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Muth-Pawlak D, Kakko L, Kallio P, Aro EM. Interplay between photosynthetic electron flux and organic carbon sinks in sucrose-excreting Synechocystis sp. PCC 6803 revealed by omics approaches. Microb Cell Fact 2024; 23:188. [PMID: 38951789 PMCID: PMC11218172 DOI: 10.1186/s12934-024-02462-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/17/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND Advancing the engineering of photosynthesis-based prokaryotic cell factories is important for sustainable chemical production and requires a deep understanding of the interplay between bioenergetic and metabolic pathways. Rearrangements in photosynthetic electron flow to increase the efficient use of the light energy for carbon fixation must be balanced with a strong carbon sink to avoid photoinhibition. In the cyanobacterium Synechocystis sp. PCC 6803, the flavodiiron protein Flv3 functions as an alternative electron acceptor of photosystem I and represents an interesting engineering target for reorganizing electron flow in attempts to enhance photosynthetic CO2 fixation and increase production yield. RESULTS We have shown that inactivation of Flv3 in engineered sucrose-excreting Synechocystis (S02:Δflv3) induces a transition from photoautotrophic sucrose production to mixotrophic growth sustained by sucrose re-uptake and the formation of intracellular carbon sinks such as glycogen and polyhydroxybutyrate. The growth of S02:Δflv3 exceeds that of the sucrose-producing strain (S02) and demonstrates unforeseen proteomic and metabolomic changes over the course of the nine-day cultivation. In the absence of Flv3, a down-regulation of proteins related to photosynthetic light reactions and CO2 assimilation occurred concomitantly with up-regulation of those related to glycolytic pathways, before any differences in sucrose production between S02 and S02:Δflv3 strains were observed. Over time, increased sucrose degradation in S02:Δflv3 led to the upregulation of respiratory pathway components, such as the plastoquinone reductase complexes NDH-11 and NDH-2 and the terminal respiratory oxidases Cyd and Cox, which transfer electrons to O2. While glycolytic metabolism is significantly up-regulated in S02:Δflv3 to provide energy for the cell, the accumulation of intracellular storage compounds and the increase in respiration serve as indirect sinks for photosynthetic electrons. CONCLUSIONS Our results show that the presence of strong carbon sink in the engineered sucrose-producing Synechocystis S02 strain, operating under high light, high CO2 and salt stress, cannot compensate for the lack of Flv3 by directly balancing the light transducing source and carbon fixing sink reactions. Instead, the cells immediately sense the imbalance, leading to extensive reprogramming of cellular bioenergetic, metabolic and ion transport pathways that favor mixotrophic growth rather than enhancing photoautotrophic sucrose production.
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Affiliation(s)
- Dorota Muth-Pawlak
- Department of Life Technologies, Molecular Plant Biology, University of Turku, Turku, FIN-20014, Finland.
| | - Lauri Kakko
- Department of Life Technologies, Molecular Plant Biology, University of Turku, Turku, FIN-20014, Finland
| | - Pauli Kallio
- Department of Life Technologies, Molecular Plant Biology, University of Turku, Turku, FIN-20014, Finland
| | - Eva-Mari Aro
- Department of Life Technologies, Molecular Plant Biology, University of Turku, Turku, FIN-20014, Finland
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2
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Ran Z, Du Z, Miao G, Zheng M, Luo L, Pang X, Wei L, Li D, Ma W. Identification of a c-type heme oxygenase and its function during acclimation of cyanobacteria to nitrogen fluctuations. Commun Biol 2023; 6:944. [PMID: 37714932 PMCID: PMC10504260 DOI: 10.1038/s42003-023-05315-x] [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: 10/19/2022] [Accepted: 09/01/2023] [Indexed: 09/17/2023] Open
Abstract
The mechanisms of acclimating to a nitrogen-fluctuating environment are necessary for the survival of aquatic cyanobacteria in their natural habitats, but our understanding is still far from complete. Here, the synthesis of phycobiliprotein is confirmed to be much earlier than that of photosystem components during recovery from nitrogen chlorosis and an unknown protein Ssr1698 is discovered to be involved in this synthetic process. The unknown protein is further identified as a c-type heme oxygenase (cHO) in tetrapyrrole biosynthetic pathway and catalyzes the opening of heme ring to form biliverdin IXα, which is required for phycobilin production and ensuing phycobiliprotein synthesis. In addition, the cHO-dependent phycobiliprotein is found to be vital for the growth of cyanobacterial cells during chlorosis and regreening through its nitrogen-storage and light-harvesting functions, respectively. Collectively, the cHO expressed preferentially during recovery from nitrogen chlorosis is identified in photosynthetic organisms and the dual function of this enzyme-dependent phycobiliprotein is proposed to be an important mechanism for acclimation of aquatic cyanobacteria to a nitrogen-fluctuating environment.
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Affiliation(s)
- Zhaoxing Ran
- School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Zhenyu Du
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Gengkai Miao
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Mei Zheng
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Ligang Luo
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Xiaoqin Pang
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Lanzhen Wei
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China.
| | - Dezhi Li
- School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China.
- Key Laboratory of Urbanization and Ecological Restoration of Shanghai, 200241, Shanghai, China.
- Institute of Eco-Chongming (IEC), 20 Cuiniao Rd, Chenjia Zhen, Chongming, 202162, Shanghai, China.
- Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, 200062, Shanghai, China.
| | - Weimin Ma
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China.
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3
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Zhang X, Ai S, Wei J, Yang X, Huang Y, Hu J, Wang Q, Wang H. Biphasic effects of typical chlorinated organophosphorus flame retardants on Microcystis aeruginosa. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 241:113813. [PMID: 36068742 DOI: 10.1016/j.ecoenv.2022.113813] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The potential accumulation of chlorinated organophosphorus flame retardants (Cl-OPFRs) in aquatic environments sparked interest in studying the effects of Cl-OPFRs on cyanobacterial blooms. In this work, two common Cl-OPFRs, tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and tris(2-chloroethyl) phosphate (TCEP), induced dose-dependent biphasic effect on bloom-forming M. aeruginosa. The hormetic response to low-dose Cl-OPFRs was associated with the upregulation of the type I NADH dehydrogenase (NDH-1) complex and its mediated cyclic electron transfer (CET) pathway, as reflected by a transient post-illumination increase in chlorophyll fluorescence, the dark reduction of P700+ and the change of NDH-1-related gene expression. The increased CET activity and carotenoid content jointly reduced the intracellular ROS production, facilitating cyanobacterial growth. Conversely, a higher concentration of both Cl-OPFRs induced severe inhibition of growth and photosynthetic oxygen-evolving activity through an imbalance between PSII and PSI. Toxic-dose Cl-OPFRs inhibited state transition and fixed cells into the State I with a higher PSII/PSI ratio, as indicated by chlorophyll fluorescence induction, 77 K fluorescence emission spectra and photosystem stoichiometry. The elevated PSII/PSI ratio created an imbalance between the two photosystems and eventually lead to ROS overproduction, which generate adverse effects on cell growth. This work provides important insights into the hormetic mechanism of Cl-OPFRs on Microcystis aeruginosa and their potential roles in harmful cyanobacteria blooms.
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Affiliation(s)
- Xin Zhang
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China
| | - Sijie Ai
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China
| | - Jialu Wei
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China
| | - Xu Yang
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China
| | - Yichen Huang
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China
| | - Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Haiying Wang
- College of Life Science, South-Central Minzu University, Wuhan, Hubei 430074, China.
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4
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Sheikh T, Hamid B, Baba Z, Iqbal S, Yatoo A, Fatima S, Nabi A, Kanth R, Dar K, Hussain N, Alturki AI, Sunita K, Sayyed R. Extracellular polymeric substances in psychrophilic cyanobacteria: A potential bioflocculant and carbon sink to mitigate cold stress. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102375] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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5
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Zhao J, Jiang Y, Tian Y, Mao J, Wei L, Ma W. New insights into the effect of NdhO levels on cyanobacterial cell death triggered by high temperature. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:533-541. [PMID: 34428393 DOI: 10.1071/fp21097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/05/2021] [Indexed: 06/13/2023]
Abstract
NdhO, a regulatory oxygenic photosynthesis-specific subunit, is close to the ferredoxin-binding site of cyanobacterial NDH-1, and its levels are negatively associated with the rates of cyclic electron transfer around PSI mediated by NDH-1 (NDH-CET). However, the effect of NdhO levels on cyanobacterial cell death triggered by high temperature remains elusive. Here, our results uncovered a synergistic effect of NdhO levels on the cell death and reactive oxygen species (ROS) accumulation when cyanobacterial cells grown at 30°C for 1 day were transferred to 45°C for 2 days. Such synergistic effect was found to be closely associated with the activities of NDH-CET and CO2 assimilation during high temperature. Collectively, we propose that the effect of NdhO levels on the cyanobacterial cell bleaching and cell death triggered by high temperature is a result of influencing production of ROS by NDH-CET, which is considered to be vital to balance the ATP/NADPH ratio and improve the Calvin-Benson cycle.
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Affiliation(s)
- Jiaohong Zhao
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Yuanyuan Jiang
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Yuhao Tian
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Jun Mao
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Lanzhen Wei
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China; and Corresponding author
| | - Weimin Ma
- Shanghai Key laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China; and Corresponding author
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6
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Blaha ME, Hasan S, Dusny C, Belder D. Fluorescence lifetime activated droplet sorting (FLADS) for label-free sorting of Synechocystis sp. PCC6803. LAB ON A CHIP 2022; 22:1604-1614. [PMID: 35332894 DOI: 10.1039/d2lc00032f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study presents the label-free sorting of cyanobacterial cells in droplets with single-cell sensitivity based on their fluorescence lifetime. We separated living and dead cyanobacteria (Synechocystis sp. PCC6803) using fluorescence lifetime signals of the photopigment autofluorescence to indicate their photosynthetic activity. We developed a setup and a chip design to achieve live/dead sorting accuracies of more than 97% at a droplet frequency of 100 Hz with a PDMS-based chip system and standard optics using fluorescence lifetime as the sorting criterion. The obtained sorting accuracies could be experimentally confirmed by cell plating and observing the droplet sorting process via a high-speed camera. The herein presented results demonstrate the capabilities of the developed system for studying the effects of stressors on cyanobacterial physiology and the subsequent deterministic sorting of different stress-response phenotypes. This technology eliminates the need for tedious staining of cyanobacterial cells, which makes it particularly attractive for its application in the field of phototrophic microbial bio(techno)logic and in the context of cell secretion studies.
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Affiliation(s)
| | - Sadat Hasan
- Institute for Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany.
| | - Christian Dusny
- Department Solar Materials, Helmoltz-Centre for Environmental Research - UFZ Leipzig, Permoserstr. 15, 04318 Leipzig, Germany
| | - Detlev Belder
- Institute for Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany.
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7
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Li M, Long B, Dai SY, Golden JW, Wang X, Yuan JS. Altered Carbon Partitioning Enhances CO 2 to Terpene Conversion in Cyanobacteria. BIODESIGN RESEARCH 2022; 2022:9897425. [PMID: 37850123 PMCID: PMC10521692 DOI: 10.34133/2022/9897425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/11/2022] [Indexed: 10/19/2023] Open
Abstract
Photosynthetic terpene production represents one of the most carbon and energy-efficient routes for converting CO2 into hydrocarbon. In photosynthetic organisms, metabolic engineering has led to limited success in enhancing terpene productivity, partially due to the low carbon partitioning. In this study, we employed systems biology analysis to reveal the strong competition for carbon substrates between primary metabolism (e.g., sucrose, glycogen, and protein synthesis) and terpene biosynthesis in Synechococcus elongatus PCC 7942. We then engineered key "source" and "sink" enzymes. The "source" limitation was overcome by knocking out either sucrose or glycogen biosynthesis to significantly enhance limonene production via altered carbon partitioning. Moreover, a fusion enzyme complex with geranyl diphosphate synthase (GPPS) and limonene synthase (LS) was designed to further improve pathway kinetics and substrate channeling. The synergy between "source" and "sink" achieved a limonene titer of 21.0 mg/L. Overall, the study demonstrates that balancing carbon flux between primary and secondary metabolism can be an effective approach to enhance terpene bioproduction in cyanobacteria. The design of "source" and "sink" synergy has significant potential in improving natural product yield in photosynthetic species.
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Affiliation(s)
- Man Li
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of ScienceChina
| | - Bin Long
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
| | - Susie Y. Dai
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
| | - James W. Golden
- Section of Molecular Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Xin Wang
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
- Department of Microbiology, Miami University, Oxford, Ohio 45056, USA
| | - Joshua S. Yuan
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
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8
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Ma M, Liu Y, Bai C, Yong JWH. The Significance of Chloroplast NAD(P)H Dehydrogenase Complex and Its Dependent Cyclic Electron Transport in Photosynthesis. FRONTIERS IN PLANT SCIENCE 2021; 12:661863. [PMID: 33968117 PMCID: PMC8102782 DOI: 10.3389/fpls.2021.661863] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/22/2021] [Indexed: 05/11/2023]
Abstract
Chloroplast NAD(P)H dehydrogenase (NDH) complex, a multiple-subunit complex in the thylakoid membranes mediating cyclic electron transport, is one of the most important alternative electron transport pathways. It was identified to be essential for plant growth and development during stress periods in recent years. The NDH-mediated cyclic electron transport can restore the over-reduction in stroma, maintaining the balance of the redox system in the electron transfer chain and providing the extra ATP needed for the other biochemical reactions. In this review, we discuss the research history and the subunit composition of NDH. Specifically, the formation and significance of NDH-mediated cyclic electron transport are discussed from the perspective of plant evolution and physiological functionality of NDH facilitating plants' adaptation to environmental stress. A better understanding of the NDH-mediated cyclic electron transport during photosynthesis may offer new approaches to improving crop yield.
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Affiliation(s)
- Mingzhu Ma
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
| | - Yifei Liu
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
| | - Chunming Bai
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
- Liaoning Academy of Agricultural Sciences, Shenyang, China
| | - Jean Wan Hong Yong
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Alnarp, Sweden
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9
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Sangphukieo A, Laomettachit T, Ruengjitchatchawalya M. PhotoModPlus: A web server for photosynthetic protein prediction from genome neighborhood features. PLoS One 2021; 16:e0248682. [PMID: 33730083 PMCID: PMC7968678 DOI: 10.1371/journal.pone.0248682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 03/03/2021] [Indexed: 11/20/2022] Open
Abstract
A new web server called PhotoModPlus is presented as a platform for predicting photosynthetic proteins via genome neighborhood networks (GNN) and genome neighborhood-based machine learning. GNN enables users to visualize the overview of the conserved neighboring genes from multiple photosynthetic prokaryotic genomes and provides functional guidance on the query input. In the platform, we also present a new machine learning model utilizing genome neighborhood features for predicting photosynthesis-specific functions based on 24 prokaryotic photosynthesis-related GO terms, namely PhotoModGO. The new model performed better than the sequence-based approaches with an F1 measure of 0.872, based on nested five-fold cross-validation. Finally, we demonstrated the applications of the webserver and the new model in the identification of novel photosynthetic proteins. The server is user-friendly, compatible with all devices, and available at bicep.kmutt.ac.th/photomod.
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Affiliation(s)
- Apiwat Sangphukieo
- Bioinformatics and Systems Biology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi (KMUTT), Bang Khun Thian, Bangkok, Thailand
- School of Information Technology, KMUTT, Thung Khru, Bangkok, Thailand
| | - Teeraphan Laomettachit
- Bioinformatics and Systems Biology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi (KMUTT), Bang Khun Thian, Bangkok, Thailand
| | - Marasri Ruengjitchatchawalya
- Bioinformatics and Systems Biology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi (KMUTT), Bang Khun Thian, Bangkok, Thailand
- Biotechnology Program, School of Bioresources and Technology, KMUTT, Bang Khun Thian, Bangkok, Thailand
- Algal Biotechnology Research Group, Pilot Plant Development and Training Institute, KMUTT, Bang Khun Thian, Bangkok, Thailand
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10
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Miller NT, Vaughn MD, Burnap RL. Electron flow through NDH-1 complexes is the major driver of cyclic electron flow-dependent proton pumping in cyanobacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148354. [PMID: 33338488 DOI: 10.1016/j.bbabio.2020.148354] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 01/12/2023]
Abstract
Cyclic electron flow (CEF) around photosystem I is vital to balancing the photosynthetic energy budget of cyanobacteria and other photosynthetic organisms. The coupling of CEF to proton pumping has long been hypothesized to occur, providing proton motive force (PMF) for the synthesis of ATP with no net cost to [NADPH]. This is thought to occur largely through the activity of NDH-1 complexes, of which cyanobacteria have four with different activities. While a much work has been done to understand the steady-state PMF in both the light and dark, and fluorescent probes have been developed to observe these fluxes in vivo, little has been done to understand the kinetics of these fluxes, particularly with regard to NDH-1 complexes. To monitor the kinetics of proton pumping in Synechocystis sp. PCC 6803, the pH sensitive dye Acridine Orange was used alongside a suite of inhibitors in order to observe light-dependent proton pumping. The assay was demonstrated to measure photosynthetically driven proton pumping and used to measure the rates of proton pumping unimpeded by dark ΔpH. Here, the cyanobacterial NDH-1 complexes are shown to pump a sizable portion of proton flux when CEF-driven and LEF-driven proton pumping rates are observed and compared in mutants lacking some or all NDH-1 complexes. It is also demonstrated that PSII and LEF are responsible for the bulk of light induced proton pumping, though CEF and NDH-1 are capable of generating ~40% of the proton pumping rate when LEF is inactivated.
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Affiliation(s)
- Neil T Miller
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Michael D Vaughn
- SpectroLogix LLC, 9050 Executive Park Drive, Knoxville, TN 37923, USA
| | - Robert L Burnap
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA.
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11
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Nikkanen L, Santana Sánchez A, Ermakova M, Rögner M, Cournac L, Allahverdiyeva Y. Functional redundancy between flavodiiron proteins and NDH-1 in Synechocystis sp. PCC 6803. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1460-1476. [PMID: 32394539 DOI: 10.1111/tpj.14812] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 05/09/2023]
Abstract
In oxygenic photosynthetic organisms, excluding angiosperms, flavodiiron proteins (FDPs) catalyze light-dependent reduction of O2 to H2 O. This alleviates electron pressure on the photosynthetic apparatus and protects it from photodamage. In Synechocystis sp. PCC 6803, four FDP isoforms function as hetero-oligomers of Flv1 and Flv3 and/or Flv2 and Flv4. An alternative electron transport pathway mediated by the NAD(P)H dehydrogenase-like complex (NDH-1) also contributes to redox hemostasis and the photoprotection of photosynthesis. Four NDH-1 types have been characterized in cyanobacteria: NDH-11 and NDH-12 , which function in respiration; and NDH-13 and NDH-14 , which function in CO2 uptake. All four types are involved in cyclic electron transport. Along with single FDP mutants (∆flv1 and Δflv3) and the double NDH-1 mutants (∆d1d2, which is deficient in NDH-11,2 and ∆d3d4, which is deficient in NDH-13,4 ), we studied triple mutants lacking one of Flv1 or Flv3, and NDH-11,2 or NDH-13,4 . We show that the presence of either Flv1/3 or NDH-11,2 , but not NDH-13,4 , is indispensable for survival during changes in growth conditions from high CO2 /moderate light to low CO2 /high light. Our results show functional redundancy between FDPs and NDH-11,2 under the studied conditions. We suggest that ferredoxin probably functions as a primary electron donor to both Flv1/3 and NDH-11,2 , allowing their functions to be dynamically coordinated for efficient oxidation of photosystem I and for photoprotection under variable CO2 and light availability.
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Affiliation(s)
- Lauri Nikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Anita Santana Sánchez
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Maria Ermakova
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Matthias Rögner
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Laurent Cournac
- Eco&Sols, University of Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
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12
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Patil PP, Vass I, Kodru S, Szabó M. A multi-parametric screening platform for photosynthetic trait characterization of microalgae and cyanobacteria under inorganic carbon limitation. PLoS One 2020; 15:e0236188. [PMID: 32701995 PMCID: PMC7377499 DOI: 10.1371/journal.pone.0236188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/30/2020] [Indexed: 11/18/2022] Open
Abstract
Microalgae and cyanobacteria are considered as important model organisms to investigate the biology of photosynthesis; moreover, they are valuable sources of biomolecules for several biotechnological applications. Understanding the species-specific traits of photosynthetic electron transport is extremely important, because it contributes to the regulation of ATP/NADPH ratio, which has direct/indirect links to carbon fixation and other metabolic pathways and thus overall growth and biomass production. In the present work, a cuvette-based setup is developed, in which a combination of measurements of dissolved oxygen, pH, chlorophyll fluorescence and NADPH kinetics can be performed without disturbing the physiological status of the sample. The suitability of the system is demonstrated using a model cyanobacterium Synechocystis sp. PCC6803, as well as biofuel-candidate microalgae species, such as Chlorella sorokiniana, Dunaliella salina and Nannochloropsis limnetica undergoing inorganic carbon (Ci) limitation. Inorganic carbon limitation, induced by photosynthetic Ci uptake under continuous illumination, caused a decrease in the effective quantum yield of PSII (Y(II)) and loss of oxygen-evolving capacity in all species investigated here; these effects were largely recovered by the addition of NaHCO3. Detailed analysis of the dark-light and light-dark transitions of NADPH production/uptake and changes in chlorophyll fluorescence kinetics revealed species- and condition-specific responses. These responses indicate that the impact of decreased Calvin-Benson cycle activity on photosynthetic electron transport pathways involving several sections of the electron transport chain (such as electron transfer via the QA-QB-plastoquinone pool, the redox state of the plastoquinone pool) can be analyzed with high sensitivity in a comparative manner. Therefore, the integrated system presented here can be applied for screening for specific traits in several significant species at different stages of inorganic carbon limitation, a condition that strongly impacts primary productivity.
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Affiliation(s)
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Sandeesha Kodru
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Biology PhD School, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Milán Szabó
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Climate Change Cluster, University of Technology Sydney, Ultimo, Australia
- * E-mail:
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Ran Z, Zhao J, Tong G, Gao F, Wei L, Ma W. Ssl3451 is Important for Accumulation of NDH-1 Assembly Intermediates in the Cytoplasm of Synechocystis sp. Strain PCC 6803. PLANT & CELL PHYSIOLOGY 2019; 60:1374-1385. [PMID: 30847493 DOI: 10.1093/pcp/pcz045] [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: 06/07/2018] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
Two mutants sensitive to high light for growth and impaired in NDH-1 activity were isolated from a transposon-tagged library of Synechocystis sp. strain PCC 6803. Both mutants were tagged in the ssl3451 gene encoding a hypothetical protein, which shares a significant homology with the Arabidopsis (Arabidopsis thaliana) CHLORORESPIRATORY REDUCTION 42 (CRR42). In Arabidopsis, CRR42 associates only with an NDH-1 hydrophilic arm assembly intermediate (NAI) of about 400 kDa (NAI400), one of total three NAIs (NAI800, NAI500 and NAI400), and its deletion has little, if any, effect on accumulation of any NAIs in the stroma. In comparison, the ssl3451 product was localized mainly in the cytoplasm and associates with two NAIs of about 300 kDa (NAI300) and 130 kDa (NAI130). Deletion of Ssl3451 reduced the abundance of the NAI300 complex to levels no longer visible on gels and of the NAI130 complex to a low level, thereby impeding the assembly process of NDH-1 hydrophilic arm. Further, Ssl3451 interacts with another assembly factor Ssl3829 and they have a similar effect on accumulation of NAIs and NdhI maturation factor Slr1097 in the cytoplasm. We thus propose that Ssl3451 plays an important role in accumulation of the NAI300 and NAI130 complexes in the cytoplasm via its interacting protein Ssl3829.
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Affiliation(s)
- Zhaoxing Ran
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
| | - Jiaohong Zhao
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
| | - Guifang Tong
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
| | - Fudan Gao
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
| | - Lanzhen Wei
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
| | - Weimin Ma
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai, China
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Characterization of TrxC, an Atypical Thioredoxin Exclusively Present in Cyanobacteria. Antioxidants (Basel) 2018; 7:antiox7110164. [PMID: 30428557 PMCID: PMC6262485 DOI: 10.3390/antiox7110164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/08/2018] [Accepted: 11/11/2018] [Indexed: 12/15/2022] Open
Abstract
Cyanobacteria form a diverse group of oxygenic photosynthetic prokaryotes considered to be the antecessor of plant chloroplast. They contain four different thioredoxins isoforms, three of them corresponding to m, x and y type present in plant chloroplast, while the fourth one (named TrxC) is exclusively found in cyanobacteria. TrxC has a modified active site (WCGLC) instead of the canonical (WCGPC) present in most thioredoxins. We have purified it and assayed its activity but surprisingly TrxC lacked all the classical activities, such as insulin precipitation or activation of the fructose-1,6-bisphosphatase. Mutants lacking trxC or over-expressing it were generated in the model cyanobacterium Synechocystis sp. PCC 6803 and their phenotypes have been analyzed. The ΔtrxC mutant grew at similar rates to WT in all conditions tested although it showed an increased carotenoid content especially under low carbon conditions. Overexpression strains showed reduced growth under the same conditions and accumulated lower amounts of carotenoids. They also showed lower oxygen evolution rates at high light but higher Fv’/Fm’ and Non-photochemical-quenching (NPQ) in dark adapted cells, suggesting a more oxidized plastoquinone pool. All these data suggest that TrxC might have a role in regulating photosynthetic adaptation to low carbon and/or high light conditions.
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