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Mallén-Ponce MJ, Florencio FJ, Huertas MJ. Thioredoxin A regulates protein synthesis to maintain carbon and nitrogen partitioning in cyanobacteria. PLANT PHYSIOLOGY 2024; 195:2921-2936. [PMID: 38386687 PMCID: PMC11288746 DOI: 10.1093/plphys/kiae101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/24/2024]
Abstract
Thioredoxins play an essential role in regulating enzyme activity in response to environmental changes, especially in photosynthetic organisms. They are crucial for metabolic regulation in cyanobacteria, but the key redox-regulated central processes remain to be determined. Physiological, metabolic, and transcriptomic characterization of a conditional mutant of the essential Synechocystis sp. PCC 6803 thioredoxin trxA gene (STXA2) revealed that decreased TrxA levels alter cell morphology and induce a dormant-like state. Furthermore, TrxA depletion in the STXA2 strain inhibited protein synthesis and led to changes in amino acid pools and nitrogen/carbon reserve polymers, accompanied by oxidation of the elongation factor-Tu. Transcriptomic analysis of TrxA depletion in STXA2 revealed a robust transcriptional response. Downregulated genes formed a large cluster directly related to photosynthesis, ATP synthesis, and CO2 fixation. In contrast, upregulated genes were grouped into different clusters related to respiratory electron transport, carotenoid biosynthesis, amino acid metabolism, and protein degradation, among others. These findings highlight the complex regulatory mechanisms that govern cyanobacterial metabolism, where TrxA acts as a critical regulator that orchestrates the transition from anabolic to maintenance metabolism and regulates carbon and nitrogen balance.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
| | - Francisco Javier Florencio
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
| | - María José Huertas
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
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2
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Deng D, Meng H, Ma Y, Guo Y, Wang Z, He H, Xie W, Liu JE, Zhang L. The cumulative impact of temperature and nitrogen availability on the potential nitrogen fixation and extracellular polymeric substances secretion by Dolichospermum. HARMFUL ALGAE 2024; 135:102633. [PMID: 38830715 DOI: 10.1016/j.hal.2024.102633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/02/2024] [Accepted: 04/24/2024] [Indexed: 06/05/2024]
Abstract
Nitrogen-fixing cyanobacteria not only cause severe blooms but also play an important role in the nitrogen input processes of lakes. The production of extracellular polymeric substances (EPS) and the ability to fix nitrogen from the atmosphere provide nitrogen-fixing cyanobacteria with a competitive advantage over other organisms. Temperature and nitrogen availability are key environmental factors in regulating the growth of cyanobacteria. In this study, Dolichospermum (formerly known as Anabaena) was cultivated at three different temperatures (10 °C, 20 °C, and 30 °C) to examine the impact of temperature and nitrogen availability on nitrogen fixation capacity and the release of EPS. Initially, confocal laser scanning microscopy (CLSM) and the quantification of heterocysts at different temperatures revealed that lower temperatures (10 °C) hindered the differentiation of heterocysts under nitrogen-deprived conditions. Additionally, while heterocysts inhibited the photosynthetic activity of Dolichospermum, the secretion of EPS was notably affected by nitrogen limitation, particularly at 30 °C. Finally, real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of nitrogen-utilizing genes (ntcA and nifH) and EPS synthesis-related genes (wzb and wzc). The results indicated that under nitrogen-deprived conditions, the expression of each gene was upregulated, and there was a significant correlation between the upregulation of nitrogen-utilizing and EPS synthesis genes (P < 0.05). Our findings suggested that Dolichospermum responded to temperature variation by affecting the formation of heterocysts, impacting its potential nitrogen fixation capacity. Furthermore, the quantity of EPS released was more influenced by nitrogen availability than temperature. This research enhances our comprehension of interconnections between nitrogen deprivation and EPS production under the different temperatures.
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Affiliation(s)
- Dailan Deng
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Han Meng
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - You Ma
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Yongqi Guo
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Zixuan Wang
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Huan He
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Wenming Xie
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Jin-E Liu
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China.
| | - Limin Zhang
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Green Economy Development Institute, Nanjing University of Finance and Economics, Nanjing 210023, PR China
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Xiang J, Li M, Li Y, Liu Y, Wei L, Zheng T, Wu J, Yu Y, Cheng J. Overexpression of Grapevine VyTRXy Improves Drought Tolerance by Maintaining Photosynthesis and Enhancing the Antioxidant and Osmolyte Capacity of Plants. Int J Mol Sci 2023; 24:16388. [PMID: 38003578 PMCID: PMC10671229 DOI: 10.3390/ijms242216388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Drought stress profoundly affects plant growth and development, posing a significant challenge that is extensively researched in the field. Thioredoxins (TRXs), small proteins central to redox processes, are crucial to managing both abiotic and biotic stresses. In this research, the VyTRXy gene, cloned from wild Yanshan grapes, was validated as a functional TRX through enzyme activity assays. VyTRXy was found to bolster photosynthesis, augment levels of osmotic regulators, stimulate antioxidant enzyme activities, and strengthen drought resilience in transgenic plants. These enhancements were evidenced by higher survival rates, optimized photosynthetic metrics, increased proline levels, augmented chlorophyll concentration, reduced electrolyte leakage, and decreased malondialdehyde and hydrogen peroxide (H2O2) levels. Furthermore, there was a surge in the activities of enzymes such as catalase, ascorbate peroxidase, glutathione peroxidase, dehydroascorbate reductase, and glutathione reductase, along with an increased expression of TRX peroxidase. Notably, under drought stress, there was a marked elevation in the expression of stress-responsive genes, including the adversity stress-inducible expression gene (NtRD29A) and DRE-binding protein (NtDREB), in transgenic tobacco. This investigation is pivotal in the quest for drought-resistant grapevine varieties and provides significant insights into the molecular functionality of VyTRXy in enhancing grapevine drought tolerance.
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Affiliation(s)
- Jiang Xiang
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (J.X.); (L.W.); (T.Z.); (J.W.)
| | - Min Li
- Henan Engineering Technology Research Center of Quality Regulation and Controlling of Horticultural Plants, College of Horticultural and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China; (M.L.); (Y.L.); (Y.L.); (Y.Y.)
| | - Yiyi Li
- Henan Engineering Technology Research Center of Quality Regulation and Controlling of Horticultural Plants, College of Horticultural and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China; (M.L.); (Y.L.); (Y.L.); (Y.Y.)
| | - Yi Liu
- Henan Engineering Technology Research Center of Quality Regulation and Controlling of Horticultural Plants, College of Horticultural and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China; (M.L.); (Y.L.); (Y.L.); (Y.Y.)
| | - Lingzhu Wei
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (J.X.); (L.W.); (T.Z.); (J.W.)
| | - Ting Zheng
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (J.X.); (L.W.); (T.Z.); (J.W.)
| | - Jiang Wu
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (J.X.); (L.W.); (T.Z.); (J.W.)
| | - Yihe Yu
- Henan Engineering Technology Research Center of Quality Regulation and Controlling of Horticultural Plants, College of Horticultural and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China; (M.L.); (Y.L.); (Y.L.); (Y.Y.)
| | - Jianhui Cheng
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (J.X.); (L.W.); (T.Z.); (J.W.)
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The atypical thioredoxin 'Alr2205', a newly identified partner of the typical 2-Cys-Peroxiredoxin, safeguards the cyanobacterium Anabaena from oxidative stress. Biochem J 2023; 480:87-104. [PMID: 36594794 DOI: 10.1042/bcj20220524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/20/2022] [Accepted: 01/03/2023] [Indexed: 01/04/2023]
Abstract
Thioredoxins (Trxs) are ubiquitous proteins that play vital roles in several physiological processes. Alr2205, a thioredoxin-like protein from Anabaena PCC 7120, was found to be evolutionarily closer to the Trx-domain of the NADPH-Thioredoxin Reductase C than the other thioredoxins. The Alr2205 protein showed disulfide reductase activity despite the presence a non-canonical active site motif 'CPSC'. Alr2205 not only physically interacted with, but also acted as a physiological reductant of Alr4641 (the typical 2-Cys-Peroxiredoxin from Anabaena), supporting its peroxidase function. Structurally, Alr2205 was a monomeric protein that formed an intramolecular disulfide bond between the two active site cysteines (Cys-38 and Cys-41). However, the Alr2205C41S protein, wherein the resolving cysteine was mutated to serine, was capable of forming intermolecular disulfide bond and exist as a dimer when treated with H2O2. Overproduction of Alr2205 in E. coli protected cells from heavy metals, but not oxidative stress. To delve into its physiological role, Alr2205/Alr2205C41S was overexpressed in Anabaena, and the ability of the corresponding strains (An2205+ or An2205C41S+) to withstand environmental stresses was assessed. An2205+ showed higher resistance to H2O2 than An2205C41S+, indicating that the disulfide reductase function of this protein was critical to protect cells from this peroxide. Although, An2205+ did not show increased capability to withstand cadmium stress, An2205C41S+ was more susceptible to this heavy metal. This is the first study that provides a vital understanding into the function of atypical thioredoxins in countering the toxic effects of heavy metals/H2O2 in prokaryotes.
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Mallén-Ponce MJ, Huertas MJ, Sánchez-Riego AM, Florencio FJ. Depletion of m-type thioredoxin impairs photosynthesis, carbon fixation, and oxidative stress in cyanobacteria. PLANT PHYSIOLOGY 2021; 187:1325-1340. [PMID: 34618018 PMCID: PMC8566235 DOI: 10.1093/plphys/kiab321] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Thioredoxins (Trxs) are disulfide oxidoreductases that regulate many biological processes. The m-type thioredoxin (TrxA) is the only Trx present in all oxygenic photosynthetic organisms. Extensive biochemical and proteomic analyses have identified many TrxA target proteins in different photosynthetic organisms. However, the precise function of this essential protein in vivo is still poorly known. In this study, we generated a conditional Synechocystis sp. PCC 6803 mutant strain (STXA2) using an on-off promoter that is able to survive with only 2% of the TrxA level of the wild-type (WT) strain. STXA2 characterization revealed that TrxA depletion results in growth arrest and pronounced impairment of photosynthesis and the Calvin-Benson-Bassham (CBB) cycle. Analysis of the in vivo redox state of the bifunctional enzyme fructose-1,6-bisphosphatase/sedoheptulose-1,7-bisphosphatase showed higher levels of oxidation that affected enzyme activity in STXA2. This result implies that TrxA-mediated redox regulation of the CBB cycle is conserved in both cyanobacteria and chloroplasts, although the targets have different evolutionary origins. The STXA2 strain also accumulated more reactive oxygen species and was more sensitive to oxidative stress than the WT. Analysis of the in vivo redox state of 2-Cys peroxiredoxin revealed full oxidation, corresponding with TrxA depletion. Overall, these results indicate that depletion of TrxA in STXA2 greatly alters the cellular redox state, interfering with essential processes such as photosynthetic machinery operativity, carbon assimilation, and oxidative stress response. The TrxA regulatory role appears to be conserved along the evolution of oxygenic photosynthetic organisms.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - María José Huertas
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Ana María Sánchez-Riego
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Francisco J Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
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Mihara S, Sugiura K, Yoshida K, Hisabori T. Thioredoxin targets are regulated in heterocysts of cyanobacterium Anabaena sp. PCC 7120 in a light-independent manner. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2018-2027. [PMID: 31863668 PMCID: PMC7242069 DOI: 10.1093/jxb/erz561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/18/2019] [Indexed: 05/22/2023]
Abstract
In the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, glucose 6-phosphate dehydrogenase (G6PDH) plays an important role in producing the power for reducing nitrogenase under light conditions. Our previous study showed that thioredoxin suppresses G6PDH by reducing its activator protein OpcA, implying that G6PDH is inactivated under light conditions because thioredoxins are reduced by the photosynthetic electron transport system in cyanobacteria. To address how Anabaena sp. PCC 7120 maintains G6PDH activity even under light conditions when nitrogen fixation occurs, we investigated the redox regulation system in vegetative cells and specific nitrogen-fixing cells named heterocysts, individually. We found that thioredoxin target proteins were more oxidized in heterocysts than in vegetative cells under light conditions. Alterations in the redox regulation mechanism of heterocysts may affect the redox states of thioredoxin target proteins, including OpcA, so that G6PDH is activated in heterocysts even under light conditions.
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Affiliation(s)
- Shoko Mihara
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Kazunori Sugiura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Present address: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Correspondence:
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