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Ogasawara S, Ezaki M, Ishida R, Sueyoshi K, Saito S, Hiradate Y, Kudo T, Obara M, Kojima S, Uozumi N, Tanemura K, Hayakawa T. Rice amino acid transporter-like 6 (OsATL6) is involved in amino acid homeostasis by modulating the vacuolar storage of glutamine in roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1616-1630. [PMID: 34216173 DOI: 10.1111/tpj.15403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/02/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Glutamine is a product of ammonium (NH4+ ) assimilation catalyzed by glutamine synthetase (GS) and glutamate synthase (GOGAT). The growth of NH4+ -preferring paddy rice (Oryza sativa L.) depends on root NH4+ assimilation and the subsequent root-to-shoot allocation of glutamine; however, little is known about the mechanism of glutamine storage in roots. Here, using transcriptome and reverse genetics analyses, we show that the rice amino acid transporter-like 6 (OsATL6) protein exports glutamine to the root vacuoles under NH4+ -replete conditions. OsATL6 was expressed, along with OsGS1;2 and OsNADH-GOGAT1, in wild-type (WT) roots fed with sufficient NH4 Cl, and was induced by glutamine treatment. We generated two independent Tos17 retrotransposon insertion mutants showing reduced OsATL6 expression to determine the function of OsATL6. Compared with segregants lacking the Tos17 insertion, the OsATL6 knock-down mutant seedlings exhibited lower root glutamine content but higher glutamine concentration in the xylem sap and greater shoot growth under NH4+ -replete conditions. The transient expression of monomeric red fluorescent protein-fused OsATL6 in onion epidermal cells confirmed the tonoplast localization of OsATL6. When OsATL6 was expressed in Xenopus laevis oocytes, glutamine efflux from the cell into the acidic bath solution increased. Under sufficient NH4+ supply, OsATL6 transiently accumulated in sclerenchyma and pericycle cells, which are located adjacent to the Casparian strip, thus obstructing the apoplastic solute path, and in vascular parenchyma cells of WT roots before the peak accumulation of GS1;2 and NADH-GOGAT1 occurred. These findings suggest that OsATL6 temporarily stores excess glutamine, produced by NH4+ assimilation, in root vacuoles before it can be translocated to the shoot.
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Affiliation(s)
- Saori Ogasawara
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Masataka Ezaki
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Ryusuke Ishida
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Kuni Sueyoshi
- Faculty of Agriculture, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181, Japan
| | - Shunya Saito
- Graduate School of Engineering, Tohoku University, 6-6-07 Aobayama, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Yuki Hiradate
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Toru Kudo
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Mitsuhiro Obara
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences, 1-1 Ohwashi, Tsukuba, Ibaraki, 305-8686, Japan
| | - Soichi Kojima
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Nobuyuki Uozumi
- Graduate School of Engineering, Tohoku University, 6-6-07 Aobayama, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Kentaro Tanemura
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Toshihiko Hayakawa
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
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Ghiasi S, Lehmann MM, Badeck FW, Ghashghaie J, Hänsch R, Meinen R, Streb S, Hüdig M, Ruckle ME, Carrera DÁ, Siegwolf RTW, Buchmann N, Werner RA. Nitrate and ammonium differ in their impact on δ 13C of plant metabolites and respired CO 2 from tobacco leaves. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2021; 57:11-34. [PMID: 32885670 DOI: 10.1080/10256016.2020.1810683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
The carbon isotopic composition (δ13C) of foliage is often used as proxy for plant performance. However, the effect of N O 3 - vs. N H 4 + supply on δ13C of leaf metabolites and respired CO2 is largely unknown. We supplied tobacco plants with a gradient of N O 3 - to N H 4 + concentration ratios and determined gas exchange variables, concentrations and δ13C of tricarboxylic acid (TCA) cycle intermediates, δ13C of dark-respired CO2, and activities of key enzymes nitrate reductase, malic enzyme and phosphoenolpyruvate carboxylase. Net assimilation rate, dry biomass and concentrations of organic acids and starch decreased along the gradient. In contrast, respiration rates, concentrations of intercellular CO2, soluble sugars and amino acids increased. As N O 3 - decreased, activities of all measured enzymes decreased. δ13C of CO2 and organic acids closely co-varied and were more positive under N O 3 - supply, suggesting organic acids as potential substrates for respiration. Together with estimates of intra-molecular 13C enrichment in malate, we conclude that a change in the anaplerotic reaction of the TCA cycle possibly contributes to 13C enrichment in organic acids and respired CO2 under N O 3 - supply. Thus, the effect of N O 3 - vs. N H 4 + on δ13C is highly relevant, particularly if δ13C of leaf metabolites or respiration is used as proxy for plant performance.
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Affiliation(s)
- Shiva Ghiasi
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Franz-W Badeck
- Council for Agricultural Research and Economics, Research Centre for Genomics and Bioinformatics (CREA-GB), Fiorenzuola d´Arda, Italy
| | - Jaleh Ghashghaie
- Laboratoire d'Ecologie Systématique Evolution (ESE), Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Robert Hänsch
- Institute of Plant Biology, Technische Universität Braunschweig, Braunschweig, Germany
- Center of Molecular Ecophysiology (CMEP), College of Resources and Environment, Southwest University, Chongqing, People's Republic of China
| | - Rieke Meinen
- Institute of Plant Biology, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Meike Hüdig
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany
| | - Michael E Ruckle
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Dániel Á Carrera
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Rolf T W Siegwolf
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Roland A Werner
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
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Zhang H, Huo Y, Xu Z, Guo K, Wang Y, Zhang X, Xu N, Sun G. Physiological and proteomics responses of nitrogen assimilation and glutamine/glutamine family of amino acids metabolism in mulberry ( Morus alba L.) leaves to NaCl and NaHCO 3 stress. PLANT SIGNALING & BEHAVIOR 2020; 15:1798108. [PMID: 32729371 PMCID: PMC8550533 DOI: 10.1080/15592324.2020.1798108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 05/04/2023]
Abstract
In order to find out the response mechanism of nitrogen assimilation and glutamine/glutamine family of amino acids metabolism in mulberry (Morus alba L.) leaves under NaCl and NaHCO3 stress, and to reveal its role in salt alkali adaptation. The effects of the nitrogen metabolism of mulberry leaves were studied under 100 mmol L-1 NaCl and NaHCO3 stress.The results showed that the activity of NR and the content of TN and SP did not change significantly, the expression of NiR, Fd-NiR, Fd-NiR gene and theactivity of NiR increased significantly under NaCl stress, but nitrogen assimilation was inhibited under NaHCO3 stress. NaCl stress had no significant effect on the expression and activity of GS and GOGAT in mulberry leaves. Under NaHCO3 stress, the expression of Fd-GOGAT, Fd-GOGAT2, Fd-GOGAT gene, and the activity of GS and GOGAT were significantly decreased. NaCl stress can promote the accumulation of Pro, Put and Spd in mulberry leaves. The accumulation of Pro under NaHCO3 stress is greater than that under NaCl stress. NaCl stress also induced the up-regulation of GAD, GAD1 and GAD1 gene expression, so promoting the synthesis of GABA may be an adaptive mechanism for mulberry to cope with NaCl stress, but the expression of GAD did not change significantly and GAD gene expression lower than CK under NaHCO3 stress. Although both NaCl and NaHCO3 stress could promote the synthesis of GSH by up-regulation of GCLM expression, GSH under NaHCO3 stress was significantly higher than that under NaCl stress, the content of H2O2 was still significantly higher than that of NaCl stress, that means GSH may not play a key role in alleviating the oxidative damage in mulberry leaves caused by salt and alkali.
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Affiliation(s)
- Huihui Zhang
- College of Resources and Environment, NortheastAgriculturalUniversity, Harbin, Heilongjiang, China
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Yuze Huo
- College of Resources and Environment, NortheastAgriculturalUniversity, Harbin, Heilongjiang, China
| | - Zisong Xu
- College of Resources and Environment, NortheastAgriculturalUniversity, Harbin, Heilongjiang, China
| | - Kaiwen Guo
- College of Resources and Environment, NortheastAgriculturalUniversity, Harbin, Heilongjiang, China
| | - Yue Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Xiaosong Zhang
- Department of Research and Education, Dalian Academy of Agricultural Sciences, Dalian, Liaoning, China
| | - Nan Xu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China
- Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, Harbin University, Harbin, Heilongjiang, China
- Natural Resources and Ecology Institute, Heilongjiang Sciences Academy, Harbin, Heilongjiang, China
| | - Guangyu Sun
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China
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Gong Q, Li Z, Wang L, Dai T, Kang Q, Niu D. Exogenous of Indole-3-Acetic Acid Application Alleviates Copper Toxicity in Spinach Seedlings by Enhancing Antioxidant Systems and Nitrogen Metabolism. TOXICS 2019; 8:E1. [PMID: 31878158 PMCID: PMC7151742 DOI: 10.3390/toxics8010001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/11/2019] [Accepted: 12/13/2019] [Indexed: 01/31/2023]
Abstract
Indole-3-acetic acid (IAA) is a potential mediator in the protection of plants from copper (Cu) toxicity and the enhancement of Cu tolerance. In this paper, spinach (Spinacia oleracea L.) seedlings were cultivated in soil containing 700 mg kg-1 Cu and the leaves of seedlings were sprayed with different concentrations of IAA. Exogenous IAA treatment reduced the malondialdehyde (MDA) concentrations in Cu-stressed seedlings and increased biomass, proline content, and the activities of antioxidant enzymes. Exogenous IAA treatment also increased the levels of nitrogen (N) assimilation compounds and the activities of N-metabolizing enzymes, but reduced NH4+ content. Notably, lower concentrations of IAA (10-40 mg L-1) increased the Cu concentrations in roots and reduced the Cu concentrations in leaves, while higher concentrations of IAA (50 mg L-1) reduced the Cu concentrations in both roots and leaves to the lowest levels. The findings indicated that the application of IAA reduced Cu accumulation, alleviated Cu toxicity, and enhanced Cu tolerance in spinach seedlings. IAA application could be used as an alternative strategy for reducing Cu accumulation in vegetable crops and for remediating Cu-contaminated soil, in turn reducing the hazardous effects of heavy metal contamination on human health and the environment.
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Affiliation(s)
- Qin Gong
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
- Further Education Colleges, Xinjiang Vocation College of Agriculture, Changji 831100, China
| | - Zhaohua Li
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
- Hubei Rural Safe Drinking Water Engineering Technology Research Center, Wuhan 430062, China
| | - Ling Wang
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
| | - Tongwei Dai
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
| | - Qun Kang
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
| | - Duandan Niu
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; (Q.G.); (L.W.); (T.D.); (Q.K.); (D.N.)
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Zhong C, Cao X, Bai Z, Zhang J, Zhu L, Huang J, Jin Q. Nitrogen metabolism correlates with the acclimation of photosynthesis to short-term water stress in rice (Oryza sativa L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 125:52-62. [PMID: 29413631 DOI: 10.1016/j.plaphy.2018.01.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/18/2018] [Accepted: 01/23/2018] [Indexed: 05/12/2023]
Abstract
Nitrogen metabolism is as sensitive to water stress as photosynthesis, but its role in plant under soil drying is not well understood. We hypothesized that the alterations in N metabolism could be related to the acclimation of photosynthesis to water stress. The features of photosynthesis and N metabolism in a japonica rice 'Jiayou 5' and an indica rice 'Zhongzheyou 1' were investigated under mild and moderate soil drying with a pot experiment. Soil drying increased non-photochemical quenching (NPQ) and reduced photon quantum efficiency of PSII and CO2 fixation in 'Zhongzheyou 1', whereas the effect was much slighter in 'Jiayou 5'. Nevertheless, the photosynthetic rate of the two cultivars showed no significant difference between control and water stress. Soil drying increased nitrate reducing in leaves of 'Zhongzheyou 1', characterized by enhanced nitrate reductase (NR) activity and lowered nitrate content; whereas glutamate dehydrogenase (GDH), glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were relative slightly affected. 'Jiayou 5' plants increased the accumulation of nitrate under soil drying, although its NR activity was increased. In addition, the activities of GDH, GOT and GPT were typically increased under soil drying. Besides, amino acids and soluble sugar were significantly increased under mild and moderate soil drying, respectively. The accumulation of nitrate, amino acid and sugar could serve as osmotica in 'Jiayou 5'. The results reveal that N metabolism plays diverse roles in the photosynthetic acclimation of rice plants to soil drying.
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Affiliation(s)
- Chu Zhong
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China; Crop Physiology and Production Center, Huazhong Agricultural University, Wuhan 420007, China
| | - Xiaochuang Cao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Zhigang Bai
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Junhua Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Lianfeng Zhu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Jianliang Huang
- Crop Physiology and Production Center, Huazhong Agricultural University, Wuhan 420007, China
| | - Qianyu Jin
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
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Curtis TY, Bo V, Tucker A, Halford NG. Construction of a network describing asparagine metabolism in plants and its application to the identification of genes affecting asparagine metabolism in wheat under drought and nutritional stress. Food Energy Secur 2018; 7:e00126. [PMID: 29938110 PMCID: PMC5993343 DOI: 10.1002/fes3.126] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/04/2018] [Accepted: 01/07/2018] [Indexed: 01/01/2023] Open
Abstract
A detailed network describing asparagine metabolism in plants was constructed using published data from Arabidopsis (Arabidopsis thaliana) maize (Zea mays), wheat (Triticum aestivum), pea (Pisum sativum), soybean (Glycine max), lupin (Lupus albus), and other species, including animals. Asparagine synthesis and degradation is a major part of amino acid and nitrogen metabolism in plants. The complexity of its metabolism, including limiting and regulatory factors, was represented in a logical sequence in a pathway diagram built using yED graph editor software. The network was used with a Unique Network Identification Pipeline in the analysis of data from 18 publicly available transcriptomic data studies. This identified links between genes involved in asparagine metabolism in wheat roots under drought stress, wheat leaves under drought stress, and wheat leaves under conditions of sulfur and nitrogen deficiency. The network represents a powerful aid for interpreting the interactions not only between the genes in the pathway but also among enzymes, metabolites and smaller molecules. It provides a concise, clear understanding of the complexity of asparagine metabolism that could aid the interpretation of data relating to wider amino acid metabolism and other metabolic processes.
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Affiliation(s)
- Tanya Y Curtis
- Plant Sciences Department Rothamsted Research Harpenden Hertfordshire UK
| | - Valeria Bo
- College of Engineering, Design and Physical Sciences Brunel University London Uxbridge Middlesex UK.,Present address: Cancer Research UK Cambridge Institute University of Cambridge Li Ka Shing Centre Robinson Way Cambridge UK
| | - Allan Tucker
- College of Engineering, Design and Physical Sciences Brunel University London Uxbridge Middlesex UK
| | - Nigel G Halford
- Plant Sciences Department Rothamsted Research Harpenden Hertfordshire UK
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Coskun D, Britto DT, Kronzucker HJ. Nutrient constraints on terrestrial carbon fixation: The role of nitrogen. JOURNAL OF PLANT PHYSIOLOGY 2016; 203:95-109. [PMID: 27318532 DOI: 10.1016/j.jplph.2016.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/26/2016] [Accepted: 05/30/2016] [Indexed: 06/06/2023]
Abstract
Carbon dioxide (CO2) concentrations in the earth's atmosphere are projected to rise from current levels near 400ppm to over 700ppm by the end of the 21st century. Projections over this time frame must take into account the increases in total net primary production (NPP) expected from terrestrial plants, which result from elevated CO2 (eCO2) and have the potential to mitigate the impact of anthropogenic CO2 emissions. However, a growing body of evidence indicates that limitations in soil nutrients, particularly nitrogen (N), the soil nutrient most limiting to plant growth, may greatly constrain future carbon fixation. Here, we review recent studies about the relationships between soil N supply, plant N nutrition, and carbon fixation in higher plants under eCO2, highlighting key discoveries made in the field, particularly from free-air CO2 enrichment (FACE) technology, and relate these findings to physiological and ecological mechanisms.
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Affiliation(s)
- Devrim Coskun
- Department of Biological Sciences and the Canadian Centre for World Hunger Research (CCWHR), University of Toronto, Canada
| | - Dev T Britto
- Department of Biological Sciences and the Canadian Centre for World Hunger Research (CCWHR), University of Toronto, Canada
| | - Herbert J Kronzucker
- Department of Biological Sciences and the Canadian Centre for World Hunger Research (CCWHR), University of Toronto, Canada.
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Mattiello L, Riaño-Pachón DM, Martins MCM, da Cruz LP, Bassi D, Marchiori PER, Ribeiro RV, Labate MTV, Labate CA, Menossi M. Physiological and transcriptional analyses of developmental stages along sugarcane leaf. BMC PLANT BIOLOGY 2015; 15:300. [PMID: 26714767 PMCID: PMC4696237 DOI: 10.1186/s12870-015-0694-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/17/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND Sugarcane is one of the major crops worldwide. It is cultivated in over 100 countries on 22 million ha. The complex genetic architecture and the lack of a complete genomic sequence in sugarcane hamper the adoption of molecular approaches to study its physiology and to develop new varieties. Investments on the development of new sugarcane varieties have been made to maximize sucrose yield, a trait dependent on photosynthetic capacity. However, detailed studies on sugarcane leaves are scarce. In this work, we report the first molecular and physiological characterization of events taking place along a leaf developmental gradient in sugarcane. RESULTS Photosynthetic response to CO2 indicated divergence in photosynthetic capacity based on PEPcase activity, corroborated by activity quantification (both in vivo and in vitro) and distinct levels of carbon discrimination on different segments along leaf length. Additionally, leaf segments had contrasting amount of chlorophyll, nitrogen and sugars. RNA-Seq data indicated a plethora of biochemical pathways differentially expressed along the leaf. Some transcription factors families were enriched on each segment and their putative functions corroborate with the distinct developmental stages. Several genes with higher expression in the middle segment, the one with the highest photosynthetic rates, were identified and their role in sugarcane productivity is discussed. Interestingly, sugarcane leaf segments had a different transcriptional behavior compared to previously published data from maize. CONCLUSION This is the first report of leaf developmental analysis in sugarcane. Our data on sugarcane is another source of information for further studies aiming to understand and/or improve C4 photosynthesis. The segments used in this work were distinct in their physiological status allowing deeper molecular analysis. Although limited in some aspects, the comparison to maize indicates that all data acquired on one C4 species cannot always be easily extrapolated to other species. However, our data indicates that some transcriptional factors were segment-specific and the sugarcane leaf undergoes through the process of suberizarion, photosynthesis establishment and senescence.
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Affiliation(s)
- Lucia Mattiello
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
- Laboratório de Genoma Funcional, Instituto de Biologia, Universidade Estadual de Campinas Campinas, Caixa Postal 6109, Campinas, 13083-862, SP, Brazil.
| | - Diego Mauricio Riaño-Pachón
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Marina Camara Mattos Martins
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Larissa Prado da Cruz
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Denis Bassi
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Paulo Eduardo Ribeiro Marchiori
- Laboratório de Fisiologia de Plantas "Coaracy M. Franco", Centro de Pesquisa e Desenvolvimento em Ecofisiologia e Biofísica, Instituto Agronômico, Caixa Postal 28, Campinas, 13020-902, SP, Brazil.
| | - Rafael Vasconcelos Ribeiro
- Departamento de Biologia de Plantas, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, 13083-970, SP, Brazil.
| | - Mônica T Veneziano Labate
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, Universidade de São Paulo, Caixa Postal 83, Piracicaba, 13400-970, SP, Brazil.
| | - Carlos Alberto Labate
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, Universidade de São Paulo, Caixa Postal 83, Piracicaba, 13400-970, SP, Brazil.
| | - Marcelo Menossi
- Laboratório de Genoma Funcional, Instituto de Biologia, Universidade Estadual de Campinas Campinas, Caixa Postal 6109, Campinas, 13083-862, SP, Brazil.
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9
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Kojima S, Konishi N, Beier MP, Ishiyama K, Maru I, Hayakawa T, Yamaya T. NADH-dependent glutamate synthase participated in ammonium assimilation in Arabidopsis root. PLANT SIGNALING & BEHAVIOR 2014; 9:e29402. [PMID: 25763622 PMCID: PMC4203567 DOI: 10.4161/psb.29402] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 05/29/2014] [Accepted: 05/29/2014] [Indexed: 05/24/2023]
Abstract
Higher plants have 2 GOGAT species, Fd-GOGAT and NADH-GOGAT. While Fd-GOGAT mainly assimilates ammonium in leaves, which is derived from photorespiration, the function of NADH-GOGAT, which is highly expressed in roots, (1) needs to be elucidated. The aim of this study was to clarify the role of NADH-GOGAT in Arabidopsis roots. The supply of ammonium to the roots caused an accumulation of NADH-GOGAT, while Fd-GOGAT 1 and Fd-GOGAT 2 showed no response. A promoter-GUS fusion analysis and immunohistochemistry showed that NADH-GOGAT was located in non-green tissues like vascular bundles, shoot apical meristem, pollen, stigma, and roots. The localization of NADH-GOGAT and Fd-GOGAT was not overlapped. NADH-GOGAT T-DNA insertion lines showed a reduction of glutamate and biomass under normal CO2 conditions. These data emphasizes the importance of NADH-GOGAT in the ammonium assimilation of Arabidopsis roots.
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10
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Kendziorek M, Paszkowski A, Zagdańska B. Biochemical characterization and kinetic properties of alanine aminotransferase homologues partially purified from wheat (Triticum aestivum L.). PHYTOCHEMISTRY 2012; 82:7-14. [PMID: 22863564 DOI: 10.1016/j.phytochem.2012.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 05/16/2023]
Abstract
Four homologues of alanine aminotransferase have been isolated from shoots of wheat seedlings and purified by saline precipitation, gel filtration, preparative electrophoresis and anion exchange chromatography on Protein-Pak Q 8HR column attached to HPLC. Alanine aminotransferase 1 (AlaAT1) and 2 (AlaAT2) were purified 303- and 452-fold, respectively, whereas l-glutamate: glyoxylate aminotransferase 1 (GGAT1) and 2 (GGAT2) were purified 485- and 440-fold, respectively. Consistent inhibition of AlaAT (EC 2.6.1.2) and GGAT (EC 2.6.1.4) activities by p-hydroxymercuribenzoate points on participation of cysteine residues in the enzyme activity. The molecular weight of AlaAT1 and AlaAT2 was estimated to be 65kDa and both of them are monomers in native state. Nonsignificant differences between K(m) using alanine as substrate and catalytic efficiency (k(cat)/K(m)) for l-alanine in reaction with 2-oxoglutarate indicate comparable kinetic constants for AlaAT1 and AlaAT2. Similar kinetic constants for l-alanine in reaction with 2-oxoglutarate and for l-glutamate in reaction with pyruvate for all four homologues suggest equally efficient reaction in both forward and reverse directions. GGAT1 and GGAT2 were able to catalyze transamination between l-glutamate and glyoxylate, l-alanine and glyoxylate and reverse reactions between glycine and 2-oxoglutarate or pyruvate. Both GGATs also consisted of a single subunit with molecular weight of about 50kDa. The estimated K(m) for GGAT1 (3.22M) and GGAT2 (1.27M) using l-glutamate as substrate was lower in transamination with glyoxylate than with pyruvate (9.52 and 9.09mM, respectively). Moreover, distinctively higher values of catalytic efficiency for l-glutamate in reaction with glyoxylate than for l-glutamate in reaction with pyruvate confirm involvement of these homologues into photorespiratory metabolism.
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Affiliation(s)
- Maria Kendziorek
- Biochemistry Department, Warsaw University of Life Sciences, Nowoursynowska 159, Warsaw, Poland
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11
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Qian H, Wang R, Chen J, Ding H, Yong W, Songlin R, Fu Z. Analysis of enantioselective biochemical, physiological, and transcriptional effects of the chiral herbicide diclofop methyl on rice seedlings. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:5515-5523. [PMID: 22612386 DOI: 10.1021/jf301688a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Diclofop methyl (DM) is a chiral herbicide that is widely used as a racemic mixture. This study analyzed the enantioselective effects of R- and S-DM on rice at the physiological and molecular levels. DM exerts an enantioselective effect on rice growth, reactive oxygen substance (ROS) formation, and antioxidant gene expression, with R-DM acting as a more potent stressor than S-DM. An analysis of chlorophyll fluorescence demonstrated that photosynthesis process was more strongly inhibited by R-DM than by S-DM. Microarray results showed that many metabolic pathways, including starch and sucrose metabolism, oxidative phosphorylation, and amino acid biosynthesis and metabolism, were affected by DM in an enantioselective manner. These results suggest that R-DM is more active to plant growth than S-DM and that this activity is induced not only by repression of fatty acid synthesis but also by R-DM affecting the transcription of genes in other metabolic pathways in an enantioselective manner.
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Affiliation(s)
- Haifeng Qian
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China
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12
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Fertilizer-Nitrogen Use Efficiency and Its Physiological Mechanism under Site- Specific Nitrogen Management in Rice. ACTA AGRONOMICA SINICA 2009. [DOI: 10.3724/sp.j.1006.2009.01672] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Obara M, Sato T, Sasaki S, Kashiba K, Nagano A, Nakamura I, Ebitani T, Yano M, Yamaya T. Identification and characterization of a QTL on chromosome 2 for cytosolic glutamine synthetase content and panicle number in rice. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 110:1-11. [PMID: 15549232 DOI: 10.1007/s00122-004-1828-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 09/27/2004] [Indexed: 05/08/2023]
Abstract
A quantitative trait locus (QTL) associated with the protein content of cytosolic glutamine synthetase (GS1; EC 6.3.1.2) in senescing leaves, panicle number, and panicle weight was characterized in rice (Oryza sativa L.). A near-isogenic line (NIL), C-22, developed by marker-assisted selection was grown under different nitrogen levels in the greenhouse and in a paddy field. Chromosome 2 of C-22 had an approximately 50-cM segment substituted from the Kasalath (indica) chromosome in a Koshihikari (japonica) genetic background. C-22 showed a 12-37% lower content of GS1 protein in leaf blades than Koshihikari, which was in good agreement with a QTL region positively affected by the japonica chromosome. At an early vegetative stage, C-22 had more active tillers than Koshihikari in the greenhouse. At the reproductive stage, both panicle number and total panicle weight of C-22 were significantly higher than those of Koshihikari, particularly when the plants were grown under a low-nitrogen condition. These traits of C-22 were further confirmed in a paddy field. Thus, tiller development was positively affected by the Kasalath chromosome at an early vegetative stage, which resulted in an increased panicle number and panicle weight at the mature stage in C-22. These data indicate that the target QTL (Pnn1; panicle number 1) is important in the development of tillers and panicles in rice. Linkage analyses for panicle number and ratio of developing tiller formation in the second axil (RDT) revealed that Pnn1 was delimited at the 6.7-cM region.
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Affiliation(s)
- Mitsuhiro Obara
- Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidoori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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14
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Sakurai N, Katayama Y, Yamaya T. Overlapping expression of cytosolic glutamine synthetase and phenylalanine ammonia-lyase in immature leaf blades of rice. PHYSIOLOGIA PLANTARUM 2001; 113:400-408. [PMID: 12060286 DOI: 10.1034/j.1399-3054.2001.1130314.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to estimate whether cytosolic glutamine synthetase (GS1; EC 6.3.1.2) is partly coupled to the reaction of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) in developing organs of rice (Oryza sativa L.), we compared the expression pattern of transcripts and proteins for GS1 and PAL in the tissue sections from leaf blades at various stages of development. In immature vascular bundles of unexpanded leaf blades, GS1 mRNA was mainly detected in xylem parenchyma cells, mestome-sheath cells, and sclerenchyma cells. PAL transcripts were also accumulated in these cell types. Vascular bundles in midribs of immature leaf blades contained mRNAs and proteins for both GS1 and PAL abundantly in sclerenchyma cells, although distribution of these two proteins was not completely overlapped. In immature vascular bundles in midribs, lignin deposition was observed in cell walls of xylem parenchyma cells, mestome-sheath cells and sclerenchyma cells. These results implied that a part of GS1 in unexpanded leaf blades is possibly involved in reassimilation of ammonia released from PAL reaction during the lignin production.
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Affiliation(s)
- Nozomu Sakurai
- Department of Applied Plant Science, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan Graduate School of Bio-Applications and System Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 183-8509, Japan The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan
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15
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Orea A, Pajuelo P, Pajuelo E, Márquez AJ, Romero JM. Characterisation and expression studies of a root cDNA encoding for ferredoxin-nitrite reductase from Lotus japonicus. PHYSIOLOGIA PLANTARUM 2001; 113:193-202. [PMID: 12060296 DOI: 10.1034/j.1399-3054.2001.1130206.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A full-length cDNA encoding for ferredoxin-nitrite reductase (NiR, EC 1.7.7.1), has been isolated from a root cDNA library from the legume Lotus japonicus and characterised. The NiR gene (Nii) is present as a single copy in this plant, and encodes a protein of 582 amino acids. The Lotus NiR protein is synthesised as a precursor with an amino-terminal transit peptide consisting of 25 amino acid residues. Sequence comparisons with leaf NiRs from different plant species and with other related redox proteins identified in the root NiR the same highly conserved residues involved in the cofactor binding than previously reported for leaves. Besides, a putative binding site for ferredoxin was also found in the N-terminal region of the protein. The NiR gene is expressed in roots and leaves, although the level of expression is much higher in roots, in accordance with the fact that L. japonicus assimilates nitrate mainly in roots. NiR mRNA, protein and activity are induced by nitrate in roots and leaves, while ammonium-grown plants only showed basal levels. No oscillations of NiR mRNA, protein and activity were observed during the day/night cycle, neither in roots nor leaves, making an interesting difference with rhythms observed in other plant species.
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Affiliation(s)
- Alicia Orea
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Química. Universidad de Sevilla, Apdo. 553, E-41080-Sevilla, Spain Instituto de Bioquímica Vegetal y Fotosíntesis. Centro de Investigaciones Científicas Isla de la Cartuja, c/ Americo Vespucio s/n, E-41092-Sevilla, Spain
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16
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Grossman A, Takahashi H. MACRONUTRIENT UTILIZATION BY PHOTOSYNTHETIC EUKARYOTES AND THE FABRIC OF INTERACTIONS. ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY 2001; 52:163-210. [PMID: 11337396 DOI: 10.1146/annurev.arplant.52.1.163] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Organisms acclimate to a continually fluctuating nutrient environment. Acclimation involves responses specific for the limiting nutrient as well as responses that are more general and occur when an organism experiences different stress conditions. Specific responses enable organisms to efficiently scavenge the limiting nutrient and may involve the induction of high-affinity transport systems and the synthesis of hydrolytic enzymes that facilitate the release of the nutrient from extracellular organic molecules or from internal reserves. General responses include changes in cell division rates and global alterations in metabolic activities. In photosynthetic organisms there must be precise regulation of photosynthetic activity since when severe nutrient limitation prevents continued cell growth, excitation of photosynthetic pigments could result in the formation of reactive oxygen species, which can severely damage structural and functional features of the cell. This review focuses on ways that photosynthetic eukaryotes assimilate the macronutrients nitrogen, sulfur, and phosphorus, and the mechanisms that govern assimilatory activities. Also discussed are molecular responses to macronutrient limitation and the elicitation of those responses through integration of environmental and cellular cues.
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Affiliation(s)
- Arthur Grossman
- Department of Plant Biology, The Carnegie Institution of Washington 260 Panama Street, Stanford, California 94305; e-mail: , RIKEN Plant Science Center, 2-l Hirosawa, Wako, Saitama, 351-0198, Japan; e-mail:
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17
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Obara M, Kajiura M, Fukuta Y, Yano M, Hayashi M, Yamaya T, Sato T. Mapping of QTLs associated with cytosolic glutamine synthetase and NADH-glutamate synthase in rice (Oryza sativa L.). JOURNAL OF EXPERIMENTAL BOTANY 2001; 52:1209-1217. [PMID: 11432939 DOI: 10.1093/jexbot/52.359.1209] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ninety-eight backcross inbred lines (BC1F6) developed between Nipponbare, a japonica rice, and Kasalath, an indica rice were employed to detect putative quantitative trait loci (QTLs) associated with the contents of cytosolic glutamine synthetase (GS1; EC 6.3.1.2) and NADH-glutamate synthase (NADH-GOGAT; EC 1.4.1.14) in leaves. Immunoblotting analyses showed transgressive segregations toward lower or greater contents of these enzyme proteins in these backcross inbred lines. Seven chromosomal QTL regions for GS1 protein content and six for NADH-GOGAT protein content were detected. Some of these QTLs were located in QTL regions for various biochemical and physiological traits affected by nitrogen recycling. These findings suggested that the variation in GS1 and NADH-GOGAT protein contents in this population is related to the changes in the rate of nitrogen recycling from senescing organs to developing organs, leading to changes in these physiological traits. Furthermore, a structural gene for GS1 was mapped between two RFLP markers, C560 and C1408, on chromosome 2 and co-located in the QTL region for one-spikelet weight. A QTL region for NADH-GOGAT protein content was detected at the position mapped for the NADH-GOGAT structural gene on chromosome 1. A QTL region for soluble protein content in developing leaves was also detected in this region. Although fine mapping is required to identify individual genes in the future, QTL analysis could be a useful post-genomic tool to study the gene functions for regulation of nitrogen recycling in rice.
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Affiliation(s)
- M Obara
- Department of Applied Plant Science, Graduate School of Agricultural Sciences, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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18
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Majerowicz N, Kerbauy GB, Nievola CC, Suzuki RM. Growth and nitrogen metabolism of Catasetum fimbriatum (orchidaceae) grown with different nitrogen sources. ENVIRONMENTAL AND EXPERIMENTAL BOTANY 2000; 44:195-206. [PMID: 11064040 DOI: 10.1016/s0098-8472(00)00066-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Catasetum fimbriatum is an epiphytic orchid from South America that has been used for 15 years as a model plant for metabolic and developmental studies in our laboratory. In this work, C. fimbriatum plants were aseptically grown with 6 mol m(-3) of either glutamine or inorganic nitrogen forms (NO(3)(-):NH(4)(+) ratios). The highest biomass accumulation was found in plants supplied with glutamine; no significant difference was observed in plants incubated in the presence of inorganic nitrogen sources. Nitrogen assimilation was limited in the presence NO(3)(-) as a sole nitrogen source. C. fimbriatum did not accumulate NO(3)(-) and very low rates of in vivo nitrate reductase activity were observed. Most nitrate reductase activity (70%) was detected in the 2 cm apical roots. Nitrate-treated plants exhibited relatively lower amounts of free amino-N, chlorophyll and free NH(4)(+) contents and higher soluble sugar contents than the NH(4)(+)-treated plants. While shoot glutamine synthetase activity was only slightly affected by nitrogen sources, root glutamine synthetase activity was not modified by any nitrogen form. Glutamate dehydrogenase-NADH activity in shoot tissues was not influenced by any nitrogen source. However, the glutamate dehydrogenase-NADH activity in roots was enhanced when NH(4)(+) tissue contents was augmented by increasing NH(4)(+) in the medium and by the presence of glutamine. Our results strongly suggest that organic nitrogen and NH(4)(+) are probably the most important nitrogen sources to C. fimbriatum plants.
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Affiliation(s)
- N Majerowicz
- Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Rod. BR 465-Km 7 (Km 47-Antiga Rio-SP), RJ. CEP 23.890-000, Seropédica, Brazil
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19
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Nakano K, Suzuki T, Hayakawa T, Yamaya T. Organ and cellular localization of asparagine synthetase in rice plants. PLANT & CELL PHYSIOLOGY 2000; 41:874-80. [PMID: 10965944 DOI: 10.1093/pcp/pcd006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
DNA gel blot analysis suggested that asparagine synthetase (AS; EC 6.3.5.4) occurred as a single gene in rice. A fusion protein consisting of 17 kDa tagged-region from pET32a(+) expression plasmid and 42 kDa N-terminal region of rice AS was first expressed in Escherichia coli. The resulting polypeptide was purified and a mono-specific antibody for rice AS was prepared after affinity-purification with the antigen. Immunoblotting revealed a high content of AS protein in the leaf sheath at the second position from the fully expanded top leaf and in grains at the middle stage of ripening. Accumulation of mRNA for AS was also observed in these organs. During the ripening of the spikelets, the AS protein contents increased during the first 21 days after flowering, then declined rapidly. Immunolocalization analysis revealed signals for AS protein in the companion cells of vascular bundles of leaf sheath and phloem-parenchyma cells, nucellar projection, and nucellar epidermis of dorsal vascular bundles of grains.
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Affiliation(s)
- K Nakano
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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20
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Finnemann J, Schjoerring JK. Translocation of NH 4
+
in oilseed rape plants in relation to glutamine synthetase isogene expression and activity. PHYSIOLOGIA PLANTARUM 1999. [PMID: 0 DOI: 10.1034/j.1399-3054.1999.105311.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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21
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Hayakawa, Hopkins, Peat, Yamaya, Tobin. Quantitative intercellular localization of NADH-dependent glutamate synthase protein in different types of root cells in rice plants. PLANT PHYSIOLOGY 1999; 119:409-16. [PMID: 9952435 PMCID: PMC32116 DOI: 10.1104/pp.119.2.409] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/1998] [Accepted: 11/02/1998] [Indexed: 05/20/2023]
Abstract
The quantitative analysis with immunogold-electron microscopy using a single-affinity-purified anti-NADH-glutamate synthase (GOGAT) immunoglobulin G (IgG) as the primary antibody showed that the NADH-GOGAT protein was present in various forms of plastids in the cells of the epidermis and exodermis, in the cortex parenchyma, and in the vascular parenchyma of root tips (<10 mm) of rice (Oryza sativa) seedlings supplied with 1 mM NH4+ for 24 h. The values of the mean immunolabeling density of plastids were almost equal among these different cell types in the roots. However, the number of plastids per individual cell type was not identical, and some parts of the cells in the epidermis and exodermis contained large numbers of plastids that were heavily immunolabeled. Although there was an indication of labeling in the mitochondria using the single-affinity-purified anti-NADH-GOGAT IgG, this was not confirmed when a twice-affinity-purified IgG was used, indicating an exclusively plastidial location of the NADH-GOGAT protein in rice roots. These results, together with previous work from our laboratory (K. Ishiyama, T. Hayakawa, and T. Yamaya [1998] Planta 204: 288-294), suggest that the assimilation of exogeneously supplied NH4+ ions is primarily via the cytosolic glutamine synthetase/plastidial NADH-GOGAT cycle in specific regions of the epidermis and exodermis in rice roots. We also discuss the role of the NADH-GOGAT protein in vascular parenchyma cells.
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Affiliation(s)
- Hayakawa
- Laboratory of Plant Cell Biochemistry, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan (T.H., T. Y.)
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22
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Singh S, Lewis NG, Towers GH. Nitrogen recycling during phenylpropanoid metabolism in sweet potato tubers. JOURNAL OF PLANT PHYSIOLOGY 1998; 153:316-323. [PMID: 11543585 DOI: 10.1016/s0176-1617(98)80157-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In the first step of the phenylpropanoid metabolic pathway, L-phenylalanine (L-Phe) is deaminated to form E-cinnamate, in a conversion catalyzed by phenylalanine ammonia-lyase (PAL; EC 4.3.1.5). The metabolic fate of the ammonium ion (NH4+) produced in this reaction was investigated in sweet potato (Ipomoea batatas) tuber discs. [15N]-Labeled substrates including L-Phe, in the presence or absence of specific enzyme inhibitors, were administered to sweet potato discs in light under aseptic conditions. 15N-Nuclear magnetic resonance spectroscopic analyses revealed that the 15NH4+ liberated during the PAL reaction is first incorporated into the amide nitrogen of L-glutamine (L-Gln) and then into L-glutamate (L-Glu). These results extend our previous observations in pine and potato that PAL-generated NH4+ is assimilated by the glutamine synthetase (GS; EC 6.3.1.2)/glutamate synthase (GOGAT; EC 1.4.1.13) pathway, with the NH4+ so formed ultimately being recycled back to L-Phe via L-Glu as aminoreceptor and donor.
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Affiliation(s)
- S Singh
- Department of Botany, University of British Columbia, Vancouver, Canada
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23
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Goto S, Akagawa T, Kojima S, Hayakawa T, Yamaya T. Organization and structure of NADH-dependent glutamate synthase gene from rice plants. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1387:298-308. [PMID: 9748637 DOI: 10.1016/s0167-4838(98)00142-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Genomic clones for NADH-dependent glutamate synthase (NADH-GOGAT; EC 1.4.1.14) were obtained from a genomic library of rice (Oryza sativa L. cv. Sasanishki). A genomic clone (lambdaOS42, 14 kb) covered an entire structural gene and a 3.7 kb 5'-upstream region from the first methionine. Another clone (lambdaOS23, 14 kb) contained a 2.8 kb 3'-downstream region from the stop codon. A 7047 bp long clone (lambdaOSR51) consisting of full length cDNA for NADH-GOGAT was isolated from a cDNA library prepared using mRNA from roots of rice seedlings treated with 1 mM NH4Cl for 12 h. The presumed transcribed region (11.7 kb) consisted of 23 exons separated by 22 introns. Rice NADH-GOGAT is synthesized as a 2166 amino acid protein with a molecular mass of 236.7 kDa that includes a 99 amino acid presequence. DNA gel blot analysis suggested that NADH-GOGAT occurred as a single gene in rice. Primer extension experiments map the transcription start of NADH-GOGAT to identical positions. The 3. 7 kb 5'-upstream region was able to transiently express a reporter gene in cultured rice cells. Putative motifs related to the regulation of NADH-GOGAT gene expression were looked for within the 5'-upstream region by database.
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Affiliation(s)
- S Goto
- Department of Life Science, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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Purnell MP, Stewart GR, Botella JR. Cloning and characterisation of a glutamate dehydrogenase cDNA from tomato (Lycopersicon esculentum L.). Gene 1997; 186:249-54. [PMID: 9074503 DOI: 10.1016/s0378-1119(96)00716-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A full-length cDNA (legdh1) has been cloned encoding glutamate dehydrogenase (GDH) from tomato (Lycopersicon esculentum L.). legdh1 is 1568 bp long and contains an open reading frame encoding a 44.8 kDa polypeptide with a putative mitochondrial-matrix-targeting pre-sequence at its N-terminus. Southern analysis indicates the existence of one copy of legdh1 per haploid genome, and no closely related genes were detected by Southern analysis at low stringency. We hypothesise that in tomato, the two GDH subunits may arise from post-transcriptional modifications of a single gene. Northern analysis reveals high expression of legdh1 in roots, lower levels of expression in stems, flowers and leaves, and no detectable expression in fruits. In general, there was no correlation between steady-state mRNA level and protein activity in the tissues analysed, again suggesting the importance of post-transcriptional events in the regulation of GDH. Comparison of cloned plant GDH proteins reveals a high degree of homology throughout the sequence except for a very specific, highly divergent region.
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Affiliation(s)
- M P Purnell
- Department of Botany, University of Queensland, Brisbane, Australia
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25
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Lam HM, Coschigano KT, Oliveira IC, Melo-Oliveira R, Coruzzi GM. THE MOLECULAR-GENETICS OF NITROGEN ASSIMILATION INTO AMINO ACIDS IN HIGHER PLANTS. ACTA ACUST UNITED AC 1996; 47:569-593. [PMID: 15012301 DOI: 10.1146/annurev.arplant.47.1.569] [Citation(s) in RCA: 395] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nitrogen assimilation is a vital process controlling plant growth and development. Inorganic nitrogen is assimilated into the amino acids glutamine, glutamate, asparagine, and aspartate, which serve as important nitrogen carriers in plants. The enzymes glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), aspartate aminotransferase (AspAT), and asparagine synthetase (AS) are responsible for the biosynthesis of these nitrogen-carrying amino acids. Biochemical studies have revealed the existence of multiple isoenzymes for each of these enzymes. Recent molecular analyses demonstrate that each enzyme is encoded by a gene family wherein individual members encode distinct isoenzymes that are differentially regulated by environmental stimuli, metabolic control, developmental control, and tissue/cell-type specificity. We review the recent progress in using molecular-genetic approaches to delineate the regulatory mechanisms controlling nitrogen assimilation into amino acids and to define the physiological role of each isoenzyme involved in this metabolic pathway.
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Affiliation(s)
- H.-M. Lam
- Department of Biology, New York University, New York, NY 10003
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26
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Sukanya R, Li MG, Snustad DP. Root- and shoot-specific responses of individual glutamine synthetase genes of maize to nitrate and ammonium. PLANT MOLECULAR BIOLOGY 1994; 26:1935-1946. [PMID: 7858228 DOI: 10.1007/bf00019504] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The responses of the five cytosolic-type glutamine synthetase (GS1) genes of maize to treatment of hydroponically grown seedlings with 10 mM KNO3 or 10 mM NH4Cl were analyzed. Non-coding 3' gene-specific hybridization probes and radioanalytic imaging were used to quantitate individual gene transcript levels in excised roots and shoots before treatment and at selected times after treatment. Genes GS1-1 and GS1-2 exhibited distinct organ-specific responses to treatment with either nitrogen source. The GS1-1 transcript level increased over three-fold in roots, but changed little if any in shoots. In contrast, the GS1-2 transcript level increased over two-fold in shoots, but decreased in roots after treatment. Increased transcript levels were evident at 4 h after treatment with either nitrogen source, with maximum accumulations present at 8 h after treatment with ammonium and at 10-12 h after treatment with nitrate. The GS1-3 gene transcript level showed little or no change after treatment with either nitrogen source. The GS1-4 gene transcript level remained constant in shoots of treated seedlings, whereas in roots, it exhibited relatively minor, but complex responses to these two nitrogen sources. The GS1-5 gene transcript is present in very small amounts in seedlings, making it difficult to analyze its response to metabolites in young plants. These results provide support for the possibility that different cytosolic GS genes of maize play distinct roles in nitrogen metabolism during plant growth and differentiation.
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Affiliation(s)
- R Sukanya
- Department of Genetics & Cell Biology, University of Minnesota, St. Paul 55108-1095
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Li MG, Villemur R, Hussey PJ, Silflow CD, Gantt JS, Snustad DP. Differential expression of six glutamine synthetase genes in Zea mays. PLANT MOLECULAR BIOLOGY 1993; 23:401-7. [PMID: 8106013 DOI: 10.1007/bf00029015] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The maize genome has been shown to contain six glutamine synthetase (GS) genes with at least four different expression patterns. Noncoding 3' gene-specific probes were constructed from all six GS cDNA clones and used to examine transcript levels in selected organs by RNA gel blot hybridization experiments. The transcript of the single putative chloroplastic GS2 gene was found to accumulate primarily in green tissues, whereas the transcripts of the five putative GS1 genes were shown to accumulate preferentially in roots. The specific patterns of transcript accumulation were quite distinct for the five GS1 genes, with the exception of two closely related genes.
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Affiliation(s)
- M G Li
- Department of Genetics and Cell Biology, University of Minnesota, St. Paul 55108-1095
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Control of Metabolism and Development in Higher Plant Plastids. INTERNATIONAL REVIEW OF CYTOLOGY VOLUME 145 1993. [DOI: 10.1016/s0074-7696(08)60427-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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