1
|
Yang Z, Zhang X, Ye S, Zheng J, Huang X, Yu F, Chen Z, Cai S, Zhang P. Molecular mechanism underlying regulation of Arabidopsis CLCa transporter by nucleotides and phospholipids. Nat Commun 2023; 14:4879. [PMID: 37573431 PMCID: PMC10423218 DOI: 10.1038/s41467-023-40624-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
Chloride channels (CLCs) transport anion across membrane to regulate ion homeostasis and acidification of intracellular organelles, and are divided into anion channels and anion/proton antiporters. Arabidopsis thaliana CLCa (AtCLCa) transporter localizes to the tonoplast which imports NO3- and to a less extent Cl- from cytoplasm. The activity of AtCLCa and many other CLCs is regulated by nucleotides and phospholipids, however, the molecular mechanism remains unclear. Here we determine the cryo-EM structures of AtCLCa bound with NO3- and Cl-, respectively. Both structures are captured in ATP and PI(4,5)P2 bound conformation. Structural and electrophysiological analyses reveal a previously unidentified N-terminal β-hairpin that is stabilized by ATP binding to block the anion transport pathway, thereby inhibiting the AtCLCa activity. While AMP loses the inhibition capacity due to lack of the β/γ- phosphates required for β-hairpin stabilization. This well explains how AtCLCa senses the ATP/AMP status to regulate the physiological nitrogen-carbon balance. Our data further show that PI(4,5)P2 or PI(3,5)P2 binds to the AtCLCa dimer interface and occupies the proton-exit pathway, which may help to understand the inhibition of AtCLCa by phospholipids to facilitate guard cell vacuole acidification and stomatal closure. In a word, our work suggests the regulatory mechanism of AtCLCa by nucleotides and phospholipids under certain physiological scenarios and provides new insights for future study of CLCs.
Collapse
Affiliation(s)
- Zhao Yang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Xue Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Shiwei Ye
- University of Chinese Academy of Sciences, Beijing, 100039, China
- Center for Excellence in Brain Sciences and Intelligence Technology, Institute of Neuronscience, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jingtao Zheng
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiaowei Huang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Fang Yu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Zhenguo Chen
- The Fifth People's Hospital of Shanghai, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
| | - Shiqing Cai
- Center for Excellence in Brain Sciences and Intelligence Technology, Institute of Neuronscience, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
| |
Collapse
|
2
|
Yin P, Liang X, Zhao H, Xu Z, Chen L, Yang X, Qin F, Zhang J, Jiang C. Cytokinin signaling promotes salt tolerance by modulating shoot chloride exclusion in maize. MOLECULAR PLANT 2023:S1674-2052(23)00109-0. [PMID: 37101396 DOI: 10.1016/j.molp.2023.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 03/18/2023] [Accepted: 04/23/2023] [Indexed: 05/26/2023]
Abstract
Excessive accumulation of chloride (Cl-) in the aboveground tissues under saline conditions is harmful to crops. Increasing the exclusion of Cl- from shoots promotes salt tolerance in various crops. However, the underlying molecular mechanisms remain largely unknown. In this study, we demonstrated that a type A response regulator (ZmRR1) modulates Cl- exclusion from shoots and underlies natural variation of salt tolerance in maize. ZmRR1 negatively regulates cytokinin signaling and salt tolerance, likely by interacting with and inhibiting His phosphotransfer (HP) proteins that are key mediators of cytokinin signaling. A naturally occurring non-synonymous SNP variant enhances the interaction between ZmRR1 and ZmHP2, conferring maize plants with a salt-hypersensitive phenotype. We found that ZmRR1 undergoes degradation under saline conditions, leading to the release of ZmHP2 from ZmRR1 inhibition, and subsequently ZmHP2-mediated signaling improves salt tolerance primarily by promoting Cl- exclusion from shoots. Furthermore, we showed that ZmMATE29 is transcriptionally upregulated by ZmHP2-mediated signaling under highly saline conditions and encodes a tonoplast-located Cl- transporter that promotes Cl- exclusion from shoots by compartmentalizing Cl- into the vacuoles of root cortex cells. Collectively, our study provides an important mechanistic understanding of the cytokinin signaling-mediated promotion of Cl- exclusion from shoots and salt tolerance and suggests that genetic modification to promote Cl- exclusion from shoots is a promising route for developing salt-tolerant maize.
Collapse
Affiliation(s)
- Pan Yin
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China
| | - Xiaoyan Liang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China
| | - Hanshu Zhao
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing 100193, China
| | - Zhipeng Xu
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China
| | - Limei Chen
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100094, China
| | - Xiaohong Yang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100094, China; Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China
| | - Feng Qin
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China
| | - Jingbo Zhang
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing 100193, China.
| | - Caifu Jiang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100094, China; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100094, China; Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China; Outstanding Discipline Program for the Universities in Beijing, Beijing 100094, China.
| |
Collapse
|
3
|
Nedelyaeva OI, Popova LG, Khramov DE, Volkov VS, Balnokin YV. Chloride Channel Family in the Euhalophyte Suaeda altissima (L.) Pall: Cloning of Novel Members SaCLCa2 and SaCLCc2, General Characterization of the Family. Int J Mol Sci 2023; 24:ijms24020941. [PMID: 36674457 PMCID: PMC9867446 DOI: 10.3390/ijms24020941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/30/2022] [Accepted: 01/01/2023] [Indexed: 01/06/2023] Open
Abstract
CLC family genes, comprising anion channels and anion/H+ antiporters, are widely represented in nearly all prokaryotes and eukaryotes. CLC proteins carry out a plethora of functions at the cellular level. Here the coding sequences of the SaCLCa2 and SaCLCc2 genes, homologous to Arabidopsis thaliana CLCa and CLCc, were cloned from the euhalophyte Suaeda altissima (L.) Pall. Both the genes cloned belong to the CLC family as supported by the presence of the key conserved motifs and glutamates inherent for CLC proteins. SaCLCa2 and SaCLCc2 were heterologously expressed in Saccharomyces cerevisiae GEF1 disrupted strain, Δgef1, where GEF1 encodes the only CLC family protein, the Cl− transporter Gef1p, in undisrupted strains of yeast. The Δgef1 strain is characterized by inability to grow on YPD yeast medium containing Mn2+ ions. Expression of SaCLCa2 in Δgef1 cells growing on this medium did not rescue the growth defect phenotype of the mutant. However, a partial growth restoration occurred when the Δgef1 strain was transformed by SaCLCa2(C544T), the gene encoding protein in which proline, specific for nitrate, was replaced with serine, specific for chloride, in the selectivity filter. Unlike SaCLCa2, expression of SaCLCc2 in Δgef1 resulted in a partial growth restoration under these conditions. Analysis of SaCLCa2 and SaCLCc2 expression in the euhalophyte Suaeda altissima (L.) Pall by quantitative real-time PCR (qRT-PCR) under different growth conditions demonstrated stimulation of SaCLCa2 expression by nitrate and stimulation of SaCLCc2 expression by chloride. The results of yeast complementation assay, the presence of both the “gating” and “proton” glutamates in aa sequences of both the proteins, as well results of the gene expression in euhalophyte Suaeda altissima (L.) Pall suggest that SaCLCa2 and SaCLCc2 function as anion/H+ antiporters with nitrate and chloride specificities, respectively. The general bioinformatic overview of seven CLC genes cloned from euhalophyte Suaeda altissima is given, together with results on their expression in roots and leaves under different levels of salinity.
Collapse
|
4
|
Hodin J, Lind C, Marmagne A, Espagne C, Bianchi MW, De Angeli A, Abou-Choucha F, Bourge M, Chardon F, Thomine S, Filleur S. Proton exchange by the vacuolar nitrate transporter CLCa is required for plant growth and nitrogen use efficiency. THE PLANT CELL 2023; 35:318-335. [PMID: 36409008 PMCID: PMC9806559 DOI: 10.1093/plcell/koac325] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
Nitrate is a major nutrient and osmoticum for plants. To deal with fluctuating nitrate availability in soils, plants store this nutrient in their vacuoles. Chloride channel a (CLCa), a 2NO3-/1H+ exchanger localized to the vacuole in Arabidopsis (Arabidopsis thaliana), ensures this storage process. CLCa belongs to the CLC family, which includes anion/proton exchangers and anion channels. A mutation in a glutamate residue conserved across CLC exchangers is likely responsible for the conversion of exchangers to channels. Here, we show that CLCa with a mutation in glutamate 203 (E203) behaves as an anion channel in its native membrane. We introduced the CLCaE203A point mutation to investigate its physiological importance into the Arabidopsis clca knockout mutant. These CLCaE203A mutants displayed a growth deficit linked to the disruption of water homeostasis. Additionally, CLCaE203A expression failed to complement the defect in nitrate accumulation of clca and favored higher N-assimilation at the vegetative stage. Further analyses at the post-flowering stages indicated that CLCaE203A expression results in an increase in N uptake allocation to seeds, leading to a higher nitrogen use efficiency compared to the wild-type. Altogether, these results point to the critical function of the CLCa exchanger on the vacuole for plant metabolism and development.
Collapse
Affiliation(s)
- Julie Hodin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
- UFR Sciences du Vivant, Université Paris Cité, F-75205 Paris Cedex 13, France
| | - Christof Lind
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Anne Marmagne
- AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, INRAE, 78000 Versailles, France
| | - Christelle Espagne
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Michele Wolfe Bianchi
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
- Université Paris-Est-Créteil-Val-de-Marne, 94010 Creteil Cedex, France
| | - Alexis De Angeli
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Fadi Abou-Choucha
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Mickaël Bourge
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Fabien Chardon
- AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, INRAE, 78000 Versailles, France
| | - Sebastien Thomine
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Sophie Filleur
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
- UFR Sciences du Vivant, Université Paris Cité, F-75205 Paris Cedex 13, France
| |
Collapse
|
5
|
Cryo-EM structure of the plant nitrate transporter AtCLCa reveals characteristics of the anion-binding site and the ATP-binding pocket. J Biol Chem 2022; 299:102833. [PMID: 36581207 PMCID: PMC9898749 DOI: 10.1016/j.jbc.2022.102833] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/27/2022] Open
Abstract
Nitrate is one of the major nitrogen sources for most plants. Chloride channel (CLC) proteins mediate the transport and vacuole storage of nitrate in plants, but the structural basis of nitrate transport by plant CLC proteins remains unknown. Here, we solved the cryo-EM structure of ATP-bound Arabidopsis thaliana CLCa (AtCLCa) at 2.8 Å resolution. Structural comparison between nitrate-selective AtCLCa and chloride-selective CLC-7 reveals key differences in the central anion-binding site. We observed that the central nitrate is shifted by ∼1.4 Å from chloride, which is likely caused by a weaker interaction between the anion and Pro160; the side chains of aromatic residues around the central binding site are rearranged to accommodate the larger nitrate. Additionally, we identified the ATP-binding pocket of AtCLCa to be located between the cytosolic cystathionine β-synthase domains and the N-terminus. The N-terminus may mediate the ATP inhibition of AtCLCa by interacting with both ATP and the pore-forming transmembrane helix. Together, our studies provide insights into the nitrate selectivity and ATP regulation of plant CLCs.
Collapse
|
6
|
The mechanisms of chromogranin B-regulated Cl- homeostasis. Biochem Soc Trans 2022; 50:1659-1672. [PMID: 36511243 DOI: 10.1042/bst20220435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022]
Abstract
Chloride is the most abundant inorganic anions in almost all cells and in human circulation systems. Its homeostasis is therefore important for systems physiology and normal cellular activities. This topic has been extensively studied with chloride loaders and extruders expressed in both cell surfaces and intracellular membranes. With the newly discovered, large-conductance, highly selective Cl- channel formed by membrane-bound chromogranin B (CHGB), which differs from all other known anion channels of conventional transmembrane topology, and is distributed in plasma membranes, endomembrane systems, endosomal, and endolysosomal compartments in cells expressing it, we will discuss the potential physiological importance of the CHGB channels to Cl- homeostasis, cellular excitability and volume control, and cation uptake or release at the cellular and subcellular levels. These considerations and CHGB's association with human diseases make the CHGB channel a possible druggable target for future molecular therapeutics.
Collapse
|
7
|
Leisle L, Lam K, Dehghani-Ghahnaviyeh S, Fortea E, Galpin JD, Ahern CA, Tajkhorshid E, Accardi A. Backbone amides are determinants of Cl - selectivity in CLC ion channels. Nat Commun 2022; 13:7508. [PMID: 36473856 PMCID: PMC9726985 DOI: 10.1038/s41467-022-35279-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022] Open
Abstract
Chloride homeostasis is regulated in all cellular compartments. CLC-type channels selectively transport Cl- across biological membranes. It is proposed that side-chains of pore-lining residues determine Cl- selectivity in CLC-type channels, but their spatial orientation and contributions to selectivity are not conserved. This suggests a possible role for mainchain amides in selectivity. We use nonsense suppression to insert α-hydroxy acids at pore-lining positions in two CLC-type channels, CLC-0 and bCLC-k, thus exchanging peptide-bond amides with ester-bond oxygens which are incapable of hydrogen-bonding. Backbone substitutions functionally degrade inter-anion discrimination in a site-specific manner. The presence of a pore-occupying glutamate side chain modulates these effects. Molecular dynamics simulations show backbone amides determine ion energetics within the bCLC-k pore and how insertion of an α-hydroxy acid alters selectivity. We propose that backbone-ion interactions are determinants of Cl- specificity in CLC channels in a mechanism reminiscent of that described for K+ channels.
Collapse
Affiliation(s)
- Lilia Leisle
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
| | - Kin Lam
- Theoretical and Computational Biophysics Group, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- NIH Center for Macromolecular Modeling and Bioinformatics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Sepehr Dehghani-Ghahnaviyeh
- Theoretical and Computational Biophysics Group, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- NIH Center for Macromolecular Modeling and Bioinformatics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Eva Fortea
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
| | - Jason D Galpin
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- NIH Center for Macromolecular Modeling and Bioinformatics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA.
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA.
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, USA.
| |
Collapse
|
8
|
Carillo P, Rouphael Y. Nitrate Uptake and Use Efficiency: Pros and Cons of Chloride Interference in the Vegetable Crops. FRONTIERS IN PLANT SCIENCE 2022; 13:899522. [PMID: 35783949 PMCID: PMC9244799 DOI: 10.3389/fpls.2022.899522] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/20/2022] [Indexed: 05/29/2023]
Abstract
Over the past five decades, nitrogen (N) fertilization has been an essential tool for boosting crop productivity in agricultural systems. To avoid N pollution while preserving the crop yields and profit margins for farmers, the scientific community is searching for eco-sustainable strategies aimed at increasing plants' nitrogen use efficiency (NUE). The present article provides a refined definition of the NUE based on the two important physiological factors (N-uptake and N-utilization efficiency). The diverse molecular and physiological mechanisms underlying the processes of N assimilation, translocation, transport, accumulation, and reallocation are revisited and critically discussed. The review concludes by examining the N uptake and NUE in tandem with chloride stress and eustress, the latter being a new approach toward enhancing productivity and functional quality of the horticultural crops, particularly facilitated by soilless cultivation.
Collapse
Affiliation(s)
- Petronia Carillo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Youssef Rouphael
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy
| |
Collapse
|
9
|
Nedelyaeva OI, Popova LG, Volkov VS, Balnokin YV. Molecular Cloning and Characterization of SaCLCd, SaCLCf, and SaCLCg, Novel Proteins of the Chloride Channel Family (CLC) from the Halophyte Suaeda altissima (L.) Pall. PLANTS (BASEL, SWITZERLAND) 2022; 11:409. [PMID: 35161390 PMCID: PMC8839641 DOI: 10.3390/plants11030409] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/28/2022] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Coding sequences of the CLC family genes SaCLCd, SaCLCf, and SaCLCg, the putative orthologs of Arabidopsis thaliana AtCLCd, AtCLCf, and AtCLCg genes, were cloned from the euhalophyte Suaeda altissima (L.) Pall. The key conserved motifs and glutamates inherent in proteins of the CLC family were identified in SaCLCd, SaCLCf, and SaCLCg amino acid sequences. SaCLCd and SaCLCg were characterized by higher homology to eukaryotic (human) CLCs, while SaCLCf was closer to prokaryotic CLCs. Ion specificities of the SaCLC proteins were studied in complementation assays by heterologous expression of the SaCLC genes in the Saccharomyces cerevisiae GEF1 disrupted strain Δgef1. GEF1 encoded the only CLC family protein, the Cl- transporter Gef1p, in undisrupted strains of this organism. Expression of SaCLCd in Δgef1 cells restored their ability to grow on selective media. The complementation test and the presence of both the "gating" and "proton" conservative glutamates in SaCLCd amino acid sequence and serine specific for Cl- in its selectivity filter suggest that this protein operates as a Cl-/H+ antiporter. By contrast, expression of SaCLCf and SaCLCg did not complement the growth defect phenotype of Δgef1 cells. The selectivity filters of SaCLCf and SaCLCg also contained serine. However, SaCLCf included only the "gating" glutamate, while SaCLCg contained the "proton" glutamate, suggesting that SaCLCf and SaCLCg proteins act as Cl- channels. The SaCLCd, SaCLCf, and SaCLCg genes were shown to be expressed in the roots and leaves of S. altissima. In response to addition of NaCl to the growth medium, the relative transcript abundances of all three genes of S. altissima increased in the leaves but did not change significantly in the roots. The increase in expression of SaCLCd, SaCLCf, and SaCLCg in the leaves in response to increasing salinity was in line with Cl- accumulation in the leaf cells, indicating the possible participation of SaCLCd, SaCLCf, and SaCLCg proteins in Cl- sequestration in cell organelles. Generally, these results suggest the involvement of SaCLC proteins in the response of S. altissima plants to increasing salinity and possible participation in mechanisms underlying salt tolerance.
Collapse
|
10
|
Scholl S, Hillmer S, Krebs M, Schumacher K. ClCd and ClCf act redundantly at the trans-Golgi network/early endosome and prevent acidification of the Golgi stack. J Cell Sci 2021; 134:272608. [PMID: 34528690 DOI: 10.1242/jcs.258807] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 09/13/2021] [Indexed: 12/20/2022] Open
Abstract
The trans-Golgi network/early endosome (TGN/EE) serves as the central hub in which exocytic and endocytic trafficking pathways converge and specificity of cargo routing needs to be achieved. Acidification is a hallmark of the TGN/EE and is maintained by the vacuolar H+-ATPase (V-ATPase) with support of proton-coupled antiporters. We show here that ClCd and ClCf, two distantly related members of the Arabidopsis Cl- channel (ClC) family, colocalize in the TGN/EE, where they act redundantly, and are essential for male gametophyte development. Combining an inducible knockdown approach and in vivo pH measurements, we show here that reduced ClC activity does not affect pH in the TGN/EE but causes hyperacidification of trans-Golgi cisternae. Taken together, our results show that ClC-mediated anion transport into the TGN/EE is essential and affects spatiotemporal aspects of TGN/EE maturation as well as its functional separation from the Golgi stack.
Collapse
Affiliation(s)
- Stefan Scholl
- Department of Cell Biology, Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Stefan Hillmer
- Electron Microscopy Core Facility, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
| | - Melanie Krebs
- Department of Cell Biology, Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Karin Schumacher
- Department of Cell Biology, Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| |
Collapse
|
11
|
Subba A, Tomar S, Pareek A, Singla-Pareek SL. The chloride channels: Silently serving the plants. PHYSIOLOGIA PLANTARUM 2021; 171:688-702. [PMID: 33034380 DOI: 10.1111/ppl.13240] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 05/12/2023]
Abstract
Chloride channels (CLCs), member of anion transporting proteins, are present ubiquitously in all life forms. Diverging from its name, the CLC family includes both channel and exchanger (proton-coupled) proteins; nevertheless, they share conserved structural organization. They are engaged in diverse indispensable functions such as acid and fluoride tolerance in prokaryotes to muscle stabilization, transepithelial transport, and neuronal development in mammals. Mutations in genes encoding CLCs lead to several physiological disorders in different organisms, including severe diseases in humans. Even in plants, loss of CLC protein function severely impairs various cellular processes critical for normal growth and development. These proteins sequester Cl- into the vacuole, thus, making them an attractive target for improving salinity tolerance in plants caused by high abundance of salts, primarily NaCl. Besides, some CLCs are involved in NO3 - transport and storage function in plants, thus, influencing their nitrogen use efficiency. However, despite their high significance, not many studies have been carried out in plants. Here, we have attempted to concisely highlight the basic structure of CLC proteins and critical residues essential for their function and classification. We also present the diverse functions of CLCs in plants from their first cloning back in 1996 to the knowledge acquired as of now. We stress the need for carrying out more in-depth studies on CLCs in plants, for they may have future applications towards crop improvement.
Collapse
Affiliation(s)
- Ashish Subba
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Surabhi Tomar
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sneh L Singla-Pareek
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| |
Collapse
|
12
|
Miranda-Apodaca J, Agirresarobe A, Martínez-Goñi XS, Yoldi-Achalandabaso A, Pérez-López U. N metabolism performance in Chenopodium quinoa subjected to drought or salt stress conditions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 155:725-734. [PMID: 32862022 DOI: 10.1016/j.plaphy.2020.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/01/2020] [Accepted: 08/03/2020] [Indexed: 05/23/2023]
Abstract
Currently it is estimated that the 20% of total cultivated land is affected by salt. Besides, drought events will increase worldwide. These factors are affecting plant growth and crop production compromising food security. Within this context, quinoa (Chenopodium quinoa) is becoming an alternative pseudocereal for food supply due to its capacity to grow under harsh environmental conditions. Besides, it is being proposed as key model species to study the physiological processes that permit this tolerance, although how N metabolism responds has been barely studied. This paper addresses, on one hand, the response of quinoa's N metabolism (N uptake, translocation, reduction and assimilation) under the forthcoming climatic conditions and, on the other hand, the comparison of the effects of both stresses when plants have similar relative water content and photosynthetic rates. Under mild salt stress (120 and 240 mM NaCl) N assimilation is not affected, while the N uptake is favored. Under severe salt stress (500 mM NaCl), N uptake is reduced, decreasing leaf nitrate and protein concentration; nevertheless, leaf free amino acids are maintained -to perform osmotic adjustment-. N uptake rate is more affected under drought than under severe salt; furthermore, under severe salt stress, quinoa allocates more nitrogen to roots to finely regulate NO3- and Cl- uptake, while under drought it allocates more to leaves to ensure photosynthesis. These results indicate that quinoa's N metabolism is tolerant to drought and salt stress, although the strategies of this species for coping with the aforementioned stresses are different.
Collapse
Affiliation(s)
- J Miranda-Apodaca
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Apdo. 644, E-48080, Bilbao, Spain.
| | - A Agirresarobe
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Apdo. 644, E-48080, Bilbao, Spain.
| | - X S Martínez-Goñi
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Apdo. 644, E-48080, Bilbao, Spain.
| | - A Yoldi-Achalandabaso
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Apdo. 644, E-48080, Bilbao, Spain.
| | - U Pérez-López
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Apdo. 644, E-48080, Bilbao, Spain.
| |
Collapse
|
13
|
Dynamic measurement of cytosolic pH and [NO 3 -] uncovers the role of the vacuolar transporter AtCLCa in cytosolic pH homeostasis. Proc Natl Acad Sci U S A 2020; 117:15343-15353. [PMID: 32546525 PMCID: PMC7334523 DOI: 10.1073/pnas.2007580117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ion transporters are key players of cellular processes. The mechanistic properties of ion transporters have been well elucidated by biophysical methods. Meanwhile, the understanding of their exact functions in cellular homeostasis is limited by the difficulty of monitoring their activity in vivo. The development of biosensors to track subtle changes in intracellular parameters provides invaluable tools to tackle this challenging issue. AtCLCa (Arabidopsis thaliana Chloride Channel a) is a vacuolar NO3 -/H+ exchanger regulating stomata aperture in A thaliana Here, we used a genetically encoded biosensor, ClopHensor, reporting the dynamics of cytosolic anion concentration and pH to monitor the activity of AtCLCa in vivo in Arabidopsis guard cells. We first found that ClopHensor is not only a Cl- but also, an NO3 - sensor. We were then able to quantify the variations of NO3 - and pH in the cytosol. Our data showed that AtCLCa activity modifies cytosolic pH and NO3 - In an AtCLCa loss of function mutant, the cytosolic acidification triggered by extracellular NO3 - and the recovery of pH upon treatment with fusicoccin (a fungal toxin that activates the plasma membrane proton pump) are impaired, demonstrating that the transport activity of this vacuolar exchanger has a profound impact on cytosolic homeostasis. This opens a perspective on the function of intracellular transporters of the Chloride Channel (CLC) family in eukaryotes: not only controlling the intraorganelle lumen but also, actively modifying cytosolic conditions.
Collapse
|
14
|
Fuertes-Mendizábal T, Bastías EI, González-Murua C, González-Moro MB. Nitrogen Assimilation in the Highly Salt- and Boron-Tolerant Ecotype Zea mays L. Amylacea. PLANTS (BASEL, SWITZERLAND) 2020; 9:E322. [PMID: 32143321 PMCID: PMC7154838 DOI: 10.3390/plants9030322] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/24/2020] [Accepted: 02/27/2020] [Indexed: 01/14/2023]
Abstract
The Lluta Valley in Northern Chile is an important agricultural area affected by both salinity and boron (B) toxicity. Zea mays L. amylacea, an ecotype arisen because of the seed selection practiced in this valley, shows a high tolerance to salt and B levels. In the present study the interaction between B and salt was studied after 20 days of treatment at low (100 mM) and high salinity (430 mM NaCl), assessing changes in nitrogen metabolites and in the activity of key nitrogen-assimilating enzymes. Under non-saline conditions, the presence of excessive B favored higher nitrate and ammonium mobilization to leaves, increasing nitrate reductase (NR) activity but not glutamine synthetase (GS). Thus, the increment of nitrogen use efficiency by B application would contribute partially to maintain the biomass production in this ecotype. Positive relationships between NR activity, nitrate, and stomatal conductance were observed in leaves. The increment of major amino acids alanine and serine would indicate a photoprotective role of photorespiration under low-salinity conditions, thus the inhibition of nitrogen assimilation pathway (NR and GS activities) occurred only at high salinity. The role of cytosolic GS regarding the proline accumulation is discussed.
Collapse
Affiliation(s)
- Teresa Fuertes-Mendizábal
- Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain; (T.F.-M.); (C.G.-M.)
| | - Elizabeth Irica Bastías
- Departamento de Producción Agrícola, Facultad de Ciencias Agronómicas, Universidad de Tarapacá, Arica 1000000, Chile;
| | - Carmen González-Murua
- Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain; (T.F.-M.); (C.G.-M.)
| | - Mª Begoña González-Moro
- Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain; (T.F.-M.); (C.G.-M.)
| |
Collapse
|
15
|
Xing A, Ma Y, Wu Z, Nong S, Zhu J, Sun H, Tao J, Wen B, Zhu X, Fang W, Li X, Wang Y. Genome-wide identification and expression analysis of the CLC superfamily genes in tea plants (Camellia sinensis). Funct Integr Genomics 2020; 20:497-508. [PMID: 31897824 DOI: 10.1007/s10142-019-00725-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/17/2019] [Accepted: 11/05/2019] [Indexed: 11/30/2022]
Abstract
The voltage-gated chloride channel (CLC) superfamily is one of the most important anion channels that is widely distributed in bacteria and plants. CLC is involved in transporting various anions such as chloride (Cl-) and fluoride (F-) in and out of cells. Although Camellia sinensis is a hyper-accumulated F plant, there is no studies on the CLC gene superfamily in the tea plant. Here, 8 CLC genes were identified from C. sinensis and they were named CsCLC1-8. The structure of CsCLC genes and the proteins were not conserved; the number of exons varied from 3 to 24, and the number of transmembrane domains contained 2 to 10. Furthermore, phylogenetic analysis revealed that CsCLC4-8 in subclass I contained the typical conserved domains GxGIPE (I), GKxGPxxH (II) and PxxGxLF (III), and CsCLC1-3 in subclass II did not contain any of the three conserved residues. We measured the expression levels of CsCLCs in roots, stems and leaves to assess the responses to different concentrations of Cl- and F-. The result indicated that CsCLCs participated in subfunctionalization in response to Cl- and F-, and CsCLC1-3 was more sensitive to F- treatments than CsCLC4-8, CsCLC6 and CsCLC7 may participate in absorption and long-distance transport of Cl-.
Collapse
Affiliation(s)
- Anqi Xing
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuanchun Ma
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zichen Wu
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shouhua Nong
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiaojiao Zhu
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hua Sun
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jing Tao
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bo Wen
- College of Landscape Architecture, Nanjing Forestry University, Nanjing, 210037, China
| | - Xujun Zhu
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wanping Fang
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaocheng Li
- Jiaozhou Vocational Education Center School, Qingdao, 266300, China
| | - Yuhua Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
16
|
David R, Byrt CS, Tyerman SD, Gilliham M, Wege S. Roles of membrane transporters: connecting the dots from sequence to phenotype. ANNALS OF BOTANY 2019; 124:201-208. [PMID: 31162525 PMCID: PMC6758574 DOI: 10.1093/aob/mcz066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 05/06/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND Plant membrane transporters are involved in diverse cellular processes underpinning plant physiology, such as nutrient acquisition, hormone movement, resource allocation, exclusion or sequestration of various solutes from cells and tissues, and environmental and developmental signalling. A comprehensive characterization of transporter function is therefore key to understanding and improving plant performance. SCOPE AND CONCLUSIONS In this review, we focus on the complexities involved in characterizing transporter function and the impact that this has on current genomic annotations. Specific examples are provided that demonstrate why sequence homology alone cannot be relied upon to annotate and classify transporter function, and to show how even single amino acid residue variations can influence transporter activity and specificity. Misleading nomenclature of transporters is often a source of confusion in transporter characterization, especially for people new to or outside the field. Here, to aid researchers dealing with interpretation of large data sets that include transporter proteins, we provide examples of transporters that have been assigned names that misrepresent their cellular functions. Finally, we discuss the challenges in connecting transporter function at the molecular level with physiological data, and propose a solution through the creation of new databases. Further fundamental in-depth research on specific transport (and other) proteins is still required; without it, significant deficiencies in large-scale data sets and systems biology approaches will persist. Reliable characterization of transporter function requires integration of data at multiple levels, from amino acid residue sequence annotation to more in-depth biochemical, structural and physiological studies.
Collapse
Affiliation(s)
- Rakesh David
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, Australia
| | - Caitlin S Byrt
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Stephen D Tyerman
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, Australia
| | - Matthew Gilliham
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, Australia
| | - Stefanie Wege
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, Australia
- For correspondence. E-mail
| |
Collapse
|
17
|
Nedelyaeva OI, Shuvalov AV, Karpichev IV, Beliaev DV, Myasoedov NA, Khalilova LA, Khramov DE, Popova LG, Balnokin YV. Molecular cloning and characterisation of SaCLCa1, a novel protein of the chloride channel (CLC) family from the halophyte Suaeda altissima (L.) Pall. JOURNAL OF PLANT PHYSIOLOGY 2019; 240:152995. [PMID: 31252320 DOI: 10.1016/j.jplph.2019.152995] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/07/2019] [Accepted: 06/07/2019] [Indexed: 06/09/2023]
Abstract
The SaCLCa1 gene, a putative orthologue of AtCLCa, the Arabidopsis thaliana gene encoding a NO3-/H+ antiporter, was cloned from the halophyte Suaeda altissima. It belonged to the CLC family, comprising anionic channels and anion/H+ antiporters. SaCLCa1 ion specificity was studied by heterologous expression of this gene in Saccharomyces cerevisiae GEF1 disrupted strain, Δgef1, where GEF1 encoded the only CLC family protein, the Cl- transporter Gef1p, in undisrupted strains of this organism. For comparison, the function of another recently identified S. altissima CLC family gene, SaCLCc1, was also characterised. Expression of SaCLCc1 in Δgef1 cells restored their ability to grow on selective media. This supported the chloride specificity of this transporter. By contrast, expression of SaCLCa1 did not complement the growth defect phenotype of Δgef1 cells. However, growth of the Δgef1 mutant on the selective media was partially restored when it was transformed with SaCLCa1(C562 T), encoding the modified protein SaCLCa1(P188S), in which proline responsible for NO3- selectivity in selective filter was replaced by serine providing chloride selectivity. Quantitative real-time polymerase chain reactions (qRT-PCR) showed that significant induction of SaCLCa1 occurred in the roots of S. altissima when plants were grown on nitrate-deficient medium, while SaCLCc1 activation was observed in S. altissima leaves of plants grown in increasing Cl- concentrations of nutrient solution. These results suggested that SaCLCa1 and SaCLCc1 function as anionic transporters with nitrate and chloride specificities, respectively.
Collapse
Affiliation(s)
- O I Nedelyaeva
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - A V Shuvalov
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - I V Karpichev
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - D V Beliaev
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - N A Myasoedov
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - L A Khalilova
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - D E Khramov
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - L G Popova
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| | - Y V Balnokin
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 127276, Moscow, Botanicheskaya str., 35, Russia.
| |
Collapse
|
18
|
Omeprazole Promotes Chloride Exclusion and Induces Salt Tolerance in Greenhouse Basil. AGRONOMY-BASEL 2019. [DOI: 10.3390/agronomy9070355] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The role of small bioactive molecules (<500 Da) in mechanisms improving resource use efficiency in plants under stress conditions draws increasing interest. One such molecule is omeprazole (OMP), a benzimidazole derivative and inhibitor of animal proton pumps shown to improve nitrate uptake and exclusion of toxic ions, especially of chloride from the cytosol of salt-stressed leaves. Currently, OMP was applied as substrate drench at two rates (0 or 10 μM) on hydroponic basil (Ocimum basilicum L. cv. Genovese) grown under decreasing NO3−:Cl− ratio (80:20, 60:40, 40:60, or 20:80). Chloride concentration and stomatal resistance increased while transpiration, net CO2 assimilation rate and beneficial ions (NO3−, PO43−, and SO42−) decreased with reduced NO3−:Cl− ratio under the 0 μM OMP treatment. The negative effects of chloride were not only mitigated by the 10 μM OMP application in all treatments, with the exception of 20:80 NO3−:Cl−, but plant growth at 80:20, 60:40, and 40:60 NO3−:Cl− ratios receiving OMP application showed maximum fresh yield (+13%, 24%, and 22%, respectively), shoot (+10%, 25%, and 21%, respectively) and root (+32%, 76%, and 75%, respectively) biomass compared to the corresponding untreated treatments. OMP was not directly involved in ion homeostasis and compartmentalization of vacuolar or apoplastic chloride. However, it was active in limiting chloride loading into the shoot, as manifested by the lower chloride concentration in the 80:20, 60:40, and 40:60 NO3−:Cl− treatments compared to the respective controls (−41%, −37%, and −24%), favoring instead that of nitrate and potassium while also boosting photosynthetic activity. Despite its unequivocally beneficial effect on plants, the large-scale application of OMP is currently limited by the molecule’s high cost. However, further studies are warranted to unravel the molecular mechanisms of OMP-induced reduction of chloride loading to shoot and improved salt tolerance.
Collapse
|
19
|
Wei P, Che B, Shen L, Cui Y, Wu S, Cheng C, Liu F, Li MW, Yu B, Lam HM. Identification and functional characterization of the chloride channel gene, GsCLC-c2 from wild soybean. BMC PLANT BIOLOGY 2019; 19:121. [PMID: 30935372 PMCID: PMC6444504 DOI: 10.1186/s12870-019-1732-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/19/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND The anionic toxicity of plants under salt stress is mainly caused by chloride (Cl-). Thus Cl- influx, transport and their regulatory mechanisms should be one of the most important aspects of plant salt tolerance studies, but are often sidelined by the focus on sodium (Na+) toxicity and its associated adaptations. Plant chloride channels (CLCs) are transport proteins for anions including Cl- and nitrate (NO3-), and are critical for nutrition uptake and transport, adjustment of cellular turgor, stomatal movement, signal transduction, and Cl- and NO3- homeostasis under salt stress. RESULTS Among the eight soybean CLC genes, the tonoplast-localized c2 has uniquely different transcriptional patterns between cultivated soybean N23674 and wild soybean BB52. Using soybean hairy root transformation, we found that GsCLC-c2 over-expression contributed to Cl- and NO3- homeostasis, and therefore conferred salt tolerance, through increasing the accumulation of Cl- in the roots, thereby reducing their transportation to the shoots where most of the cellular damages occur. Also, by keeping relatively high levels of NO3- in the aerial part of the plant, GsCLC-c2 could reduce the Cl-/NO3- ratio. Wild type GsCLC-c2, but not its mutants (S184P, E227V and E294G) with mutations in the conserved domains, is able to complement Saccharomyces cerevisiae △gef1 Cl- sensitive phenotype. Using two-electrode voltage clamp on Xenopus laevis oocytes injected with GsCLC-c2 cRNA, we found that GsCLC-c2 transports both Cl- and NO3- with slightly different affinity, and the affinity toward Cl- was pH-independent. CONCLUSION This study revealed that the expression of GsCLC-c2 is induced by NaCl-stress in the root of wild soybean. The tonoplast localized GsCLC-c2 transports Cl- with a higher affinity than NO3- in a pH-independent fashion. GsCLC-c2 probably alleviates salt stress in planta through the sequestration of excess Cl- into the vacuoles of root cells and thus preventing Cl- from entering the shoots where it could result in cellular damages.
Collapse
Affiliation(s)
- Peipei Wei
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Benning Che
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Like Shen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 China
| | - Yiqing Cui
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shengyan Wu
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Cong Cheng
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Feng Liu
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Man-Wah Li
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Bingjun Yu
- Laboratory of Plant Stress Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Hon-Ming Lam
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| |
Collapse
|
20
|
Bazihizina N, Colmer TD, Cuin TA, Mancuso S, Shabala S. Friend or Foe? Chloride Patterning in Halophytes. TRENDS IN PLANT SCIENCE 2019; 24:142-151. [PMID: 30558965 DOI: 10.1016/j.tplants.2018.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/11/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
In this opinion article, we challenge the traditional view that breeding for reduced Cl- uptake would benefit plant salinity tolerance. A negative correlation between shoot Cl- concentration and plant biomass does not hold for halophytes - naturally salt tolerant species. We argue that, under physiologically relevant conditions, Cl- uptake requires plants to invest metabolic energy, and that the poor selectivity of Cl--transporting proteins may explain the reported negative correlation between Cl- accumulation and crop salinity tolerance. We propose a new paradigm: salinity tolerance could be achieved by improving the selectivity of some of the broadly selective anion-transporting proteins (e.g., for NO3->Cl-), alongside tight control of Cl- uptake, rather than targeting traits mediating its efflux from the root.
Collapse
Affiliation(s)
- Nadia Bazihizina
- Department of Agrifood Production and Environmental Sciences, Università degli Studi di Firenze, Viale delle Idee 30, 50019 Sesto Fiorentino, Florence, Italy; Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7001, Australia.
| | - Timothy D Colmer
- UWA School of Agriculture and Environment, Faculty of Science, University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Tracey Ann Cuin
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7001, Australia
| | - Stefano Mancuso
- Department of Agrifood Production and Environmental Sciences, Università degli Studi di Firenze, Viale delle Idee 30, 50019 Sesto Fiorentino, Florence, Italy
| | - Sergey Shabala
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7001, Australia.
| |
Collapse
|
21
|
Lagostena L, Zifarelli G, Picollo A. New Insights into the Mechanism of NO 3 - Selectivity in the Human Kidney Chloride Channel ClC-Ka and the CLC Protein Family. J Am Soc Nephrol 2019; 30:293-302. [PMID: 30635372 DOI: 10.1681/asn.2018060593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 12/01/2018] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The mechanism of anion selectivity in the human kidney chloride channels ClC-Ka and ClC-Kb is unknown. However, it has been thought to be very similar to that of other channels and antiporters of the CLC protein family, and to rely on anions interacting with a conserved Ser residue (Sercen) at the center of three anion binding sites in the permeation pathway Scen. In both CLC channels and antiporters, mutations of Sercen alter the anion selectivity. Structurally, the side chain of Sercen of CLC channels and antiporters typically projects into the pore and coordinates the anion bound at Scen. METHODS To investigate the role of several residues in anion selectivity of ClC-Ka, we created mutations that resulted in amino acid substitutions in these residues. We also used electrophysiologic techniques to assess the properties of the mutants. RESULTS Mutations in ClC-Ka that change Sercen to Gly, Pro, or Thr have only minor effects on anion selectivity, whereas the mutations in residues Y425A, F519A, and Y520A increase the NO3 -/Cl- permeability ratio, with Y425A having a particularly strong effect. CONCLUSION s ClC-Ka's mechanism of anion selectivity is largely independent of Sercen, and it is therefore unique in the CLC protein family. We identified the residue Y425 in ClC-Ka-and the corresponding residue (A417) in the chloride channel ClC-0-as residues that contribute to NO3 - discrimination in these channels. This work provides important and timely insight into the relationship between structure and function for the kidney chloride channels ClC-Ka and ClC-Kb, and for CLC proteins in general.
Collapse
Affiliation(s)
- Laura Lagostena
- Dulbecco Telethon Laboratory, Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy; and
| | - Giovanni Zifarelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Alessandra Picollo
- Dulbecco Telethon Laboratory, Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy; and
| |
Collapse
|
22
|
Liao Q, Zhou T, Yao JY, Han QF, Song HX, Guan CY, Hua YP, Zhang ZH. Genome-scale characterization of the vacuole nitrate transporter Chloride Channel (CLC) genes and their transcriptional responses to diverse nutrient stresses in allotetraploid rapeseed. PLoS One 2018; 13:e0208648. [PMID: 30571734 PMCID: PMC6301700 DOI: 10.1371/journal.pone.0208648] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 11/20/2018] [Indexed: 12/18/2022] Open
Abstract
The Chloride Channel (CLC) gene family is reported to be involved in vacuolar nitrate (NO3-) transport. Nitrate distribution to the cytoplasm is beneficial for enhancing NO3- assimilation and plays an important role in the regulation of nitrogen (N) use efficiency (NUE). In this study, genomic information, high-throughput transcriptional profiles, and gene co-expression analysis were integrated to identify the CLCs (BnaCLCs) in Brassica napus. The decreased NO3- concentration in the clca-2 mutant up-regulated the activities of nitrate reductase and glutamine synthetase, contributing to increase N assimilation and higher NUE in Arabidopsis thaliana. The genome-wide identification of 22BnaCLC genes experienced strong purifying selection. Segmental duplication was the major driving force in the expansion of the BnaCLC gene family. The most abundant cis-acting regulatory elements in the gene promoters, including DNA-binding One Zinc Finger, W-box, MYB, and GATA-box, might be involved in the transcriptional regulation of BnaCLCs expression. High-throughput transcriptional profiles and quantitative real-time PCR results showed that BnaCLCs responded differentially to distinct NO3- regimes. Transcriptomics-assisted gene co-expression network analysis identified BnaA7.CLCa-3 as the core member of the BnaCLC family, and this gene might play a central role in vacuolar NO3- transport in crops. The BnaCLC members also showed distinct expression patterns under phosphate depletion and cadmium toxicity. Taken together, our results provide comprehensive insights into the vacuolar BnaCLCs and establish baseline information for future studies on BnaCLCs-mediated vacuolar NO3- storage and its effect on NUE.
Collapse
Affiliation(s)
- Qiong Liao
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
| | - Ting Zhou
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
| | - Jun-yue Yao
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
| | - Qing-fen Han
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
| | - Hai-xing Song
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
| | - Chun-yun Guan
- National Center of Oilseed Crops Improvement, Hunan Branch, Changsha, China
| | - Ying-peng Hua
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
- * E-mail: (ZHZ); (YPH)
| | - Zhen-hua Zhang
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University, Changsha, China
- * E-mail: (ZHZ); (YPH)
| |
Collapse
|
23
|
Hrmova M, Gilliham M. Plants fighting back: to transport or not to transport, this is a structural question. CURRENT OPINION IN PLANT BIOLOGY 2018; 46:68-76. [PMID: 30138844 DOI: 10.1016/j.pbi.2018.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/06/2018] [Accepted: 07/12/2018] [Indexed: 06/08/2023]
Abstract
Membrane-embedded transport proteins are fundamental to life; their co-ordinated action controls the movement and distribution of solutes into, around and out of cells for signalling, metabolism, nutrition, stress tolerance and development. Here we outline two case studies of transport systems that plants use to tolerate soil elemental toxicity, demonstrating how iterative studies of protein structure and function result in unparalleled insights into transport mechanics. Further, we propose that integrative platforms of biological, biochemical and biophysical tools can provide quantitative data on substrate specificity and transport rates, which are important in understanding transporter evolution and their roles in cell biology and whole plant physiology. Such knowledge equips biotechnologists and breeders with the power to deliver improvements in crop yields in sub-optimal soils.
Collapse
Affiliation(s)
- Maria Hrmova
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia; School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China.
| | - Matthew Gilliham
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia; Australian Research Council Centre of Excellence in Plant Energy Biology, University of Adelaide, Waite Research Institute, Glen Osmond, South Australia 5064, Australia
| |
Collapse
|
24
|
Sun H, Shen L, Qin Y, Liu X, Hao K, Li Y, Wang J, Yang J, Wang F. CLC-Nt1 affects Potato Virus Y infection via regulation of endoplasmic reticulum luminal Ph. THE NEW PHYTOLOGIST 2018; 220:539-552. [PMID: 30022473 DOI: 10.1111/nph.15310] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Chloride channel (CLC) proteins are important anion transporters conserved in organisms ranging from bacteria and yeast to plants and animals. According to sequence comparison, some plant CLCs are predicted to function as Cl- /H+ antiporters, but not Cl- channels. However, no direct evidence was provided to verify the role of these plant CLCs in regulating the pH of the intracellular compartment. We identified tobacco CLC-Nt1 interacting with the Potato virus Y (PVY) 6K2 protein. To investigate its physiological function, homologous genes of CLC-Nt1 in Nicotiana benthamiana were knocked out using the CRISPR/Cas9 system. Complementation experiments were subsequently performed by expression of wild-type or point-mutated CLC-Nt1 in knockout mutants. The data presented herein demonstrate that CLC-Nt1 is localized at endoplasmic reticulum (ER). Using a pH-sensitive fluorescent protein (pHluorin), we found that loss of CLC-Nt1 function resulted in a decreased ER luminal pH. Secreted GFP (secGFP) was retained mostly in ER in knockout mutants, indicating that CLC-Nt1 is also involved in protein secretion. PVY infection induced a rise in ER luminal pH, which was dependent on functional CLC-Nt1. By contrast, loss of CLC-Nt1 function inhibited PVY intracellular replication and systemic infection. We propose that PVY alters ER luminal pH for infection in a CLC-Nt1-dependent manner.
Collapse
Affiliation(s)
- Hangjun Sun
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Lili Shen
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yuanxia Qin
- College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China
| | - Xiaowei Liu
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Kaiqiang Hao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
| | - Ying Li
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jie Wang
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jinguang Yang
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Fenglong Wang
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| |
Collapse
|
25
|
Cao-Pham AH, Urano D, Ross-Elliott TJ, Jones AM. Nudge-nudge, WNK-WNK (kinases), say no more? THE NEW PHYTOLOGIST 2018; 220:35-48. [PMID: 29949669 DOI: 10.1111/nph.15276] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/01/2018] [Indexed: 05/09/2023]
Abstract
Contents Summary 35 I Overview of animal and plant WNK kinases 35 II. Structure: domains and topology 36 III. Phylogeny-evolutionary relationships 41 IV. Plant WNK kinase distribution and regulation of WNK expression and activity 41 V. Functions of WNK family members in physiology and development 41 VI. Say no more? Still many questions to be answered 45 Acknowledgements 46 References 46 SUMMARY: WITH NO LYSINE (WNK) kinases are serine/threonine kinases uniquely characterized by an anomalous placement of a catalytic lysine, hence their moniker. In animals, WNK protein kinases play critical roles in protein trafficking of components that mediate renal ion transport processes and regulate osmoregulation of cell volume. In plants, the WNK kinase gene family is larger and more diverse. Recent studies revealed WNK kinase roles in orchestrating the trafficking of an ion channel, a lipid kinase complex in animals, and a heterotrimeric G protein signaling component in plants that is necessary for signal transduction. For this reason, new attention is geared toward investigating the mechanisms adopted by WNK kinases to nudge intracellular proteins to their destinations. In this review, the functions of WNK kinases in protein trafficking are derived from what we have learned from the model organism Arabidopsis thaliana. To place this new idea in context, we provide the predicted WNK kinase structures, their predicted expression patterns, a speculated evolutionary pathway, and the regulatory roles of plant WNKs in transport processes and other physiologies. We brazenly predict that the WNK kinases in both plants and animals will soon be recognized as a nexus for trafficking-based signal transduction.
Collapse
Affiliation(s)
- Anh H Cao-Pham
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - Daisuke Urano
- Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 117604, Singapore
| | - Timothy J Ross-Elliott
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Alan M Jones
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| |
Collapse
|
26
|
Böhm J, Messerer M, Müller HM, Scholz-Starke J, Gradogna A, Scherzer S, Maierhofer T, Bazihizina N, Zhang H, Stigloher C, Ache P, Al-Rasheid KAS, Mayer KFX, Shabala S, Carpaneto A, Haberer G, Zhu JK, Hedrich R. Understanding the Molecular Basis of Salt Sequestration in Epidermal Bladder Cells of Chenopodium quinoa. Curr Biol 2018; 28:3075-3085.e7. [PMID: 30245105 DOI: 10.1016/j.cub.2018.08.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/20/2018] [Accepted: 08/01/2018] [Indexed: 02/03/2023]
Abstract
Soil salinity is destroying arable land and is considered to be one of the major threats to global food security in the 21st century. Therefore, the ability of naturally salt-tolerant halophyte plants to sequester large quantities of salt in external structures, such as epidermal bladder cells (EBCs), is of great interest. Using Chenopodium quinoa, a pseudo-cereal halophyte of great economic potential, we have shown previously that, upon removal of salt bladders, quinoa becomes salt sensitive. In this work, we analyzed the molecular mechanism underlying the unique salt dumping capabilities of bladder cells in quinoa. The transporters differentially expressed in the EBC transcriptome and functional electrophysiological testing of key EBC transporters in Xenopus oocytes revealed that loading of Na+ and Cl- into EBCs is mediated by a set of tailored plasma and vacuole membrane-based sodium-selective channel and chloride-permeable transporter.
Collapse
Affiliation(s)
- Jennifer Böhm
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
| | - Maxim Messerer
- Plant Genome and Systems Biology, Helmholtz Center Munich, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Heike M Müller
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs Platz 2, 97082 Wuerzburg, Germany
| | - Joachim Scholz-Starke
- Institute of Biophysics, National Research Council (CNR), Via De Marini 6, 16149 Genova, Italy
| | - Antonella Gradogna
- Institute of Biophysics, National Research Council (CNR), Via De Marini 6, 16149 Genova, Italy
| | - Sönke Scherzer
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs Platz 2, 97082 Wuerzburg, Germany
| | - Tobias Maierhofer
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs Platz 2, 97082 Wuerzburg, Germany
| | - Nadia Bazihizina
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia; Department of Agrifood Production and Environmental Sciences, Università degli Studi di Firenze, Viale delle Idee 30, 50019 Sesto Fiorentino, Florence, Italy
| | - Heng Zhang
- Shanghai Center for Plant Stress Biology, and CAS Center for Excellence in Molecular Plant Sciences, 3888 Chenhua Road, Shanghai 201602, China
| | - Christian Stigloher
- Imaging Core Facility, Biocenter, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Peter Ache
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs Platz 2, 97082 Wuerzburg, Germany
| | - Khaled A S Al-Rasheid
- Zoology Department, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Klaus F X Mayer
- Plant Genome and Systems Biology, Helmholtz Center Munich, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Sergey Shabala
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia; Department of Horticulture, Foshan University, Foshan 528000, PRC
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council (CNR), Via De Marini 6, 16149 Genova, Italy; Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132 Genova, Italy
| | - Georg Haberer
- Plant Genome and Systems Biology, Helmholtz Center Munich, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, and CAS Center for Excellence in Molecular Plant Sciences, 3888 Chenhua Road, Shanghai 201602, China; Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs Platz 2, 97082 Wuerzburg, Germany.
| |
Collapse
|
27
|
Jentsch TJ, Pusch M. CLC Chloride Channels and Transporters: Structure, Function, Physiology, and Disease. Physiol Rev 2018; 98:1493-1590. [DOI: 10.1152/physrev.00047.2017] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CLC anion transporters are found in all phyla and form a gene family of eight members in mammals. Two CLC proteins, each of which completely contains an ion translocation parthway, assemble to homo- or heteromeric dimers that sometimes require accessory β-subunits for function. CLC proteins come in two flavors: anion channels and anion/proton exchangers. Structures of these two CLC protein classes are surprisingly similar. Extensive structure-function analysis identified residues involved in ion permeation, anion-proton coupling and gating and led to attractive biophysical models. In mammals, ClC-1, -2, -Ka/-Kb are plasma membrane Cl−channels, whereas ClC-3 through ClC-7 are 2Cl−/H+-exchangers in endolysosomal membranes. Biological roles of CLCs were mostly studied in mammals, but also in plants and model organisms like yeast and Caenorhabditis elegans. CLC Cl−channels have roles in the control of electrical excitability, extra- and intracellular ion homeostasis, and transepithelial transport, whereas anion/proton exchangers influence vesicular ion composition and impinge on endocytosis and lysosomal function. The surprisingly diverse roles of CLCs are highlighted by human and mouse disorders elicited by mutations in their genes. These pathologies include neurodegeneration, leukodystrophy, mental retardation, deafness, blindness, myotonia, hyperaldosteronism, renal salt loss, proteinuria, kidney stones, male infertility, and osteopetrosis. In this review, emphasis is laid on biophysical structure-function analysis and on the cell biological and organismal roles of mammalian CLCs and their role in disease.
Collapse
Affiliation(s)
- Thomas J. Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany; and Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - Michael Pusch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany; and Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy
| |
Collapse
|
28
|
Geilfus CM. Chloride: from Nutrient to Toxicant. PLANT & CELL PHYSIOLOGY 2018; 59:877-886. [PMID: 29660029 DOI: 10.1093/pcp/pcy071] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 03/05/2018] [Indexed: 05/25/2023]
Abstract
In salinized soils in which chloride (Cl-) is the dominant salt anion, growth of plants that tolerate only low concentrations of salt (glycophytes) is disturbed by Cl- toxicity. Chlorotic discolorations precede necrotic lesions, causing yield reductions. Little is known about the effects of Cl- toxicity on these dysfunctions. A lack of understanding exists regarding (i) the molecular and physiological mechanisms that lead to Cl--induced damage and (ii) the adaptive aspects of induced tolerance to Cl- salinity. Here, mechanistic explanations for the Cl--induced stress responses are proposed and novel ideas and strategies by which glycophytic plants avoid the excessive accumulation of Cl- are reviewed. New experiments are suggested to test the proposed hypotheses. Cl- salinity constrains global food security and thus we urgently need more research into the causes and consequences of Cl- salinity.
Collapse
Affiliation(s)
- Christoph-Martin Geilfus
- Controlled Environment Horticulture, Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Albrecht-Thaer-Weg 1, D-14195 Berlin, Germany
| |
Collapse
|
29
|
Tegeder M, Masclaux-Daubresse C. Source and sink mechanisms of nitrogen transport and use. THE NEW PHYTOLOGIST 2018; 217:35-53. [PMID: 29120059 DOI: 10.1111/nph.14876] [Citation(s) in RCA: 303] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/09/2017] [Indexed: 05/03/2023]
Abstract
Contents Summary 35 I. Introduction 35 II. Nitrogen acquisition and assimilation 36 III. Root-to-shoot transport of nitrogen 38 IV. Nitrogen storage pools in vegetative tissues 39 V. Nitrogen transport from source leaf to sink 40 VI. Nitrogen import into sinks 42 VII. Relationship between source and sink nitrogen transport processes and metabolism 43 VIII. Regulation of nitrogen transport 43 IX. Strategies for crop improvement 44 X. Conclusions 46 Acknowledgements 47 References 47 SUMMARY: Nitrogen is an essential nutrient for plant growth. World-wide, large quantities of nitrogenous fertilizer are applied to ensure maximum crop productivity. However, nitrogen fertilizer application is expensive and negatively affects the environment, and subsequently human health. A strategy to address this problem is the development of crops that are efficient in acquiring and using nitrogen and that can achieve high seed yields with reduced nitrogen input. This review integrates the current knowledge regarding inorganic and organic nitrogen management at the whole-plant level, spanning from nitrogen uptake to remobilization and utilization in source and sink organs. Plant partitioning and transient storage of inorganic and organic nitrogen forms are evaluated, as is how they affect nitrogen availability, metabolism and mobilization. Essential functions of nitrogen transporters in source and sink organs and their importance in regulating nitrogen movement in support of metabolism, and vegetative and reproductive growth are assessed. Finally, we discuss recent advances in plant engineering, demonstrating that nitrogen transporters are effective targets to improve crop productivity and nitrogen use efficiency. While inorganic and organic nitrogen transporters were examined separately in these studies, they provide valuable clues about how to successfully combine approaches for future crop engineering.
Collapse
Affiliation(s)
- Mechthild Tegeder
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
| | - Céline Masclaux-Daubresse
- INRA-AgroParisTech, Institut Jean-Pierre Bourgin, UMR1318, ERL CNRS 3559, Saclay Plant Sciences, Versailles, France
| |
Collapse
|
30
|
Bose J, Munns R, Shabala S, Gilliham M, Pogson B, Tyerman SD. Chloroplast function and ion regulation in plants growing on saline soils: lessons from halophytes. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3129-3143. [PMID: 28472512 DOI: 10.1093/jxb/erx142] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Salt stress impacts multiple aspects of plant metabolism and physiology. For instance it inhibits photosynthesis through stomatal limitation, causes excessive accumulation of sodium and chloride in chloroplasts, and disturbs chloroplast potassium homeostasis. Most research on salt stress has focused primarily on cytosolic ion homeostasis with few studies of how salt stress affects chloroplast ion homeostasis. This review asks the question whether membrane-transport processes and ionic relations are differentially regulated between glycophyte and halophyte chloroplasts and whether this contributes to the superior salt tolerance of halophytes. The available literature indicates that halophytes can overcome stomatal limitation by switching to CO2 concentrating mechanisms and increasing the number of chloroplasts per cell under saline conditions. Furthermore, salt entry into the chloroplast stroma may be critical for grana formation and photosystem II activity in halophytes but not in glycophytes. Salt also inhibits some stromal enzymes (e.g. fructose-1,6-bisphosphatase) to a lesser extent in halophyte species. Halophytes accumulate more chloride in chloroplasts than glycophytes and appear to use sodium in functional roles. We propose the molecular identities of candidate transporters that move sodium, chloride and potassium across chloroplast membranes and discuss how their operation may regulate photochemistry and photosystem I and II activity in chloroplasts.
Collapse
Affiliation(s)
- Jayakumar Bose
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Rana Munns
- Australian Research Council Centre of Excellence in Plant Energy Biology, and School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
| | - Matthew Gilliham
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Barry Pogson
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Stephen D Tyerman
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| |
Collapse
|
31
|
Wege S, Gilliham M, Henderson SW. Chloride: not simply a 'cheap osmoticum', but a beneficial plant macronutrient. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3057-3069. [PMID: 28379459 DOI: 10.1093/jxb/erx050] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
At macronutrient levels, chloride has positive effects on plant growth, which are distinct from its function in photosynthesis..
Collapse
Affiliation(s)
- Stefanie Wege
- Australian Research Council Centre of Excellence in Plant Energy Biology & The University of Adelaide, School of Agriculture, Food and Wine, Waite Research Precinct, PMB1, Glen Osmond, South Australia 5064, Australia
| | - Matthew Gilliham
- Australian Research Council Centre of Excellence in Plant Energy Biology & The University of Adelaide, School of Agriculture, Food and Wine, Waite Research Precinct, PMB1, Glen Osmond, South Australia 5064, Australia
| | - Sam W Henderson
- Australian Research Council Centre of Excellence in Plant Energy Biology & The University of Adelaide, School of Agriculture, Food and Wine, Waite Research Precinct, PMB1, Glen Osmond, South Australia 5064, Australia
| |
Collapse
|
32
|
Calatrava V, Chamizo-Ampudia A, Sanz-Luque E, Ocaña-Calahorro F, Llamas A, Fernandez E, Galvan A. How Chlamydomonas handles nitrate and the nitric oxide cycle. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2593-2602. [PMID: 28201747 DOI: 10.1093/jxb/erw507] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The green alga Chlamydomonas is a valuable model system capable of assimilating different forms of nitrogen (N). Nitrate (NO3-) has a relevant role in plant-like organisms, first as a nitrogen source for growth and second as a signalling molecule. Several modules are necessary for Chlamydomonas to handle nitrate, including transporters, nitrate reductase (NR), nitrite reductase (NiR), GS/GOGAT enzymes for ammonium assimilation, and regulatory protein(s). Transporters provide a first step for influx/efflux, homeostasis, and sensing of nitrate; and NIT2 is the key transcription factor (RWP-RK) for mediating the nitrate-dependent activation of a number of genes. Here, we review how NR participates in the cycle NO3- →NO2- →NO →NO3-. NR uses the partner protein amidoxime-reducing component/nitric oxide-forming nitrite reductase (ARC/NOFNiR) for the conversion of nitrite (NO2-) into nitric oxide (NO). It also uses the truncated haemoglobin THB1 in the conversion of nitric oxide to nitrate. Nitric oxide is a negative signal for nitrate assimilation; it inhibits the activity and expression of high-affinity nitrate/nitrite transporters and NR. During this cycle, the positive signal of nitrate is transformed into the negative signal of nitric oxide, which can then be converted back into nitrate. Thus, NR is back in the spotlight as a strategic regulator of the nitric oxide cycle and the nitrate assimilation pathway.
Collapse
Affiliation(s)
- Victoria Calatrava
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Alejandro Chamizo-Ampudia
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Emanuel Sanz-Luque
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Francisco Ocaña-Calahorro
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Angel Llamas
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Emilio Fernandez
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Aurora Galvan
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| |
Collapse
|
33
|
Li B, Tester M, Gilliham M. Chloride on the Move. TRENDS IN PLANT SCIENCE 2017; 22:236-248. [PMID: 28081935 DOI: 10.1016/j.tplants.2016.12.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/21/2016] [Accepted: 12/11/2016] [Indexed: 05/20/2023]
Abstract
Chloride (Cl-) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process - the transfer of Cl- from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO3-) to shoots - is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl- into the xylem, and others that act on endomembranes in 'gatekeeper' cell types in the root stele to control root-to-shoot delivery of Cl-.
Collapse
Affiliation(s)
- Bo Li
- King Abdullah University of Science and Technology (KAUST), Division of Biological and Environmental Sciences and Engineering, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Mark Tester
- King Abdullah University of Science and Technology (KAUST), Division of Biological and Environmental Sciences and Engineering, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Matthew Gilliham
- Plant Transport and Signalling Group, Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064, Australia.
| |
Collapse
|
34
|
Dagenais Bellefeuille S, Morse D. The main nitrate transporter of the dinoflagellate Lingulodinium polyedrum is constitutively expressed and not responsible for daily variations in nitrate uptake rates. HARMFUL ALGAE 2016; 55:272-281. [PMID: 28073541 DOI: 10.1016/j.hal.2016.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 06/06/2023]
Abstract
Dinoflagellates are unicellular eukaryotes capable of forming spectacular harmful algal blooms (HABs). Eutrophication of coastal waters by fertilizer runoff, nitrate in particular, has contributed to recent increases in the frequency, magnitude and geographic extent of HABs. Although physiological nitrate uptake and assimilation in dinoflagellates have often been measured in the field and in the laboratory, no molecular components involved in nitrate transport have yet been reported. This study reports the first identification and characterization of dinoflagellate nitrate transporters, found in the transcriptome of the bloom-forming Lingulodinium polyedrum. Of the 23 putative transporters found by BLAST searches, only members of the nitrate transporter 2 (NRT2) family contained all key amino acids known to be essential for nitrate transport. The dinoflagellate NRT2 sequences have 12 predicted transmembrane domains, as do the NRT2 sequences of bacteria, plants and fungi. The NRT2 sequences in Lingulodinium appear to have two different evolutionary origins, as determined by phylogenetic analyses. The most expressed transcript of all putative nitrate transporters was determined by RNA-Seq to be LpNRT2.1. An antibody raised against this transporter showed that the same amount of protein was found at different times over the light dark cycle and with different sources of N. Finally, global nitrate uptake was assessed using a 15N tracer, which showed that the process was not under circadian-control as previously suggested, but simply light-regulated.
Collapse
Affiliation(s)
- Steve Dagenais Bellefeuille
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada H1X 2B2
| | - David Morse
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada H1X 2B2.
| |
Collapse
|
35
|
Nguyen CT, Agorio A, Jossier M, Depré S, Thomine S, Filleur S. Characterization of the Chloride Channel-Like, AtCLCg, Involved in Chloride Tolerance in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2016; 57:764-75. [PMID: 26556649 DOI: 10.1093/pcp/pcv169] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/28/2015] [Indexed: 05/22/2023]
Abstract
In plant cells, anion channels and transporters are essential for key functions such as nutrition, ion homeostasis and resistance to biotic or abiotic stresses. We characterized AtCLCg, a member of the chloride channel (CLC) family in Arabidopsis localized in the vacuolar membrane. When grown on NaCl or KCl, atclcg knock-out mutants showed a decrease in biomass. In the presence of NaCl, these mutants overaccumulate chloride in shoots. No difference in growth was detected in response to osmotic stress by mannitol. These results suggest a physiological function of AtCLCg in the chloride homeostasis during NaCl stress. AtCLCg shares a high degree of identity (62%) with AtCLCc, another vacuolar CLC essential for NaCl tolerance. However, the atclcc atclccg double mutant is not more sensitive to NaCl than single mutants. As the effects of both mutations are not additive, gene expression analyses were performed and revealed that: (i)AtCLCg is expressed in mesophyll cells, hydathodes and phloem while AtCLCc is expressed in stomata; and (ii)AtCLCg is repressed in the atclcc mutant background, and vice versa. Altogether these results demonstrate that both AtCLCc and AtCLCg are important for tolerance to excess chloride but not redundant, and form part of a regulatory network controlling chloride sensitivity.
Collapse
Affiliation(s)
- Chi Tam Nguyen
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France
| | - Astrid Agorio
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France
| | - Mathieu Jossier
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France
| | - Sylvain Depré
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France
| | - Sébastien Thomine
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France
| | - Sophie Filleur
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, F-91198 Gif-sur-Yvette, France Université Paris 7 Denis Diderot, UFR Sciences du Vivant, 35 rue Hélène Brion, F-75205 Paris Cedex 13, France
| |
Collapse
|
36
|
Herdean A, Nziengui H, Zsiros O, Solymosi K, Garab G, Lundin B, Spetea C. The Arabidopsis Thylakoid Chloride Channel AtCLCe Functions in Chloride Homeostasis and Regulation of Photosynthetic Electron Transport. FRONTIERS IN PLANT SCIENCE 2016; 7:115. [PMID: 26904077 PMCID: PMC4746265 DOI: 10.3389/fpls.2016.00115] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/21/2016] [Indexed: 05/20/2023]
Abstract
Chloride ions can be translocated across cell membranes through Cl(-) channels or Cl(-)/H(+) exchangers. The thylakoid-located member of the Cl(-) channel CLC family in Arabidopsis thaliana (AtCLCe) was hypothesized to play a role in photosynthetic regulation based on the initial photosynthetic characterization of clce mutant lines. The reduced nitrate content of Arabidopsis clce mutants suggested a role in regulation of plant nitrate homeostasis. In this study, we aimed to further investigate the role of AtCLCe in the regulation of ion homeostasis and photosynthetic processes in the thylakoid membrane. We report that the size and composition of proton motive force were mildly altered in two independent Arabidopsis clce mutant lines. Most pronounced effects in the clce mutants were observed on the photosynthetic electron transport of dark-adapted plants, based on the altered shape and associated parameters of the polyphasic OJIP kinetics of chlorophyll a fluorescence induction. Other alterations were found in the kinetics of state transition and in the macro-organization of photosystem II supercomplexes, as indicated by circular dichroism measurements. Pre-treatment with KCl but not with KNO3 restored the wild-type photosynthetic phenotype. Analyses by transmission electron microscopy revealed a bow-like arrangement of the thylakoid network and a large thylakoid-free stromal region in chloroplast sections from the dark-adapted clce plants. Based on these data, we propose that AtCLCe functions in Cl(-) homeostasis after transition from light to dark, which affects chloroplast ultrastructure and regulation of photosynthetic electron transport.
Collapse
Affiliation(s)
- Andrei Herdean
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Hugues Nziengui
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Ottó Zsiros
- Biological Research Center, Hungarian Academy of SciencesSzeged, Hungary
| | - Katalin Solymosi
- Department of Plant Anatomy, Eötvös Loránd UniversityBudapest, Hungary
| | - Győző Garab
- Biological Research Center, Hungarian Academy of SciencesSzeged, Hungary
| | - Björn Lundin
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
- *Correspondence: Cornelia Spetea
| |
Collapse
|
37
|
Li B, Qiu J, Jayakannan M, Xu B, Li Y, Mayo GM, Tester M, Gilliham M, Roy SJ. AtNPF2.5 Modulates Chloride (Cl -) Efflux from Roots of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2016; 7:2013. [PMID: 28111585 PMCID: PMC5216686 DOI: 10.3389/fpls.2016.02013] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/19/2016] [Indexed: 05/18/2023]
Abstract
The accumulation of high concentrations of chloride (Cl-) in leaves can adversely affect plant growth. When comparing different varieties of the same Cl- sensitive plant species those that exclude relatively more Cl- from their shoots tend to perform better under saline conditions; however, the molecular mechanisms involved in maintaining low shoot Cl- remain largely undefined. Recently, it was shown that the NRT1/PTR Family 2.4 protein (NPF2.4) loads Cl- into the root xylem, which affects the accumulation of Cl- in Arabidopsis shoots. Here we characterize NPF2.5, which is the closest homolog to NPF2.4 sharing 83.2% identity at the amino acid level. NPF2.5 is predominantly expressed in root cortical cells and its transcription is induced by salt. Functional characterisation of NPF2.5 via its heterologous expression in yeast (Saccharomyces cerevisiae) and Xenopus laevis oocytes indicated that NPF2.5 is likely to encode a Cl- permeable transporter. Arabidopsis npf2.5 T-DNA knockout mutant plants exhibited a significantly lower Cl- efflux from roots, and a greater Cl- accumulation in shoots compared to salt-treated Col-0 wild-type plants. At the same time, [Formula: see text] content in the shoot remained unaffected. Accumulation of Cl- in the shoot increased following (1) amiRNA-induced knockdown of NPF2.5 transcript abundance in the root, and (2) constitutive over-expression of NPF2.5. We suggest that both these findings are consistent with a role for NPF2.5 in modulating Cl- transport. Based on these results, we propose that NPF2.5 functions as a pathway for Cl- efflux from the root, contributing to exclusion of Cl- from the shoot of Arabidopsis.
Collapse
Affiliation(s)
- Bo Li
- Australian Centre for Plant Functional GenomicsAdelaide, SA, Australia
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and TechnologyThuwal, Saudi Arabia
| | - Jiaen Qiu
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- ARC Centre of Excellence in Plant Energy BiologyAdelaide, SA, Australia
| | - Maheswari Jayakannan
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- ARC Centre of Excellence in Plant Energy BiologyAdelaide, SA, Australia
| | - Bo Xu
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- ARC Centre of Excellence in Plant Energy BiologyAdelaide, SA, Australia
| | - Yuan Li
- Australian Centre for Plant Functional GenomicsAdelaide, SA, Australia
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
| | - Gwenda M. Mayo
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
| | - Mark Tester
- Australian Centre for Plant Functional GenomicsAdelaide, SA, Australia
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and TechnologyThuwal, Saudi Arabia
| | - Matthew Gilliham
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- ARC Centre of Excellence in Plant Energy BiologyAdelaide, SA, Australia
- *Correspondence: Matthew Gilliham
| | - Stuart J. Roy
- Australian Centre for Plant Functional GenomicsAdelaide, SA, Australia
- School of Agriculture, Food and Wine, Waite Research Institute, University of AdelaideAdelaide, SA, Australia
- Stuart J. Roy
| |
Collapse
|
38
|
Accardi A. Structure and gating of CLC channels and exchangers. J Physiol 2015; 593:4129-38. [PMID: 26148215 DOI: 10.1113/jp270575] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 06/28/2015] [Indexed: 11/08/2022] Open
Abstract
Since their serendipitous discovery the CLC family of Cl(-) transporting proteins has been a never ending source of surprises. From their double-barrelled architecture to their complex structure and divergence as channels and transporters, the CLCs never cease to amaze biophysicists, biochemists and physiologists alike. These unusual functional properties allow the CLCs to fill diverse physiological niches, regulating processes that range from muscle contraction to acidification of intracellular organelles, nutrient accumulation and survival of bacteria to environmental stresses. Over the last 15 years, the availability of atomic-level information on the structure of the CLCs, coupled to the discovery that the family is divided into passive channels and secondary active transporters, has revolutionized our understanding of their function. These breakthroughs led to the identification of the key structural elements regulating gating, transport, selectivity and regulation by ligands. Unexpectedly, many lines of evidence indicate that the CLC exchangers function according to a non-conventional transport mechanism that defies the fundamental tenets of the alternating-access paradigm for exchange transport, paving the way for future unexpected insights into the principles underlying active transport and channel gating.
Collapse
Affiliation(s)
- Alessio Accardi
- Departments of Anaesthesiology, Physiology & Biophysics, and Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10021, USA
| |
Collapse
|
39
|
Zifarelli G. A tale of two CLCs: biophysical insights toward understanding ClC-5 and ClC-7 function in endosomes and lysosomes. J Physiol 2015; 593:4139-50. [PMID: 26036722 DOI: 10.1113/jp270604] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 05/22/2015] [Indexed: 11/08/2022] Open
Abstract
The CLC protein family comprises both Cl(-) channels and H(+) -coupled anion transporters. The understanding of the critical role of CLC proteins in a number of physiological functions has greatly contributed to a revision of the classical paradigm that attributed to Cl(-) ions only a marginal role in human physiology. The endosomal ClC-5 and the lysosomal ClC-7 are the best characterized human CLC transporters. Their dysfunction causes Dent's disease and osteopetrosis, respectively. It had been originally proposed that they would provide a Cl(-) shunt conductance allowing efficient acidification of intracellular compartments. However, this model seems to conflict with the transport properties of these proteins and with recent physiological evidence. Currently, there is no consensus on their specific physiological role. CLC proteins present also a number of peculiar biophysical properties, such as the dimeric architecture, the co-existence of intrinsically different thermodynamic modes of transport based on similar structural principles, and the gating mechanism recently emerging for the transporters, just to name a few. This review focuses on the biophysical properties and physiological roles of ClC-5 and ClC-7.
Collapse
Affiliation(s)
- Giovanni Zifarelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| |
Collapse
|
40
|
Krapp A. Plant nitrogen assimilation and its regulation: a complex puzzle with missing pieces. CURRENT OPINION IN PLANT BIOLOGY 2015; 25:115-22. [PMID: 26037390 DOI: 10.1016/j.pbi.2015.05.010] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/12/2015] [Accepted: 05/13/2015] [Indexed: 05/18/2023]
Abstract
Nitrogen (N) is an essential element for plants that is available in agricultural soils mainly as macronutrients in the form of nitrate and ammonium. Interplay between high-affinity and low-affinity transporters ensures efficient uptake from the soil even under highly fluctuating N availability. After uptake, N assimilation comprises the reduction of nitrate to ammonium and its subsequent incorporation into amino acids. Amino acids, but also nitrate, are transported from root to shoot and vice versa. Most steps of N transport and assimilation are tightly controlled by a regulatory network acting both cell-autonomously and systemically. N sensors, transcription factors and further regulatory players have been identified during recent years, elucidating parts of the huge puzzle that represents the efficient use of N by plants.
Collapse
Affiliation(s)
- Anne Krapp
- Institut National de la Recherche Agronomique (INRA), UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, RD10, F-78000 Versailles, France; AgroParisTech, Institut Jean-Pierre Bourgin, RD10, F-78000 Versailles, France.
| |
Collapse
|
41
|
Pusch M, Zifarelli G. ClC-5: Physiological role and biophysical mechanisms. Cell Calcium 2014; 58:57-66. [PMID: 25443653 DOI: 10.1016/j.ceca.2014.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/19/2014] [Accepted: 09/20/2014] [Indexed: 01/05/2023]
Abstract
Cl(-) transport in animal cells has fundamental physiological roles and it is mediated by a variety of protein families, one of them being the CLC family of ion channels and transporters. Besides their physiological relevance, CLC proteins show peculiar biophysical properties. This review will focus on a member of the CLC protein family, the endosomal Cl(-)/H(+) antiporter ClC-5. ClC-5 mutations cause Dent's disease, a renal syndrome due to defective protein reabsorption in the proximal tubule. This established the critical function of ClC-5 for endocytosis. However, our understanding of ClC-5's molecular role in endosomes and of its biophysical properties has proved elusive in spite of important progress achieved in the last two decades. Early models in which ClC-5 would provide a shunt conductance to enable efficient endosomal acidification conflicted with the antiport activity of ClC-5 that has more recently emerged. Currently, the physiological role of ClC-5 is hotly debated and its biophysical properties are still not fully understood.
Collapse
Affiliation(s)
- Michael Pusch
- Istituto di Biofisica, CNR, Via De Marini 6, 16149 Genoa, Italy
| | | |
Collapse
|
42
|
Henderson SW, Baumann U, Blackmore DH, Walker AR, Walker RR, Gilliham M. Shoot chloride exclusion and salt tolerance in grapevine is associated with differential ion transporter expression in roots. BMC PLANT BIOLOGY 2014; 14:273. [PMID: 25344057 PMCID: PMC4220414 DOI: 10.1186/s12870-014-0273-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/03/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND Salt tolerance in grapevine is associated with chloride (Cl-) exclusion from shoots; the rate-limiting step being the passage of Cl- between the root symplast and xylem apoplast. Despite an understanding of the physiological mechanism of Cl- exclusion in grapevine, the molecular identity of membrane proteins that control this process have remained elusive. To elucidate candidate genes likely to control Cl- exclusion, we compared the root transcriptomes of three Vitis spp. with contrasting shoot Cl- exclusion capacities using a custom microarray. RESULTS When challenged with 50 mM Cl-, transcriptional changes of genotypes 140 Ruggeri (shoot Cl- excluding rootstock), K51-40 (shoot Cl- including rootstock) and Cabernet Sauvignon (intermediate shoot Cl- excluder) differed. The magnitude of salt-induced transcriptional changes in roots correlated with the amount of Cl- accumulated in shoots. Abiotic-stress responsive transcripts (e.g. heat shock proteins) were induced in 140 Ruggeri, respiratory transcripts were repressed in Cabernet Sauvignon, and the expression of hypersensitive response and ROS scavenging transcripts was altered in K51-40. Despite these differences, no obvious Cl- transporters were identified. However, under control conditions where differences in shoot Cl- exclusion between rootstocks were still significant, genes encoding putative ion channels SLAH3, ALMT1 and putative kinases SnRK2.6 and CPKs were differentially expressed between rootstocks, as were members of the NRT1 (NAXT1 and NRT1.4), and CLC families. CONCLUSIONS These results suggest that transcriptional events contributing to the Cl- exclusion mechanism in grapevine are not stress-inducible, but constitutively different between contrasting varieties. We have identified individual genes from large families known to have members with roles in anion transport in other plants, as likely candidates for controlling anion homeostasis and Cl- exclusion in Vitis species. We propose these genes as priority candidates for functional characterisation to determine their role in chloride transport in grapevine and other plants.
Collapse
Affiliation(s)
- Sam W Henderson
- />Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, & Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, South Australia, 5064 Australia
| | - Ute Baumann
- />Australian Centre for Plant Functional Genomics, South Australia, 5064 Australia
| | - Deidre H Blackmore
- />CSIRO Plant Industry, PO Box 350, Glen Osmond, South Australia 5064 Australia
| | - Amanda R Walker
- />CSIRO Plant Industry, PO Box 350, Glen Osmond, South Australia 5064 Australia
| | - Rob R Walker
- />CSIRO Plant Industry, PO Box 350, Glen Osmond, South Australia 5064 Australia
| | - Matthew Gilliham
- />Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, & Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, South Australia, 5064 Australia
| |
Collapse
|
43
|
Wege S, De Angeli A, Droillard MJ, Kroniewicz L, Merlot S, Cornu D, Gambale F, Martinoia E, Barbier-Brygoo H, Thomine S, Leonhardt N, Filleur S. Phosphorylation of the vacuolar anion exchanger AtCLCa is required for the stomatal response to abscisic acid. Sci Signal 2014; 7:ra65. [PMID: 25005229 DOI: 10.1126/scisignal.2005140] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Eukaryotic anion/proton exchangers of the CLC (chloride channel) family mediate anion fluxes across intracellular membranes. The Arabidopsis thaliana anion/proton exchanger AtCLCa is involved in vacuolar accumulation of nitrate. We investigated the role of AtCLCa in leaf guard cells, a specialized plant epidermal cell that controls gas exchange and water loss through pores called stomata. We showed that AtCLCa not only fulfilled the expected role of accumulating anions in the vacuole during stomatal opening but also mediated anion release during stomatal closure in response to the stress hormone abscisic acid (ABA). We found that this dual role resulted from a phosphorylation-dependent change in the activity of AtCLCa. The protein kinase OST1 (also known as SnRK2.6) is a key signaling player and central regulator in guard cells in response to ABA. Phosphorylation of Thr(38) in the amino-terminal cytoplasmic domain of AtCLCa by OST1 increased the outward anion fluxes across the vacuolar membrane, which are essential for stomatal closure. We provide evidence that bidirectional activities of an intracellular CLC exchanger are physiologically relevant and that phosphorylation regulates the transport mode of this exchanger.
Collapse
Affiliation(s)
- Stefanie Wege
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Alexis De Angeli
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France. Istituto di Biofisica, C.N.R., Via De Marini 6, 16149 Genova, Italy. Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Marie-Jo Droillard
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Laetitia Kroniewicz
- Laboratoire de Biologie du Développement des Plantes, Unité Mixte de Recherche 7265, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille II, Commissariat à l'Energie Atomique Cadarache Bât. 156, 13108 St Paul-lez-Durance, France
| | - Sylvain Merlot
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - David Cornu
- CNRS-FRC5115, Centre de Recherche de Gif, Imagif, Bât. 21, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Franco Gambale
- Istituto di Biofisica, C.N.R., Via De Marini 6, 16149 Genova, Italy
| | - Enrico Martinoia
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Hélène Barbier-Brygoo
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Sébastien Thomine
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
| | - Nathalie Leonhardt
- Laboratoire de Biologie du Développement des Plantes, Unité Mixte de Recherche 7265, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille II, Commissariat à l'Energie Atomique Cadarache Bât. 156, 13108 St Paul-lez-Durance, France
| | - Sophie Filleur
- CNRS-UPR 2355, Institut des Sciences du Végétal, Saclay Plant Sciences Labex, Bât. 22, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France. Université Paris 7 Denis Diderot, U.F.R. Sciences du Vivant, 35 rue Hélène Brion, 75205 Paris Cedex 13, France.
| |
Collapse
|
44
|
Marchand G, Huynh-Thu VA, Kane NC, Arribat S, Varès D, Rengel D, Balzergue S, Rieseberg LH, Vincourt P, Geurts P, Vignes M, Langlade NB. Bridging physiological and evolutionary time-scales in a gene regulatory network. THE NEW PHYTOLOGIST 2014; 203:685-696. [PMID: 24786523 DOI: 10.1111/nph.12818] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 03/17/2014] [Indexed: 06/03/2023]
Abstract
Gene regulatory networks (GRNs) govern phenotypic adaptations and reflect the trade-offs between physiological responses and evolutionary adaptation that act at different time-scales. To identify patterns of molecular function and genetic diversity in GRNs, we studied the drought response of the common sunflower, Helianthus annuus, and how the underlying GRN is related to its evolution. We examined the responses of 32,423 expressed sequences to drought and to abscisic acid (ABA) and selected 145 co-expressed transcripts. We characterized their regulatory relationships in nine kinetic studies based on different hormones. From this, we inferred a GRN by meta-analyses of a Gaussian graphical model and a random forest algorithm and studied the genetic differentiation among populations (FST ) at nodes. We identified two main hubs in the network that transport nitrate in guard cells. This suggests that nitrate transport is a critical aspect of the sunflower physiological response to drought. We observed that differentiation of the network genes in elite sunflower cultivars is correlated with their position and connectivity. This systems biology approach combined molecular data at different time-scales and identified important physiological processes. At the evolutionary level, we propose that network topology could influence responses to human selection and possibly adaptation to dry environments.
Collapse
Affiliation(s)
- Gwenaëlle Marchand
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326, Castanet-Tolosan, France
| | - Vân Anh Huynh-Thu
- Department of Electrical Engineering and Computer Science and GIGA-R, Systems and Modeling, University of Liège, Liège, Belgium
| | - Nolan C Kane
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, 80309, USA
| | - Sandrine Arribat
- INRA, Unité de Recherche en Génomique Végétale (URGV), UMR1165 - Université d'Evry Val d'Essonne - ERL CNRS 8196, CP 5708, F-91057, Evry Cedex, France
| | - Didier Varès
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326, Castanet-Tolosan, France
| | - David Rengel
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326, Castanet-Tolosan, France
| | - Sandrine Balzergue
- INRA, Unité de Recherche en Génomique Végétale (URGV), UMR1165 - Université d'Evry Val d'Essonne - ERL CNRS 8196, CP 5708, F-91057, Evry Cedex, France
| | - Loren H Rieseberg
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Patrick Vincourt
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326, Castanet-Tolosan, France
| | - Pierre Geurts
- Department of Electrical Engineering and Computer Science and GIGA-R, Systems and Modeling, University of Liège, Liège, Belgium
| | - Matthieu Vignes
- INRA, Mathématiques et Informatique Appliquées (MIA), UPR875, F-31326, Castanet-Tolosan, France
| | - Nicolas B Langlade
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326, Castanet-Tolosan, France
| |
Collapse
|
45
|
Krapp A, David LC, Chardin C, Girin T, Marmagne A, Leprince AS, Chaillou S, Ferrario-Méry S, Meyer C, Daniel-Vedele F. Nitrate transport and signalling in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:789-98. [PMID: 24532451 DOI: 10.1093/jxb/eru001] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plants have developed adaptive responses allowing them to cope with nitrogen (N) fluctuation in the soil and maintain growth despite changes in external N availability. Nitrate is the most important N form in temperate soils. Nitrate uptake by roots and its transport at the whole-plant level involves a large panoply of transporters and impacts plant performance. Four families of nitrate-transporting proteins have been identified so far: nitrate transporter 1/peptide transporter family (NPF), nitrate transporter 2 family (NRT2), the chloride channel family (CLC), and slow anion channel-associated homologues (SLAC/SLAH). Nitrate transporters are also involved in the sensing of nitrate. It is now well established that plants are able to sense external nitrate availability, and hence that nitrate also acts as a signal molecule that regulates many aspects of plant intake, metabolism, and gene expression. This review will focus on a global picture of the nitrate transporters so far identified and the recent advances in the molecular knowledge of the so-called primary nitrate response, the rapid regulation of gene expression in response to nitrate. The recent discovery of the NIN-like proteins as master regulators for nitrate signalling has led to a new understanding of the regulation cascade.
Collapse
Affiliation(s)
- Anne Krapp
- Institut National de la Recherche Agronomique (INRA), UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, RD10, F-78000 Versailles, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
AtALMT9 is a malate-activated vacuolar chloride channel required for stomatal opening in Arabidopsis. Nat Commun 2013; 4:1804. [PMID: 23653216 PMCID: PMC3644109 DOI: 10.1038/ncomms2815] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 03/27/2013] [Indexed: 01/30/2023] Open
Abstract
Water deficit strongly affects crop productivity. Plants control water loss and CO2 uptake by regulating the aperture of the stomatal pores within the leaf epidermis. Stomata aperture is regulated by the two guard cells forming the pore and changing their size in response to ion uptake and release. While our knowledge about potassium and chloride fluxes across the plasma membrane of guard cells is advanced, little is known about fluxes across the vacuolar membrane. Here we present the molecular identification of the long-sought-after vacuolar chloride channel. AtALMT9 is a chloride channel activated by physiological concentrations of cytosolic malate. Single-channel measurements demonstrate that this activation is due to a malate-dependent increase in the channel open probability. Arabidopsis thaliana atalmt9 knockout mutants exhibited impaired stomatal opening and wilt more slowly than the wild type. Our findings show that AtALMT9 is a vacuolar chloride channel having a major role in controlling stomata aperture. Aluminium-activated malate transporters are exclusive to plants, regulating the transport of ions across the membranes on which they are expressed. De Angeli and colleagues show that AtALMT9 acts as a vacuolar chloride channel that is activated by cytosolic malate, and that this regulates stomata aperture.
Collapse
|
47
|
Saleh L, Plieth C. A9C sensitive Cl⁻-accumulation in A. thaliana root cells during salt stress is controlled by internal and external calcium. PLANT SIGNALING & BEHAVIOR 2013; 8:e24259. [PMID: 23603974 PMCID: PMC3925454 DOI: 10.4161/psb.24259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/11/2013] [Accepted: 03/11/2013] [Indexed: 05/11/2023]
Abstract
The involvement of chloride in salt stress symptoms and salt tolerance mechanisms in plants has been less investigated in the past. Therefore, we studied the salt-induced chloride influx in Arabidopsis expressing the GFP-based anion indicator Clomeleon. High salt concentrations induce two phases of chloride influx. The fast kinetic phase is likely caused by membrane depolarization, and is assumed to be mediated by channels. This is followed by a slower "saturation" phase, where chloride is accumulated in the cytoplasm. Both phases of chloride uptake are dependent on the presence of external calcium. In general: with high [Ca (2+)] less chloride is accumulated in the cytoplasm. Surprisingly, also the internal calcium availability has an impact on chloride transport. A complete block of the second phase of chloride influx is achieved by the anion channel blocker A9C and trivalent cations (La (3+), Gd (3+), and Al (3+)). Other channel blockers and diuretics were found to inhibit the process partially. The results suggest that several transporter species are involved here, including electroneutral cation-chloride-cotransporters, and a part of chloride possibly enters the cells through cation channels after salt application.
Collapse
Affiliation(s)
- Livia Saleh
- Zentrum fur Biochemie und Molekularbiologie; Christian-Albrechts-Universitat; Kiel, Germany
| | - Christoph Plieth
- Zentrum fur Biochemie und Molekularbiologie; Christian-Albrechts-Universitat; Kiel, Germany
| |
Collapse
|
48
|
Seidel T, Siek M, Marg B, Dietz KJ. Energization of vacuolar transport in plant cells and its significance under stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:57-131. [PMID: 23809435 DOI: 10.1016/b978-0-12-407696-9.00002-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant vacuole is of prime importance in buffering environmental perturbations and in coping with abiotic stress caused by, for example, drought, salinity, cold, or UV. The large volume, the efficient integration in anterograde and retrograde vesicular trafficking, and the dynamic equipment with tonoplast transporters enable the vacuole to fulfill indispensible functions in cell biology, for example, transient and permanent storage, detoxification, recycling, pH and redox homeostasis, cell expansion, biotic defence, and cell death. This review first focuses on endomembrane dynamics and then summarizes the functions, assembly, and regulation of secretory and vacuolar proton pumps: (i) the vacuolar H(+)-ATPase (V-ATPase) which represents a multimeric complex of approximately 800 kDa, (ii) the vacuolar H(+)-pyrophosphatase, and (iii) the plasma membrane H(+)-ATPase. These primary proton pumps regulate the cytosolic pH and provide the driving force for secondary active transport. Carriers and ion channels modulate the proton motif force and catalyze uptake and vacuolar compartmentation of solutes and deposition of xenobiotics or secondary compounds such as flavonoids. ABC-type transporters directly energized by MgATP complement the transport portfolio that realizes the multiple functions in stress tolerance of plants.
Collapse
Affiliation(s)
- Thorsten Seidel
- Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
| | | | | | | |
Collapse
|
49
|
Wang YY, Hsu PK, Tsay YF. Uptake, allocation and signaling of nitrate. TRENDS IN PLANT SCIENCE 2012; 17:458-67. [PMID: 22658680 DOI: 10.1016/j.tplants.2012.04.006] [Citation(s) in RCA: 321] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/20/2012] [Accepted: 04/26/2012] [Indexed: 05/18/2023]
Abstract
Plants need to acquire nitrogen (N) efficiently from the soil for growth. Nitrate is one of the major N sources for higher plants. Therefore, nitrate uptake and allocation are key factors in efficient N utilization. Membrane-bound transporters are required for nitrate uptake from the soil and for the inter- and intracellular movement of nitrate inside the plants. Four gene families, nitrate transporter 1/peptide transporter (NRT1/PTR), NRT2, chloride channel (CLC), and slow anion channel-associated 1 homolog 3 (SLAC1/SLAH), are involved in nitrate uptake, allocation, and storage in higher plants. Recent studies of these transporters or channels have provided new insights into the molecular mechanisms of nitrate uptake and allocation. Interestingly, several of these transporters also play versatile roles in nitrate sensing, plant development, pathogen defense, and/or stress response.
Collapse
Affiliation(s)
- Ya-Yun Wang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | | |
Collapse
|
50
|
Robert N, d'Erfurth I, Marmagne A, Erhardt M, Allot M, Boivin K, Gissot L, Monachello D, Michaud M, Duchêne AM, Barbier-Brygoo H, Maréchal-Drouard L, Ephritikhine G, Filleur S. Voltage-dependent-anion-channels (VDACs) in Arabidopsis have a dual localization in the cell but show a distinct role in mitochondria. PLANT MOLECULAR BIOLOGY 2012; 78:431-46. [PMID: 22294207 DOI: 10.1007/s11103-012-9874-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 12/26/2011] [Indexed: 05/22/2023]
Abstract
In mammals, the Voltage-dependent anion channels (VDACs) are predominant proteins of the outer mitochondrial membrane (OMM) where they contribute to the exchange of small metabolites essential for respiration. They were shown to be as well associated with the plasma membrane (PM) and act as redox enzyme or are involved in ATP release for example. In Arabidopsis, we show that four out of six genomic sequences encode AtVDAC proteins. All four AtVDACs are ubiquitously expressed in the plant but each of them displays a specific expression pattern in root cell types. Using two complementary approaches, we demonstrate conclusively that the four expressed AtVDACs are targeted to both mitochondria and plasma membrane but in differential abundance, AtVDAC3 being the most abundant in PM, and conversely, AtVDAC4 almost exclusively associated with mitochondria. These are the first plant proteins to be shown to reside in both these two membranes. To investigate a putative function of AtVDACs, we analyzed T-DNA insertion lines in each of the corresponding genes. Knock-out mutants for AtVDAC1, AtVDAC2 and AtVDAC4 present slow growth, reduced fertility and yellow spots in leaves when atvdac3 does not show any visible difference compared to wildtype plants. Analyses of atvdac1 and atvdac4 reveal that yellow areas correspond to necrosis and the mitochondria are swollen in these two mutants. All these results suggest that, in spite of a localization in plasma membrane for three of them, AtVDAC1, AtVDAC2 and AtVDAC4 have a main function in mitochondria.
Collapse
Affiliation(s)
- Nadia Robert
- Institut des Sciences du Végétal, CNRS-UPR 2355, Bât. 22, 91198 Gif sur Yvette Cedex, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|