Interestingly, not all photoprotective players were reported to be under the control of TRXs. In this review, we discuss recent findings regarding the mechanisms that allow an appropriate electron flux to avoid the detrimental consequences of photosynthesis redox imbalances.
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Mellon M, Storti M, Vera-Vives AM, Kramer DM, Alboresi A, Morosinotto T. Inactivation of mitochondrial complex I stimulates chloroplast ATPase in Physcomitrium patens. PLANT PHYSIOLOGY 2021; 187:931-946. [PMID: 34608952 PMCID: PMC8491079 DOI: 10.1093/plphys/kiab276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 05/18/2021] [Indexed: 06/11/2023]
Abstract
Light is the ultimate source of energy for photosynthetic organisms, but respiration is fundamental for supporting metabolism during the night or in heterotrophic tissues. In this work, we isolated Physcomitrella (Physcomitrium patens) plants with altered respiration by inactivating Complex I (CI) of the mitochondrial electron transport chain by independently targeting on two essential subunits. Inactivation of CI caused a strong growth impairment even in fully autotrophic conditions in tissues where all cells are photosynthetically active, demonstrating that respiration is essential for photosynthesis. CI mutants showed alterations in the stoichiometry of respiratory complexes while the composition of photosynthetic apparatus was substantially unaffected. CI mutants showed altered photosynthesis with high activity of both Photosystems I and II, likely the result of high chloroplast ATPase activity that led to smaller ΔpH formation across thylakoid membranes, decreasing photosynthetic control on cytochrome b6f in CI mutants. These results demonstrate that alteration of respiratory activity directly impacts photosynthesis in P. patens and that metabolic interaction between organelles is essential in their ability to use light energy for growth.
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Affiliation(s)
- Marco Mellon
- Department of Biology, University of Padova, 35121 Padova, Italy
| | - Mattia Storti
- Department of Biology, University of Padova, 35121 Padova, Italy
| | | | - David M. Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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Yoshida K, Hisabori T. Biochemical Basis for Redox Regulation of Chloroplast-Localized Phosphofructokinase from Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2021; 62:401-410. [PMID: 33416847 DOI: 10.1093/pcp/pcaa174] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 12/20/2020] [Indexed: 05/10/2023]
Abstract
Various proteins in plant chloroplasts are subject to thiol-based redox regulation, allowing light-responsive control of chloroplast functions. Most redox-regulated proteins are known to be reductively activated in the light in a thioredoxin (Trx)-dependent manner, but its regulatory network remains incompletely understood. Using a biochemical procedure, we here show that a specific form of phosphofructokinase (PFK) is a novel redox-regulated protein whose activity is suppressed upon reduction. PFK is a key enzyme in the glycolytic pathway. In Arabidopsis thaliana, PFK5 is targeted to chloroplasts and uniquely contains an insertion sequence harboring two Cys residues (Cys152 and Cys157) in the N-terminal region. Redox shift assays using a thiol-modifying reagent indicated that PFK5 is efficiently reduced by a specific type of Trx, namely, Trx-f. PFK5 enzyme activity was lowered with the Trx-f-dependent reduction. PFK5 redox regulation was bidirectional; PFK5 was also oxidized and activated by the recently identified Trx-like2/2-Cys peroxiredoxin pathway. Mass spectrometry-based peptide mapping analysis revealed that Cys152 and Cys157 are critical for the intramolecular disulfide bond formation in PFK5. The involvement of Cys152 and Cys157 in PFK5 redox regulation was further supported by a site-directed mutagenesis study. PFK5 catalyzes the reverse reaction of fructose 1,6-bisphosphatase (FBPase), which is reduced and activated specifically by Trx-f. Our data suggest that PFK5 redox regulation, together with that of FBPase, constitutes a checkpoint for switching light/dark metabolism in chloroplasts.
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Affiliation(s)
- Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, 226-8503 Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, 226-8503 Japan
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Milrad Y, Schweitzer S, Feldman Y, Yacoby I. Bi-directional electron transfer between H2 and NADPH mitigates light fluctuation responses in green algae. PLANT PHYSIOLOGY 2021; 186:168-179. [PMID: 33793951 PMCID: PMC8154092 DOI: 10.1093/plphys/kiab051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/21/2021] [Indexed: 05/05/2023]
Abstract
The metabolism of green algae has been the focus of much research over the last century. These photosynthetic organisms can thrive under various conditions and adapt quickly to changing environments by concomitant usage of several metabolic apparatuses. The main electron coordinator in their chloroplasts, nicotinamide adenine dinucleotide phosphate (NADPH), participates in many enzymatic activities and is also responsible for inter-organellar communication. Under anaerobic conditions, green algae also accumulate molecular hydrogen (H2), a promising alternative for fossil fuels. However, to scale-up its accumulation, a firm understanding of its integration in the photosynthetic apparatus is still required. While it is generally accepted that NADPH metabolism correlates to H2 accumulation, the mechanism of this collaboration is still vague and relies on indirect measurements. Here, we investigated this connection in Chlamydomonas reinhardtii using simultaneous measurements of both dissolved gases concentration, NADPH fluorescence and electrochromic shifts at 520-546 nm. Our results indicate that energy transfer between H2 and NADPH is bi-directional and crucial for the maintenance of redox balance under light fluctuations. At light onset, NADPH consumption initially eventuates in H2 evolution, which initiates the photosynthetic electron flow. Later on, as illumination continues the majority of NADPH is diverted to the Calvin-Benson-Bassham cycle. Dark onset triggers re-assimilation of H2, which produces NADPH and so, enables initiation of dark fermentative metabolism.
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Affiliation(s)
- Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Shira Schweitzer
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Yael Feldman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
- Author for communication: (I.Y.)
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Rotor subunits adaptations in ATP synthases from photosynthetic organisms. Biochem Soc Trans 2021; 49:541-550. [PMID: 33890627 PMCID: PMC8106487 DOI: 10.1042/bst20190936] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 11/17/2022]
Abstract
Driven by transmembrane electrochemical ion gradients, F-type ATP synthases are the primary source of the universal energy currency, adenosine triphosphate (ATP), throughout all domains of life. The ATP synthase found in the thylakoid membranes of photosynthetic organisms has some unique features not present in other bacterial or mitochondrial systems. Among these is a larger-than-average transmembrane rotor ring and a redox-regulated switch capable of inhibiting ATP hydrolysis activity in the dark by uniquely adapted rotor subunit modifications. Here, we review recent insights into the structure and mechanism of ATP synthases specifically involved in photosynthesis and explore the cellular physiological consequences of these adaptations at short and long time scales.
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Sytykiewicz H, Łukasik I, Goławska S, Sprawka I, Goławski A, Sławianowska J, Kmieć K. Expression of Thioredoxin/Thioredoxin Reductase System Genes in Aphid-Challenged Maize Seedlings. Int J Mol Sci 2020; 21:ijms21176296. [PMID: 32878074 PMCID: PMC7503728 DOI: 10.3390/ijms21176296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/27/2020] [Accepted: 08/29/2020] [Indexed: 11/16/2022] Open
Abstract
Thioredoxins (Trxs) and thioredoxin reductases (TrxRs) encompass a highly complex network involved in sustaining thiol-based redox homeostasis in plant tissues. The purpose of the study was to gain a new insight into transcriptional reprogramming of the several genes involved in functioning of Trx/TrxR system in maize (Zea mays L.) seedlings, exposed to the bird cherry-oat aphid (Rhopalosiphum padi L.) or the rose-grass aphid (Metopolophium dirhodum Walk.) infestation. The biotests were performed on two maize genotypes (susceptible Złota Karłowa and relatively resistant Waza). The application of real-time qRT-PCR technique allowed to identify a molecular mechanism triggered in more resistant maize plants, linked to upregulation of thioredoxins-encoding genes (Trx-f, Trx-h, Trx-m, Trx-x) and thioredoxin reductase genes (Ftr1, Trxr2). Significant enhancement of TrxR activity in aphid-infested Waza seedlings was also demonstrated. Furthermore, we used an electrical penetration graph (EPG) recordings of M. dirhodum stylet activities in seedlings of the two studied maize varieties. Duration of phloem phase (E1 and E2 models) of rose-grass aphids was about three times longer while feeding in Waza plants, compared to Złota Karłowa cv. The role of activation of Trx/TrxR system in maintaining redox balance and counteracting oxidative-induced damages of macromolecules in aphid-stressed maize plants is discussed.
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Affiliation(s)
- Hubert Sytykiewicz
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
- Correspondence: ; Tel.: +48-25-643-12-98
| | - Iwona Łukasik
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
| | - Sylwia Goławska
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
| | - Iwona Sprawka
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
| | - Artur Goławski
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
| | - Julia Sławianowska
- Institute of Biological Sciences, Faculty of Exact and Natural Sciences, Siedlce University of Natural Sciences and Humanities, 14 Prusa St., 08-110 Siedlce, Poland; (I.Ł.); (S.G.); (I.S.); (A.G.); (J.S.)
| | - Katarzyna Kmieć
- Department of Plant Protection, Faculty of Horticulture and Landscape Architecture, University of Life Sciences in Lublin, 7 Leszczyńskiego St., 20-069 Lublin, Poland;
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