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Harindintwali JD, Wen X, He C, Zhao M, Wang J, Dou Q, Xiang L, Fu Y, Alessi DS, Jiang X, Jiang J, Wang F. Synergistic mitigation of atrazine-induced oxidative stress on soybeans in black soil using biochar and Paenarthrobacter sp. AT5. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 359:120951. [PMID: 38669877 DOI: 10.1016/j.jenvman.2024.120951] [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: 02/28/2024] [Revised: 04/12/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024]
Abstract
Atrazine, a widely used herbicide in modern agriculture, can lead to soil contamination and adverse effects on specific crops. To address this, we investigated the efficacy of biochar loaded with Paenarthrobacter sp. AT5 (an atrazine-degrading bacterial strain) in mitigating atrazine's impact on soybeans in black soil. Bacterially loaded biochar (BBC) significantly enhanced atrazine removal rates in both unplanted and planted soil systems. Moreover, BBC application improved soybean biomass, photosynthetic pigments, and antioxidant systems while mitigating alterations in metabolite pathways induced by atrazine exposure. These findings demonstrate the effectiveness of BBC in reducing atrazine-induced oxidative stress on soybeans in black soil, highlighting its potential for sustainable agriculture.
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Affiliation(s)
- Jean Damascene Harindintwali
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin Wen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chao He
- Institute of Environment Pollution Control and Treatment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Mingxu Zhao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jianhao Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qingyuan Dou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Leilei Xiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuhao Fu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Daniel S Alessi
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada
| | - Xin Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiandong Jiang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, Nanjing, 210095, China
| | - Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China; RWTH Aachen University, Institute for Environmental Research, WorringerWeg 1, 52074, Aachen, Germany.
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Fortunato S, Nigro D, Lasorella C, Marcotuli I, Gadaleta A, de Pinto MC. The Role of Glutamine Synthetase (GS) and Glutamate Synthase (GOGAT) in the Improvement of Nitrogen Use Efficiency in Cereals. Biomolecules 2023; 13:1771. [PMID: 38136642 PMCID: PMC10742212 DOI: 10.3390/biom13121771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Cereals are the most broadly produced crops and represent the primary source of food worldwide. Nitrogen (N) is a critical mineral nutrient for plant growth and high yield, and the quality of cereal crops greatly depends on a suitable N supply. In the last decades, a massive use of N fertilizers has been achieved in the desire to have high yields of cereal crops, leading to damaging effects for the environment, ecosystems, and human health. To ensure agricultural sustainability and the required food source, many attempts have been made towards developing cereal crops with a more effective nitrogen use efficiency (NUE). NUE depends on N uptake, utilization, and lastly, combining the capability to assimilate N into carbon skeletons and remobilize the N assimilated. The glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle represents a crucial metabolic step of N assimilation, regulating crop yield. In this review, the physiological and genetic studies on GS and GOGAT of the main cereal crops will be examined, giving emphasis on their implications in NUE.
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Affiliation(s)
- Stefania Fortunato
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (S.F.)
| | - Domenica Nigro
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (D.N.); (I.M.)
| | - Cecilia Lasorella
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (S.F.)
| | - Ilaria Marcotuli
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (D.N.); (I.M.)
| | - Agata Gadaleta
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (D.N.); (I.M.)
| | - Maria Concetta de Pinto
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy; (S.F.)
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Ancín M, Larraya L, Florez-Sarasa I, Bénard C, Fernández-San Millán A, Veramendi J, Gibon Y, Fernie AR, Aranjuelo I, Farran I. Overexpression of thioredoxin m in chloroplasts alters carbon and nitrogen partitioning in tobacco. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4949-4964. [PMID: 33963398 PMCID: PMC8219043 DOI: 10.1093/jxb/erab193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/27/2021] [Indexed: 06/02/2023]
Abstract
In plants, there is a complex interaction between carbon (C) and nitrogen (N) metabolism, and its coordination is fundamental for plant growth and development. Here, we studied the influence of thioredoxin (Trx) m on C and N partitioning using tobacco plants overexpressing Trx m from the chloroplast genome. The transgenic plants showed altered metabolism of C (lower leaf starch and soluble sugar accumulation) and N (with higher amounts of amino acids and soluble protein), which pointed to an activation of N metabolism at the expense of carbohydrates. To further delineate the effect of Trx m overexpression, metabolomic and enzymatic analyses were performed on these plants. These results showed an up-regulation of the glutamine synthetase-glutamate synthase pathway; specifically tobacco plants overexpressing Trx m displayed increased activity and stability of glutamine synthetase. Moreover, higher photorespiration and nitrate accumulation were observed in these plants relative to untransformed control plants, indicating that overexpression of Trx m favors the photorespiratory N cycle rather than primary nitrate assimilation. Taken together, our results reveal the importance of Trx m as a molecular mediator of N metabolism in plant chloroplasts.
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Affiliation(s)
- María Ancín
- Institute for Multidisciplinary Applied Biology (IMAB), Dpto. Agronomía, Biotecnología y Alimentación, Universidad Publica de Navarra (UPNA), Campus Arrosadia, 31006 Pamplona, Spain
| | - Luis Larraya
- Institute for Multidisciplinary Applied Biology (IMAB), Dpto. Agronomía, Biotecnología y Alimentación, Universidad Publica de Navarra (UPNA), Campus Arrosadia, 31006 Pamplona, Spain
| | - Igor Florez-Sarasa
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Camille Bénard
- UMR 1332 Biologie du Fruit et Pathologie and Plateforme Metabolome Bordeaux, INRA, Bordeaux University, 33882 Villenave d’Ornon, France
| | - Alicia Fernández-San Millán
- Institute for Multidisciplinary Applied Biology (IMAB), Dpto. Agronomía, Biotecnología y Alimentación, Universidad Publica de Navarra (UPNA), Campus Arrosadia, 31006 Pamplona, Spain
| | - Jon Veramendi
- Institute for Multidisciplinary Applied Biology (IMAB), Dpto. Agronomía, Biotecnología y Alimentación, Universidad Publica de Navarra (UPNA), Campus Arrosadia, 31006 Pamplona, Spain
| | - Yves Gibon
- UMR 1332 Biologie du Fruit et Pathologie and Plateforme Metabolome Bordeaux, INRA, Bordeaux University, 33882 Villenave d’Ornon, France
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Iker Aranjuelo
- Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Avda. Pamplona 123, 31192 Mutilva, Spain
| | - Inmaculada Farran
- Institute for Multidisciplinary Applied Biology (IMAB), Dpto. Agronomía, Biotecnología y Alimentación, Universidad Publica de Navarra (UPNA), Campus Arrosadia, 31006 Pamplona, Spain
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Zhu J, Song S, Sun Z, Lian L, Shi L, Ren A, Zhao M. Regulation of glutamine synthetase activity by transcriptional and posttranslational modifications negatively influences ganoderic acid biosynthesis in Ganoderma lucidum. Environ Microbiol 2021; 23:1286-1297. [PMID: 33438292 DOI: 10.1111/1462-2920.15400] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/15/2020] [Accepted: 01/09/2021] [Indexed: 12/01/2022]
Abstract
Glutamine synthetase (GS), a central nitrogen metabolic enzyme, plays important roles in the nitrogen regulation network and secondary metabolism in fungi. However, the mechanisms by which external nitrogen sources regulate fungal GS activity have not been determined. Here, we found that GS activity was inhibited under nitrate conditions in Ganoderma lucidum. By constructing gs-silenced strains and adding 1 mM GS inhibitor to inhibit GS activity, we found that a decrease in GS activity led to a decrease in ganoderic acid biosynthesis. The transcription of gs increased approximately five fold under nitrate conditions compared with that under ammonia. Electrophoretic mobility shift and yeast one-hybrid assay showed that gs was transcriptionally regulated by AreA. Although both gs expression and GS protein content increased under nitrate conditions, the GS activity still decreased. Treatment of recombinant GS with SIN-1 (protein nitration donor) resulted in a strengthened nitration accompanied by a 71% decrease in recombinant GS activity. Furthermore, intracellular GS could be nitrated from mycelia cultivated under nitrate conditions. These results indicated that GS activity could be inhibited by NO-mediated protein nitration. Our findings provide the first insight into the role of transcriptional and posttranslational regulation of GS activity in regulating secondary metabolism in fungi.
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Affiliation(s)
- Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Shuqi Song
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Zehua Sun
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Lingdan Lian
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Mingwen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
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Kaur H, Peel A, Acosta K, Gebril S, Ortega JL, Sengupta‐Gopalan C. Comparison of alfalfa plants overexpressing glutamine synthetase with those overexpressing sucrose phosphate synthase demonstrates a signaling mechanism integrating carbon and nitrogen metabolism between the leaves and nodules. PLANT DIRECT 2019; 3:e00115. [PMID: 31245757 PMCID: PMC6508842 DOI: 10.1002/pld3.115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/21/2018] [Accepted: 12/26/2018] [Indexed: 05/29/2023]
Abstract
Alfalfa, like other legumes, establishes a symbiotic relationship with the soil bacteria, Sinorhizobium meliloti, which results in the formation of the root nodules. Nodules contain the bacteria enclosed in a membrane-bound vesicle, the symbiosome where it fixes atmospheric N2 and converts it into ammonia using the bacterial enzyme, nitrogenase. The ammonia released into the cytoplasm from the symbiosome is assimilated into glutamine (Gln) using carbon skeletons produced by the metabolism of sucrose (Suc), which is imported into the nodules from the leaves. The key enzyme involved in the synthesis of Suc in the leaves is sucrose phosphate synthase (SPS) and glutamine synthetase (GS) is the enzyme with a role in ammonia assimilation in the root nodules. Alfalfa plants, overexpressing SPS or GS, or both showed increased growth and an increase in nodule function. The endogenous genes for the key enzymes in C/N metabolism showed increased expression in the nodules of both sets of transformants. Furthermore, the endogenous SPS and GS genes were also induced in the leaves and nodules of the transformants, irrespective of the transgene, suggesting that the two classes of plants share a common signaling pathway regulating C/N metabolism in the nodules. This study reaffirms the utility of the nodulated legume plant to study C/N interaction and the cross talk between the source and sink for C and N.
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Affiliation(s)
- Harmanpreet Kaur
- Department of Plant and Environmental SciencesNew Mexico State UniversityLas CrucesNew Mexico
| | - Amanda Peel
- Department of Learning, Teaching and CurriculumUniversity of MissouriColumbiaMissouri
| | - Karen Acosta
- Department of Biochemistry and BiophysicsPerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Sayed Gebril
- Department of HorticultureSohag UniversitySohagEgypt
| | - Jose Luis Ortega
- Department of Plant and Environmental SciencesNew Mexico State UniversityLas CrucesNew Mexico
| | - Champa Sengupta‐Gopalan
- Department of Plant and Environmental SciencesNew Mexico State UniversityLas CrucesNew Mexico
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Aroca A, Gotor C, Romero LC. Hydrogen Sulfide Signaling in Plants: Emerging Roles of Protein Persulfidation. FRONTIERS IN PLANT SCIENCE 2018; 9:1369. [PMID: 30283480 PMCID: PMC6157319 DOI: 10.3389/fpls.2018.01369] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Hydrogen sulfide (H2S) has been largely referred as a toxic gas and environmental hazard, but recent years, it has emerged as an important gas-signaling molecule with effects on multiple physiological processes in both animal and plant systems. The regulatory functions of H2S in plants are involved in important processes such as the modulation of defense responses, plant growth and development, and the regulation of senescence and maturation. The main signaling pathway involving sulfide has been proven to be through protein persulfidation (alternatively called S-sulfhydration), in which the thiol group of cysteine (-SH) in proteins is modified into a persulfide group (-SSH). This modification may cause functional changes in protein activities, structures, and subcellular localizations of the target proteins. New shotgun proteomic approaches and bioinformatic analyses have revealed that persulfidated cysteines regulate important biological processes, highlighting their importance in cell signaling, since about one in 20 proteins in Arabidopsis is persulfidated. During oxidative stress, an increased persulfidation has been reported and speculated that persulfidation is the protective mechanism for protein oxidative damage. Nevertheless, cysteine residues are also oxidized to different post-translational modifications such S-nitrosylation or S-sulfenylation, which seems to be interconvertible. Thus, it must imply a tight cysteine redox regulation essential for cell survival. This review is aimed to focus on the current knowledge of protein persulfidation and addresses the regulation mechanisms that are disclosed based on the knowledge from other cysteine modifications.
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Sweetlove LJ, Nielsen J, Fernie AR. Engineering central metabolism - a grand challenge for plant biologists. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:749-763. [PMID: 28004455 DOI: 10.1111/tpj.13464] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 12/14/2016] [Accepted: 12/15/2016] [Indexed: 06/06/2023]
Abstract
The goal of increasing crop productivity and nutrient-use efficiency is being addressed by a number of ambitious research projects seeking to re-engineer photosynthetic biochemistry. Many of these projects will require the engineering of substantial changes in fluxes of central metabolism. However, as has been amply demonstrated in simpler systems such as microbes, central metabolism is extremely difficult to rationally engineer. This is because of multiple layers of regulation that operate to maintain metabolic steady state and because of the highly connected nature of central metabolism. In this review we discuss new approaches for metabolic engineering that have the potential to address these problems and dramatically improve the success with which we can rationally engineer central metabolism in plants. In particular, we advocate the adoption of an iterative 'design-build-test-learn' cycle using fast-to-transform model plants as test beds. This approach can be realised by coupling new molecular tools to incorporate multiple transgenes in nuclear and plastid genomes with computational modelling to design the engineering strategy and to understand the metabolic phenotype of the engineered organism. We also envisage that mutagenesis could be used to fine-tune the balance between the endogenous metabolic network and the introduced enzymes. Finally, we emphasise the importance of considering the plant as a whole system and not isolated organs: the greatest increase in crop productivity will be achieved if both source and sink metabolism are engineered.
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Affiliation(s)
- Lee J Sweetlove
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE41128, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK2800, Lyngby, Denmark
- Science for Life Laboratory, Royal Institute of Technology, SE17121, Stockholm, Sweden
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
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Tian YS, Wang RT, Zhao W, X J, Xing XJ, Fu XY, Peng RH, Yao QH. Distinct properties of two glutamine synthetase isoforms in soybean root nodules. APPL BIOCHEM MICRO+ 2016. [DOI: 10.1134/s0003683816060156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Wang X, Wei Y, Shi L, Ma X, Theg SM. New isoforms and assembly of glutamine synthetase in the leaf of wheat (Triticum aestivum L.). JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6827-34. [PMID: 26307137 PMCID: PMC4623691 DOI: 10.1093/jxb/erv388] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Glutamine synthetase (GS; EC 6.3.1.2) plays a crucial role in the assimilation and re-assimilation of ammonia derived from a wide variety of metabolic processes during plant growth and development. Here, three developmentally regulated isoforms of GS holoenzyme in the leaf of wheat (Triticum aestivum L.) seedlings are described using native-PAGE with a transferase activity assay. The isoforms showed different mobilities in gels, with GSII>GSIII>GSI. The cytosolic GSI was composed of three subunits, GS1, GSr1, and GSr2, with the same molecular weight (39.2kDa), but different pI values. GSI appeared at leaf emergence and was active throughout the leaf lifespan. GSII and GSIII, both located in the chloroplast, were each composed of a single 42.1kDa subunit with different pI values. GSII was active mainly in green leaves, while GSIII showed brief but higher activity in green leaves grown under field conditions. LC-MS/MS experiments revealed that GSII and GSIII have the same amino acid sequence, but GSII has more modification sites. With a modified blue native electrophoresis (BNE) technique and in-gel catalytic activity analysis, only two GS isoforms were observed: one cytosolic and one chloroplastic. Mass calibrations on BNE gels showed that the cytosolic GS1 holoenzyme was ~490kDa and likely a dodecamer, and the chloroplastic GS2 holoenzyme was ~240kDa and likely a hexamer. Our experimental data suggest that the activity of GS isoforms in wheat is regulated by subcellular localization, assembly, and modification to achieve their roles during plant development.
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Affiliation(s)
- Xiaochun Wang
- Collaborative Innovation Center of Henan Grain Crops, Henan Agriculture University, Zhengzhou 450002, China State Key Laboratory of Wheat and Maize Crop Science in China, Henan Agriculture University, Zhengzhou 450002, China Department of Biochemistry, College of Life Science, Henan Agriculture University, Zhengzhou 450002, China
| | - Yihao Wei
- Department of Biochemistry, College of Life Science, Henan Agriculture University, Zhengzhou 450002, China
| | - Lanxin Shi
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Xinming Ma
- Collaborative Innovation Center of Henan Grain Crops, Henan Agriculture University, Zhengzhou 450002, China
| | - Steven M Theg
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
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Gómez-Baena G, Domínguez-Martín MA, Donaldson RP, García-Fernández JM, Diez J. Glutamine Synthetase Sensitivity to Oxidative Modification during Nutrient Starvation in Prochlorococcus marinus PCC 9511. PLoS One 2015; 10:e0135322. [PMID: 26270653 PMCID: PMC4535847 DOI: 10.1371/journal.pone.0135322] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 07/21/2015] [Indexed: 11/19/2022] Open
Abstract
Glutamine synthetase plays a key role in nitrogen metabolism, thus the fine regulation of this enzyme in Prochlorococcus, which is especially important in the oligotrophic oceans where this marine cyanobacterium thrives. In this work, we studied the metal-catalyzed oxidation of glutamine synthetase in cultures of Prochlorococcus marinus strain PCC 9511 subjected to nutrient limitation. Nitrogen deprivation caused glutamine synthetase to be more sensitive to metal-catalyzed oxidation (a 36% increase compared to control, non starved samples). Nutrient starvation induced also a clear increase (three-fold in the case of nitrogen) in the concentration of carbonyl derivatives in cell extracts, which was also higher (22%) upon addition of the inhibitor of electron transport, DCMU, to cultures. Our results indicate that nutrient limitations, representative of the natural conditions in the Prochlorococcus habitat, affect the response of glutamine synthetase to oxidative inactivating systems. Implications of these results on the regulation of glutamine synthetase by oxidative alteration prior to degradation of the enzyme in Prochlorococcus are discussed.
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Affiliation(s)
- Guadalupe Gómez-Baena
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Universidad de Córdoba, Córdoba, Spain
- * E-mail:
| | | | - Robert P. Donaldson
- Department of Biological Sciences, The George Washington University, Washington, D.C., United States of America
| | | | - Jesús Diez
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Universidad de Córdoba, Córdoba, Spain
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Seabra AR, Carvalho HG. Glutamine synthetase in Medicago truncatula, unveiling new secrets of a very old enzyme. FRONTIERS IN PLANT SCIENCE 2015; 6:578. [PMID: 26284094 PMCID: PMC4515544 DOI: 10.3389/fpls.2015.00578] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/13/2015] [Indexed: 05/03/2023]
Abstract
Glutamine synthetase (GS) catalyzes the first step at which nitrogen is brought into cellular metabolism and is also involved in the reassimilation of ammonium released by a number of metabolic pathways. Due to its unique position in plant nitrogen metabolism, GS plays essential roles in all aspects of plant development, from germination to senescence, and is a key component of nitrogen use efficiency (NUE) and plant yield. Understanding the mechanisms regulating GS activity is therefore of utmost importance and a great effort has been dedicated to understand how GS is regulated in different plant species. The present review summarizes exciting recent developments concerning the structure and regulation of GS isoenzymes, using the model legume Medicago truncatula. These include the understanding of the structural determinants of both the cytosolic and plastid located isoenzymes, the existence of a seed-specific GS gene unique to M. truncatula and closely related species and the discovery that GS isoenzymes are regulated by nitric oxide at the post-translational level. The data is discussed and integrated with the potential roles of the distinct GS isoenzymes within the whole plant context.
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Affiliation(s)
| | - Helena G. Carvalho
- *Correspondence: Helena G. Carvalho, Laboratory of Molecular Biology of Nitrogen Assimilation, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal,
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Seger M, Gebril S, Tabilona J, Peel A, Sengupta-Gopalan C. Impact of concurrent overexpression of cytosolic glutamine synthetase (GS1) and sucrose phosphate synthase (SPS) on growth and development in transgenic tobacco. PLANTA 2015; 241:69-81. [PMID: 25213117 DOI: 10.1007/s00425-014-2165-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/03/2014] [Indexed: 05/19/2023]
Abstract
MAIN CONCLUSION The outcome of simultaneously increasing SPS and GS activities in transgenic tobacco, suggests that sucrose is the major determinant of growth and development, and is not affected by changes in N assimilation. Carbon (C) and nitrogen (N) are the major components required for plant growth and the metabolic pathways for C and N assimilation are very closely interlinked. Maintaining an appropriate balance or ratio of sugar to nitrogen metabolites in the cell, is important for the regulation of plant growth and development. To understand how C and N metabolism interact, we manipulated the expression of key genes in C and N metabolism individually and concurrently and checked for the repercussions. Transgenic tobacco plants with a cytosolic soybean glutamine synthetase (GS1) gene and a sucrose phosphate synthase (SPS) gene from maize, both driven by the CaMV 35S promoter were produced. Co-transformants, with both the transgenes were produced by sexual crosses. While GS is the key enzyme in N assimilation, involved in the synthesis of glutamine, SPS plays a key role in C metabolism by catalyzing the synthesis of sucrose. Moreover, to check if nitrate has any role in this interaction, the plants were grown under both low and high nitrogen. The SPS enzyme activity in the SPS and SPS/GS1 co-transformants were the same under both nitrogen regimens. However, the GS activity was lower in the co-transformants compared to the GS1 transformants, specifically under low nitrogen conditions. The GS1/SPS transformants showed a phenotype similar to the SPS transformants, suggesting that sucrose is the major determinant of growth and development in tobacco, and its effect is only marginally affected by increased N assimilation. Sucrose may be functioning in a metabolic capacity or as a signaling molecule.
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Affiliation(s)
- Mark Seger
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, 88003, USA
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14
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Thomsen HC, Eriksson D, Møller IS, Schjoerring JK. Cytosolic glutamine synthetase: a target for improvement of crop nitrogen use efficiency? TRENDS IN PLANT SCIENCE 2014; 19:656-63. [PMID: 25017701 DOI: 10.1016/j.tplants.2014.06.002] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 05/19/2023]
Abstract
Overexpression of the cytosolic enzyme glutamine synthetase 1 (GS1) has been investigated in numerous cases with the goal of improving crop nitrogen use efficiency. However, the outcome has generally been inconsistent. Here, we review possible reasons underlying the lack of success and conclude that GS1 activity may be downregulated via a chain of processes elicited by metabolic imbalances and environmental constraints. We suggest that a pivotal role of GS1 may be related to the maintenance of essential nitrogen (N) flows and internal N sensing during critical stages of plant development. A number of more refined overexpression strategies exploiting gene stacking combined with tissue and cell specific targeting to overcome metabolic bottlenecks are considered along with their potential in relation to new N management strategies.
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Affiliation(s)
- Hanne C Thomsen
- Department of Plant and Environmental Sciences, Plant and Soil Science Section, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Dennis Eriksson
- Department of Plant and Environmental Sciences, Plant and Soil Science Section, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Inge S Møller
- Department of Plant and Environmental Sciences, Plant and Soil Science Section, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Jan K Schjoerring
- Department of Plant and Environmental Sciences, Plant and Soil Science Section, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
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15
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Dragićević M, Todorović S, Bogdanović M, Filipović B, Mišić D, Simonović A. Knockout mutants as a tool to identify the subunit composition of Arabidopsis glutamine synthetase isoforms. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 79:1-9. [PMID: 24657507 DOI: 10.1016/j.plaphy.2014.02.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/25/2014] [Indexed: 06/03/2023]
Abstract
Glutamine synthetase (GS) is a key enzyme in nitrogen assimilation, which catalyzes the formation of glutamine from ammonia and glutamate. Plant GS isoforms are multimeric enzymes, recently shown to be decamers. The Arabidopsis genome encodes five cytosolic (GS1) proteins labeled as GLN1;1 through GLN1;5 and one chloroplastic (GS2) isoform, GLN2;0. However, as many as 11 GS activity bands were resolved from different Arabidopsis tissues by Native PAGE and activity staining. Western analysis showed that all 11 isoforms are composed exclusively of 40 kDa GS1 subunits. Of five GS1 genes, only GLN1;1, GLN1;2 and GLN1;3 transcripts accumulated to significant levels in vegetative tissues, indicating that only subunits encoded by these three genes produce the 11-band zymogram. Even though the GS2 gene also had significant expression, the corresponding activity was not detected, probably due to inactivation. To resolve the subunit composition of 11 active GS1 isoforms, homozygous knockout mutants deficient in the expression of different GS1 genes were selected from the progeny of T-DNA insertional SALK and SAIL lines. Comparison of GS isoenzyme patterns of the selected GS1 knockout mutants indicated that all of the detected isoforms consist of varying proportions of GLN1;1, GLN1;2 and GLN1;3 subunits, and that GLN1;1 and GLN1;3, as well as GLN1;2 and GLN1;3 and possibly GLN1;1 and GLN1;2 proteins combine in all proportions to form active homo- and heterodecamers.
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Affiliation(s)
- Milan Dragićević
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Slađana Todorović
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Milica Bogdanović
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Biljana Filipović
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Danijela Mišić
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Ana Simonović
- Institute for Biological Research "Siniša Stanković", Department for Plant Physiology, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
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16
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Cheng TS, Hung MJ, Cheng YI, Cheng LJ. Calcium-induced proline accumulation contributes to amelioration of NaCl injury and expression of glutamine synthetase in greater duckweed (Spirodela polyrhiza L.). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 144-145:265-274. [PMID: 24200992 DOI: 10.1016/j.aquatox.2013.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 10/07/2013] [Accepted: 10/12/2013] [Indexed: 06/02/2023]
Abstract
The calcium-mediated proline accumulation is a critical response under NaCl stress and the function of the induced proline as a glutamine synthetase (GS) protectant in greater duckweed was investigated. The plants were treated with solutions containing 100mM NaCl, 200 mM NaCl, 200 mM NaCl plus 10mM CaCl2, or 10mM CaCl2 alone for 4 days. At the end of the experiment, the fronds of inoculum treated with 200 mM NaCl showed the chlorotic effect, higher glutamate dehydrogenase (NADH-GDH) activity and lower GS activity. At the lower salinity, the activities of GS and NADH-GDH were not altered markedly. A significant accumulation of proline was not found under either low or high salinity. The activity of Δ(1)-pyrroline-5-carboxylate reductase (P5CR) was enhanced only at 200 mM NaCl but remained unchanged at 100mM NaCl. The activity of Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) did not change under salinity-stressed. Addition of CaCl2 to the salt stressed plants not only lowered NaCl injury but also showed an elevated level of proline contents in response to the salinity treatment. In addition, both GS activity and corresponding polypeptides were expressed close to the level of control. Exogenous proline protects GS2 and the 32 kDa protein in photosystem II reaction center (D1) from H2O2-induced redox degradation in the chloroplast lysates of duckweed. The results suggest that calcium-induced proline accumulation may play an important role as a GS protectant under NaCl exposure in S. polyrhiza.
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Affiliation(s)
- Tai-Sheng Cheng
- Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan, ROC
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17
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Ortega JL, Wilson OL, Sengupta-Gopalan C. The 5' untranslated region of the soybean cytosolic glutamine synthetase β(1) gene contains prokaryotic translation initiation signals and acts as a translational enhancer in plants. Mol Genet Genomics 2012; 287:881-93. [PMID: 23080263 PMCID: PMC3881598 DOI: 10.1007/s00438-012-0724-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 10/04/2012] [Indexed: 01/03/2023]
Abstract
Glutamine synthetase (GS) catalyzes the synthesis of glutamine from glutamate and ammonia. In plants, it occurs as two major isoforms, a cytosolic form (GS(1)) and a nuclear encoded chloroplastic form. The focus of this paper is to determine the role of the 5'UTR of a GS(1) gene. GS(1) gene constructs with and without its 5' and 3' UTRs, driven by a constitutive promoter, were agroinfiltrated into tobacco leaves and the tissues were analyzed for both transgene transcript and protein accumulation. The constructs were also tested in an in vitro transcription/translation system and in Escherichia coli. Our results showed that while the 3'UTR functioned in the destabilization of the transcript, the 5'UTR acted as a translation enhancer in plant cells but not in the in vitro translation system. The 5'UTR of the GS(1) gene when placed in front of a reporter gene (uidA), showed a 20-fold increase in the level of GUS expression in agroinfiltrated leaves when compared to the same gene construct without the 5'UTR. The 5'UTR-mediated translational enhancement is probably another step in the regulation of GS in plants. The presence of the GS(1) 5'UTR in front of the GS(1) coding region allowed for its translation in E. coli suggesting the commonality of the translation initiation mechanism for this gene between plants and bacteria.
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Affiliation(s)
- Jose Luis Ortega
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA
| | - Olivia L. Wilson
- Molecular Biology Graduate Program, New Mexico State University, Las Cruces, NM 88003, USA
| | - Champa Sengupta-Gopalan
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA,
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18
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Sharmin SA, Alam I, Kim KH, Kim YG, Kim PJ, Bahk JD, Lee BH. Chromium-induced physiological and proteomic alterations in roots of Miscanthus sinensis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 187:113-26. [PMID: 22404839 DOI: 10.1016/j.plantsci.2012.02.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/31/2012] [Accepted: 02/02/2012] [Indexed: 05/23/2023]
Abstract
Despite the widespread occurrence of chromium toxicity, its molecular mechanism is poorly documented in plants compared to other heavy metals. To investigate the molecular mechanisms that regulate the response of Miscanthus sinensis roots to elevated level of chromium, seedlings were grown for 4 weeks and exposed to potassium dichromate for 3 days. Physiological, biochemical and proteomic changes in roots were investigated. Lipid peroxidation and H₂O₂ content in roots were significantly increased. Protein profiles analyzed by two-dimensional gel electrophoresis revealed that 36 protein spots were differentially expressed in chromium-treated root samples. Of these, 13 protein spots were up-regulated, 21 protein spots were down-regulated and 2 spots were newly induced. These differentially displayed proteins were identified by MALDI-TOF and MALDI-TOF/TOF mass spectrometry. The identified proteins included known heavy metal-inducible proteins such as carbohydrate and nitrogen metabolism, molecular chaperone proteins and novel proteins such as inositol monophosphatase, nitrate reductase, adenine phosphoribosyl transferase, formate dehydrogenase and a putative dihydrolipoamide dehydrogenase that were not known previously as chromium-responsive. Taken together, these results suggest that Cr toxicity is linked to heavy metal tolerance and senescence pathways, and associated with altered vacuole sequestration, nitrogen metabolism and lipid peroxidation in Miscanthus roots.
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Affiliation(s)
- Shamima Akhtar Sharmin
- Division of Applied Life Science (BK21 program), IALS, PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea
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19
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Melo PM, Silva LS, Ribeiro I, Seabra AR, Carvalho HG. Glutamine synthetase is a molecular target of nitric oxide in root nodules of Medicago truncatula and is regulated by tyrosine nitration. PLANT PHYSIOLOGY 2011; 157:1505-17. [PMID: 21914816 PMCID: PMC3252174 DOI: 10.1104/pp.111.186056] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 09/12/2011] [Indexed: 05/20/2023]
Abstract
Nitric oxide (NO) is emerging as an important regulatory player in the Rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. To unravel the signal transduction cascade and ultimately NO function, it is necessary to identify its molecular targets. This study provides evidence that glutamine synthetase (GS), a key enzyme for root nodule metabolism, is a molecular target of NO in root nodules of Medicago truncatula, being regulated by tyrosine (Tyr) nitration in relation to active nitrogen fixation. In vitro studies, using purified recombinant enzymes produced in Escherichia coli, demonstrated that the M. truncatula nodule GS isoenzyme (MtGS1a) is subjected to NO-mediated inactivation through Tyr nitration and identified Tyr-167 as the regulatory nitration site crucial for enzyme inactivation. Using a sandwich enzyme-linked immunosorbent assay, it is shown that GS is nitrated in planta and that its nitration status changes in relation to active nitrogen fixation. In ineffective nodules and in nodules fed with nitrate, two conditions in which nitrogen fixation is impaired and GS activity is reduced, a significant increase in nodule GS nitration levels was observed. Furthermore, treatment of root nodules with the NO donor sodium nitroprusside resulted in increased in vivo GS nitration accompanied by a reduction in GS activity. Our results support a role of NO in the regulation of nitrogen metabolism in root nodules and places GS as an important player in the process. We propose that the NO-mediated GS posttranslational inactivation is related to metabolite channeling to boost the nodule antioxidant defenses in response to NO.
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20
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Liu G, Ji Y, Bhuiyan NH, Pilot G, Selvaraj G, Zou J, Wei Y. Amino acid homeostasis modulates salicylic acid-associated redox status and defense responses in Arabidopsis. THE PLANT CELL 2010; 22:3845-63. [PMID: 21097712 PMCID: PMC3015111 DOI: 10.1105/tpc.110.079392] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 09/13/2010] [Accepted: 10/28/2010] [Indexed: 05/17/2023]
Abstract
The tight association between nitrogen status and pathogenesis has been broadly documented in plant-pathogen interactions. However, the interface between primary metabolism and disease responses remains largely unclear. Here, we show that knockout of a single amino acid transporter, LYSINE HISTIDINE TRANSPORTER1 (LHT1), is sufficient for Arabidopsis thaliana plants to confer a broad spectrum of disease resistance in a salicylic acid-dependent manner. We found that redox fine-tuning in photosynthetic cells was causally linked to the lht1 mutant-associated phenotypes. Furthermore, the enhanced resistance in lht1 could be attributed to a specific deficiency of its main physiological substrate, Gln, and not to a general nitrogen deficiency. Thus, by enabling nitrogen metabolism to moderate the cellular redox status, a plant primary metabolite, Gln, plays a crucial role in plant disease resistance.
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Affiliation(s)
- Guosheng Liu
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Yuanyuan Ji
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Nazmul H. Bhuiyan
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Guillaume Pilot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Gopalan Selvaraj
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Jitao Zou
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
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21
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Lin YL, Chao YY, Kao CH. Exposure of rice seedlings to heat shock protects against subsequent Cd-induced decrease in glutamine synthetase activity and increase in specific protease activity in leaves. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:1061-1065. [PMID: 20399533 DOI: 10.1016/j.jplph.2010.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 03/09/2010] [Accepted: 03/10/2010] [Indexed: 05/29/2023]
Abstract
In the present study, we investigated the effect of heat shock (HS) on the subsequent Cd-induced decrease in the activity of glutamine synthetase (GS) and increase in the specific activity of protease in rice leaves. HS exposure of rice seedlings for 3h in the dark was effective in reducing subsequent Cd-induced decrease in the activity of glutamine synthetase and increase in the specific activity of protease. The effect of HS can be mimicked by pretreatment of rice seedlings with exogenous H(2)O(2) or reduced glutathione (GSH) under non-HS conditions. We also found that HS protected against subsequent Cd-induced decrease in the activity of GS and increase in the specific activity of protease can be counteracted by imidazole, a NADPH oxidase inhibitor. Pretreatment with buthione sulfoximine (a GSH synthesis inhibitor) under HS conditions enhanced subsequent Cd effects on the activity of GS and the specific activity of protease. Moreover, the effect of BSO can be reversed by the addition of GSH. The mechanisms of the protective effect of HS effect against subsequent Cd effects are discussed.
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Affiliation(s)
- Ya-Lin Lin
- Department of Agronomy, National Taiwan University, Taipei, Taiwan, ROC
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22
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Seger M, Ortega JL, Bagga S, Gopalan CS. Repercussion of mesophyll-specific overexpression of a soybean cytosolic glutamine synthetase gene in alfalfa ( Medicago sativa L.) and tobacco ( Nicotiana tabaccum L.). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2009; 176:119-129. [PMID: 25067868 PMCID: PMC4108266 DOI: 10.1016/j.plantsci.2008.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Glutamine synthetase (GS) plays a central role in plant nitrogen metabolism. Plant GS occurs as a number of isoenzymes present in either the cytosol (GS1) or chloroplast/plastid (GS2). There are several reports of improved performance in transgenic plants overexpressing GS1 transgenes driven by the constitutive CaMV35S promoter. Improvement has been attributed to the GS1 transgene product functioning to enhance re-assimilation of NH4+ released by photorespiration or protein degradation. In this paper, alfalfa and tobacco transformants expressing a soybean gene driven by a photosynthetic cell-specific promoter have been compared to transformants with the same transgene driven by the stronger CaMV35S promoter. The two classes of alfalfa and tobacco transformants showed differences in the level of GS1 transcript and GS1 protein accumulation, but the difference in the total GS activity was small. The discrepancy in the transgene expression level and GS activity has been attributed to posttranslational regulation at the level of holoprotein stability. Both classes of transformants exhibited similar level of improvement in soluble protein and in the rates of photosynthesis and photorespiration. The data supports the hypothesis that GS1 made in the mesophyll cells is involved in the re-assimilation of NH4+ released via photorespiration and/or protein degradation.
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Affiliation(s)
- Mark Seger
- Graduate Program in Molecular Biology, New Mexico State University, 945 College Ave, MSC-3Q, Las Cruces, NM 88003 USA
| | - Jose Luis Ortega
- Department of Plant and Environmental Sciences, New Mexico State University, 945 College Ave, MSC-3Q, Las Cruces, NM 88003 USA
| | - Suman Bagga
- Department of Plant and Environmental Sciences, New Mexico State University, 945 College Ave, MSC-3Q, Las Cruces, NM 88003 USA
| | - Champa-Sengupta Gopalan
- Graduate Program in Molecular Biology, New Mexico State University, 945 College Ave, MSC-3Q, Las Cruces, NM 88003 USA
- Department of Plant and Environmental Sciences, New Mexico State University, 945 College Ave, MSC-3Q, Las Cruces, NM 88003 USA
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Clement M, Lambert A, Herouart D, Boncompagni E. Identification of new up-regulated genes under drought stress in soybean nodules. Gene 2008; 426:15-22. [PMID: 18817859 DOI: 10.1016/j.gene.2008.08.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 07/28/2008] [Accepted: 08/13/2008] [Indexed: 10/21/2022]
Abstract
Legumes/rhizobium biological N(2) fixation (BNF) is dramatically affected under abiotic stress such as drought, salt, cold and heavy metal stresses. Nodule response to drought stress at the molecular level was analysed using soybean (Glycine max) and Bradyrhizobium japonicum as a model, since this symbiotic partnership is extremely sensitive to this stress. To gain insight into molecular mechanisms involved in drought-induced BNF inhibition, we have constructed a SSH (Suppression Subtractive Hybridisation) cDNA library from nodular tissue of plants irrigated at field capacity or plants water deprived for 5 days. Sequence analysis of the first set of 128 non redundant ESTs using protein databases and the Blastx program indicated that 70% of ESTs could be classified into putative known functions. Using reverse northern hybridization, 56 ESTs were validated as up-regulated genes in response to drought. Interestingly, only a few of them had been previously described as involved in plant response to drought, therefore most of the ESTs could be considered as new markers of drought stress. Here we discuss the potential role of some of these up-regulated genes in response to drought. Our analysis focused on two genes, encoding respectively a ferritin and a metallothionein, which are known to be involved in homeostasis and detoxification of metals and in response to oxidative stress. Their spatiotemporal expression patterns showed a high accumulation of transcripts restricted to infected cells of nodules in response to drought.
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Affiliation(s)
- Mathilde Clement
- UMR "UMR Interactions Biotiques et Santé Végétale" INRA 1301-CNRS 6243-Université de Nice-Sophia Antipolis 400, routes des Chappes F-06903 SOPHIA-ANTIPOLIS cedex, France
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24
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Activities and kinetic characteristics of glutamine synthetase fromPenicillium cyclopium. ANN MICROBIOL 2008. [DOI: 10.1007/bf03175576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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25
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Bernard SM, Møller ALB, Dionisio G, Kichey T, Jahn TP, Dubois F, Baudo M, Lopes MS, Tercé-Laforgue T, Foyer CH, Parry MAJ, Forde BG, Araus JL, Hirel B, Schjoerring JK, Habash DZ. Gene expression, cellular localisation and function of glutamine synthetase isozymes in wheat (Triticum aestivum L.). PLANT MOLECULAR BIOLOGY 2008; 67:89-105. [PMID: 18288574 DOI: 10.1007/s11103-008-9303-y] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Accepted: 01/28/2008] [Indexed: 05/25/2023]
Abstract
We present the first cloning and study of glutamine synthetase (GS) genes in wheat (Triticum aestivum L.). Based on sequence analysis, phylogenetic studies and mapping data, ten GS sequences were classified into four sub-families: GS2 (a, b and c), GS1 (a, b and c), GSr (1 and 2) and GSe (1 and 2). Phylogenetic analysis showed that the wheat GS sub-families together with the GS genes from other monocotyledonous species form four distinct clades. Immunolocalisation studies in leaves, stems and rachis in plants at flowering showed GS protein to be present in parenchyma, phloem companion and perifascicular sheath cells. In situ localisation confirmed that GS1 transcripts were present in the perifascicular sheath cells whilst those for GSr were confined to the vascular cells. Studies of the expression and protein profiles showed that all GS sub-families were differentially expressed in the leaves, peduncle, glumes and roots. Expression of GS genes in leaves was developmentally regulated, with both GS2 and GS1 assimilating or recycling ammonia in leaves during the period of grain development and filling. During leaf senescence the cytosolic isozymes, GS1 and GSr, were the predominant forms, suggesting major roles in assimilating ammonia during the critical phases of remobilisation of nitrogen to the grain. A preliminary analysis of three different wheat genotypes showed that the ratio of leaf GS2 protein to GS1 protein was variable. Use of this genetic variation should inform future efforts to modulate this enzyme for pre-breeding efforts to improve nitrogen use in wheat.
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Affiliation(s)
- Stéphanie M Bernard
- Plant Science Department, Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Hertfordshire, UK
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26
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Abat JK, Mattoo AK, Deswal R. S-nitrosylated proteins of a medicinal CAM plant Kalanchoe pinnata- ribulose-1,5-bisphosphate carboxylase/oxygenase activity targeted for inhibition. FEBS J 2008; 275:2862-72. [PMID: 18445036 DOI: 10.1111/j.1742-4658.2008.06425.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Nitric oxide (NO) is a signaling molecule that affects a myriad of processes in plants. However, the mechanistic details are limited. NO post-translationally modifies proteins by S-nitrosylation of cysteines. The soluble S-nitrosoproteome of a medicinal, crassulacean acid metabolism (CAM) plant, Kalanchoe pinnata, was purified using the biotin switch technique. Nineteen targets were identified by MALDI-TOF mass spectrometry, including proteins associated with carbon, nitrogen and sulfur metabolism, the cytoskeleton, stress and photosynthesis. Some were similar to those previously identified in Arabidopsis thaliana, but kinesin-like protein, glycolate oxidase, putative UDP glucose 4-epimerase and putative DNA topoisomerase II had not been identified as targets previously for any organism. In vitro and in vivo nitrosylation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), one of the targets, was confirmed by immunoblotting. Rubisco plays a central role in photosynthesis, and the effect of S-nitrosylation on its enzymatic activity was determined using NaH14CO3. The NO-releasing compound S-nitrosoglutathione inhibited its activity in a dose-dependent manner suggesting Rubisco inactivation by nitrosylation for the first time.
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Affiliation(s)
- Jasmeet K Abat
- Department of Botany, Plant Molecular Physiology and Biochemistry Laboratory, University of Delhi, India
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Hung KT, Kao CH. The participation of hydrogen peroxide in methyl jasmonate-induced NH(4)(+) accumulation in rice leaves. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:1469-79. [PMID: 17215059 DOI: 10.1016/j.jplph.2006.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/14/2006] [Accepted: 10/17/2006] [Indexed: 05/13/2023]
Abstract
Ammonium is a central intermediate in the nitrogen metabolism of plants. We have previously shown that methyl jasmonate (MJ) not only increases the content of H(2)O(2), but also causes NH(4)(+) accumulation in rice leaves. More recently, H(2)O(2) is thought to constitute a general signal molecule participating in the recognition of and the response to stress factors. In this study, we examined the role of H(2)O(2) as a link between MJ and subsequent NH(4)(+) accumulation in detached rice leaves. MJ treatment resulted in an accumulation of NH(4)(+) in detached rice leaves, which was preceded by a decrease in the activity of glutamine synthetase (GS) and an increase in the specific activities of protease and phenylalanine ammonia-lyase (PAL). GS, PAL, and protease appear to be the enzymes responsible for the accumulation of NH(4)(+) in MJ-treated detached rice leaves. Dimethylthiourea (DMTU), a chemical trap for H(2)O(2), was observed to be effective in inhibiting MJ-induced NH(4)(+) accumulation in detached rice leaves. Scavengers of free radicals (sodium benzoate, SB, and glutathione, GSH), nitric oxide donor (N-tert-butyl-alpha-phenylnitrone, PBN), the inhibitors of NADPH oxidase (diphenyleneiodonium chloride, DPI, and imidazole, IMD), and inhibitors of phosphatidylinositol 3-kinase (wortmannin, WM, and LY 294002, LY), which have previously been shown to prevent MJ-induced H(2)O(2) production in detached rice leaves, inhibited MJ-induced NH(4)(+) accumulation. Similarly, changes in enzymes responsible for NH(4)(+) accumulation induced by MJ were observed to be inhibited by DMTU, SB, GSH, PBN DPI, IMD, WM, or LY. Seedlings of rice cultivar Taichung Native 1 (TN1) are jasmonic acid (JA)-sensitive and those of cultivar Tainung 67 (TNG67) are JA-insensitive. On treatment with JA, H(2)O(2) accumulated in the leaves of TN1 seedlings but not in the leaves of TNG67. Ethylene action inhibitor, silver thiosulfate, was observed to inhibit MJ- and abscisic acid-induced accumulation of NH(4)(+) and changes in enzymes responsible for NH(4)(+) accumulation in detached rice leaves, suggesting that the action of MJ and ABA is ethylene dependent.
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Affiliation(s)
- Kuo Tung Hung
- Department of Agronomy, National Taiwan University, Taipei, Taiwan, Republic of China
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28
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Effect of chilling and acclimation on the activity of glutamine synthetase isoforms in maize seedlings. ARCH BIOL SCI 2007. [DOI: 10.2298/abs0703177s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Effects of chilling and acclimation on the activity of cytosolic (GS1) and plastidic (GS2) isoforms of glutamine synthetase (E.C. 6.3.1.2) were studied in chilling-sensitive and acclimation-responsive maize inbred G50. Glutamine synthetase activity in mesocotyls and roots of chilled (7 d/4?C) and rewarmed (1 d/27?C) etiolated plants was "1/3 that of controls. In coleoptiles+leaves of light-grown plants, GS1 was reduced to 75%, and GS2 to 50%. Acclimation (3 d/14?C) increased GS activity and alleviated the effects of chilling. Exposure to H2O2 or menadione also reduced GS activity. Since chilling causes oxidative stress in maize, acclimation probably preserves GS activity by protecting GS from oxidative inactivation. .
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Debouba M, Gouia H, Valadier MH, Ghorbel MH, Suzuki A. Salinity-induced tissue-specific diurnal changes in nitrogen assimilatory enzymes in tomato seedlings grown under high or low nitrate medium. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2006; 44:409-19. [PMID: 16889971 DOI: 10.1016/j.plaphy.2006.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Indexed: 05/11/2023]
Abstract
We studied the salt stress (100 mM NaCl) effects on the diurnal changes in N metabolism enzymes in tomato seedlings (Lycopersicon esculentum Mill. cv. Chibli F1) that were grown under high nitrogen (HN, 5 mM NO(3)(-)) or low nitrogen (LN, 0.1 mM NO(3)(-)). NaCl stress led to a decrease in plant DW production and leaf surface to higher extent in HN than in LN plants. Total leaf chlorophyll (Chl) content was decreased by salinity in HN plants, but unchanged in LN plants. Soluble protein content was decreased by salt in the leaves from HN and LN plants, but increased in the stems-petioles from LN plants. Nitrate reductase (NR, EC 1.6.1.6) showed an activity peak during first part of the light period, but no diurnal changes were observed for the nitrite reductase (NiR, EC 1.7.7.1) activity. Glutamine synthetase (GS, EC 6.3.1.2) and glutamate synthase (Fd-GOGAT, EC 1.4.7.1) activities increased in HN plant leaves during the second part of the light period, probably when enough ammonium is produced by nitrate reduction. NR and NiR activities in the leaves were more decreased by NaCl in LN than in HN plants, whereas the opposite response was obtained for the GS activity. Fd-GOGAT activity was inhibited by NaCl in HN plant leaves, while salinity did not shift the peak of the NR and Fd-GOGAT activities during a diurnal cycle. The induction by NaCl stress occurred for the NR and GS activities in the roots of both HN and LN plants. Glutamate dehydrogenase (GDH, EC 1.4.1.2) activity shifted from the deaminating activity to the aminating activity in all tissues of HN plants. In LN plants, both aminating and deaminating activities were increased by salinity in the leaves and roots. The differences in the sensitivity to NaCl between HN and LN plants are discussed in relation to the N metabolism status brought on by salt stress.
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Affiliation(s)
- M Debouba
- Unité de Recherche Nutrition et Métabolisme Azotés et Proteines de Stress 99/C09-20, Département de Biologie, Faculté des Sciences de Tunis, Tunisia
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30
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Kung CCS, Huang WN, Huang YC, Yeh KC. Proteomic survey of copper-binding proteins inArabidopsis roots by immobilized metal affinity chromatography and mass spectrometry. Proteomics 2006; 6:2746-58. [PMID: 16526091 DOI: 10.1002/pmic.200500108] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To plants, copper is vitally essential at low concentrations but extremely toxic at elevated concentrations. Plants have evolved a suite of mechanisms that modulate the uptake, distribution, and utilization of copper ions. These mechanisms require copper-interacting proteins for transporting, chelating, and sequestrating copper ions. In this study, we have systematically screened for copper-interacting proteins in Arabidopsis roots via copper-immobilized metal affinity chromatography (Cu-IMAC). We also compared Arabidopsis root metalloproteomes with affinity to Cu-IMAC and Zn-IMAC. From the identities of 38 protein spots with affinity to Cu-IMAC, 35 unique proteins were identified. Functional classification of these proteins includes redox/hydrolytic reactions, amino acid metabolism, glutathione metabolism, phosphorylation, translation machinery, membrane-associated proteins, and vegetative storage proteins. Potential copper-interacting motifs were predicted and scored. Six candidate motifs, H-(X)5 -H, H-(X)7 -H, H-(X)12 -H, H-(X)6 -M, M-(X)7 -H, and H-(X)3 -C, are present in Cu-IMAC-isolated proteins with higher frequency than in the whole Arabidopsis proteome.
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Affiliation(s)
- Cheng-Che S Kung
- Institute of BioAgricultural Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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31
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Ortega JL, Moguel-Esponda S, Potenza C, Conklin CF, Quintana A, Sengupta-Gopalan C. The 3' untranslated region of a soybean cytosolic glutamine synthetase (GS1) affects transcript stability and protein accumulation in transgenic alfalfa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 45:832-46. [PMID: 16460515 PMCID: PMC3881554 DOI: 10.1111/j.1365-313x.2005.02644.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Higher plants assimilate nitrogen in the form of ammonia through the concerted activity of glutamine synthetase (GS) and glutamate synthase (GOGAT). The GS enzyme is either located in the cytoplasm (GS1) or in the chloroplast (GS2). Glutamine synthetase 1 is regulated in different plants at the transcriptional level and there are some reports of regulation at the level of protein stability. Here we present data that clearly establish that GS1 in plants is also regulated at the level of transcript turnover and at the translational level. Using a Glycine max (soybean) GS1 transgene, with and without its 3' untranslated region (UTR), driven by the constitutive CaMV 35S promoter in Medicago sativa (alfalfa) and Nicotiana tabacum (tobacco), we show that the 3' UTR plays a major role in both transcript turnover and translation repression in both the leaves and the nodules. Our data suggest that the 3' UTR mediated turnover of the transcript is regulated by a nitrogen metabolite or carbon/nitrogen ratios. We also show that the 3' UTR of the gene for the soybean GS1 confers post-transcriptional regulation on a reporter gene. Our dissection of post-transcriptional and translational levels of regulation of GS in plants shows that the situation in plants strongly resembles that in other organisms where GS is regulated at almost all levels. Multistep regulation of GS shows the high priority given by organisms to regulating and ensuring optimal control of nitrogen substrates and preventing overproduction of glutamine and drainage of the glutamate pool.
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Affiliation(s)
| | | | - Carol Potenza
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Cristina F. Conklin
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Anita Quintana
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Champa Sengupta-Gopalan
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
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32
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Lima L, Seabra A, Melo P, Cullimore J, Carvalho H. Phosphorylation and subsequent interaction with 14-3-3 proteins regulate plastid glutamine synthetase in Medicago truncatula. PLANTA 2006; 223:558-67. [PMID: 16136328 DOI: 10.1007/s00425-005-0097-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Accepted: 07/13/2005] [Indexed: 05/04/2023]
Abstract
In this report we demonstrate that plastid glutamine synthetase of Medicago truncatula (MtGS2) is regulated by phosphorylation and 14-3-3 interaction. To investigate regulatory aspects of GS2 phosphorylation, we have produced non-phosphorylated GS2 proteins by expressing the plant cDNA in E. coli and performed in vitro phosphorylation assays. The recombinant isoenzyme was phosphorylated by calcium dependent kinase(s) present in leaves, roots and nodules. Using an (His)6-tagged 14-3-3 protein column affinity purification method, we demonstrate that phosphorylated GS2 interacts with 14-3-3 proteins and that this interaction leads to selective proteolysis of the plastid located isoform, resulting in inactivation of the isoenzyme. By site directed mutagenesis we were able to identify a GS2 phosphorylation site (Ser97) crucial for the interaction with 14-3-3s. Phosphorylation of this target residue can be functionally mimicked by replacing Ser97 by Asp, indicating that the introduction of a negative charge contributes to the interaction with 14-3-3 proteins and subsequent specific proteolysis. Furthermore, we document that plant extracts contain protease activity that cleaves the GS2 protein only when it is bound to 14-3-3 proteins following either phosphorylation or mimicking of phosphorylation by Ser97Asp.
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Affiliation(s)
- Lígia Lima
- Instituto de Biologia Molecular e Celular Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
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Yu CC, Hung KT, Kao CH. Nitric oxide reduces Cu toxicity and Cu-induced NH4+ accumulation in rice leaves. JOURNAL OF PLANT PHYSIOLOGY 2005; 162:1319-30. [PMID: 16425450 DOI: 10.1016/j.jplph.2005.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nitric oxide (NO) is a highly reactive, membrane-permeable free radical, which has recently emerged as an important antioxidant. Here we investigated the protective effect of NO against the toxicity and NH4+ accumulation in rice leaves caused by excess CuSO4 (10mmol L(-1)). It was found that free radical scavengers (sodium benzoate, thiourea, and reduced glutathione) reduced the toxicity and NH4+ accumulation in rice leaves caused by excess CuSO4. NO donor sodium nitroprusside (SNP) was also effective in reducing CuSO4-induced toxicity and NH4+ accumulation in rice leaves. The protective effect of SNP on the toxicity and NH4+ accumulation can be reversed by 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, suggesting that the protective effect of SNP is attributable to NO released. Results obtained in the present study suggest that reduction of CuSO4-induced toxicity and NH4+ accumulation by SNP is most likely mediated through its ability to scavenge active oxygen species.
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Affiliation(s)
- Chia Chi Yu
- Department of Agronomy, National Taiwan University, Taipei, Taiwan, China
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34
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Hung KT, Kao CH. Hydrogen peroxide is required for abscisic acid-induced NH4+ accumulation in rice leaves. JOURNAL OF PLANT PHYSIOLOGY 2005; 162:1022-9. [PMID: 16173463 DOI: 10.1016/j.jplph.2004.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The role of H2O2 in abscisic acid (ABA)-induced NH4+ accumulation in rice leaves was investigated. ABA treatment resulted in an accumulation of NH4+ in rice leaves, which was preceded by a decrease in the activity of glutamine synthetase (GS) and an increase in the specific activities of protease and phenylalanine ammonia-lyase (PAL). GS, PAL, and protease seem to be the enzymes responsible for the accumulation of NH4+ in ABA-treated rice leaves. Dimethylthiourea (DMTU), a chemical trap for H2O2, was observed to be effective in inhibiting ABA-induced accumulation of NH4+ in rice Leaves. Inhibitors of NADPH oxidase, diphenyleneiodonium chloride (DPI) and imidazole (IMD), and nitric oxide donor (N-tert-butyl-alpha-phenylnitrone, PBN), which have previously been shown to prevent ABA-induced increase in H2O2 contents in rice leaves, inhibited ABA-induced increase in the content of NH4+. Similarly, the changes of enzymes responsible for NH4+ accumulation induced by ABA were observed to be inhibited by DMTU, DPI, IMD, and PBN. Exogenous application of H2O2 was found to increase NH4+ content, decrease GS activity, and increase protease and PAL-specific activities in rice leaves. Our results suggest that H2O2 is involved in ABA-induced NH4+ accumulation in rice leaves.
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Affiliation(s)
- Kuo Tung Hung
- Department of Agronomy, National Taiwan University, Taipei, Taiwan, Republic of China
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35
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Hancock JT, Henson D, Nyirenda M, Desikan R, Harrison J, Lewis M, Hughes J, Neill SJ. Proteomic identification of glyceraldehyde 3-phosphate dehydrogenase as an inhibitory target of hydrogen peroxide in Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2005; 43:828-35. [PMID: 16289945 DOI: 10.1016/j.plaphy.2005.07.012] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Revised: 06/08/2005] [Accepted: 07/30/2005] [Indexed: 05/05/2023]
Abstract
Hydrogen peroxide (H2O2) is now recognised as a key signalling molecule in eukaryotes. In plants, H2O2 is involved in regulating stomatal closure, gravitropic responses, gene expression and programmed cell death. Although several kinases, such as oxidative signal-inducible 1 (OXI1) kinase and mitogen-activated protein kinases are known to be activated by exogenous H2O2, little is known about the proteins that directly react with H2O2. Here, we utilised a proteomic approach, using iodoacetamide-based fluorescence tagging of proteins in conjunction with mass spectrometric analysis, to identify several proteins that might be potential targets of H2O2 in the cytosolic fraction of Arabidopsis thaliana, the most prominent of which was cytosolic glyceraldehyde 3-phosphate dehydrogenase (cGAPDH; EC 1.2.1.12). cGAPDH from Arabidopsis is inactivated by H2O2 in vitro, and this inhibition is reversible by the subsequent addition of reductants such as reduced glutathione (GSH). It has been suggested recently that Arabidopsis GAPDH has roles outside of its catalysis as part of glycolysis, while in other systems this includes that of mediating reactive oxygen species (ROS) signalling. Here, we suggest that cGAPDH in Arabidopsis might also have such a role in mediating ROS signalling in plants.
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Affiliation(s)
- John T Hancock
- Centre for Research in Plant Science, Genomics Research Institute, Faculty of Applied Sciences, University of the West of England, Bristol, Coldharbour Lane, Bristol BS16 1QY, UK.
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36
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Ortega JL, Temple SJ, Bagga S, Ghoshroy S, Sengupta-Gopalan C. Biochemical and molecular characterization of transgenic Lotus japonicus plants constitutively over-expressing a cytosolic glutamine synthetase gene. PLANTA 2004; 219:807-18. [PMID: 15197594 PMCID: PMC3881563 DOI: 10.1007/s00425-004-1292-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Accepted: 04/17/2004] [Indexed: 05/20/2023]
Abstract
Higher plants assimilate nitrogen in the form of ammonia through the concerted activity of glutamine synthetase (GS) and glutamate synthase (GOGAT). The GS enzyme is either located in the cytoplasm (GS1) or in the chloroplast (GS2). To understand how modulation of GS activity affects plant performance, Lotus japonicus L. plants were transformed with an alfalfa GS1 gene driven by the CaMV 35S promoter. The transformants showed increased GS activity and an increase in GS1 polypeptide level in all the organs tested. GS was analyzed by non-denaturing gel electrophoresis and ion-exchange chromatography. The results showed the presence of multiple GS isoenzymes in the different organs and the presence of a novel isoform in the transgenic plants. The distribution of GS in the different organs was analyzed by immunohistochemical localization. GS was localized in the mesophyll cells of the leaves and in the vasculature of the stem and roots of the transformants. Our results consistently showed higher soluble protein concentration, higher chlorophyll content and a higher biomass accumulation in the transgenic plants. The total amino acid content in the leaves and stems of the transgenic plants was 22-24% more than in the tissues of the non-transformed plants. The relative abundance of individual amino acid was similar except for aspartate/asparagine and proline, which were higher in the transformants.
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Affiliation(s)
- Jose Luis Ortega
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Stephen J. Temple
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Suman Bagga
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
| | - Soumitra Ghoshroy
- Department of Agronomy and Horticulture, New Mexico State University, Las Cruces, NM 88003, USA
- Electron Microscopy Laboratory, New Mexico State University, Las Cruces, NM 88003, USA
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37
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Breuninger M, Trujillo CG, Serrano E, Fischer R, Requena N. Different nitrogen sources modulate activity but not expression of glutamine synthetase in arbuscular mycorrhizal fungi. Fungal Genet Biol 2004; 41:542-52. [PMID: 15050543 DOI: 10.1016/j.fgb.2004.01.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Accepted: 01/07/2004] [Indexed: 11/29/2022]
Abstract
Glutamine synthetase (GS) is a central enzyme of nitrogen metabolism that allows assimilation of nitrogen and biosynthesis of glutamine. We isolated the cDNA encoding GS from two arbuscular mycorrhizal fungi, Glomus mosseae (GmGln1) and Glomus intraradices (GiGln1). The deduced protein orthologues have a high degree of similarity (92%) with each other as well as with GSs from other fungi. GmGln1 was constitutively expressed during all stages of the fungal life cycle, i.e., spore germination, intraradical and extraradical mycelium. Feeding experiments with different nitrogen sources did not induce any change in the mRNA level of both genes independent of the symbiotic status of the fungus. However, GS activity of extraradical hypahe in G. intraradices was considerably modulated in response to different nitrogen sources. Thus, in a N re-supplementation time-course experiment, GS activity responded quickly to addition of nitrate, ammonium or glutamine. Re-feeding with ammonium produced a general increase in GS activity when compared with hyphae grown in nitrate as a sole N source.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Base Sequence
- DNA, Complementary/chemistry
- DNA, Complementary/isolation & purification
- DNA, Fungal/chemistry
- DNA, Fungal/isolation & purification
- Enzyme Activators/metabolism
- Fungi/enzymology
- Fungi/genetics
- Fungi/growth & development
- Gene Expression Regulation, Fungal
- Glutamate-Ammonia Ligase/chemistry
- Glutamate-Ammonia Ligase/genetics
- Glutamate-Ammonia Ligase/metabolism
- Glutamine/metabolism
- Molecular Sequence Data
- Mycelium/enzymology
- Mycelium/genetics
- Mycelium/growth & development
- Mycorrhizae/metabolism
- Nitrates/metabolism
- Nitrogen/metabolism
- Phylogeny
- Quaternary Ammonium Compounds/metabolism
- RNA, Fungal/analysis
- RNA, Messenger/analysis
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Spores, Fungal/enzymology
- Spores, Fungal/genetics
- Spores, Fungal/growth & development
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Affiliation(s)
- Magdalene Breuninger
- Physiological Ecology of Plants Department, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany
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Harrison J, Pou de Crescenzo MA, Sené O, Hirel B. Does lowering glutamine synthetase activity in nodules modify nitrogen metabolism and growth of Lotus japonicus? PLANT PHYSIOLOGY 2003; 133:253-62. [PMID: 12970491 PMCID: PMC196602 DOI: 10.1104/pp.102.016766] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2002] [Revised: 02/17/2003] [Accepted: 05/29/2003] [Indexed: 05/18/2023]
Abstract
A cDNA encoding cytosolic glutamine synthetase (GS) from Lotus japonicus was fused in the antisense orientation relative to the nodule-specific LBC3 promoter of soybean (Glycine max) and introduced into L. japonicus via transformation with Agrobacterium tumefaciens. Among the 12 independent transformed lines into which the construct was introduced, some of them showed diminished levels of GS1 mRNA and lower levels of GS activity. Three of these lines were selected and their T(1) progeny was further analyzed both for plant biomass production and carbon and nitrogen (N) metabolites content under symbiotic N-fixing conditions. Analysis of these plants revealed an increase in fresh weight in nodules, roots and shoots. The reduction in GS activity was found to correlate with an increase in amino acid content of the nodules, which was primarily due to an increase in asparagine content. Thus, this study supports the hypothesis that when GS becomes limiting, other enzymes (e.g. asparagine synthetase) that have the capacity to assimilate ammonium may be important in controlling the flux of reduced N in temperate legumes such as L. japonicus. Whether these alternative metabolic pathways are important in the control of plant biomass production still remains to be fully elucidated.
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Affiliation(s)
- Judith Harrison
- Laboratoire Nutrition Azotée des Plantes, Institut National de la Recherche Agronomique, Route de St. Cyr, 78280 Versailles cedex, France
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Morey KJ, Ortega JL, Sengupta-Gopalan C. Cytosolic glutamine synthetase in soybean is encoded by a multigene family, and the members are regulated in an organ-specific and developmental manner. PLANT PHYSIOLOGY 2002; 128:182-93. [PMID: 11788764 PMCID: PMC148970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/20/2001] [Revised: 07/09/2001] [Accepted: 09/27/2001] [Indexed: 05/23/2023]
Abstract
Gln synthetase (GS) is the key enzyme in N metabolism and it catalyzes the synthesis of Gln from glutamic acid, ATP, and NH4+. There are two major isoforms of GS in plants, a cytosolic form (GS1) and a chloroplastic form (GS2). In leaves, GS2 functions to assimilate ammonia produced by nitrate reduction and photorespiration, and GS1 is the major isoform assimilating NH3 produced by all other metabolic processes, including symbiotic N2 fixation in the nodules. GS1 is encoded by a small multigene family in soybean (Glycine max), and cDNA clones for the different members have been isolated. Based on sequence divergence in the 3'-untranslated region, three distinct classes of GS1 genes have been identified (alpha, beta, and gamma). Genomic Southern analysis and analysis of hybrid-select translation products suggest that each class has two distinct members. The alpha forms are the major isoforms in the cotyledons and young roots. The beta forms, although constitutive in their expression pattern, are ammonia inducible and show high expression in N2-fixing nodules. The gamma1 gene appears to be more nodule specific, whereas the gamma2 gene member, although nodule enhanced, is also expressed in the cotyledons and flowers. The two members of the alpha and beta class of GS1 genes show subtle differences in the expression pattern. Analysis of the promoter regions of the gamma1 and gamma2 genes show sequence conservation around the TATA box but complete divergence in the rest of the promoter region. We postulate that each member of the three GS1 gene classes may be derived from the two ancestral genomes from which the allotetraploid soybean was derived.
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Affiliation(s)
- Kevin J Morey
- Graduate Program in Molecular Biology, New Mexico State University, Las Cruces, New Mexico 88003, USA
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40
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Morey KJ, Ortega JL, Sengupta-Gopalan C. Cytosolic glutamine synthetase in soybean is encoded by a multigene family, and the members are regulated in an organ-specific and developmental manner. PLANT PHYSIOLOGY 2002; 128:182-193. [PMID: 11788764 DOI: 10.1104/pp.010380] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Gln synthetase (GS) is the key enzyme in N metabolism and it catalyzes the synthesis of Gln from glutamic acid, ATP, and NH4+. There are two major isoforms of GS in plants, a cytosolic form (GS1) and a chloroplastic form (GS2). In leaves, GS2 functions to assimilate ammonia produced by nitrate reduction and photorespiration, and GS1 is the major isoform assimilating NH3 produced by all other metabolic processes, including symbiotic N2 fixation in the nodules. GS1 is encoded by a small multigene family in soybean (Glycine max), and cDNA clones for the different members have been isolated. Based on sequence divergence in the 3'-untranslated region, three distinct classes of GS1 genes have been identified (alpha, beta, and gamma). Genomic Southern analysis and analysis of hybrid-select translation products suggest that each class has two distinct members. The alpha forms are the major isoforms in the cotyledons and young roots. The beta forms, although constitutive in their expression pattern, are ammonia inducible and show high expression in N2-fixing nodules. The gamma1 gene appears to be more nodule specific, whereas the gamma2 gene member, although nodule enhanced, is also expressed in the cotyledons and flowers. The two members of the alpha and beta class of GS1 genes show subtle differences in the expression pattern. Analysis of the promoter regions of the gamma1 and gamma2 genes show sequence conservation around the TATA box but complete divergence in the rest of the promoter region. We postulate that each member of the three GS1 gene classes may be derived from the two ancestral genomes from which the allotetraploid soybean was derived.
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Affiliation(s)
- Kevin J Morey
- Graduate Program in Molecular Biology, New Mexico State University, Las Cruces, New Mexico 88003, USA
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Ortega JL, Temple SJ, Sengupta-Gopalan C. Constitutive overexpression of cytosolic glutamine synthetase (GS1) gene in transgenic alfalfa demonstrates that GS1 may be regulated at the level of RNA stability and protein turnover. PLANT PHYSIOLOGY 2001; 126:109-21. [PMID: 11351075 PMCID: PMC102286 DOI: 10.1104/pp.126.1.109] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2000] [Revised: 01/08/2001] [Accepted: 01/30/2001] [Indexed: 05/18/2023]
Abstract
Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of NH4+ with glutanate to yield glutamine. Gene constructs consisting of the cauliflower mosaic virus (CaMV) 35S promoter driving a cytosolic isoform of GS (GS1) gene have been introduced into alfalfa (Medicago sativa). Although transcripts for the transgene were shown to accumulate to high levels in the leaves, they were undetectable in the nodules. However, significant amounts of beta-glucuronidase activity could be detected in nodules of plants containing the CaMV 35S promoter-beta-glucuronidase gene construct, suggesting that the transcript for the GS1 transgene is not stable in the root nodules. Leaves of alfalfa plants with the CaMV 35S promoter-GS1 gene showed high levels of accumulation of the transcript for the transgene when grown under low-nitrogen conditions and showed a significant drop in the level of GS1 transcripts when fed with high levels of NO3-. However, no increase in GS activity or polypeptide level was detected in the leaves of transgenic plants. The results suggest that GS1 is regulated at the level of RNA stability and protein turnover.
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Affiliation(s)
- J L Ortega
- Agronomy and Horticulture Department, New Mexico State University, Las Cruces, New Mexico 88003, USA
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Finnemann J, Schjoerring JK. Post-translational regulation of cytosolic glutamine synthetase by reversible phosphorylation and 14-3-3 protein interaction. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:171-81. [PMID: 11069692 DOI: 10.1046/j.1365-313x.2000.00863.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Regulation of the cytosolic isozyme of glutamine synthetase (GS(1); EC 6.3.1.2) was studied in leaves of Brassica napus L. Expression and immunodetection studies showed that GS(1) was the only active GS isozyme in senescing leaves. By use of [gamma-(32)P]ATP followed by immunodetection, it was shown that GS(1) is a phospho-protein. GS(1) is regulated post-translationally by reversible phosphorylation catalysed by protein kinases and microcystin-sensitive serine/threonine protein phosphatases. Dephosphorylated GS(1) is much more susceptible to degradation than the phosphorylated form. The phosphorylation status of GS(1) changes during light/dark transitions and depends in vitro on the ATP/AMP ratio. Phosphorylated GS(1) interacts with 14-3-3 proteins as verified by two different methods: a His-tag 14-3-3 protein column affinity method combined with immunodetection, and a far-Western method with overlay of 14-3-3-GFP. The degree of interaction with 14-3-3-proteins could be modified in vitro by decreasing or increasing the phosphorylation status of GS(1). Thus, the results demonstrate that 14-3-3 protein is an activator molecule of cytosolic GS and provide the first evidence of a protein involved in the activation of plant cytosolic GS. The role of post-translational regulation of cytosolic GS and interactions between phosphorylated cytosolic GS and 14-3-3 proteins in senescing leaves is discussed in relation to nitrogen remobilization.
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Affiliation(s)
- J Finnemann
- Plant Nutrition Laboratory, Department of Agricultural Sciences, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, Denmark.
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