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Siegl A, Afjehi-Sadat L, Wienkoop S. Systemic long-distance sulfur transport and its role in symbiotic root nodule protein turnover. JOURNAL OF PLANT PHYSIOLOGY 2024; 297:154260. [PMID: 38701679 DOI: 10.1016/j.jplph.2024.154260] [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: 02/29/2024] [Revised: 04/15/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
Sulfur is an essential nutrient for all plants, but also crucial for the nitrogen fixing symbiosis between legumes and rhizobia. Sulfur limitation can hamper nodule development and functioning. Until now, it remained unclear whether sulfate uptake into nodules is local or mainly systemic via the roots, and if long-distance transport from shoots to roots and into nodules occurs. Therefore, this work investigates the systemic regulation of sulfur transportation in the model legume Lotus japonicus by applying stable isotope labeling to a split-root system. Metabolite and protein extraction together with mass spectrometry analyses were conducted to determine the plants molecular phenotype and relative isotope protein abundances. Data show that treatments of varying sulfate concentrations including the absence of sulfate on one side of a nodulated root was not affecting nodule development as long as the other side of the root system was provided with sufficient sulfate. Concentrations of shoot metabolites did not indicate a significant stress response caused by a lack of sulfur. Further, we did not observe any quantitative changes in proteins involved in biological nitrogen fixation in response to the different sulfate treatments. Relative isotope abundance of 34S confirmed a long-distance transport of sulfur from one side of the roots to the other side and into the nodules. Altogether, these results provide evidence for a systemic long-distance transport of sulfur via the upper part of the plant to the nodules suggesting a demand driven sulfur distribution for the maintenance of symbiotic N-fixation.
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Affiliation(s)
- Alina Siegl
- Plant-Microsymbiont Interaction Lab, Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria; Research Support Facilities, Mass Spectrometry Unit UBB, University of Vienna, Vienna, Austria
| | - Leila Afjehi-Sadat
- Research Support Facilities, Mass Spectrometry Unit UBB, University of Vienna, Vienna, Austria
| | - Stefanie Wienkoop
- Plant-Microsymbiont Interaction Lab, Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.
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2
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Ye X, Gao Z, Xu K, Li B, Ren T, Li X, Cong R, Lu Z, Cakmak I, Lu J. Photosynthetic plasticity aggravates the susceptibility of magnesium-deficient leaf to high light in rapeseed plants: the importance of Rubisco and mesophyll conductance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:483-497. [PMID: 37901950 DOI: 10.1111/tpj.16504] [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: 05/10/2023] [Revised: 09/14/2023] [Accepted: 10/06/2023] [Indexed: 10/31/2023]
Abstract
Plants grown under low magnesium (Mg) soils are highly susceptible to encountering light intensities that exceed the capacity of photosynthesis (A), leading to a depression of photosynthetic efficiency and eventually to photooxidation (i.e., leaf chlorosis). Yet, it remains unclear which processes play a key role in limiting the photosynthetic energy utilization of Mg-deficient leaves, and whether the plasticity of A in acclimation to irradiance could have cross-talk with Mg, hence accelerating or mitigating the photodamage. We investigated the light acclimation responses of rapeseed (Brassica napus) grown under low- and adequate-Mg conditions. Magnesium deficiency considerably decreased rapeseed growth and leaf A, to a greater extent under high than under low light, which is associated with higher level of superoxide anion radical and more severe leaf chlorosis. This difference was mainly attributable to a greater depression in dark reaction under high light, with a higher Rubisco fallover and a more limited mesophyll conductance to CO2 (gm ). Plants grown under high irradiance enhanced the content and activity of Rubisco and gm to optimally utilize more light energy absorbed. However, Mg deficiency could not fulfill the need to activate the higher level of Rubisco and Rubisco activase in leaves of high-light-grown plants, leading to lower Rubisco activation and carboxylation rate. Additionally, Mg-deficient leaves under high light invested more carbon per leaf area to construct a compact leaf structure with smaller intercellular airspaces, lower surface area of chloroplast exposed to intercellular airspaces, and CO2 diffusion conductance through cytosol. These caused a more severe decrease in within-leaf CO2 diffusion rate and substrate availability. Taken together, plant plasticity helps to improve photosynthetic energy utilization under high light but aggravates the photooxidative damage once the Mg nutrition becomes insufficient.
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Affiliation(s)
- Xiaolei Ye
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Ziyi Gao
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Ke Xu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Binglin Li
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Tao Ren
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaokun Li
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Rihuan Cong
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Zhifeng Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Ismail Cakmak
- Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, 34956, Turkey
| | - Jianwei Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
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3
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Waheeda K, Kitchel H, Wang Q, Chiu PL. Molecular mechanism of Rubisco activase: Dynamic assembly and Rubisco remodeling. Front Mol Biosci 2023; 10:1125922. [PMID: 36845545 PMCID: PMC9951593 DOI: 10.3389/fmolb.2023.1125922] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/31/2023] [Indexed: 02/12/2023] Open
Abstract
Ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) enzyme is the limiting step of photosynthetic carbon fixation, and its activation is regulated by its co-evolved chaperone, Rubisco activase (Rca). Rca removes the intrinsic sugar phosphate inhibitors occupying the Rubisco active site, allowing RuBP to split into two 3-phosphoglycerate (3PGA) molecules. This review summarizes the evolution, structure, and function of Rca and describes the recent findings regarding the mechanistic model of Rubisco activation by Rca. New knowledge in these areas can significantly enhance crop engineering techniques used to improve crop productivity.
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Affiliation(s)
- Kazi Waheeda
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Heidi Kitchel
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Quan Wang
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Po-Lin Chiu
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
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4
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Shokravi H, Heidarrezaei M, Shokravi Z, Ong HC, Lau WJ, Din MFM, Ismail AF. Fourth generation biofuel from genetically modified algal biomass for bioeconomic development. J Biotechnol 2022; 360:23-36. [PMID: 36272575 DOI: 10.1016/j.jbiotec.2022.10.010] [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: 07/11/2021] [Revised: 09/03/2022] [Accepted: 10/17/2022] [Indexed: 12/12/2022]
Abstract
Biofuels from microalgae have promising potential for a sustainable bioeconomy. Algal strains' oil content and biomass yield are the most influential cost drivers in the fourth generation biofuel (FGB) production. Genetic modification is the key to improving oil accumulation and biomass yield, consequently developing the bioeconomy. This paper discusses current practices, new insights, and emerging trends in genetic modification and their bioeconomic impact on FGB production. It was demonstrated that enhancing the oil and biomass yield could significantly improve the probability of economic success and the net present value of the FGB production process. The techno-economic and socioeconomic burden of using genetically modified (GM) strains and the preventive control strategies on the bioeconomy of FGB production is reviewed. It is shown that the fully lined open raceway pond could cost up to 25% more than unlined ponds. The cost of a plastic hoop air-supported greenhouse covering cultivation ponds is estimated to be US 60,000$ /ha. The competitiveness and profitability of large-scale cultivation of GM biomass are significantly locked to techno-economic and socioeconomic drivers. Nonetheless, it necessitates further research and careful long-term follow-up studies to understand the mechanism that affects these parameters the most.
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Affiliation(s)
- Hoofar Shokravi
- Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
| | - Mahshid Heidarrezaei
- Faculty of Chemical & Energy Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia; Institute of Bioproduct Development (IBD), Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
| | - Zahra Shokravi
- Department of Microbiology, Faculty of Basic Science, Islamic Azad University, Science and Research Branch of Tehran, Markazi, 1477893855, Iran
| | - Hwai Chyuan Ong
- Future Technology Research Center, National Yunlin University of Science and Technology, 123 University Road, Section 3, Douliou, Yunlin 64002, Taiwan.
| | - Woei Jye Lau
- Faculty of Chemical & Energy Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia; Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
| | - Mohd Fadhil Md Din
- Centre for Environmental Sustainability and Water Security (IPASA), School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
| | - Ahmad Fauzi Ismail
- Faculty of Chemical & Energy Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia; Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
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5
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Junglas B, Axt A, Siebenaller C, Sonel H, Hellmann N, Weber SAL, Schneider D. Membrane destabilization and pore formation induced by the Synechocystis IM30 protein. Biophys J 2022; 121:3411-3421. [PMID: 35986519 PMCID: PMC9515227 DOI: 10.1016/j.bpj.2022.08.014] [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: 03/18/2022] [Revised: 07/21/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
The inner membrane-associated protein of 30 kDa (IM30) is essential in chloroplasts and cyanobacteria. The spatio-temporal cellular localization of the protein appears to be highly dynamic and triggered by internal as well as external stimuli, mainly light intensity. The soluble fraction of the protein is localized in the cyanobacterial cytoplasm or the chloroplast stroma, respectively. Additionally, the protein attaches to the thylakoid membrane as well as to the chloroplast inner envelope or the cyanobacterial cytoplasmic membrane, respectively, especially under conditions of membrane stress. IM30 is involved in thylakoid membrane biogenesis and/or maintenance, where it either stabilizes membranes and/or triggers membrane-fusion processes. These apparently contradicting functions have to be tightly controlled and separated spatiotemporally in chloroplasts and cyanobacteria. IM30's fusogenic activity depends on Mg2+ binding to IM30; yet, it still is unclear how Mg2+-loaded IM30 interacts with membranes and promotes membrane fusion. Here, we show that the interaction of Mg2+ with IM30 results in increased binding of IM30 to native, as well as model, membranes. Via atomic force microscopy in liquid, IM30-induced bilayer defects were observed in solid-supported bilayers in the presence of Mg2+. These structures differ dramatically from the membrane-stabilizing carpet structures that were previously observed in the absence of Mg2+. Thus, Mg2+-induced alterations of the IM30 structure switch the IM30 activity from a membrane-stabilizing to a membrane-destabilizing function, a crucial step in membrane fusion.
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Affiliation(s)
- Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Amelie Axt
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hilal Sonel
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan A L Weber
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany; Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany.
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6
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Long SP, Taylor SH, Burgess SJ, Carmo-Silva E, Lawson T, De Souza AP, Leonelli L, Wang Y. Into the Shadows and Back into Sunlight: Photosynthesis in Fluctuating Light. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:617-648. [PMID: 35595290 DOI: 10.1146/annurev-arplant-070221-024745] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and improvement of leaf CO2 assimilation (A) have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, in modern crop canopies of several leaf layers, light is rarely constant, and the majority of leaves experience marked light fluctuations throughout the day. It takes several minutes for photosynthesis to regain efficiency in both sun-shade and shade-sun transitions, costing a calculated 10-40% of potential crop CO2 assimilation. Transgenic manipulations to accelerate the adjustment in sun-shade transitions have already shown a substantial productivity increase in field trials. Here, we explore means to further accelerate these adjustments and minimize these losses through transgenic manipulation, gene editing, and exploitation of natural variation. Measurement andanalysis of photosynthesis in sun-shade and shade-sun transitions are explained. Factors limiting speeds of adjustment and how they could be modified to effect improved efficiency are reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, and stomatal responses.
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Affiliation(s)
- Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Samuel H Taylor
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Steven J Burgess
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | | | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Amanda P De Souza
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | - Lauriebeth Leonelli
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yu Wang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
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7
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Ishfaq M, Wang Y, Yan M, Wang Z, Wu L, Li C, Li X. Physiological Essence of Magnesium in Plants and Its Widespread Deficiency in the Farming System of China. FRONTIERS IN PLANT SCIENCE 2022; 13:802274. [PMID: 35548291 PMCID: PMC9085447 DOI: 10.3389/fpls.2022.802274] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/14/2022] [Indexed: 05/14/2023]
Abstract
Magnesium (Mg) is an essential nutrient for a wide array of fundamental physiological and biochemical processes in plants. It largely involves chlorophyll synthesis, production, transportation, and utilization of photoassimilates, enzyme activation, and protein synthesis. As a multifaceted result of the introduction of high-yielding fertilizer-responsive cultivars, intensive cropping without replenishment of Mg, soil acidification, and exchangeable Mg (Ex-Mg) leaching, Mg has become a limiting nutrient for optimum crop production. However, little literature is available to better understand distinct responses of plants to Mg deficiency, the geographical distribution of soil Ex-Mg, and the degree of Mg deficiency. Here, we summarize the current state of knowledge of key plant responses to Mg availability and, as far as possible, highlight spatial Mg distribution and the magnitude of Mg deficiency in different cultivated regions of the world with a special focus on China. In particular, ~55% of arable lands in China are revealed Mg-deficient (< 120 mg kg-1 soil Ex-Mg), and Mg deficiency literally becomes increasingly severe from northern (227-488 mg kg-1) to southern (32-89 mg kg-1) China. Mg deficiency primarily traced back to higher depletion of soil Ex-Mg by fruits, vegetables, sugarcane, tubers, tea, and tobacco cultivated in tropical and subtropical climate zones. Further, each unit decline in soil pH from neutral reduced ~2-fold soil Ex-Mg. This article underscores the physiological importance of Mg, potential risks associated with Mg deficiency, and accordingly, to optimize fertilization strategies for higher crop productivity and better quality.
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Affiliation(s)
- Muhammad Ishfaq
- Key Laboratory of Plant-Soil Interactions, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Ministry of Education, China Agricultural University, Beijing, China
| | - Yongqi Wang
- Key Laboratory of Plant-Soil Interactions, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Ministry of Education, China Agricultural University, Beijing, China
| | - Minwen Yan
- Key Laboratory of Plant-Soil Interactions, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Ministry of Education, China Agricultural University, Beijing, China
| | | | - Liangquan Wu
- International Magnesium Institute, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chunjian Li
- Key Laboratory of Plant-Soil Interactions, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Ministry of Education, China Agricultural University, Beijing, China
- International Magnesium Institute, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xuexian Li
- Key Laboratory of Plant-Soil Interactions, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Ministry of Education, China Agricultural University, Beijing, China
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8
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Shankar U, Lenka SK, Leigh Ackland M, Callahan DL. Review of the structures and functions of algal photoreceptors to optimize bioproduct production with novel bioreactor designs for strain improvement. Biotechnol Bioeng 2022; 119:2031-2045. [PMID: 35441370 DOI: 10.1002/bit.28116] [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: 11/19/2021] [Revised: 04/15/2022] [Accepted: 04/15/2022] [Indexed: 11/11/2022]
Abstract
Microalgae are important renewable feedstock to produce biodiesel and high-value chemicals. Different wavelengths of light influence the growth and metabolic activities of algae. Recent research has identified the light-sensing proteins called photoreceptors that respond to blue or red light. Structural elucidations of algal photoreceptors have gained momentum over recent years. These include channelrhodopsins, PHOT proteins, animal-like cryptochromes, blue-light sensors utilizing flavin-adenine dinucleotide (BLUF) proteins. Pulsing light has also been investigated as a means to optimize energy inputs into bioreactors. This review summarizes the current structural and functional basis of photoreceptor modulation to optimize the growth, production of carotenoids and other high-value metabolites from microalgae. The review also encompasses novel photobioreactor designs that implement different light regimes including light wavelengths and time to optimize algal growth and desired metabolite profiles for high-value products. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Uttara Shankar
- TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute, Gurugram, Haryana, 122001, India.,Deakin University, Geelong, Australia. School of Life and Environmental Sciences, (Burwood Campus), Centre for Cellular and Molecular biology. 221 Burwood Highway, Burwood, VIC, 3125, Australia
| | - Sangram K Lenka
- TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute, Gurugram, Haryana, 122001, India.,Gujarat Biotechnology University, Gandhinagar, Gujarat, 382355, India
| | - M Leigh Ackland
- Deakin University, Geelong, Australia. School of Life and Environmental Sciences, (Burwood Campus), Centre for Cellular and Molecular biology. 221 Burwood Highway, Burwood, VIC, 3125, Australia
| | - Damien L Callahan
- Deakin University, Geelong, Australia. School of Life and Environmental Sciences, (Burwood Campus), Centre for Cellular and Molecular biology. 221 Burwood Highway, Burwood, VIC, 3125, Australia
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9
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Li Q, Liu R, Li Z, Fan H, Song J. Positive effects of NaCl on the photoreaction and carbon assimilation efficiency in Suaeda salsa. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 177:32-37. [PMID: 35240360 DOI: 10.1016/j.plaphy.2022.02.019] [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: 11/24/2021] [Revised: 02/02/2022] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
Suaeda salsa L. is a typical euhalophyte and can be used as a model halophyte for research on salt tolerance. S. salsa seedlings were cultured with 0, 200 and 500 mM NaCl for 2 and 14 days. The results revealed that 200 mM NaCl promoted the shoot dry weight, net photosynthetic rate (Pn), chlorophyll content, electron transfer rate, NADPH level, activities of ferredoxin-NADP oxidoreductase, ribulose-1, 5-bisphosphate carboxylase (Rubisco) and Rubisco activase, particularly the Rubisco activity, chlorophyll content and Pn, when the seedlings were treated with 200 mM NaCl for 14 days. Moreover, 500 mM NaCl had no adverse effects on those parameters. In conclusion, NaCl improved the photoreaction and carbon assimilation efficiency of S. salsa. The increased Rubisco activity and chlorophyll content may play critical roles in the enhancement of the photosynthetic efficiency in S. salsa under saline conditions, which may explain why S. salsa can produce the highest biomass at approximately 200 mM NaCl.
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Affiliation(s)
- Qiang Li
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014, China; College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Ru Liu
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014, China
| | - Zihan Li
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014, China
| | - Hai Fan
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014, China.
| | - Jie Song
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014, China.
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10
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Muthukrishnan L. Bio‐engineering of microalgae: Challenges and future prospects toward industrial and environmental applications. J Basic Microbiol 2022; 62:310-329. [DOI: 10.1002/jobm.202100417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/28/2021] [Accepted: 01/08/2022] [Indexed: 01/29/2023]
Affiliation(s)
- Lakshmipathy Muthukrishnan
- Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals Saveetha Institute of Medical and Technical Sciences Chennai Tamil Nadu India
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11
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Tian XY, He DD, Bai S, Zeng WZ, Wang Z, Wang M, Wu LQ, Chen ZC. Physiological and molecular advances in magnesium nutrition of plants. PLANT AND SOIL 2021; 468:1-17. [PMID: 0 DOI: 10.1007/s11104-021-05139-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/25/2021] [Indexed: 05/27/2023]
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12
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Shao Y, Li S, Gao L, Sun C, Hu J, Ullah A, Gao J, Li X, Liu S, Jiang D, Cao W, Tian Z, Dai T. Magnesium Application Promotes Rubisco Activation and Contributes to High-Temperature Stress Alleviation in Wheat During the Grain Filling. FRONTIERS IN PLANT SCIENCE 2021; 12:675582. [PMID: 34177993 PMCID: PMC8231710 DOI: 10.3389/fpls.2021.675582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/21/2021] [Indexed: 06/01/2023]
Abstract
Inhibited photosynthesis caused by post-anthesis high-temperature stress (HTS) leads to decreased wheat grain yield. Magnesium (Mg) plays critical roles in photosynthesis; however, its function under HTS during wheat grain filling remains poorly understood. Therefore, in this study, we investigated the effects of Mg on the impact of HTS on photosynthesis during wheat grain filling by conducting pot experiments in controlled-climate chambers. Plants were subjected to a day/night temperature cycle of 32°C/22°C for 5 days during post-anthesis; the control temperature was set at 26°C/16°C. Mg was applied at the booting stage, with untreated plants used as a control. HTS reduced the yield and net photosynthetic rate (P n ) of wheat plants. The maximum carboxylation rate (V Cmax ), which is limited by Rubisco activity, decreased earlier than the light-saturated potential electron transport rate. This decrease in V Cmax was caused by decreased Rubisco activation state under HTS. Mg application reduced yield loss by stabilizing P n . Rubisco activation was enhanced by increasing Rubisco activase activity following Mg application, thereby stabilizing P n . We conclude that Mg maintains Rubisco activation, thereby helping to stabilize P n under HTS.
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Affiliation(s)
- Yuhang Shao
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Shiyu Li
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Lijun Gao
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Chuanjiao Sun
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Jinling Hu
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Attiq Ullah
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Jingwen Gao
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Xinxin Li
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Sixi Liu
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
- Chengdu Agricultural Technology Extension Station, Chengdu, China
| | - Dong Jiang
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Weixing Cao
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Zhongwei Tian
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
| | - Tingbo Dai
- Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China
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Magnesium Foliar Supplementation Increases Grain Yield of Soybean and Maize by Improving Photosynthetic Carbon Metabolism and Antioxidant Metabolism. PLANTS 2021; 10:plants10040797. [PMID: 33921574 PMCID: PMC8072903 DOI: 10.3390/plants10040797] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 12/20/2022]
Abstract
(1) Background: The aim of this study was to explore whether supplementary magnesium (Mg) foliar fertilization to soybean and maize crops established in a soil without Mg limitation can improve the gas exchange and Rubisco activity, as well as improve antioxidant metabolism, converting higher plant metabolism into grain yield. (2) Methods: Here, we tested foliar Mg supplementation in soybean followed by maize. Nutritional status of plants, photosynthesis, PEPcase and Rubisco activity, sugar concentration on leaves, oxidative stress, antioxidant metabolism, and finally the crops grain yields were determined. (3) Results: Our results demonstrated that foliar Mg supplementation increased the net photosynthetic rate and stomatal conductance, and reduced the sub-stomatal CO2 concentration and leaf transpiration by measuring in light-saturated conditions. The improvement in photosynthesis (gas exchange and Rubisco activity) lead to an increase in the concentration of sugar in the leaves before grain filling. In addition, we also confirmed that foliar Mg fertilization can improve anti-oxidant metabolism, thereby reducing the environmental stress that plants face during their crop cycle in tropical field conditions. (4) Conclusions: Our research brings the new glimpse of foliar Mg fertilization as a strategy to increase the metabolism of crops, resulting in increased grain yields. This type of biological strategy could be encouraged for wide utilization in cropping systems.
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14
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Flecken M, Wang H, Popilka L, Hartl FU, Bracher A, Hayer-Hartl M. Dual Functions of a Rubisco Activase in Metabolic Repair and Recruitment to Carboxysomes. Cell 2020; 183:457-473.e20. [PMID: 32979320 DOI: 10.1016/j.cell.2020.09.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/13/2020] [Accepted: 09/01/2020] [Indexed: 01/19/2023]
Abstract
Rubisco, the key enzyme of CO2 fixation in photosynthesis, is prone to inactivation by inhibitory sugar phosphates. Inhibited Rubisco undergoes conformational repair by the hexameric AAA+ chaperone Rubisco activase (Rca) in a process that is not well understood. Here, we performed a structural and mechanistic analysis of cyanobacterial Rca, a close homolog of plant Rca. In the Rca:Rubisco complex, Rca is positioned over the Rubisco catalytic site under repair and pulls the N-terminal tail of the large Rubisco subunit (RbcL) into the hexamer pore. Simultaneous displacement of the C terminus of the adjacent RbcL opens the catalytic site for inhibitor release. An alternative interaction of Rca with Rubisco is mediated by C-terminal domains that resemble the small Rubisco subunit. These domains, together with the N-terminal AAA+ hexamer, ensure that Rca is packaged with Rubisco into carboxysomes. The cyanobacterial Rca is a dual-purpose protein with functions in Rubisco repair and carboxysome organization.
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Affiliation(s)
- Mirkko Flecken
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Leonhard Popilka
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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15
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Degen GE, Worrall D, Carmo-Silva E. An isoleucine residue acts as a thermal and regulatory switch in wheat Rubisco activase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:742-751. [PMID: 32363739 DOI: 10.1111/tpj.14766] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/21/2020] [Accepted: 03/24/2020] [Indexed: 05/25/2023]
Abstract
The regulation of Rubisco, the gatekeeper of carbon fixation into the biosphere, by its molecular chaperone Rubisco activase (Rca) is essential for photosynthesis and plant growth. Using energy from ATP hydrolysis, Rca promotes the release of inhibitors and restores catalytic competence to Rubisco-active sites. Rca is sensitive to moderate heat stress, however, and becomes progressively inhibited as the temperature increases above the optimum for photosynthesis. Here, we identify a single amino acid substitution (M159I) that fundamentally alters the thermal and regulatory properties of Rca in bread wheat (Triticum aestivum L.). Using site-directed mutagenesis, we demonstrate that the M159I substitution extends the temperature optimum of the most abundant Rca isoform by 5°C in vitro, while maintaining the efficiency of Rubisco activation by Rca. The results suggest that this single amino acid substitution acts as a thermal and regulatory switch in wheat Rca that can be exploited to improve the climate resilience and efficiency of carbon assimilation of this cereal crop as temperatures become warmer and more volatile.
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Affiliation(s)
- Gustaf E Degen
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Dawn Worrall
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
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16
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Bouillet S, Wu T, Chen S, Stock AM, Gao R. Structural asymmetry does not indicate hemiphosphorylation in the bacterial histidine kinase CpxA. J Biol Chem 2020; 295:8106-8117. [PMID: 32094228 DOI: 10.1074/jbc.ra120.012757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/19/2020] [Indexed: 11/06/2022] Open
Abstract
Histidine protein kinases (HKs) are prevalent prokaryotic sensor kinases that are central to phosphotransfer in two-component signal transduction systems, regulating phosphorylation of response regulator proteins that determine the output responses. HKs typically exist as dimers and can potentially autophosphorylate at each conserved histidine residue in the individual protomers, leading to diphosphorylation. However, analyses of HK phosphorylation in biochemical assays in vitro suggest negative cooperativity, whereby phosphorylation in one protomer of the dimer inhibits phosphorylation in the second protomer, leading to ∼50% phosphorylation of the available sites in dimers. This negative cooperativity is often correlated with an asymmetric domain arrangement, a common structural characteristic of autophosphorylation states in many HK structures. In this study, we engineered covalent dimers of the cytoplasmic domains of Escherichia coli CpxA, enabling us to quantify individual species: unphosphorylated, monophosphorylated, and diphosphorylated dimers. Together with mathematical modeling, we unambiguously demonstrate no cooperativity in autophosphorylation of CpxA despite its asymmetric structures, indicating that these asymmetric domain arrangements are not linked to negative cooperativity and hemiphosphorylation. Furthermore, the modeling indicated that many parameters, most notably minor amounts of ADP generated during autophosphorylation reactions or present in ATP preparations, can produce ∼50% total phosphorylation that may be mistakenly attributed to negative cooperativity. This study also establishes that the engineered covalent heterodimer provides a robust experimental system for investigating cooperativity in HK autophosphorylation and offers a useful tool for testing how symmetric or asymmetric structural features influence HK functions.
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Affiliation(s)
- Sophie Bouillet
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Ti Wu
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Shaoxing Chen
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Ann M Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Rong Gao
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
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17
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Chen Z, Chen J, Liu J, Li L, Qin S, Huang Q. Transcriptomic and metabolic analysis of an astaxanthin-hyperproducing Haematococcus pluvialis mutant obtained by low-temperature plasma (LTP) mutagenesis under high light irradiation. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101746] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Scafaro AP, De Vleesschauwer D, Bautsoens N, Hannah MA, den Boer B, Gallé A, Van Rie J. A single point mutation in the C-terminal extension of wheat Rubisco activase dramatically reduces ADP inhibition via enhanced ATP binding affinity. J Biol Chem 2019; 294:17931-17940. [PMID: 31530638 PMCID: PMC6879333 DOI: 10.1074/jbc.ra119.010684] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/15/2019] [Indexed: 01/23/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase (Rca) is a AAA+ enzyme that uses ATP to remove inhibitors from the active site of Rubisco, the central carboxylation enzyme of photosynthesis. Rca α and β isoforms exist in most higher plant species, with the α isoform being identical to the β form but having an additional 25-45 amino acids at the Rca C terminus, known as the C-terminal extension (CTE). Rca is inhibited by ADP, and the extent of ADP sensitivity of the Rca complex can be modulated by the CTE of the α isoform, particularly in relation to a disulfide bond structure that is specifically reduced by the redox-regulatory enzyme thioredoxin-f. Here, we introduced single point mutations of Lys-428 in the CTE of Rca-α from wheat (Triticum aestivum) (TaRca2-α). Substitution of Lys-428 with Arg dramatically altered ADP inhibition, independently of thioredoxin-f regulation. We determined that the reduction in ADP inhibition in the K428R variant is not due to a change in ADP affinity, as the apparent constant for ADP binding was not altered by the K428R substitution. Rather, we observed that the K428R substitution strongly increased ATP substrate affinity and ATP-dependent catalytic velocity. These results suggest that the Lys-428 residue is involved in interacting with the γ-phosphate of ATP. Considering that nucleotide-dependent Rca activity regulates Rubisco and thus photosynthesis during fluctuating irradiance, the K428R substitution could potentially provide a mechanism for boosting the performance of wheat grown in the dynamic light environments of the field.
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Affiliation(s)
- Andrew P Scafaro
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - David De Vleesschauwer
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - Nadine Bautsoens
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - Matthew A Hannah
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - Bart den Boer
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - Alexander Gallé
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
| | - Jeroen Van Rie
- BASF Belgium Coordination Center-Innovation Center Gent, Technologiepark 101, Gent 9052, Belgium
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19
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Szuba A, Marczak Ł, Karliński L, Mucha J, Tomaszewski D. Regulation of the leaf proteome by inoculation of Populus × canescens with two Paxillus involutus isolates differing in root colonization rates. MYCORRHIZA 2019; 29:503-517. [PMID: 31456074 DOI: 10.1007/s00572-019-00910-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
During ectomycorrhizal symbioses, up to 30% of the carbon produced in leaves may be translocated to the fungal partner. Given that the leaf response to root colonization is largely unknown, we performed a leaf proteome analysis of Populus × canescens inoculated in vitro with two isolates of Paxillus involutus significantly differing in root colonization rates (65 ± 7% vs 14 ± 7%), together with plant growth and leaf biochemistry analyses to determine the response of plant leaves to ectomycorrhizal root colonization. The isolate that more efficiently colonized roots (isolate H) affected 9.1% of the leaf proteome compared with control plants. Simultaneously, ectomycorrhiza in isolate H-inoculated plants led to improved plant growth and an increased abundance of leaf proteins involved in protein turnover, stress response, carbohydrate metabolism, and photosynthesis. The protein increment was also correlated with increases in chlorophyll, foliar carbon, and carbohydrate contents. Although inoculation of P. × canescens roots with the other P. involutus isolate (isolate L, characterized by a low root colonization ratio) affected 6.8% of the leaf proteome compared with control plants, most proteins were downregulated. The proteomic signals of increased carbohydrate biosynthesis were not detected, and carbohydrate, carbon, and leaf pigment levels and plant biomass did not differ from the noninoculated plants. Our results revealed that the upregulation of the photosynthetic protein abundance and levels of leaf carbohydrate are positively related to rates of root colonization. Upregulation of photosynthetic proteins, chlorophyll, and leaf carbohydrate levels in ectomycorrhizal plants was positively related to root colonization rates and resulted in increased carbon translocation and sequestration underground.
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Affiliation(s)
- Agnieszka Szuba
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland.
| | - Łukasz Marczak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704, Poznań, Poland
| | - Leszek Karliński
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland
| | - Joanna Mucha
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland
| | - Dominik Tomaszewski
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland
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20
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Rubisco activation by wheat Rubisco activase isoform 2β is insensitive to inhibition by ADP. Biochem J 2019; 476:2595-2606. [PMID: 31471529 DOI: 10.1042/bcj20190110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 11/17/2022]
Abstract
Rubisco activase (Rca) is a catalytic chaperone that remodels the active site, promotes the release of inhibitors and restores catalytic competence to Rubisco. Rca activity and its consequent effect on Rubisco activation and photosynthesis are modulated by changes to the chloroplast environment induced by fluctuations in light levels that reach the leaf, including redox status and adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio. The Triticum aestivum (wheat) genome encodes for three Rca protein isoforms: 1β (42.7 kDa), 2β (42.2 kDa) and 2α (46.0 kDa). The regulatory properties of these isoforms were characterised by measuring rates of Rubisco activation and ATP hydrolysis by purified recombinant Rca proteins in the presence of physiological ADP/ATP ratios. ATP hydrolysis by all three isoforms was sensitive to inhibition by increasing amounts of ADP in the assay. In contrast, Rubisco activation activity of Rca 2β was insensitive to ADP inhibition, while Rca 1β and 2α were inhibited. Two double and one quadruple site-directed mutants were designed to elucidate if differences in the amino acid sequences between Rca 1β and 2β could explain the differences in ADP sensitivity. Changing two amino acids in Rca 2β to the corresponding residues in 1β (T358K & Q362E) resulted in significant inhibition of Rubisco activation in presence of ADP. The results show that the wheat Rca isoforms differ in their regulatory properties and that amino acid changes in the C domain influence ADP sensitivity. Advances in the understanding of Rubisco regulation will aid efforts to improve the efficiency of photosynthetic CO2 assimilation.
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21
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Hauer-Jákli M, Tränkner M. Critical Leaf Magnesium Thresholds and the Impact of Magnesium on Plant Growth and Photo-Oxidative Defense: A Systematic Review and Meta-Analysis From 70 Years of Research. FRONTIERS IN PLANT SCIENCE 2019; 10:766. [PMID: 31275333 PMCID: PMC6592071 DOI: 10.3389/fpls.2019.00766] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/27/2019] [Indexed: 05/19/2023]
Abstract
Magnesium (Mg) deficiency in plants is a widespread problem affecting productivity and quality in agricultural systems and forestry. Although numerous studies addressed the effect of Mg deficiency on biomass and photosynthetic CO2 assimilation, a summary evaluation of the effect of Mg supply on plant growth and photosynthesis is so far missing. We performed a systematic review and meta-analysis to collect and combine all relevant scientifically published data on the relationship between Mg nutrition and parameters that can be related to plant growth such as root and shoot biomass, harvestable yield, net CO2 assimilation and antioxidant enzyme activities. Moreover, this data pool was used to calculate critical Mg leaf concentrations for biomass and net CO2 assimilation for various plant species. Summarizing all studies included in our analysis, adequate Mg supply enhances net CO2 assimilation by 140%, leading to a biomass increase of 61% compared to Mg deficient control plants. Biomass partitioning between shoot and root is not only sensitive to Mg nutrition, but highly affected by the experimental cultivation technique. If plants are grown under adequate Mg supply during initial growth stages before exposing them to Mg deficiency, the shoot-root ratio was not affected. Otherwise, the shoot-root ratio significantly decreased in contrast to Mg deficient control plants. Concentration of reactive oxygen species decreased under adequate Mg supply by 31% compared to Mg deficient plants, resulting in decreased activities of most antioxidant enzymes and metabolites under adequate Mg supply. We combined all published data relating leaf Mg concentrations to growth and found a critical leaf Mg range for dry weight between 0.1 and 0.2% which was valid for numerous crop species such as wheat, potato, rice, maize, sorghum and barley. Critical leaf Mg concentrations for net CO2 assimilation were higher than for biomass for most species, e.g., potato, rice, citrus, and cotton. In conclusion, our evaluation can be used to identify Mg nutritional status in plants and may help to optimize fertilization strategies. It quantifies the demand of Mg for various crop and tree species for maintaining important physiological processes such as net CO2 assimilation that is required for optimal plant growth and yield.
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Affiliation(s)
- Melanie Hauer-Jákli
- Department of Crop Sciences, Institute of Applied Plant Nutrition, Georg-August University Goettingen, Göttingen, Germany
| | - Merle Tränkner
- Department of Crop Sciences, Institute of Applied Plant Nutrition, Georg-August University Goettingen, Göttingen, Germany
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22
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Peng C, Chang L, Yang Q, Tong Z, Wang D, Tan Y, Sun Y, Yi X, Ding G, Xiao J, Zhang Y, Wang X. Comparative physiological and proteomic analyses of the chloroplasts in halophyte Sesuvium portulacastrum under differential salt conditions. JOURNAL OF PLANT PHYSIOLOGY 2019; 232:141-150. [PMID: 30537601 DOI: 10.1016/j.jplph.2018.10.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 10/31/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
Sesuvium portulacastrum, an important mangrove-associated true halophyte belongs to the family Aizoaceae, has excellent salt tolerance. Chloroplasts are the most sensitive organelles involved in the response to salinity. However, the regulation mechanism of chloroplasts of S. portulacastrum under salinity stress has not been reported. In this study, morphological and physiological analyses of leaves and comparative proteomics of chloroplasts isolated from the leaves of S. portulacastrum under different NaCl treatments were performed. Our results showed that the thickness of the palisade tissue, the leaf area, the maximum photochemical efficiency of photosystem II, and the electron transport rate increased remarkably after the plants were subjected to differential saline environments, indicating that salinity can increase photosynthetic efficiency and improve the growth of S. portulacastrum. Subsequently, 55 differentially expressed protein species (DEPs) from the chloroplasts of S. portulacastrum under differential salt conditions were positively identified by mass spectrometry. These DEPs were involved in multiple metabolic pathways, such as photosynthesis, carbon metabolism, ATP synthesis and the cell structure. Among these DEPs, the abundance of most proteins was induced by salt stress. Based on a combination of the morphological and physiological data, as well as the chloroplast proteome results, we speculated that S. portulacastrum can maintain photosynthetic efficiency and growth by maintaining the stability of the photosystem II complex, promoting the photochemical reaction rate, enhancing carbon fixation, developing plastoglobules, and preserving the biomembrane system of chloroplasts under salt stress.
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Affiliation(s)
- Cunzhi Peng
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China; College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China
| | - Lili Chang
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China; College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China
| | - Qian Yang
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China
| | - Zheng Tong
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China
| | - Dan Wang
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China
| | - Yanhua Tan
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China
| | - Yong Sun
- Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou Hainan 571737, China
| | - Xiaoping Yi
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China
| | - Guohua Ding
- College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China
| | - Junhan Xiao
- College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China
| | - Ying Zhang
- College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China
| | - Xuchu Wang
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou Hainan 571101, China; College of Life Sciences, Key Laboratory for Ecology of Tropical Islands, Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, China.
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23
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Serban AJ, Breen IL, Bui HQ, Levitus M, Wachter RM. Assembly-disassembly is coupled to the ATPase cycle of tobacco Rubisco activase. J Biol Chem 2018; 293:19451-19465. [PMID: 30352875 PMCID: PMC6302163 DOI: 10.1074/jbc.ra118.005047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/09/2018] [Indexed: 11/06/2022] Open
Abstract
The carbon-fixing activity of enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is regulated by Rubisco activase (Rca), a ring-forming ATPase that catalyzes inhibitor release. For higher plant Rca, the catalytic roles played by different oligomeric species have remained obscure. Here, we utilized fluorescence-correlation spectroscopy to estimate dissociation constants for the dimer-tetramer, tetramer-hexamer, hexamer-12-mer, and higher-order assembly equilibria of tobacco Rca. A comparison of oligomer composition with ATPase activity provided evidence that assemblies larger than hexamers are hydrolytically inactive. Therefore, supramolecular aggregates may serve as storage forms at low-energy charge. We observed that the tetramer accumulates only when both substrate and product nucleotides are bound. During rapid ATP turnover, about one in six active sites was occupied by ADP, and ∼36% of Rca was tetrameric. The steady-state catalytic rate reached a maximum between 0.5 and 2.5 μm Rca. In this range, significant amounts of dimers, tetramers, and hexamers coexisted, although none could fully account for the observed activity profile. Therefore, we propose that dynamic assembly-disassembly partakes in the ATPase cycle. According to this model, the association of dimers with tetramers generates a hexamer that forms a closed ring at high ATP and magnesium levels. Upon hydrolysis and product release, the toroid breaks open and dissociates into a dimer and tetramer, which may be coupled to Rubisco remodeling. Although a variant bearing the R294V substitution assembled in much the same way, highly stabilized states could be generated by binding of a transition-state analog. A tight-binding pre-hydrolysis state appears to become more accessible in thermally labile Rcas.
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Affiliation(s)
- Andrew J Serban
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Isabella L Breen
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Hoang Q Bui
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Marcia Levitus
- From the School of Molecular Sciences,
- the Biodesign Center for Single Molecule Biophysics, Arizona State University, Tempe, Arizona 85287
| | - Rebekka M Wachter
- From the School of Molecular Sciences,
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
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24
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Tränkner M, Tavakol E, Jákli B. Functioning of potassium and magnesium in photosynthesis, photosynthate translocation and photoprotection. PHYSIOLOGIA PLANTARUM 2018; 163:414-431. [PMID: 29667201 DOI: 10.1111/ppl.12747] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/22/2018] [Accepted: 04/10/2018] [Indexed: 05/03/2023]
Abstract
Potassium (K) and magnesium (Mg) are mineral nutrients that are required in large quantities by plants. Both elements critically contribute to the process of photosynthesis and the subsequent long-distance transport of photoassimilates. If K or Mg is not present in sufficient quantities in photosynthetic tissues, complex interactions of anatomical, physiological and biochemical responses result in a reduction of photosynthetic carbon assimilation. As a consequence, excessive production of reactive oxygen species causes photo-oxidation of the photosynthetic apparatus and causes an up-regulation of photoprotective mechanisms. In this article, we review the functioning of K and Mg in processes directly or indirectly associated with photosynthesis. Focus is given to chloroplast ultrastructure, light-dependent and -independent reactions of photosynthesis and the diffusion of CO2 - a major substrate for photosynthesis - into chloroplasts. We further emphasize their contribution to phloem-loading and long-distance transport of photoassimilates and to the photoprotection of the photosynthetic apparatus.
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Affiliation(s)
- Merle Tränkner
- Institute of Applied Plant Nutrition (IAPN), Georg-August University Goettingen, 37075, Goettingen, Germany
| | | | - Bálint Jákli
- Department of Crop Science, Section of Plant Nutrition & Crop Physiology, Georg-August University Goettingen, 37075, Goettingen, Germany
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25
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Wang Q, Serban AJ, Wachter RM, Moerner WE. Single-molecule diffusometry reveals the nucleotide-dependent oligomerization pathways of Nicotiana tabacum Rubisco activase. J Chem Phys 2018. [PMID: 29604852 DOI: 10.1101/191742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
Oligomerization plays an important role in the function of many proteins, but a quantitative picture of the oligomer distribution has been difficult to obtain using existing techniques. Here we describe a method that combines sub-stoichiometric labeling and recently developed single-molecule diffusometry to measure the size distribution of oligomers under equilibrium conditions in solution, one molecule at a time. We use this technique to characterize the oligomerization behavior of Nicotiana tabacum (Nt) Rubisco activase (Nt-Rca), a chaperone-like AAA-plus ATPase essential in regulating carbon fixation during photosynthesis. We directly observed monomers, dimers, and a tetramer/hexamer mixture and extracted their fractional abundance as a function of protein concentration. We show that the oligomerization pathway of Nt-Rca is nucleotide dependent: ATPγS binding strongly promotes tetramer/hexamer formation from dimers and results in a preferred tetramer/hexamer population for concentrations in the 1-10 μM range. Furthermore, we directly observed dynamic assembly and disassembly processes of single complexes in real time and from there estimated the rate of subunit exchange to be ∼0.1 s-1 with ATPγS. On the other hand, ADP binding destabilizes Rca complexes by enhancing the rate of subunit exchange by >2 fold. These observations provide a quantitative starting point to elucidate the structure-function relations of Nt-Rca complexes. We envision the method to fill a critical gap in defining and quantifying protein assembly pathways in the small-oligomer regime.
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Affiliation(s)
- Quan Wang
- Department of Chemistry, Stanford University, Stanford, California 94035, USA
| | - Andrew J Serban
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85281, USA
| | - Rebekka M Wachter
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85281, USA
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, California 94035, USA
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26
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Wang Q, Serban AJ, Wachter RM, Moerner WE. Single-molecule diffusometry reveals the nucleotide-dependent oligomerization pathways of Nicotiana tabacum Rubisco activase. J Chem Phys 2018; 148:123319. [PMID: 29604852 DOI: 10.1063/1.5005930] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Oligomerization plays an important role in the function of many proteins, but a quantitative picture of the oligomer distribution has been difficult to obtain using existing techniques. Here we describe a method that combines sub-stoichiometric labeling and recently developed single-molecule diffusometry to measure the size distribution of oligomers under equilibrium conditions in solution, one molecule at a time. We use this technique to characterize the oligomerization behavior of Nicotiana tabacum (Nt) Rubisco activase (Nt-Rca), a chaperone-like AAA-plus ATPase essential in regulating carbon fixation during photosynthesis. We directly observed monomers, dimers, and a tetramer/hexamer mixture and extracted their fractional abundance as a function of protein concentration. We show that the oligomerization pathway of Nt-Rca is nucleotide dependent: ATPγS binding strongly promotes tetramer/hexamer formation from dimers and results in a preferred tetramer/hexamer population for concentrations in the 1-10 μM range. Furthermore, we directly observed dynamic assembly and disassembly processes of single complexes in real time and from there estimated the rate of subunit exchange to be ∼0.1 s-1 with ATPγS. On the other hand, ADP binding destabilizes Rca complexes by enhancing the rate of subunit exchange by >2 fold. These observations provide a quantitative starting point to elucidate the structure-function relations of Nt-Rca complexes. We envision the method to fill a critical gap in defining and quantifying protein assembly pathways in the small-oligomer regime.
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Affiliation(s)
- Quan Wang
- Department of Chemistry, Stanford University, Stanford, California 94035, USA
| | - Andrew J Serban
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85281, USA
| | - Rebekka M Wachter
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85281, USA
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, California 94035, USA
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27
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Morales A, Kaiser E, Yin X, Harbinson J, Molenaar J, Driever SM, Struik PC. Dynamic modelling of limitations on improving leaf CO 2 assimilation under fluctuating irradiance. PLANT, CELL & ENVIRONMENT 2018; 41:589-604. [PMID: 29243271 DOI: 10.1111/pce.13119] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/24/2017] [Accepted: 12/01/2017] [Indexed: 05/21/2023]
Abstract
A dynamic model of leaf CO2 assimilation was developed as an extension of the canonical steady-state model, by adding the effects of energy-dependent non-photochemical quenching (qE), chloroplast movement, photoinhibition, regulation of enzyme activity in the Calvin cycle, metabolite concentrations, and dynamic CO2 diffusion. The model was calibrated and tested successfully using published measurements of gas exchange and chlorophyll fluorescence on Arabidopsis thaliana ecotype Col-0 and several photosynthetic mutants and transformants affecting the regulation of Rubisco activity (rca-2 and rwt43), non-photochemical quenching (npq4-1 and npq1-2), and sucrose synthesis (spsa1). The potential improvements on CO2 assimilation under fluctuating irradiance that can be achieved by removing the kinetic limitations on the regulation of enzyme activities, electron transport, and stomatal conductance were calculated in silico for different scenarios. The model predicted that the rates of activation of enzymes in the Calvin cycle and stomatal opening were the most limiting (up to 17% improvement) and that effects varied with the frequency of fluctuations. On the other hand, relaxation of qE and chloroplast movement had a strong effect on average low-irradiance CO2 assimilation (up to 10% improvement). Strong synergies among processes were found, such that removing all kinetic limitations simultaneously resulted in improvements of up to 32%.
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Affiliation(s)
- Alejandro Morales
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Elias Kaiser
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Xinyou Yin
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Jeremy Harbinson
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jaap Molenaar
- Biometris, Mathematical and Statistical Methods Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Steven M Driever
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Paul C Struik
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
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28
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Wei L, Wang Q, Xin Y, Lu Y, Xu J. Enhancing photosynthetic biomass productivity of industrial oleaginous microalgae by overexpression of RuBisCO activase. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.07.023] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Peterson-Forbrook DS, Hilton MT, Tichacek L, Henderson JN, Bui HQ, Wachter RM. Nucleotide Dependence of Subunit Rearrangements in Short-Form Rubisco Activase from Spinach. Biochemistry 2017; 56:4906-4921. [PMID: 28795566 DOI: 10.1021/acs.biochem.7b00574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Higher-plant Rubisco activase (Rca) plays a critical role in regulating the activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). In vitro, Rca is known to undergo dynamic assembly-disassembly processes, with several oligomer stoichiometries coexisting over a broad concentration range. Although the hexamer appears to be the active form, changes in quaternary structure could play a role in Rubisco regulation. Therefore, fluorescent labels were attached to the C-termini of spinach β-Rca, and the rate of subunit mixing was monitored by measuring energy transfer as a function of nucleotide and divalent cation. Only dimeric units appeared to exchange. Poorly hydrolyzable substrate analogues provided locked complexes with high thermal stabilities (apparent Tm = 60 °C) and an estimated t1/2 of at least 7 h, whereas ATP-Mg provided tight assemblies with t1/2 values of 30-40 min and ADP-Mg loose assemblies with t1/2 values of <15 min. Accumulation of ADP to 20% of the total level of adenine nucleotide substantially accelerated equilibration. An initial lag period was observed with ATP·Mg, indicating inhibition of subunit exchange at low ADP concentrations. The ADP Ki value was estimated to exceed the Km for ATP (0.772 ± 96 mM), suggesting that the equilibration rate is a function of the relative contributions of high- and low-affinity states. C-Terminal cross-linking generated covalent dimers, required the N-terminal extension to the AAA+ domain, and provided evidence of different classes of sites. We propose that oligomer reorganization may be stalled during periods of high Rubisco reactivation activity, whereas changes in quaternary structure are stimulated by the accumulation of ADP at low light levels.
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Affiliation(s)
- Dayna S Peterson-Forbrook
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
| | - Matthew T Hilton
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
| | - Laura Tichacek
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
| | - J Nathan Henderson
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
| | - Hoang Q Bui
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
| | - Rebekka M Wachter
- School of Molecular Sciences, School of Life Sciences, and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287, United States
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Shivhare D, Mueller-Cajar O. In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop. PLANT PHYSIOLOGY 2017; 174:1505-1516. [PMID: 28546437 PMCID: PMC5490924 DOI: 10.1104/pp.17.00554] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/24/2017] [Indexed: 05/19/2023]
Abstract
To maintain metabolic flux through the Calvin-Benson-Bassham cycle in higher plants, dead-end inhibited complexes of Rubisco must constantly be engaged and remodeled by the molecular chaperone Rubisco activase (Rca). In C3 plants, the thermolability of Rca is responsible for the deactivation of Rubisco and reduction of photosynthesis at moderately elevated temperatures. We reasoned that crassulacean acid metabolism (CAM) plants must possess thermostable Rca to support Calvin-Benson-Bassham cycle flux during the day when stomata are closed. A comparative biochemical characterization of rice (Oryza sativa) and Agave tequilana Rca isoforms demonstrated that the CAM Rca isoforms are approximately10°C more thermostable than the C3 isoforms. Agave Rca also possessed a much higher in vitro biochemical activity, even at low assay temperatures. Mixtures of rice and agave Rca form functional hetero-oligomers in vitro, but only the rice isoforms denature at nonpermissive temperatures. The high thermostability and activity of agave Rca mapped to the N-terminal 244 residues. A Glu-217-Gln amino acid substitution was found to confer high Rca activity to rice Rca Further mutational analysis suggested that Glu-217 restricts the flexibility of the α4-β4 surface loop that interacts with Rubisco via Lys-216. CAM plants thus promise to be a source of highly functional, thermostable Rca candidates for thermal fortification of crop photosynthesis. Careful characterization of their properties will likely reveal further protein-protein interaction motifs to enrich our mechanistic model of Rca function.
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Affiliation(s)
- Devendra Shivhare
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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31
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Mueller-Cajar O. The Diverse AAA+ Machines that Repair Inhibited Rubisco Active Sites. Front Mol Biosci 2017; 4:31. [PMID: 28580359 PMCID: PMC5437159 DOI: 10.3389/fmolb.2017.00031] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/29/2017] [Indexed: 11/13/2022] Open
Abstract
Gaseous carbon dioxide enters the biosphere almost exclusively via the active site of the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). This highly conserved catalyst has an almost universal propensity to non-productively interact with its substrate ribulose 1,5-bisphosphate, leading to the formation of dead-end inhibited complexes. In diverse autotrophic organisms this tendency has been counteracted by the recruitment of dedicated AAA+ (ATPases associated with various cellular activities) proteins that all use the energy of ATP hydrolysis to remodel inhibited Rubisco active sites leading to release of the inhibitor. Three evolutionarily distinct classes of these Rubisco activases (Rcas) have been discovered so far. Green and red-type Rca are mostly found in photosynthetic eukaryotes of the green and red plastid lineage respectively, whereas CbbQO is associated with chemoautotrophic bacteria. Ongoing mechanistic studies are elucidating how the various motors are utilizing both similar and contrasting strategies to ultimately perform their common function of cracking the inhibited Rubisco active site. The best studied mechanism utilized by red-type Rca appears to involve transient threading of the Rubisco large subunit C-terminal peptide, reminiscent of the action performed by Clp proteases. As well as providing a fascinating example of convergent molecular evolution, Rca proteins can be considered promising crop-improvement targets. Approaches aiming to replace Rubisco in plants with improved enzymes will need to ensure the presence of a compatible Rca protein. The thermolability of the Rca protein found in crop plants provides an opportunity to fortify photosynthesis against high temperature stress. Photosynthesis also appears to be limited by Rca when light conditions are fluctuating. Synthetic biology strategies aiming to enhance the autotrophic CO2 fixation machinery will need to take into consideration the requirement for Rubisco activases as well as their properties.
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Affiliation(s)
- Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological UniversitySingapore, Singapore
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32
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Bhat JY, Thieulin-Pardo G, Hartl FU, Hayer-Hartl M. Rubisco Activases: AAA+ Chaperones Adapted to Enzyme Repair. Front Mol Biosci 2017; 4:20. [PMID: 28443288 PMCID: PMC5385338 DOI: 10.3389/fmolb.2017.00020] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/23/2017] [Indexed: 01/01/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key enzyme of the Calvin-Benson-Bassham cycle of photosynthesis, requires conformational repair by Rubisco activase for efficient function. Rubisco mediates the fixation of atmospheric CO2 by catalyzing the carboxylation of the five-carbon sugar ribulose-1,5-bisphosphate (RuBP). It is a remarkably inefficient enzyme, and efforts to increase crop yields by bioengineering Rubisco remain unsuccessful. This is due in part to the complex cellular machinery required for Rubisco biogenesis and metabolic maintenance. To function, Rubisco must undergo an activation process that involves carboxylation of an active site lysine by a non-substrate CO2 molecule and binding of a Mg2+ ion. Premature binding of the substrate RuBP results in an inactive enzyme. Moreover, Rubisco can also be inhibited by a range of sugar phosphates, some of which are “misfire” products of its multistep catalytic reaction. The release of the inhibitory sugar molecule is mediated by the AAA+ protein Rubisco activase (Rca), which couples hydrolysis of ATP to the structural remodeling of Rubisco. Rca enzymes are found in the vast majority of photosynthetic organisms, from bacteria to higher plants. They share a canonical AAA+ domain architecture and form six-membered ring complexes but are diverse in sequence and mechanism, suggesting their convergent evolution. In this review, we discuss recent advances in understanding the structure and function of this important group of client-specific AAA+ proteins.
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Affiliation(s)
- Javaid Y Bhat
- Department of Cellular Biochemistry, Max-Planck-Institute of BiochemistryMartinsried, Germany
| | - Gabriel Thieulin-Pardo
- Department of Cellular Biochemistry, Max-Planck-Institute of BiochemistryMartinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max-Planck-Institute of BiochemistryMartinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max-Planck-Institute of BiochemistryMartinsried, Germany
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Characterization of the heterooligomeric red-type rubisco activase from red algae. Proc Natl Acad Sci U S A 2016; 113:14019-14024. [PMID: 27872295 DOI: 10.1073/pnas.1610758113] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The photosynthetic CO2-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) is inhibited by nonproductive binding of its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates. Reactivation requires ATP-hydrolysis-powered remodeling of the inhibited complexes by diverse molecular chaperones known as rubisco activases (Rcas). Eukaryotic phytoplankton of the red plastid lineage contain so-called red-type rubiscos, some of which have been shown to possess superior kinetic properties to green-type rubiscos found in higher plants. These organisms are known to encode multiple homologs of CbbX, the α-proteobacterial red-type activase. Here we show that the gene products of two cbbX genes encoded by the nuclear and plastid genomes of the red algae Cyanidioschyzon merolae are nonfunctional in isolation, but together form a thermostable heterooligomeric Rca that can use both α-proteobacterial and red algal-inhibited rubisco complexes as a substrate. The mechanism of rubisco activation appears conserved between the bacterial and the algal systems and involves threading of the rubisco large subunit C terminus. Whereas binding of the allosteric regulator RuBP induces oligomeric transitions to the bacterial activase, it merely enhances the kinetics of ATP hydrolysis in the algal enzyme. Mutational analysis of nuclear and plastid isoforms demonstrates strong coordination between the subunits and implicates the nuclear-encoded subunit as being functionally dominant. The plastid-encoded subunit may be catalytically inert. Efforts to enhance crop photosynthesis by transplanting red algal rubiscos with enhanced kinetics will need to take into account the requirement for a compatible Rca.
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Almeraya EV, Sánchez-de-Jiménez E. Intragenic modification of maize. J Biotechnol 2016; 238:35-41. [PMID: 27641689 DOI: 10.1016/j.jbiotec.2016.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 08/18/2016] [Accepted: 09/14/2016] [Indexed: 10/21/2022]
Abstract
The discovery of plant DNA recombination techniques triggered the development of a wide range of genetically modified crops. The transgenics were the first generation of modified plants; however, these crops were quickly questioned due to the artificial combination of DNA between different species. As a result, the second generation of modified plants known as cisgenic and/or intragenic crops arose as an alternative to genetic plant engineering. Cisgenic and/or intragenic crops development establishes the combination of DNA from the plant itself or related species avoiding the introduction of foreign genetic material, such as selection markers and/or reporter genes. Nowadays it has been made successful cisgenic and/or intragenic modifications in crops such as potato and apple. The present study shows the possibility of reaching similar approach in corn plants. This research was focused on achieve intragenic overexpression of the maize Rubisco activase (Rca) protein. The results were compared with changes in the expression of the same protein, in maize plants grown after 23 cycles of conventional selection and open field planting. Experimental evidence shows that maize intragenic modification is possible for increasing specific gene expression, preserving plant genome free of foreign DNA and achieving further significant savings in time and man labor for crop improvement.
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Heidrich J, Thurotte A, Schneider D. Specific interaction of IM30/Vipp1 with cyanobacterial and chloroplast membranes results in membrane remodeling and eventually in membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:537-549. [PMID: 27693914 DOI: 10.1016/j.bbamem.2016.09.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/19/2016] [Accepted: 09/21/2016] [Indexed: 12/22/2022]
Abstract
The photosynthetic light reaction takes place within the thylakoid membrane system in cyanobacteria and chloroplasts. Besides its global importance, the biogenesis, maintenance and dynamics of this membrane system are still a mystery. In the last two decades, strong evidence supported the idea that these processes involve IM30, the inner membrane-associated protein of 30kDa, a protein also known as the vesicle-inducing protein in plastids 1 (Vipp1). Even though we just only begin to understand the precise physiological function of this protein, it is clear that interaction of IM30 with membranes is crucial for biogenesis of thylakoid membranes. Here we summarize and discuss forces guiding IM30-membrane interactions, as the membrane properties as well as the oligomeric state of IM30 appear to affect proper interaction of IM30 with membrane surfaces. Interaction of IM30 with membranes results in an altered membrane structure and can finally trigger fusion of adjacent membranes, when Mg2+ is present. Based on recent results, we finally present a model summarizing individual steps involved in IM30-mediated membrane fusion. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider.
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Affiliation(s)
- Jennifer Heidrich
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany
| | - Adrien Thurotte
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany
| | - Dirk Schneider
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany.
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