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Leng X, Wang H, Cao L, Chang R, Zhang S, Xu C, Yu J, Xu X, Qu C, Xu Z, Liu G. Overexpressing GLUTAMINE SYNTHETASE 1;2 maintains carbon and nitrogen balance under high-ammonium conditions and results in increased tolerance to ammonium toxicity in hybrid poplar. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4052-4073. [PMID: 38497908 DOI: 10.1093/jxb/erae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 03/16/2024] [Indexed: 03/19/2024]
Abstract
The glutamine synthetase/glutamic acid synthetase (GS/GOGAT) cycle plays important roles in N metabolism, growth, development, and stress resistance in plants. Excess ammonium (NH4+) restricts growth, but GS can help to alleviate its toxicity. In this study, the 84K model clone of hybrid poplar (Populus alba × P. tremula var. glandulosa), which has reduced biomass accumulation and leaf chlorosis under high-NH4+ stress, showed less severe symptoms in transgenic lines overexpressing GLUTAMINE SYNTHETASE 1;2 (GS1;2-OE), and more severe symptoms in RNAi lines (GS1;2-RNAi). Compared with the wild type, the GS1;2-OE lines had increased GS and GOGAT activities and higher contents of free amino acids, soluble proteins, total N, and chlorophyll under high-NH4+ stress, whilst the antioxidant and NH4+ assimilation capacities of the GS1;2-RNAi lines were decreased. The total C content and C/N ratio in roots and leaves of the overexpression lines were higher under stress, and there were increased contents of various amino acids and sugar alcohols, and reduced contents of carbohydrates in the roots. Under high-NH4+ stress, genes related to amino acid biosynthesis, sucrose and starch degradation, galactose metabolism, and the antioxidant system were significantly up-regulated in the roots of the overexpression lines. Thus, overexpression of GS1;2 affected the carbon and amino acid metabolism pathways under high-NH4+ stress to help maintain the balance between C and N metabolism and alleviate the symptoms of toxicity. Modification of the GS/GOGAT cycle by genetic engineering is therefore a potential strategy for improving the NH4+ tolerance of cultivated trees.
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Affiliation(s)
- Xue Leng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- College of Agriculture, Jilin Agricultural Science and Technology University, Jilin 132109, China
| | - Hanzeng Wang
- College of Agriculture, Jilin Agricultural Science and Technology University, Jilin 132109, China
| | - Lina Cao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Ruhui Chang
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Shuang Zhang
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Caifeng Xu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Jiajie Yu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Xiuyue Xu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Chunpu Qu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- College of Forestry, Guizhou University, Guiyang 550025, China
| | - Zhiru Xu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Guanjun Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
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2
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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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Guan ZJ, Zheng M, Tang ZX, Wei W, Stewart CN. Proteomic Analysis of Bt cry1Ac Transgenic Oilseed Rape ( Brassica napus L.). PLANTS (BASEL, SWITZERLAND) 2023; 12:2319. [PMID: 37375944 DOI: 10.3390/plants12122319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
Oilseed rape (Brassica napus L.) is an important cash crop, but transgenic oilseed rape has not been grown on a commercial scale in China. It is necessary to analyze the characteristics of transgenic oilseed rape before commercial cultivation. In our study, differential expression of total protein from the leaves in two transgenic lines of oilseed rape expressing foreign Bt Cry1Ac insecticidal toxin and their non-transgenic parent plant was analyzed using a proteomic approach. Only shared changes in both of the two transgenic lines were calculated. Fourteen differential protein spots were analyzed and identified, namely, eleven upregulated expressed protein spots and three downregulated protein spots. These proteins are involved in photosynthesis, transporter function, metabolism, protein synthesis, and cell growth and differentiation. The changes of these protein spots in transgenic oilseed rape may be attributable to the insertion of the foreign transgenes. However, the transgenic manipulation might not necessarily cause significant change in proteomes of the oilseed rape.
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Affiliation(s)
- Zheng-Jun Guan
- Department of Life Sciences, Yuncheng University, Yuncheng 044000, China
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Min Zheng
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Department of Hotel Management, Linyi Technician Institute, Linyi 276005, China
| | - Zhi-Xi Tang
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Wei Wei
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - C Neal Stewart
- Department of Plant Sciences and Center for Agricultural Synthetic Biology, University of Tennessee, 2505 EJ Chapman Drive, Knoxville, TN 37996-4561, USA
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Pascual L, Solé-Medina A, Faci I, Giraldo P, Ruiz M, Benavente E. Development and marker-trait relationships of functional markers for glutamine synthetase GS1 and GS2 homoeogenes in bread wheat. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2023; 43:8. [PMID: 37309364 PMCID: PMC10248667 DOI: 10.1007/s11032-022-01354-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/28/2022] [Indexed: 06/14/2023]
Abstract
GS1 and GS2 genes encode, respectively, the main cytosolic and the plastidic isoforms of glutamine synthetase (GS). In the present study, the wheat GS1 and GS2 homoeogenes located in the A, B and D genome chromosomes have been sequenced in a group of 15 bread wheat varieties including landraces, old commercial varieties and modern cultivars. Phenotypic characterization by multi-environment field trials detected significant effects of specific GS homoeogenes on three of the seven agronomic and grain quality traits analyzed. Based on the gene sequence polymorphisms found, biallelic molecular markers that could facilitate marker-assisted breeding were developed for genes GS1A, GS2A and GS2D. The remaining genes encoding main wheat GS were excluded because of being monomorphic (GS1D) or too polymorphic (GS1B and GS2B) in the sequencing panel varieties. A collection of 187 Spanish bread wheat landraces was genotyped for these gene-based molecular markers. Data analyses conducted with phenotypic records reported for this germplasm collection in López-Fernández et al. (Plants-Basel 10: 620, 2021) have revealed the beneficial influence of some individual alleles on thousand-kernel weight (TKW), kernels per spike (KS) and grain protein content. Furthermore, genetic interactions between GS1A, a cytosolic GS isoform coding gene, and GS2A or GS2D, plastidic GS enzyme coding genes, were found to affect TKW and KS. The finding that some alleles at one locus may mask the effect of positive alleles at hypostatic GS loci should be kept in mind if gene pyramiding strategies are attempted for the improvement of N-use efficiency-related traits. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-022-01354-0.
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Affiliation(s)
- Laura Pascual
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Aida Solé-Medina
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
- Department of Forest Ecology & Genetics, Forest Research Centre (INIA, CSIC), Ctra. de La Coruña Km 7.5, 28040 Madrid, Spain
| | - Isabel Faci
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
- John Innes Centre, Norwich Research Park, Colney, NR4 7UH UK
| | - Patricia Giraldo
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Magdalena Ruiz
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), CSIC, Autovía A2, Km. 36.2, Finca La Canaleja, Alcalá de Henares, Madrid, 28805 Spain
| | - Elena Benavente
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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Kosová K, Vítámvás P, Skuhrovec J, Vítámvás J, Planchon S, Renaut J, Saska P. Proteomic responses of two spring wheat cultivars to the combined water deficit and aphid ( Metopolophium dirhodum) treatments. FRONTIERS IN PLANT SCIENCE 2022; 13:1005755. [PMID: 36452089 PMCID: PMC9704420 DOI: 10.3389/fpls.2022.1005755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/25/2022] [Indexed: 06/17/2023]
Abstract
In the field, plants usually have to face the combined effects of abiotic and biotic stresses. In our study, two spring wheat cultivars-Septima and Quintus-were subjected to three water regimes [70%, 50%, and 40% soil water capacity (SWC)], aphid (Metopolophium dirhodum) infestation, or the combination of both stresses, i.e., water deficit (50%, 40% SWC) and aphids. The study has a 2 × 3 × 2 factorial design with three biological replicates. In the present study, the results of proteomic analysis using 2D-DIGE followed by MALDI-TOF/TOF protein identification are presented. Water deficit but also aphid infestation led to alterations in 113 protein spots including proteins assigned to a variety of biological processes ranging from signaling via energy metabolism, redox regulation, and stress and defense responses to secondary metabolism indicating a long-term adaptation to adverse conditions. The absence of specific proteins involved in plant response to herbivorous insects indicates a loss of resistance to aphids in modern wheat cultivars during the breeding process and is in accordance with the "plant vigor hypothesis." Septima revealed enhanced tolerance with respect to Quintus as indicated by higher values of morphophysiological characteristics (fresh aboveground biomass, leaf length, osmotic potential per full water saturation) and relative abundance of proteins involved in mitochondrial respiration and ATP biosynthesis.
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Affiliation(s)
- Klára Kosová
- Plant Stress Biology and Biotechnology Group, Department of Plant Genetics and Breeding, Crop Research Institute, Prague, Czechia
| | - Pavel Vítámvás
- Plant Stress Biology and Biotechnology Group, Department of Plant Genetics and Breeding, Crop Research Institute, Prague, Czechia
| | - Jiří Skuhrovec
- Functional Diversity Group, Department of Plant Protection, Crop Research Institute, Prague, Czechia
| | - Jan Vítámvás
- Plant Stress Biology and Biotechnology Group, Department of Plant Genetics and Breeding, Crop Research Institute, Prague, Czechia
- Faculty of Forestry and Wood Science, Czech University of Life Sciences, Prague, Czechia
| | - Sébastien Planchon
- Biotechnologies and Environmental Analytics Platform (BEAP), Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch-sur-Alzette, Luxembourg
| | - Jenny Renaut
- Biotechnologies and Environmental Analytics Platform (BEAP), Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Esch-sur-Alzette, Luxembourg
| | - Pavel Saska
- Functional Diversity Group, Department of Plant Protection, Crop Research Institute, Prague, Czechia
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A New Perspective on the Role of Glutamine Synthetase in Nitrogen Remobilization in Wheat ( Triticum aestivum L.). Int J Mol Sci 2021; 22:ijms222011083. [PMID: 34681741 PMCID: PMC8539157 DOI: 10.3390/ijms222011083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 12/05/2022] Open
Abstract
Glutamine synthetase (GS), a key enzyme in plant nitrogen metabolism, is closely related to nitrogen remobilization. However, how GS isoforms participate in nitrogen remobilization remains unclear. Here, the spatiotemporal expression of the TaGS gene family after anthesis was investigated, and the results showed that TaGS1;1 was mainly encoded by TaGS1;1-6A, while the other isozymes were mainly encoded by TaGS localized on the A and D subgenomes. TaGS1;2-4A/4D had the highest expression level, especially in rachis and peduncle. Furthermore, immunofluorescence showed TaGS1;2 was located in the phloem of rachis and peduncle. GUS (β-glucuronidase) staining confirmed that ProTaGS1;2-4A/4D::GUS activity was mainly present in the vascular system of leaves, roots, and petal of Arabidopsis. Ureides, an important transport form of nitrogen, were mainly synthesized in flag leaves and transported to grains through the phloem of peduncle and rachis during grain filling. TaAAH, which encodes the enzyme that degrades ureides to release NH4+, had a higher expression in rachis and peduncle and was synchronized with the increase in NH4+ concentration in phloem, indicating that NH4+ in phloem is from ureide degradation. Taking the above into account, TaGS1;2, which is highly expressed in the phloem of peduncle and rachis, may participate in N remobilization by assimilating NH4+ released from ureide degradation.
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Lee Y, Szymanski DB. Multimerization variants as potential drivers of neofunctionalization. SCIENCE ADVANCES 2021; 7:eabf0984. [PMID: 33771868 PMCID: PMC7997512 DOI: 10.1126/sciadv.abf0984] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 01/29/2021] [Indexed: 05/05/2023]
Abstract
Whole-genome duplications are common during evolution, creating genetic redundancy that can enable cellular innovations. Novel protein-protein interactions provide a route to diversified gene functions, but, at present, there is limited proteome-scale knowledge on the extent to which variability in protein complex formation drives neofunctionalization. Here, we used protein correlation profiling to test for variability in apparent mass among thousands of orthologous proteins isolated from diverse species and cell types. Variants in protein complex size were unexpectedly common, in some cases appearing after relatively recent whole-genome duplications or an allopolyploidy event. In other instances, variants such as those in the carbonic anhydrase orthologous group reflected the neofunctionalization of ancient paralogs that have been preserved in extant species. Our results demonstrate that homo- and heteromer formation have the potential to drive neofunctionalization in diverse classes of enzymes, signaling, and structural proteins.
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Affiliation(s)
- Youngwoo Lee
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
- Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Daniel B Szymanski
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
- Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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Wei Y, Xiong S, Zhang Z, Meng X, Wang L, Zhang X, Yu M, Yu H, Wang X, Ma X. Localization, Gene Expression, and Functions of Glutamine Synthetase Isozymes in Wheat Grain ( Triticum aestivum L.). FRONTIERS IN PLANT SCIENCE 2021; 12:580405. [PMID: 33633754 PMCID: PMC7901976 DOI: 10.3389/fpls.2021.580405] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 01/07/2021] [Indexed: 06/08/2023]
Abstract
Glutamine synthetase (GS) plays a major role in plant nitrogen metabolism, but the roles of individual GS isoforms in grains are unknown. Here, the localization and expression of individual TaGS isozymes in wheat grain were probed with TaGS isoenzyme-specific antibodies, and the nitrogen metabolism of grain during the grain filling stage were investigated. Immunofluorescence revealed that TaGS1;1, TaGS1;3, and TaGS2 were expressed in different regions of the embryo. In grain transporting tissues, TaGS1;2 was localized in vascular bundle; TaGS1;2 and TaGS1;1 were in chalaza and placentochalaza; TaGS1;1 and TaGS1;3 were in endosperm transfer cells; and TaGS1;3 and TaGS2 were in aleurone layer. GS exhibited maximum activity and expression at 8 days after flowering (DAF) with peak glutamine content in grains; from then, NH 4 + increased largely from NO 3 - reduction, glutamate dehydrogenase (GDH) aminating activity increased continuously, and the activities of GS and glutamate synthase (GOGAT) decreased, while only TaGS1;3 kept a stable expression in different TaGS isozymes. Hence, GS-GOGAT cycle and GDH play different roles in NH 4 + assimilation of grain in different stages of grain development; TaGS1;3, located in aleurone layer and endosperm transfer cells, plays a key role in Gln into endosperm for gluten synthesis. At 30 DAF, grain amino acids are mainly transported from maternal phloem.
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Affiliation(s)
- Yihao Wei
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Shuping Xiong
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Zhiyong Zhang
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Xiaodan Meng
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Lulu Wang
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Xiaojiao Zhang
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Meiqin Yu
- Department of Biochemistry and Molecular Biology, College of Life Science, Henan Agricultural University, Zhengzhou, China
| | - Haidong Yu
- Department of Biochemistry and Molecular Biology, College of Life Science, Henan Agricultural University, Zhengzhou, China
| | - Xiaochun Wang
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
- Department of Biochemistry and Molecular Biology, College of Life Science, Henan Agricultural University, Zhengzhou, China
| | - Xinming Ma
- Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, China
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9
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Nitrogen Regulating the Expression and Localization of Four Glutamine Synthetase Isoforms in Wheat ( Triticum aestivum L.). Int J Mol Sci 2020; 21:ijms21176299. [PMID: 32878133 PMCID: PMC7504200 DOI: 10.3390/ijms21176299] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/24/2020] [Accepted: 08/28/2020] [Indexed: 12/31/2022] Open
Abstract
Glutamine synthetase (GS), the key enzyme in plant nitrogen assimilation, is strictly regulated at multiple levels, but the most relevant reports focus on the mRNA level. Using specific antibodies as probes, the effects of nitrogen on the expression and localization of individual wheat GS (TaGS) isoforms were studied. In addition to TaGS2, TaGS1;1 with high affinity to substrate and TaGS1;3 with high catalytic activity were also localized in mesophyll, and may participate in cytoplasmic assimilation of ammonium (NH4+) released from photorespiration or absorbed by roots; TaGS1;2 was localized in xylem of leaves. In roots, although there were hundreds of times more TaGS1;1 than TaGS1;2 transcripts, the amount of TaGS1;1 subunit was not higher than that of TaGS1;2; NH4+ inhibited TaGS1;1 expression but stimulated TaGS1;3 expression. In root tips, nitrate stimulated TaGS1;1, TaGS1;3, and TaGS2 expression in meristem, while NH4+ promoted tissue differentiation and TaGS1;2 expression in endodermis and vascular tissue. Only TaGS1;2 was located in vascular tissue of leaves and roots, and was activated by glutamine, suggesting a role in nitrogen transport. TaGS1;3 was induced by NH4+ in root endodermis and mesophyll, suggesting a function in relieving NH4+ toxicity. Thus, TaGS isoforms play distinct roles in nitrogen assimilation for their different kinetic properties, tissue locations, and response to nitrogen regimes.
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Kusano M, Fukushima A, Tabuchi-Kobayashi M, Funayama K, Kojima S, Maruyama K, Yamamoto YY, Nishizawa T, Kobayashi M, Wakazaki M, Sato M, Toyooka K, Osanai-Kondo K, Utsumi Y, Seki M, Fukai C, Saito K, Yamaya T. Cytosolic GLUTAMINE SYNTHETASE1;1 Modulates Metabolism and Chloroplast Development in Roots. PLANT PHYSIOLOGY 2020; 182:1894-1909. [PMID: 32024696 PMCID: PMC7140926 DOI: 10.1104/pp.19.01118] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/09/2020] [Indexed: 05/31/2023]
Abstract
Nitrogen (N) is an essential macronutrient, and the final form of endogenous inorganic N is ammonium, which is assimilated by Gln synthetase (GS) into Gln. However, how the multiple isoforms of cytosolic GSs contribute to metabolic systems via the regulation of ammonium assimilation remains unclear. In this study, we compared the effects of two rice (Oryza sativa) cytosolic GSs, namely OsGS1;1 and OsGS1;2, on central metabolism in roots using reverse genetics, metabolomic and transcriptomic profiling, and network analyses. We observed (1) abnormal sugar and organic N accumulation and (2) significant up-regulation of genes associated with photosynthesis and chlorophyll biosynthesis in the roots of Osgs1;1 but not Osgs1;2 knockout mutants. Network analysis of the Osgs1;1 mutant suggested that metabolism of Gln was coordinated with the metabolic modules of sugar metabolism, tricarboxylic acid cycle, and carbon fixation. Transcript profiling of Osgs1;1 mutant roots revealed that expression of the rice sigma-factor (OsSIG) genes in the mutants were transiently upregulated. GOLDEN2-LIKE transcription factor-encoding genes, which are involved in chloroplast biogenesis in rice, could not compensate for the lack of OsSIGs in the Osgs1;1 mutant. Microscopic analysis revealed mature chloroplast development in Osgs1;1 roots but not in the roots of Osgs1;2, Osgs1;2-complemented lines, or the wild type. Thus, organic N assimilated by OsGS1;1 affects a broad range of metabolites and transcripts involved in maintaining metabolic homeostasis and plastid development in rice roots, whereas OsGS1;2 has a more specific role, affecting mainly amino acid homeostasis but not carbon metabolism.
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Affiliation(s)
- Miyako Kusano
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Atsushi Fukushima
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | | | - Kazuhiro Funayama
- Graduate School of Agricultural Science, Tohoku University, Sendai 981-0845, Japan
| | - Soichi Kojima
- Graduate School of Agricultural Science, Tohoku University, Sendai 981-0845, Japan
| | - Kyonoshin Maruyama
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba 305-8686, Japan
| | - Yoshiharu Y Yamamoto
- The United Graduate School of Agricultural Science, Gifu University, Gifu 501-1193, Japan
| | - Tomoko Nishizawa
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Makoto Kobayashi
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Mayumi Wakazaki
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Kiminori Toyooka
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Kumiko Osanai-Kondo
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Yoshinori Utsumi
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Motoaki Seki
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Chihaya Fukai
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Kazuki Saito
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Tomoyuki Yamaya
- Graduate School of Agricultural Science, Tohoku University, Sendai 981-0845, Japan
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11
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Abstract
Nitrogen (N) is a macro-nutrient that is essential for growth development and resistance against biotic and abiotic stresses of plants. Nitrogen is a constituent of amino acids, proteins, nucleic acids, chlorophyll, and various primary and secondary metabolites. The atmosphere contains huge amounts of nitrogen but it cannot be taken up directly by plants. Plants can take up nitrogen in the form of nitrate, ammonium, urea, nitrite, or a combination of all these forms. In addition, in various leguminous rhizobia, bacteria can convert atmospheric nitrogen to ammonia and supply it to the plants. The form of nitrogen nutrition is also important in plant growth and resistance against pathogens. Nitrogen content has an important function in crop yield. Nitrogen deficiency can cause reduced root growth, change in root architecture, reduced plant biomass, and reduced photosynthesis. Hence, understanding the function and regulation of N metabolism is important. Several enzymes and intermediates are involved in nitrogen assimilation. Here we provide an overview of the important enzymes such as nitrate reductase, nitrite reductase, glutamine synthase, GOGAT, glutamate dehydrogenase, and alanine aminotransferase that are involved in nitrogen metabolism.
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Gao Y, de Bang TC, Schjoerring JK. Cisgenic overexpression of cytosolic glutamine synthetase improves nitrogen utilization efficiency in barley and prevents grain protein decline under elevated CO 2. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:1209-1221. [PMID: 30525274 PMCID: PMC6576097 DOI: 10.1111/pbi.13046] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/23/2018] [Accepted: 11/09/2018] [Indexed: 05/23/2023]
Abstract
Cytosolic glutamine synthetase (GS1) plays a central role in nitrogen (N) metabolism. The importance of GS1 in N remobilization during reproductive growth has been reported in cereal species but attempts to improve N utilization efficiency (NUE) by overexpressing GS1 have yielded inconsistent results. Here, we demonstrate that transformation of barley (Hordeum vulgare L.) plants using a cisgenic strategy to express an extra copy of native HvGS1-1 lead to increased HvGS1.1 expression and GS1 enzyme activity. GS1 overexpressing lines exhibited higher grain yields and NUE than wild-type plants when grown under three different N supplies and two levels of atmospheric CO2 . In contrast with the wild-type, the grain protein concentration in the GS1 overexpressing lines did not decline when plants were exposed to elevated (800-900 μL/L) atmospheric CO2 . We conclude that an increase in GS1 activity obtained through cisgenic overexpression of HvGS1-1 can improve grain yield and NUE in barley. The extra capacity for N assimilation obtained by GS1 overexpression may also provide a means to prevent declining grain protein levels under elevated atmospheric CO2 .
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Affiliation(s)
- Yajie Gao
- Department of Plant and Environmental SciencesFaculty of ScienceCopenhagen UniversityFrederiksbergDenmark
| | - Thomas C. de Bang
- Department of Plant and Environmental SciencesFaculty of ScienceCopenhagen UniversityFrederiksbergDenmark
| | - Jan K. Schjoerring
- Department of Plant and Environmental SciencesFaculty of ScienceCopenhagen UniversityFrederiksbergDenmark
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Comparative Proteomic Analysis Unveils Critical Pathways Underlying the Role of Nitrogen Fertilizer Treatment in American Elderberry. Proteomes 2019; 7:proteomes7010010. [PMID: 30897755 PMCID: PMC6473435 DOI: 10.3390/proteomes7010010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/04/2019] [Accepted: 03/18/2019] [Indexed: 12/24/2022] Open
Abstract
American elderberry (Sambucus nigra subsp. canadensis) is a rapidly growing specialty crop in Missouri and eastern North America. Nitrogen (N) is a major nutrient involved in plant growth and development. However, proteome changes for different genotypes of elder in response to varying levels of N-treatment remain undefined. To reveal plant responses to N, comparative proteomic analyses were performed to determine consistent changes in three genotypes of elderberry leaves (Adams II, Bob Gordon and Wyldewood) grown under different N-fertilizer treatments. 165 proteins separated by two dimensional gel electrophoresis showed significant differences in abundance (p < 0.05 and greater than 2-fold). Principal component analysis of the abundance profiles of these proteins revealed Bob Gordon as a distinct genotype. The 165 proteins were identified by mass spectrometry and showed similar functional distributions in these genotypes underlying the N-treatment. Among the proteins identified, 23 are mainly involved in photosynthesis, protein metabolism and redox homeostasis. Their abundance profiles were not altered upon exposure to N or genotype. These results provide novel insights into plant responses to fertilizer treatment at the proteome level and could lead to a better understanding of molecular mechanisms of elderberry growth.
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Németh E, Nagy Z, Pécsváradi A. Chloroplast Glutamine Synthetase, the Key Regulator of Nitrogen Metabolism in Wheat, Performs Its Role by Fine Regulation of Enzyme Activity via Negative Cooperativity of Its Subunits. FRONTIERS IN PLANT SCIENCE 2018; 9:191. [PMID: 29520285 PMCID: PMC5827528 DOI: 10.3389/fpls.2018.00191] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/01/2018] [Indexed: 05/24/2023]
Abstract
Glutamine synthetase (GS) is of central interest as the main route of ammonia assimilation in plants, and as a connection point between the organic and inorganic worlds. Even though GS activity is critical for producing high yields of crop plants, the autoregulation of substrate consumption of wheat GS remained unknown until now. Here we show kinetic evidence, that the chloroplast localized GS isoform (GS2) of wheat (Triticum aestivum L. cv. Jubilejnaja-50) takes place at the carbon-nitrogen metabolic branch point, where it is a mediator, and its enzymatic activity is regulated in a negatively cooperative allosteric manner. We have discovered that GS2 activity is described by a tetraphasic kinetic curve in response to increasing levels of glutamate supply. We constructed a model that explains the kinetic properties of glutamate consumption and this unique allosteric behavior. We also studied the subunit composition of both wheat leaf GS isoenzymes by a combination of two dimensional gel electrophoresis and protein blotting. Both leaf isozymes have homogeneous subunit composition. Glutamate is both a substrate, and an allosteric regulator of the biosynthetic reaction. We have concluded on the basis of our results and previous reports, that wheat GS2 is probably a homooctamer, and that it processes its substrate in a well-regulated, concentration dependent way, as a result of its negatively cooperative, allosteric activity. Thus, GS2 has a central role as a regulator between the nitrogen and the carbon cycles via maintaining glutamine-glutamate pool in the chloroplast on the level of substrates, in addition to its function in ammonia assimilation.
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Affiliation(s)
- Edit Németh
- Department of Plant Biology, University of Szeged, Szeged, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - Zoltán Nagy
- Cereal Research Non-profit Ltd., Szeged, Hungary
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15
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Lu T, Liu L, Wei M, Liu Y, Qu Z, Yang C, Wei H, Wei Z. The Effect of Poplar PsnGS1.2 Overexpression on Growth, Secondary Cell Wall, and Fiber Characteristics in Tobacco. FRONTIERS IN PLANT SCIENCE 2018; 9:9. [PMID: 29403519 PMCID: PMC5780347 DOI: 10.3389/fpls.2018.00009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 01/03/2018] [Indexed: 05/23/2023]
Abstract
The glutamine synthetase (GS1) is a key enzyme that catalyzes the reaction of glutamate and ammonia to produce glutamine in the nitrogen (N) metabolism. Previous studies on GS1s in several plant species suggest that overexpression of GS1s can enhance N utilization, accelerate plant vegetative growth, and change wood formation. In this study, we isolated a GS1 gene, termed PsnGS1.2, from Populus simonii × Populus nigra. This gene was expressed at a higher level in roots, and relatively lower but detectable levels in xylem, leaves and phloem of P. simonii × P. nigra. The protein encoded by PsnGS1.2 is primarily located in the cytoplasm. Overexpression of PsnGS1.2 in tobacco led to the increased GS1 activity and IAA content, the augmented N assimilation, and the enlarged leaves with altered anatomical structures. These changes presumably promoted photosynthetic, growth, and biomass productivity. It was noteworthy that the secondary cell walls and fiber characteristics changed remarkably in PsnGS1.2 transgenic tobacco. These changes aligned well with the altered expression levels of the genes involved in fiber development, secondary cell wall component biosynthesis, IAA biosynthesis, amino acid transport, and starch breakdown. Taken together, the results from our study suggest that catalytic functions of PsnGS1.2 on N assimilation and metabolism in transgenic tobacco had significant effects on vegetative growth, leaf development, and secondary cell wall formation and properties through acceleration of photosynthesis and IAA biosynthesis, and redirection of carbon flux to synthesis of more cellulose and hemicellulose.
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Affiliation(s)
- Tingting Lu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Lulu Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Minjing Wei
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Yingying Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Zianshang Qu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Chuanping Yang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Hairong Wei
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, United States
| | - Zhigang Wei
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
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16
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Zhang Z, Xiong S, Wei Y, Meng X, Wang X, Ma X. The role of glutamine synthetase isozymes in enhancing nitrogen use efficiency of N-efficient winter wheat. Sci Rep 2017; 7:1000. [PMID: 28428629 PMCID: PMC5430530 DOI: 10.1038/s41598-017-01071-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/27/2017] [Indexed: 11/26/2022] Open
Abstract
Glutamine synthetase (GS) isozymes play critical roles in nitrogen (N) metabolism. However, the exact relationship between GS and nitrogen use efficiency (NUE) remain unclear. We have selected and compared two wheat cultivars, YM49 and XN509, which were identified as the N-efficient and N-inefficient genotypes, respectively. In this study, agronomical, morphological, physiological and biochemical approaches were performed. The results showed that TaGS1 was high expressed post-anthesis, and TaGS2 was highly expressed pre-anthesis in N-efficient genotype compared to N-inefficient genotype. GS1 and GS2 isozymes were also separated by native-PAGE and found that the spatial and temporal distribution of GS isozymes, their expression of gene and protein subunits in source-sink-flow organs during development periods triggered the pool strength and influenced the N flow. According to the physiological role of GS isozymes, we illustrated four metabolic regulation points, by which acting collaboratively in different organs, accelerating the transport of nutrients to the grain. It suggested that the regulation of GS isozymes may promote flow strength and enhance NUE by a complex C-N metabolic mechanism. The relative activity or amount of GS1 and GS2 isozymes could be a potential marker to predict and select wheat genotypes with enhanced NUE.
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Affiliation(s)
- Zhiyong Zhang
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in HenanProvince, Zhengzhou, 450002, China
| | - Shuping Xiong
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in HenanProvince, Zhengzhou, 450002, China
| | - Yihao Wei
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in HenanProvince, Zhengzhou, 450002, China
| | - Xiaodan Meng
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in HenanProvince, Zhengzhou, 450002, China
| | - Xiaochun Wang
- Department of Biochemistry, College of Life Science, Henan Agriculture University, Zhengzhou, 450002, China.
| | - Xinming Ma
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China.
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
- Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in HenanProvince, Zhengzhou, 450002, China.
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Deepa P, Yusuf A. Influence of different host associations on glutamine synthetase activity and ammonium transporter in Santalumalbum L. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2016; 22:331-340. [PMID: 27729719 PMCID: PMC5039156 DOI: 10.1007/s12298-016-0368-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 06/24/2016] [Accepted: 07/31/2016] [Indexed: 06/06/2023]
Abstract
The present study was aimed at understanding the role of different hosts in ammonium transporter1;2 expressions and glutamine synthetase(GS) activity and their effects on the growth parameters in the sandal. Sandal plant associated with leguminous host expressed better growth parameters. GS activity of leguminous hosts alone and in host associated sandals was analyzed using GS transferase assay. Highest GS activity was expressed in Mimosa pudica-sandal association compared to other leguminous and non-leguminous host associations. The association of N2 fixing host with sandal enhanced C and N levels in order to maintain the C/N value. The role of ammonium transporters in N nutrition of sandal-host association was elucidated by cloning AMT1;2 from the leaves, haustoria and roots of host associated sandal and quantifying the relative expression by the [Formula: see text] method. SaAMT1;2 was strongly up-regulated in leaves, roots and haustoria of leguminous host associated sandal compared to non-leguminous host associations. The relative increase in SaAMT1;2 expressions and up-regulated GS activity positively affected the growth parameters in sandal when associated with leguminous hosts.
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Affiliation(s)
- P. Deepa
- Interuniversity Centre for Plant Biotechnology, Department of Botany, University of Calicut, Kerala, 673635 India
| | - A. Yusuf
- Interuniversity Centre for Plant Biotechnology, Department of Botany, University of Calicut, Kerala, 673635 India
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18
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Guan M, de Bang TC, Pedersen C, Schjoerring JK. Cytosolic Glutamine Synthetase Gln1;2 Is the Main Isozyme Contributing to GS1 Activity and Can Be Up-Regulated to Relieve Ammonium Toxicity. PLANT PHYSIOLOGY 2016; 171:1921-33. [PMID: 27231101 PMCID: PMC4936538 DOI: 10.1104/pp.16.01195] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 05/25/2016] [Indexed: 05/19/2023]
Abstract
Cytosolic GS1 (Gln synthetase) is central for ammonium assimilation in plants. High ammonium treatment enhanced the expression of the GS1 isogene Gln-1;2 encoding a low-affinity high-capacity GS1 protein in Arabidopsis (Arabidopsis thaliana) shoots. Under the same conditions, the expression of the high-affinity low-capacity isoform Gln-1;1 was reduced. The expression of Gln-1;3 did not respond to ammonium treatment while Gln-1;4 and Gln-1;5 isogenes in all cases were expressed at a very low level. Gln-2 was highly expressed in shoots but only at a very low level in roots. To investigate the specific functions of the two isogenes Gln-1;1 and Gln-1;2 in shoots for ammonium detoxification, single and double knock-out mutants were grown under standard N supply or with high ammonium provision. Phenotypes of the single mutant gln1;1 were similar to the wild type, while growth of the gln1;2 single mutant and the gln1;1:gln1;2 double mutant was significantly impaired irrespective of N regime. GS1 activity was significantly reduced in both gln1;2 and gln1;1:gln1;2 Along with this, the ammonium content increased while that of Gln decreased, showing that Gln-1;2 was essential for ammonium assimilation and amino acid synthesis. We conclude that Gln-1;2 is the main isozyme contributing to shoot GS1 activity in vegetative growth stages and can be up-regulated to relieve ammonium toxicity. This reveals, to our knowledge, a novel shoot function of Gln-1;2 in Arabidopsis shoots.
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Affiliation(s)
- Miao Guan
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Thomas C de Bang
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Carsten Pedersen
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Jan K Schjoerring
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
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