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Maniero RA, Koltun A, Vitti M, Factor BG, de Setta N, Câmara AS, Lima JE, Figueira A. Identification and functional characterization of the sugarcane ( Saccharum spp.) AMT2-type ammonium transporter ScAMT3;3 revealed a presumed role in shoot ammonium remobilization. FRONTIERS IN PLANT SCIENCE 2023; 14:1299025. [PMID: 38098795 PMCID: PMC10720369 DOI: 10.3389/fpls.2023.1299025] [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: 09/22/2023] [Accepted: 11/13/2023] [Indexed: 12/17/2023]
Abstract
Sugarcane (Saccharum spp.) is an important crop for sugar and bioethanol production worldwide. To maintain and increase sugarcane yields in marginal areas, the use of nitrogen (N) fertilizers is essential, but N overuse may result in the leaching of reactive N to the natural environment. Despite the importance of N in sugarcane production, little is known about the molecular mechanisms involved in N homeostasis in this crop, particularly regarding ammonium (NH4 +), the sugarcane's preferred source of N. Here, using a sugarcane bacterial artificial chromosome (BAC) library and a series of in silico analyses, we identified an AMMONIUM TRANSPORTER (AMT) from the AMT2 subfamily, sugarcane AMMONIUM TRANSPORTER 3;3 (ScAMT3;3), which is constitutively and highly expressed in young and mature leaves. To characterize its biochemical function, we ectopically expressed ScAMT3;3 in heterologous systems (Saccharomyces cerevisiae and Arabidopsis thaliana). The complementation of triple mep mutant yeast demonstrated that ScAMT3;3 is functional for NH3/H+ cotransport at high availability of NH4 + and under physiological pH conditions. The ectopic expression of ScAMT3;3 in the Arabidopsis quadruple AMT knockout mutant restored the transport capacity of 15N-NH4 + in roots and plant growth under specific N availability conditions, confirming the role of ScAMT3;3 in NH4 + transport in planta. Our results indicate that ScAMT3;3 belongs to the low-affinity transport system (Km 270.9 µM; Vmax 209.3 µmol g-1 root DW h-1). We were able to infer that ScAMT3;3 plays a presumed role in NH4 + source-sink remobilization in the shoots via phloem loading. These findings help to shed light on the functionality of a novel AMT2-type protein and provide bases for future research focusing on the improvement of sugarcane yield and N use efficiency.
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Affiliation(s)
- Rodolfo A. Maniero
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Alessandra Koltun
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Marielle Vitti
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Bruna G. Factor
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Nathalia de Setta
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | - Amanda S. Câmara
- Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Joni E. Lima
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Antonio Figueira
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
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Yang C, Huang C, Gou L, Yang H, Liu G. Functional Identification and Genetic Transformation of the Ammonium Transporter PtrAMT1;6 in Populus. Int J Mol Sci 2023; 24:ijms24108511. [PMID: 37239858 DOI: 10.3390/ijms24108511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/18/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
The ammonium transporter (AMT) family gene is an important transporter involved in ammonium uptake and transfer in plants and is mainly engaged in the uptake and transport of ammonium from the environment by roots and the reabsorption of ammonium in the aboveground parts. In this study, the expression pattern, functional identification, and genetic transformation of the PtrAMT1;6 gene, a member of the ammonium transporter protein family in P. trichocarpa, were investigated as follows: (1) Fluorescence quantitative PCR demonstrated that the PtrAMT1;6 gene was preferentially expressed in the leaves, with both dark-induced and light-inhibited expression patterns. (2) A functional restoration assay using the yeast ammonium transporter protein mutant strain indicated that the PtrAMT1;6 gene restored the ability of the mutant to transport ammonium with high affinity. (3) Arabidopsis was transformed with pCAMBIA-PtrAMT1;6P, and the transformed lines were stained with GUS, which showed that the rootstock junction, cotyledon petioles, and the leaf veins and pulp near the petioles of the transformed plants could be stained blue, indicating that the promoter of the PtrAMT1;6 gene had promoter activity. (4) The overexpression of the PtrAMT1;6 gene caused an imbalance in carbon and nitrogen metabolism and reduced nitrogen assimilation ability in '84K' poplar and ultimately reduced biomass. The above results suggest that PtrAMT1;6 may be involved in ammonia recycling during nitrogen metabolism in aboveground parts, and overexpression of PtrAMT1;6 may affect the process of carbon and nitrogen metabolism, as well as nitrogen assimilation in plants, resulting in stunted growth of overexpression plants.
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Affiliation(s)
- Chengjun Yang
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Chunxi Huang
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Luzheng Gou
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Han Yang
- State Key Laboratory of Tree Genetics and Breeding, 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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3
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Koltun A, Maniero RA, Vitti M, de Setta N, Giehl RFH, Lima JE, Figueira A. Functional characterization of the sugarcane ( Saccharum spp.) ammonium transporter AMT2;1 suggests a role in ammonium root-to-shoot translocation. FRONTIERS IN PLANT SCIENCE 2022; 13:1039041. [PMID: 36466275 PMCID: PMC9716016 DOI: 10.3389/fpls.2022.1039041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
AMMONIUM TRANSPORTER/METHYLAMMONIUM PERMEASE/RHESUS (AMT) family members transport ammonium across membranes in all life domains. Plant AMTs can be categorized into AMT1 and AMT2 subfamilies. Functional studies of AMTs, particularly AMT1-type, have been conducted using model plants but little is known about the function of AMTs from crops. Sugarcane (Saccharum spp.) is a major bioenergy crop that requires heavy nitrogen fertilization but depends on a low carbon-footprint for competitive sustainability. Here, we identified and functionally characterized sugarcane ScAMT2;1 by complementing ammonium uptake-defective mutants of Saccharomyces cerevisiae and Arabidopsis thaliana. Reporter gene driven by the ScAMT2;1 promoter in A. thaliana revealed preferential expression in the shoot vasculature and root endodermis/pericycle according to nitrogen availability and source. Arabidopsis quadruple mutant plants expressing ScAMT2;1 driven by the CaMV35S promoter or by a sugarcane endogenous promoter produced significantly more biomass than mutant plants when grown in NH4 + and showed more 15N-ammonium uptake by roots and nitrogen translocation to shoots. In A. thaliana, ScAMT2;1 displayed a Km of 90.17 µM and Vmax of 338.99 µmoles h-1 g-1 root DW. Altogether, our results suggest that ScAMT2;1 is a functional high-affinity ammonium transporter that might contribute to ammonium uptake and presumably to root-to-shoot translocation under high NH4 + conditions.
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Affiliation(s)
- Alessandra Koltun
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Rodolfo A. Maniero
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Marielle Vitti
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Nathalia de Setta
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
- Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Ricardo F. H. Giehl
- Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Joni E. Lima
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Antonio Figueira
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
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4
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Hao DL, Zhou JY, Yang SY, Qi W, Yang KJ, Su YH. Function and Regulation of Ammonium Transporters in Plants. Int J Mol Sci 2020; 21:E3557. [PMID: 32443561 PMCID: PMC7279009 DOI: 10.3390/ijms21103557] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 02/07/2023] Open
Abstract
Ammonium transporter (AMT)-mediated acquisition of ammonium nitrogen from soils is essential for the nitrogen demand of plants, especially for those plants growing in flooded or acidic soils where ammonium is dominant. Recent advances show that AMTs additionally participate in many other physiological processes such as transporting ammonium from symbiotic fungi to plants, transporting ammonium from roots to shoots, transferring ammonium in leaves and reproductive organs, or facilitating resistance to plant diseases via ammonium transport. Besides being a transporter, several AMTs are required for the root development upon ammonium exposure. To avoid the adverse effects of inadequate or excessive intake of ammonium nitrogen on plant growth and development, activities of AMTs are fine-tuned not only at the transcriptional level by the participation of at least four transcription factors, but also at protein level by phosphorylation, pH, endocytosis, and heterotrimerization. Despite these progresses, it is worth noting that stronger growth inhibition, not facilitation, unfortunately occurs when AMT overexpression lines are exposed to optimal or slightly excessive ammonium. This implies that a long road remains towards overcoming potential limiting factors and achieving AMT-facilitated yield increase to accomplish the goal of persistent yield increase under the present high nitrogen input mode in agriculture.
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Affiliation(s)
- Dong-Li Hao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (D.-L.H.); (J.-Y.Z.); (S.-Y.Y.)
| | - Jin-Yan Zhou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (D.-L.H.); (J.-Y.Z.); (S.-Y.Y.)
| | - Shun-Ying Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (D.-L.H.); (J.-Y.Z.); (S.-Y.Y.)
| | - Wei Qi
- College of Resources and Environment, Shandong Agricultural University, Taian 271018, China;
| | - Ke-Jun Yang
- Agro-Tech Extension and Service Center, Zhucheng 262200, China;
| | - Yan-Hua Su
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (D.-L.H.); (J.-Y.Z.); (S.-Y.Y.)
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5
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Dos Santos TB, Soares JDM, Lima JE, Silva JC, Ivamoto ST, Baba VY, Souza SGH, Lorenzetti APR, Paschoal AR, Meda AR, Nishiyama Júnior MY, de Oliveira ÚC, Mokochinski JB, Guyot R, Junqueira-de-Azevedo ILM, Figueira AVO, Mazzafera P, Júnior OR, Vieira LGE, Pereira LFP, Domingues DS. An integrated analysis of mRNA and sRNA transcriptional profiles in Coffea arabica L. roots: insights on nitrogen starvation responses. Funct Integr Genomics 2018; 19:151-169. [PMID: 30196429 DOI: 10.1007/s10142-018-0634-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 08/21/2018] [Accepted: 08/28/2018] [Indexed: 01/09/2023]
Abstract
Coffea arabica L. is an important agricultural commodity, accounting for 60% of traded coffee worldwide. Nitrogen (N) is a macronutrient that is usually limiting to plant yield; however, molecular mechanisms of plant acclimation to N limitation remain largely unknown in tropical woody crops. In this study, we investigated the transcriptome of coffee roots under N starvation, analyzing poly-A+ libraries and small RNAs. We also evaluated the concentration of selected amino acids and N-source preferences in roots. Ammonium was preferentially taken up over nitrate, and asparagine and glutamate were the most abundant amino acids observed in coffee roots. We obtained 34,654 assembled contigs by mRNA sequencing, and validated the transcriptional profile of 12 genes by RT-qPCR. Illumina small RNA sequencing yielded 8,524,332 non-redundant reads, resulting in the identification of 86 microRNA families targeting 253 genes. The transcriptional pattern of eight miRNA families was also validated. To our knowledge, this is the first catalog of differentially regulated amino acids, N sources, mRNAs, and sRNAs in Arabica coffee roots.
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Affiliation(s)
- Tiago Benedito Dos Santos
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil. .,Universidade do Oeste Paulista, Rodovia Raposo Tavares Km 572, Presidente Prudente, 19067-175, Brazil.
| | - João D M Soares
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil
| | - Joni E Lima
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, 13400-970, Brazil.,Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Juliana C Silva
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil.,Programa de pós-graduação em Bioinformática, Universidade Tecnológica Federal do Paraná, Cornélio Procópio, 86300-000, Brazil
| | - Suzana T Ivamoto
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil.,Departamento de Botânica, Instituto de Biociências de Rio Claro, Universidade Estadual Paulista, Rio Claro, 13506-900, Brazil
| | - Viviane Y Baba
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil
| | - Silvia G H Souza
- Laboratório de Biologia Molecular, Universidade Paranaense, Umuarama, 87502-210, Brazil
| | - Alan P R Lorenzetti
- Programa de Pós-graduação em Genética e Biologia Molecular, Universidade Estadual de Londrina, Londrina, 86057-970, Brazil
| | - Alexandre R Paschoal
- Programa de pós-graduação em Bioinformática, Universidade Tecnológica Federal do Paraná, Cornélio Procópio, 86300-000, Brazil
| | - Anderson R Meda
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil
| | | | - Úrsula C de Oliveira
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, 05503-900, Brazil
| | - João B Mokochinski
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, 13083-970, Brazil
| | - Romain Guyot
- IRD, UMR IPME, COFFEEADAPT, BP 64501, 34394, Montpellier Cedex 5, France
| | | | - Antônio V O Figueira
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, 13400-970, Brazil
| | - Paulo Mazzafera
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, 13083-970, Brazil
| | - Osvaldo R Júnior
- Life Sciences Core Facility (LaCTAD), Universidade Estadual de Campinas, Campinas, 13083-886, Brazil
| | - Luiz G E Vieira
- Universidade do Oeste Paulista, Rodovia Raposo Tavares Km 572, Presidente Prudente, 19067-175, Brazil
| | - Luiz F P Pereira
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil.,Embrapa Café, Brasília, 70770-901, Brazil
| | - Douglas S Domingues
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná, Londrina, 86047-902, Brazil.,Departamento de Botânica, Instituto de Biociências de Rio Claro, Universidade Estadual Paulista, Rio Claro, 13506-900, Brazil
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6
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dos Santos TB, Lima JE, Felicio MS, Soares JDM, Domingues DS. Genome-wide identification, classification and transcriptional analysis of nitrate and ammonium transporters in Coffea. Genet Mol Biol 2017; 40:346-359. [PMID: 28399192 PMCID: PMC5452133 DOI: 10.1590/1678-4685-gmb-2016-0041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 02/21/2017] [Indexed: 11/21/2022] Open
Abstract
Nitrogen (N) is quantitatively the main nutrient required by coffee plants, with acquisition mainly by the roots and mostly exported to coffee beans. Nitrate (NO3-) and ammonium (NH4+) are the most important inorganic sources for N uptake. Several N transporters encoded by different gene families mediate the uptake of these compounds. They have an important role in source preference for N uptake in the root system. In this study, we performed a genome-wide analysis, including in silico expression and phylogenetic analyses of AMT1, AMT2, NRT1/PTR, and NRT2 transporters in the recently sequenced Coffea canephora genome. We analyzed the expression of six selected transporters in Coffea arabica roots submitted to N deficiency. N source preference was also analyzed in C. arabica using isotopes. C. canephora N transporters follow the patterns observed for most eudicots, where each member of the AMT and NRT families has a particular role in N mobilization, and where some of these are modulated by N deficiency. Despite the prevalence of putative nitrate transporters in the Coffea genome, ammonium was the preferential inorganic N source for N-starved C. arabica roots. This data provides an important basis for fundamental and applied studies to depict molecular mechanisms involved in N uptake in coffee trees.
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Affiliation(s)
- Tiago Benedito dos Santos
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná,
Londrina, PR, Brazil
- Programa de pós-graduação em Agronomia, Universidade do Oeste
Paulista (UNOESTE), Presidente Prudente, SP, Brazil
| | - Joni Esrom Lima
- Departamento de Botânica, Instituto de Ciências Biológicas,
Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
- Centro de Energia Nuclear na Agricultura (CENA), Escola Superior de
Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Piracicaba.
SP, Brazil
| | - Mariane Silva Felicio
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná,
Londrina, PR, Brazil
| | | | - Douglas Silva Domingues
- Laboratório de Biotecnologia Vegetal, Instituto Agronômico do Paraná,
Londrina, PR, Brazil
- Departamento de Botânica, Instituto de Biociências de Rio Claro,
Universidade Estadual Paulista “Júlio Mesquita Filho” (UNESP), Rio Claro, SP,
Brazil
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7
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van den Berg B, Chembath A, Jefferies D, Basle A, Khalid S, Rutherford JC. Structural basis for Mep2 ammonium transceptor activation by phosphorylation. Nat Commun 2016; 7:11337. [PMID: 27088325 PMCID: PMC4852598 DOI: 10.1038/ncomms11337] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 03/14/2016] [Indexed: 11/18/2022] Open
Abstract
Mep2 proteins are fungal transceptors that play an important role as ammonium sensors in fungal development. Mep2 activity is tightly regulated by phosphorylation, but how this is achieved at the molecular level is not clear. Here we report X-ray crystal structures of the Mep2 orthologues from Saccharomyces cerevisiae and Candida albicans and show that under nitrogen-sufficient conditions the transporters are not phosphorylated and present in closed, inactive conformations. Relative to the open bacterial ammonium transporters, non-phosphorylated Mep2 exhibits shifts in cytoplasmic loops and the C-terminal region (CTR) to occlude the cytoplasmic exit of the channel and to interact with His2 of the twin-His motif. The phosphorylation site in the CTR is solvent accessible and located in a negatively charged pocket ∼30 Å away from the channel exit. The crystal structure of phosphorylation-mimicking Mep2 variants from C. albicans show large conformational changes in a conserved and functionally important region of the CTR. The results allow us to propose a model for regulation of eukaryotic ammonium transport by phosphorylation.
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Affiliation(s)
- Bert van den Berg
- Institute for Cell and Molecular Biosciences, The Medical
School, Newcastle University, Newcastle upon Tyne
NE2 4HH, UK
| | - Anupama Chembath
- Institute for Cell and Molecular Biosciences, The Medical
School, Newcastle University, Newcastle upon Tyne
NE2 4HH, UK
| | - Damien Jefferies
- School of Chemistry, University of Southampton,
Highfield Campus, Southampton
SO17 1BJ, UK
| | - Arnaud Basle
- Institute for Cell and Molecular Biosciences, The Medical
School, Newcastle University, Newcastle upon Tyne
NE2 4HH, UK
| | - Syma Khalid
- School of Chemistry, University of Southampton,
Highfield Campus, Southampton
SO17 1BJ, UK
| | - Julian C. Rutherford
- Institute for Cell and Molecular Biosciences, The Medical
School, Newcastle University, Newcastle upon Tyne
NE2 4HH, UK
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8
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Fontenot EB, Ditusa SF, Kato N, Olivier DM, Dale R, Lin WY, Chiou TJ, Macnaughtan MA, Smith AP. Increased phosphate transport of Arabidopsis thaliana Pht1;1 by site-directed mutagenesis of tyrosine 312 may be attributed to the disruption of homomeric interactions. PLANT, CELL & ENVIRONMENT 2015; 38:2012-22. [PMID: 25754174 DOI: 10.1111/pce.12522] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/06/2015] [Accepted: 02/14/2015] [Indexed: 05/20/2023]
Abstract
Members of the Pht1 family of plant phosphate (Pi) transporters play vital roles in Pi acquisition from soil and in planta Pi translocation to maintain optimal growth and development. The study of the specificities and biochemical properties of Pht1 transporters will contribute to improving the current understanding of plant phosphorus homeostasis and use-efficiency. In this study, we show through split in vivo interaction methods and in vitro analysis of microsomal root tissues that Arabidopsis thaliana Pht1;1 and Pht1;4 form homomeric and heteromeric complexes. Transient and heterologous expression of the Pht1;1 variants, Pht1;1(Y312D), Pht1;1(Y312A) and Pht1;1(Y312F), was used to analyse the role of a putative Pi binding residue (Tyr 312) in Pht1;1 transporter oligomerization and function. The homomeric interaction among Pht1;1 proteins was disrupted by mutation of Tyr 312 to Asp, but not to Ala or Phe. In addition, the Pht1;1(Y312D) variant conferred enhanced Pi transport when expressed in yeast cells. In contrast, mutation of Tyr 312 to Ala or Phe did not affect Pht1;1 transport kinetics. Our study demonstrates that modifications to the Pht1;1 higher-order structure affects Pi transport, suggesting that oligomerization may serve as a regulatory mechanism for modulating Pi uptake.
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Affiliation(s)
- Elena B Fontenot
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Sandra Feuer Ditusa
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Naohiro Kato
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Danielle M Olivier
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Renee Dale
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Wei-Yi Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, China
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, China
| | - Megan A Macnaughtan
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Aaron P Smith
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
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9
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Bao A, Liang Z, Zhao Z, Cai H. Overexpressing of OsAMT1-3, a High Affinity Ammonium Transporter Gene, Modifies Rice Growth and Carbon-Nitrogen Metabolic Status. Int J Mol Sci 2015; 16:9037-63. [PMID: 25915023 PMCID: PMC4463577 DOI: 10.3390/ijms16059037] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 04/11/2015] [Accepted: 04/13/2015] [Indexed: 11/16/2022] Open
Abstract
AMT1-3 encodes the high affinity NH₄⁺ transporter in rice roots and is predominantly expressed under nitrogen starvation. In order to evaluate the effect of AMT1-3 gene on rice growth, nitrogen absorption and metabolism, we generated AMT1-3-overexpressing plants and analyzed the growth phenotype, yield, carbon and nitrogen metabolic status, and gene expression profiles. Although AMT1-3 mRNA accumulated in transgenic plants, these plants displayed significant decreases in growth when compared to the wild-type plants. The nitrogen uptake assay using a 15N tracer revealed poor nitrogen uptake ability in AMT1-3-overexpressing plants. We found significant decreases in AMT1-3-overexpressing plant leaf carbon and nitrogen content accompanied with a higher leaf C/N ratio. Significant changes in soluble proteins and carbohydrates were also observed in AMT1-3-overexpressing plants. In addition, metabolite profile analysis demonstrated significant changes in individual sugars, organic acids and free amino acids. Gene expression analysis revealed distinct expression patterns of genes that participate in carbon and nitrogen metabolism. Additionally, the correlation between the metabolites and gene expression patterns was consistent in AMT1-3-overexpressing plants under both low and high nitrogen growth conditions. Therefore, we hypothesized that the carbon and nitrogen metabolic imbalance caused by AMT1-3 overexpressing attributed to the poor growth and yield of transgenic plants.
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Affiliation(s)
- Aili Bao
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Microelement Research Center, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhijun Liang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Microelement Research Center, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhuqing Zhao
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Microelement Research Center, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
| | - Hongmei Cai
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Microelement Research Center, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
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Wu X, Yang H, Qu C, Xu Z, Li W, Hao B, Yang C, Sun G, Liu G. Sequence and expression analysis of the AMT gene family in poplar. FRONTIERS IN PLANT SCIENCE 2015; 6:337. [PMID: 26052331 PMCID: PMC4440354 DOI: 10.3389/fpls.2015.00337] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 04/29/2015] [Indexed: 05/12/2023]
Abstract
Ammonium transporters (AMTs) are plasma membrane proteins that exclusively transport ammonium/ammonia. These proteins are encoded by an ancient gene family with many members. The molecular characteristics and evolutionary history of AMTs in woody plants are still poorly understood. We comprehensively evaluated the AMT gene family in the latest release of the Populus trichocarpa genome (version 3.0; Phytozome 9.0), and identified 16 AMT genes. These genes formed four clusters; AMT1 (7 genes), AMT2 (2 genes), AMT3 (2 genes), and AMT4 (5 genes). Evolutionary analyses suggested that the Populus AMT gene family has expanded via whole-genome duplication events. Among the 16 AMT genes, 15 genes are located on 11 chromosomes of Populus. Expression analyses showed that 14 AMT genes were vegetative organs expressed; AMT1;1/1;3/1;6/3;2 and AMT1;1/1;2/2;2/3;1 had high transcript accumulation level in the leaves and roots, respectively and strongly changes under the nitrogen-dependent experiments. The results imply the functional roles of AMT genes in ammonium absorption in poplar.
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Affiliation(s)
- Xiangyu Wu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
- Department of Plant Nutrition, College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Han Yang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Chunpu Qu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Zhiru Xu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
- School of Life Science, Northeast Forestry UniversityHarbin, China
| | - Wei Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Bingqing Hao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Chuanping Yang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
| | - Guangyu Sun
- School of Life Science, Northeast Forestry UniversityHarbin, China
- *Correspondence: Guangyu Sun, School of Life Science, Northeast Forestry University, 26 Hexing Road, HarBin 150040, China
| | - Guanjun Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry UniversityHarbin, China
- Guanjun Liu, State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, HarBin 150040, China
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11
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Sanz-Luque E, Ocaña-Calahorro F, Llamas A, Galvan A, Fernandez E. Nitric oxide controls nitrate and ammonium assimilation in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:3373-83. [PMID: 23918969 DOI: 10.1093/jxb/ert175] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nitrate and ammonium are major inorganic nitrogen sources for plants and algae. These compounds are assimilated by means of finely regulated processes at transcriptional and post-translational levels. In Chlamydomonas, the expression of several genes involved in high-affinity ammonium (AMT1.1, AMT1.2) and nitrate transport (NRT2.1) as well as nitrate reduction (NIA1) are downregulated by ammonium through a nitric oxide (NO)-dependent mechanism. At the post-translational level, nitrate/nitrite uptake and nitrate reductase (NR) are also inhibited by ammonium, but the mechanisms implicated in this regulation are scarcely known. In this work, the effect of NO on nitrate assimilation and the high-affinity ammonium uptake was addressed. NO inhibited the high-affinity uptake of ammonium and nitrate/nitrite, as well as the NR activity, in a reversible form. In contrast, nitrite reductase and glutamine synthetase activities were not affected. The in vivo and in vitro studies suggested that NR enzyme is inhibited by NO in a mediated process that requires the cell integrity. These data highlight a role of NO in inorganic nitrogen assimilation and suggest that this signalling molecule is an important regulator for the first steps of the pathway.
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Affiliation(s)
- Emanuel Sanz-Luque
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Campus de Excelencia Agroalimentario CeiA3, Campus de Rabanales, Edificio Severo Ochoa, Córdoba 14071, Spain
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12
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Charzewska A, Nawara M, Jakubiuk-Tomaszuk A, Obersztyn E, Hoffman-Zacharska D, Elert E, Jurek M, Bartnik M, Poznański J, Bal J. Expanding the phenotype associated with missense mutations of the ARX gene. Am J Med Genet A 2013; 161A:1813-6. [PMID: 23657928 DOI: 10.1002/ajmg.a.36003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 04/03/2013] [Indexed: 11/10/2022]
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13
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Signal transfer in the plant plasma membrane: phospholipase A(2) is regulated via an inhibitory Gα protein and a cyclophilin. Biochem J 2013; 450:497-509. [PMID: 23252374 DOI: 10.1042/bj20120793] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The plasma membrane of the California poppy is known to harbour a PLA2 (phospholipase A2) that is associated with the Gα protein which facilitates its activation by a yeast glycoprotein, thereby eliciting the biosynthesis of phytoalexins. To understand the functional architecture of the protein complex, we titrated purified plasma membranes with the Gα protein (native or recombinant) and found that critical amounts of this subunit keep PLA2 in a low-activity state from which it is released either by elicitor plus GTP or by raising the Gα concentration, which probably causes oligomerization of Gα, as supported by FRET (fluorescence resonance energy transfer)-orientated fluorescence imaging and a semiquantitative split-ubiquitin assay. All effects of Gα were blocked by specific antibodies. A low-Gα mutant showed elevated PLA2 activity and lacked the GTP-dependent stimulation by elicitor, but regained this capability after pre-incubation with Gα. The inhibition by Gα and the GTP-dependent stimulation of PLA2 were diminished by inhibitors of peptidylprolyl cis-trans isomerases. A cyclophilin was identified by sequence in the plasma membrane and in immunoprecipitates with anti-Gα antibodies. We conclude that soluble and target-associated Gα interact at the plasma membrane to build complexes of varying architecture and signal amplification. Protein-folding activity is probably required to convey conformational transitions from Gα to its target PLA2.
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Yuan L, Gu R, Xuan Y, Smith-Valle E, Loqué D, Frommer WB, von Wirén N. Allosteric regulation of transport activity by heterotrimerization of Arabidopsis ammonium transporter complexes in vivo. THE PLANT CELL 2013; 25:974-84. [PMID: 23463773 PMCID: PMC3634700 DOI: 10.1105/tpc.112.108027] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Ammonium acquisition by plant roots is mediated by AMMONIUM TRANSPORTERs (AMTs), ubiquitous membrane proteins with essential roles in nitrogen nutrition in all organisms. In microbial and plant cells, ammonium transport activity is controlled by ammonium-triggered feedback inhibition to prevent cellular ammonium toxicity. Data from heterologous expression in yeast indicate that oligomerization of plant AMTs is critical for allosteric regulation of transport activity, in which the conserved cytosolic C terminus functions as a trans-activator. Employing the coexpressed transporters AMT1;1 and AMT1;3 from Arabidopsis thaliana as a model, we show here that these two isoforms form functional homo- and heterotrimers in yeast and plant roots and that AMT1;3 carrying a phosphomimic residue in its C terminus regulates both homo- and heterotrimers in a dominant-negative fashion in vivo. (15)NH4(+) influx studies further indicate that allosteric inhibition represses ammonium transport activity in roots of transgenic Arabidopsis expressing a phosphomimic mutant together with functional AMT1;3 or AMT1;1. Our study demonstrates in planta a regulatory role in transport activity of heterooligomerization of transporter isoforms, which may enhance their versatility for signal exchange in response to environmental triggers.
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Affiliation(s)
- Lixing Yuan
- Department of Plant Nutrition, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Riliang Gu
- Department of Plant Nutrition, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Yuanhu Xuan
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Erika Smith-Valle
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Dominique Loqué
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
- Joint Bioenergy Institute, Emeryville, California 94608
| | - Wolf B. Frommer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Nicolaus von Wirén
- Molecular Plant Nutrition, Leibniz Institute for Plant Genetics and Crop Plant Research, 06466 Gatersleben, Germany
- Address correspondence to
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15
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De Michele R, Loqué D, Lalonde S, Frommer WB. Ammonium and urea transporter inventory of the selaginella and physcomitrella genomes. FRONTIERS IN PLANT SCIENCE 2012; 3:62. [PMID: 22639655 PMCID: PMC3355718 DOI: 10.3389/fpls.2012.00062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 03/14/2012] [Indexed: 05/05/2023]
Abstract
Ammonium and urea are important nitrogen sources for autotrophic organisms. Plant genomes encode several families of specific transporters for these molecules, plus other uptake mechanisms such as aquaporins and ABC transporters. Selaginella and Physcomitrella are representatives of lycophytes and bryophytes, respectively, and the recent completion of their genome sequences provided us with an opportunity for comparative genome studies, with special emphasis on the adaptive processes that accompanied the conquest of dry land and the evolution of a vascular system. Our phylogenetic analysis revealed that the number of genes encoding urea transporters underwent a progressive reduction during evolution, eventually down to a single copy in vascular plants. Conversely, no clear evolutionary pattern was found for ammonium transporters, and their number and distribution in families varies between species. In particular Selaginella, similar to rice, favors the AMT2/MEP family of ammonium transporters over the plant-specific AMT1 type. In comparison, Physcomitrella presents several members belonging to both families.
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Affiliation(s)
- Roberto De Michele
- Department of Plant Biology, Carnegie Institution for ScienceStanford, CA, USA
- Plant Genetics Institute, National Research Council of ItalyPalermo, Italy
| | | | - Sylvie Lalonde
- Department of Plant Biology, Carnegie Institution for ScienceStanford, CA, USA
| | - Wolf B. Frommer
- Department of Plant Biology, Carnegie Institution for ScienceStanford, CA, USA
- *Correspondence: Wolf B. Frommer, Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA. e-mail:
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