1
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Yue CP, Han L, Sun SS, Chen JF, Feng YN, Huang JY, Zhou T, Hua YP. Genome-wide identification of the cation/proton antiporter (CPA) gene family and functional characterization of the key member BnaA05.NHX2 in allotetraploid rapeseed. Gene 2024; 894:148025. [PMID: 38007163 DOI: 10.1016/j.gene.2023.148025] [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: 09/13/2023] [Revised: 11/08/2023] [Accepted: 11/21/2023] [Indexed: 11/27/2023]
Abstract
Rapeseed (Brassica napus L.) is susceptible to nutrient stresses during growth and development; however, the CPA (cation proton antiporter) family genes have not been identified in B. napus and their biological functions remain unclear. This study was aimed to identify the molecular characteristics of rapeseed CPAs and their transcriptional responses to multiple nutrient stresses. Through bioinformatics analysis, 117 BnaCPAs, consisting of three subfamilies: Na+/H+ antiporter (NHX), K+ efflux antiporter (KEA), and cation/H+ antiporter (CHX), were identified in the rapeseed genome. Transcriptomic profiling showed that BnaCPAs, particularly BnaNHXs, were transcriptionally responsive to diverse nutrient stresses, including Cd toxicity, K starvation, salt stress, NH4+ toxicity, and low Pi. We found that the salt tolerance of the transgenic rapeseed lines overexpressing BnaA05.NHX2 was significantly higher than that of wild type. Subcellular localization showed that BnaA05.NHX2 was localized on the tonoplast, and TEM combined with X-ray energy spectrum analysis revealed that the vacuolar Na+ concentrations of the BnaA05.NHX2-overexpressing rapeseed plants were significantly higher than those of wild type. The findings of this study will provide insights into the complexity of the BnaCPA family and a valuable resource to explore the in-depth functions of CPAs in B. napus.
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Affiliation(s)
- Cai-Peng Yue
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Liao Han
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Si-Si Sun
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Jun-Fan Chen
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Ying-Na Feng
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Jin-Yong Huang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Ting Zhou
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Ying-Peng Hua
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
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2
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Li K, Grauschopf C, Hedrich R, Dreyer I, Konrad KR. K + and pH homeostasis in plant cells is controlled by a synchronized K + /H + antiport at the plasma and vacuolar membrane. THE NEW PHYTOLOGIST 2024; 241:1525-1542. [PMID: 38017688 DOI: 10.1111/nph.19436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023]
Abstract
Stomatal movement involves ion transport across the plasma membrane (PM) and vacuolar membrane (VM) of guard cells. However, the coupling mechanisms of ion transporters in both membranes and their interplay with Ca2+ and pH changes are largely unclear. Here, we investigated transporter networks in tobacco guard cells and mesophyll cells using multiparametric live-cell ion imaging and computational simulations. K+ and anion fluxes at both, PM and VM, affected H+ and Ca2+ , as changes in extracellular KCl or KNO3 concentrations were accompanied by cytosolic and vacuolar pH shifts and changes in [Ca2+ ]cyt and the membrane potential. At both membranes, the K+ transporter networks mediated an antiport of K+ and H+ . By contrast, net transport of anions was accompanied by parallel H+ transport, with differences in transport capacity for chloride and nitrate. Guard and mesophyll cells exhibited similarities in K+ /H+ transport but cell type-specific differences in [H+ ]cyt and pH-dependent [Ca2+ ]cyt signals. Computational cell biology models explained mechanistically the properties of transporter networks and the coupling of transport across the PM and VM. Our integrated approach indicates fundamental principles of coupled ion transport at membrane sandwiches to control H+ /K+ homeostasis and points to transceptor-like Ca2+ /H+ -based ion signaling in plant cells.
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Affiliation(s)
- Kunkun Li
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Christina Grauschopf
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Rainer Hedrich
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
| | - Ingo Dreyer
- Faculty of Engineering, Center of Bioinformatics, Simulation and Modeling (CBSM), University of Talca, 3460000, Talca, Chile
| | - Kai R Konrad
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082, Wuerzburg, Germany
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3
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Mathew IE, Rhein HS, Yang J, Gradogna A, Carpaneto A, Guo Q, Tappero R, Scholz-Starke J, Barkla BJ, Hirschi KD, Punshon T. Sequential removal of cation/H + exchangers reveals their additive role in elemental distribution, calcium depletion and anoxia tolerance. PLANT, CELL & ENVIRONMENT 2024; 47:557-573. [PMID: 37916653 DOI: 10.1111/pce.14756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/21/2023] [Accepted: 10/18/2023] [Indexed: 11/03/2023]
Abstract
Multiple Arabidopsis H+ /Cation exchangers (CAXs) participate in high-capacity transport into the vacuole. Previous studies have analysed single and double mutants that marginally reduced transport; however, assessing phenotypes caused by transport loss has proven enigmatic. Here, we generated quadruple mutants (cax1-4: qKO) that exhibited growth inhibition, an 85% reduction in tonoplast-localised H+ /Ca transport, and enhanced tolerance to anoxic conditions compared to CAX1 mutants. Leveraging inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron X-ray fluorescence (SXRF), we demonstrate CAX transporters work together to regulate leaf elemental content: ICP-MS analysis showed that the elemental concentrations in leaves strongly correlated with the number of CAX mutations; SXRF imaging showed changes in element partitioning not present in single CAX mutants and qKO had a 40% reduction in calcium (Ca) abundance. Reduced endogenous Ca may promote anoxia tolerance; wild-type plants grown in Ca-limited conditions were anoxia tolerant. Sequential reduction of CAXs increased mRNA expression and protein abundance changes associated with reactive oxygen species and stress signalling pathways. Multiple CAXs participate in postanoxia recovery as their concerted removal heightened changes in postanoxia Ca signalling. This work showcases the integrated and diverse function of H+ /Cation transporters and demonstrates the ability to improve anoxia tolerance through diminishing endogenous Ca levels.
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Affiliation(s)
- Iny Elizebeth Mathew
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, Houston, Texas, USA
| | - Hormat Shadgou Rhein
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, Houston, Texas, USA
| | - Jian Yang
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, Houston, Texas, USA
| | - Antonella Gradogna
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - Armando Carpaneto
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Genova, Italy
| | - Qi Guo
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Ryan Tappero
- Brookhaven National Laboratory, Photon Sciences Department, Upton, New York, USA
| | | | - Bronwyn J Barkla
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Kendal D Hirschi
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, Houston, Texas, USA
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
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4
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Rombolá-Caldentey B, Mendoza I, Quintero FJ, Pardo JM. Structure-Guided Identification of Critical Residues in the Vacuolar Cation/Proton Antiporter NHX1 from Arabidopsis thaliana. PLANTS (BASEL, SWITZERLAND) 2023; 12:2778. [PMID: 37570932 PMCID: PMC10421325 DOI: 10.3390/plants12152778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023]
Abstract
Cation/Proton Antiporters (CPA) acting in all biological membranes regulate the volume and pH of cells and of intracellular organelles. A key issue with these proteins is their structure-function relationships since they present intrinsic regulatory features that rely on structural determinants, including pH sensitivity and the stoichiometry of ion exchange. Crystal structures are only available for prokaryotic CPA, whereas the eukaryotic ones have been modeled using the former as templates. Here, we present an updated and improved structural model of the tonoplast-localized K+, Na+/H+ antiporter NHX1 of Arabidopsis as a representative of the vacuolar NHX family that is essential for the accumulation of K+ into plant vacuoles. Conserved residues that were judged as functionally important were mutated, and the resulting protein variants were tested for activity in the yeast Saccharomyces cerevisiae. The results indicate that residue N184 in the ND-motif characteristic of CPA1 could be replaced by the DD-motif of CPA2 family members with minimal consequences for their activity. Attempts to alter the electroneutrality of AtNHX1 by different combinations of amino acid replacements at N184, R353 and R390 residues resulted in inactive or partly active proteins with a differential ability to control the vacuolar pH of the yeast.
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Affiliation(s)
| | | | | | - José M. Pardo
- Instituto de Bioquimica Vegetal y Fotosintesis, cicCartuja, Consejo Superior de Investigaciones Cientificas, Universidad de Sevilla, 41092 Sevilla, Spain; (B.R.-C.); (I.M.); (F.J.Q.)
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5
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Gradogna A, Lagostena L, Beltrami S, Tosato E, Picco C, Scholz-Starke J, Sparla F, Trost P, Carpaneto A. Tonoplast cytochrome b561 is a transmembrane ascorbate-dependent monodehydroascorbate reductase: functional characterization of electron currents in plant vacuoles. THE NEW PHYTOLOGIST 2023; 238:1957-1971. [PMID: 36806214 DOI: 10.1111/nph.18823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/14/2023] [Indexed: 05/04/2023]
Abstract
Ascorbate (Asc) is a major redox buffer of plant cells, whose antioxidant activity depends on the ratio with its one-electron oxidation product monodehydroascorbate (MDHA). The cytoplasm contains millimolar concentrations of Asc and soluble enzymes that can regenerate Asc from MDHA or fully oxidized dehydroascorbate. Also, vacuoles contain Asc, but no soluble Asc-regenerating enzymes. Here, we show that vacuoles isolated from Arabidopsis mesophyll cells contain a tonoplast electron transport system that works as a reversible, Asc-dependent transmembrane MDHA oxidoreductase. Electron currents were measured by patch-clamp on isolated vacuoles and found to depend on the availability of Asc (electron donor) and ferricyanide or MDHA (electron acceptors) on opposite sides of the tonoplast. Electron currents were catalyzed by cytochrome b561 isoform A (CYB561A), a tonoplast redox protein with cytoplasmic and luminal Asc binding sites. The Km for Asc of the luminal (4.5 mM) and cytoplasmic site (51 mM) reflected the physiological Asc concentrations in these compartments. The maximal current amplitude was similar in both directions. Mutant plants with impaired CYB561A expression showed no detectable trans-tonoplast electron currents and strong accumulation of leaf anthocyanins under excessive illumination, suggesting a redox-modulation exerted by CYB561A on the typical anthocyanin response to high-light stress.
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Affiliation(s)
| | - Laura Lagostena
- Institute of Biophysics - CNR, Via De Marini 6, 16149, Genova, Italy
| | - Sara Beltrami
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Edoardo Tosato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Cristiana Picco
- Institute of Biophysics - CNR, Via De Marini 6, 16149, Genova, Italy
| | | | - Francesca Sparla
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Paolo Trost
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Armando Carpaneto
- Institute of Biophysics - 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
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6
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Effects of Arbuscular Mycorrhizal Fungus on Sodium and Chloride Ion Channels of Casuarina glauca under Salt Stress. Int J Mol Sci 2023; 24:ijms24043680. [PMID: 36835093 PMCID: PMC9966195 DOI: 10.3390/ijms24043680] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/04/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Casuarina glauca is an important coastal protection forest species, which is exposed to high salt stress all year round. Arbuscular mycorrhizal fungi (AMF) can promote the growth and salt tolerance of C. glauca under salt stress. However, the effects of AMF on the distribution of Na+ and Cl- and the expression of related genes in C. glauca under salt stress need to be further explored. This study explored the effects of Rhizophagus irregularis on plant biomass, the distribution of Na+ and Cl-, and the expression of related genes in C. glauca under NaCl stress through pot simulation experiments. The results revealed that the mechanisms of Na+ and Cl- transport of C. glauca under NaCl stress were different. C. glauca took a salt accumulation approach to Na+, transferring Na+ from roots to shoots. Salt accumulation of Na+ promoted by AMF was associated with CgNHX7. The transport mechanism of C. glauca to Cl- might involve salt exclusion rather than salt accumulation, and Cl- was no longer transferred to shoots in large quantities but started to accumulate in roots. However, AMF alleviated Na+ and Cl- stress by similar mechanisms. AMF could promote salt dilution of C. glauca by increasing biomass and the content of K+, compartmentalizing Na+ and Cl- in vacuoles. These processes were associated with the expression of CgNHX1, CgNHX2-1, CgCLCD, CgCLCF, and CgCLCG. Our study will provide a theoretical basis for the application of AMF to improve salt tolerance in plants.
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7
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Dietrich P, Gradogna A, Carpaneto A. The Plant Vacuole as Heterologous System to Characterize the Functional Properties of TPC Channels. Handb Exp Pharmacol 2023; 278:235-247. [PMID: 35879579 DOI: 10.1007/164_2022_604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Human TPC channels are an emerging family of intracellular proteins fundamental for cell physiology and involved in various severe pathologies. Their localization in the membranes of endo-lysosomes, intracellular compartments of submicrometric dimensions, makes their study difficult with usual electrophysiological techniques. In this work, we show how the plant vacuole, a versatile organelle that can occupy up to 90% of the volume in mature plant cells, can be used as a heterologous system of expression for functional characterization. For this purpose, the use of vacuoles isolated from mesophyll cells of the Arabidopsis thaliana mutant lacking the endogenous TPC avoids unwanted interferences. The patch-clamp technique can be successfully applied to plant vacuoles in all different configuration modes; of note, the whole-vacuole configuration allows to study channel modulation by cytosolic factors. The combination of patch-clamp with fluorescence techniques, for example, by using fluorescent probes sensitive to specific ions of interest, represents a useful extension to investigate the selectivity properties of the channels. Therefore, the plant vacuole, similar to Xenopus oocytes for ion channels and transporters localized in the plasma membrane, has the capability to become a model system for functional studies on intracellular ion channels and transporters.
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Affiliation(s)
- P Dietrich
- Lehrstuhl für Molekulare Pflanzenphysiologie, Department Biologie Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | | | - A Carpaneto
- Institute of Biophysics, Genoa, Italy.
- Department of Earth, Environment and Life Sciences (DISTAV) - University of Genoa, Genoa, Italy.
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8
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Minicozzi V, Qi T, Gradogna A, Pozzolini M, Milenkovic S, Filippini A, Ceccarelli M, Carpaneto A. A commentary on the inhibition of human TPC2 channel by the natural flavonoid naringenin: Methods, experiments, and ideas. Biomol Concepts 2023; 14:bmc-2022-0036. [PMID: 37677148 DOI: 10.1515/bmc-2022-0036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023] Open
Abstract
Human endo-lysosomes possess a class of proteins called TPC channels on their membrane, which are essential for proper cell functioning. This protein family can be functionally studied by expressing them in plant vacuoles. Inhibition of hTPC activity by naringenin, one of the main flavonoids present in the human diet, has the potential to be beneficial in severe human diseases such as solid tumor development, melanoma, and viral infections. We attempted to identify the molecular basis of the interaction between hTPC2 and naringenin, using ensemble docking on molecular dynamics (MD) trajectories, but the specific binding site remains elusive, posing a challenge that could potentially be addressed in the future by increased computational power in MD and the combined use of microscopy techniques such as cryo-EM.
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Affiliation(s)
- Velia Minicozzi
- INFN and Department of Physics, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma, Italy
| | - Tianwen Qi
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132 Genova, Italy
| | - Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genova, Italy
| | - Marina Pozzolini
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132 Genova, Italy
| | - Stefan Milenkovic
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy
| | - Antonio Filippini
- Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Unit of Histology and Medical Embryology, Sapienza University, 16 Via A. Scarpa, 00161 Rome, Italy
| | - Matteo Ceccarelli
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy
| | - Armando Carpaneto
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132 Genova, Italy
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genova, Italy
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9
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Graus D, Li K, Rathje JM, Ding M, Krischke M, Müller MJ, Cuin TA, Al-Rasheid KAS, Scherzer S, Marten I, Konrad KR, Hedrich R. Tobacco leaf tissue rapidly detoxifies direct salt loads without activation of calcium and SOS signaling. THE NEW PHYTOLOGIST 2023; 237:217-231. [PMID: 36128659 DOI: 10.1111/nph.18501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 09/11/2022] [Indexed: 06/15/2023]
Abstract
Salt stress is a major abiotic stress, responsible for declining agricultural productivity. Roots are regarded as hubs for salt detoxification, however, leaf salt concentrations may exceed those of roots. How mature leaves manage acute sodium chloride (NaCl) stress is mostly unknown. To analyze the mechanisms for NaCl redistribution in leaves, salt was infiltrated into intact tobacco leaves. It initiated pronounced osmotically-driven leaf movements. Leaf downward movement caused by hydro-passive turgor loss reached a maximum within 2 h. Salt-driven cellular water release was accompanied by a transient change in membrane depolarization but not an increase in cytosolic calcium ion (Ca2+ ) level. Nonetheless, only half an hour later, the leaves had completely regained turgor. This recovery phase was characterized by an increase in mesophyll cell plasma membrane hydrogen ion (H+ ) pumping, a salt uptake-dependent cytosolic alkalization, and a return of the apoplast osmolality to pre-stress levels. Although, transcript numbers of abscisic acid- and Salt Overly Sensitive pathway elements remained unchanged, salt adaptation depended on the vacuolar H+ /Na+ -exchanger NHX1. Altogether, tobacco leaves can detoxify sodium ions (Na+ ) rapidly even under massive salt loads, based on pre-established posttranslational settings and NHX1 cation/H+ antiport activity. Unlike roots, signaling and processing of salt stress in tobacco leaves does not depend on Ca2+ signaling.
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Affiliation(s)
- Dorothea Graus
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Kunkun Li
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Jan M Rathje
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Meiqi Ding
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Markus Krischke
- Institute for Pharmaceutical Biology, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Martin J Müller
- Institute for Pharmaceutical Biology, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Tracey Ann Cuin
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7005, Australia
| | - Khaled A S Al-Rasheid
- Zoology Department, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Sönke Scherzer
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Irene Marten
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Kai R Konrad
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius von-Sachs Platz 2, D-97082, Würzburg, Germany
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10
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Gradogna A, Carpaneto A. Electrophysiology and fluorescence to investigate cation channels and transporters in isolated plant vacuoles. STRESS BIOLOGY 2022; 2:42. [PMID: 37676514 PMCID: PMC10442027 DOI: 10.1007/s44154-022-00064-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/01/2022] [Indexed: 09/08/2023]
Abstract
The plant vacuole plays a fundamental role in cell homeostasis. The successful application of patch-clamp technique on isolated vacuoles allows the determination of the functional characteristics of tonoplast ion channels and transporters. The parallel use of a sensor-based fluorescence approach capable of detecting changes in calcium and proton concentrations opens up new possibilities for investigation. In excised patch, the presence of fura-2 in the vacuolar solution reveals the direct permeation of calcium in plant TPC channels. In whole-vacuole, the activity of non-electrogenic NHX potassium proton antiporters can be measured by using the proton sensitive dye BCECF loaded in the vacuolar lumen by the patch pipette. Both vacuolar NHXs and CLCa (chloride/nitrate antiporter) are inhibited by the phosphoinositide PI(3,5)P2, suggesting a coordinated role of these proteins in salt accumulation. Increased knowledge in the molecular mechanisms of vacuolar ion channels and transporters has the potential to improve our understanding on how plants cope with a rapidly changing environment.
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Affiliation(s)
- Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy.
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132, Genoa, Italy.
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11
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Ankit A, Kamali S, Singh A. Genomic & structural diversity and functional role of potassium (K +) transport proteins in plants. Int J Biol Macromol 2022; 208:844-857. [PMID: 35367275 DOI: 10.1016/j.ijbiomac.2022.03.179] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/11/2022] [Accepted: 03/25/2022] [Indexed: 01/03/2023]
Abstract
Potassium (K+) is an essential macronutrient for plant growth and productivity. It is the most abundant cation in plants and is involved in various cellular processes. Variable K+ availability is sensed by plant roots, consequently K+ transport proteins are activated to optimize K+ uptake. In addition to K+ uptake and translocation these proteins are involved in other important physiological processes like transmembrane voltage regulation, polar auxin transport, maintenance of Na+/K+ ratio and stomata movement during abiotic stress responses. K+ transport proteins display tremendous genomic and structural diversity in plants. Their key structural features, such as transmembrane domains, N-terminal domains, C-terminal domains and loops determine their ability of K+ uptake and transport and thus, provide functional diversity. Most K+ transporters are regulated at transcriptional and post-translational levels. Genetic manipulation of key K+ transporters/channels could be a prominent strategy for improving K+ utilization efficiency (KUE) in plants. This review discusses the genomic and structural diversity of various K+ transport proteins in plants. Also, an update on the function of K+ transport proteins and their regulatory mechanism in response to variable K+ availability, in improving KUE, biotic and abiotic stresses is provided.
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Affiliation(s)
- Ankit Ankit
- National Institute of Plant Genome Research, New Delhi 110067, India
| | | | - Amarjeet Singh
- National Institute of Plant Genome Research, New Delhi 110067, India.
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12
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Gradogna A, Pardo JM, Carpaneto A. The phosphoinositide PI(3,5)P 2 inhibits the activity of plant NHX proton/potassium antiporters: Advantages of a novel electrophysiological approach. Biomol Concepts 2022; 13:119-125. [DOI: 10.1515/bmc-2022-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
In the present work, we discuss the way in which the parallel application of the patch-clamp technique and the 2′,7′-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) fluorescence detection for recording luminal proton changes allows the functional characterization of nonelectrogenic potassium/proton vacuolar antiporters of the NHX (Na+/H+ exchanger) family. Moreover, we review the functional role of the tonoplast-specific phosphoinositide PI(3,5)P2, able to simultaneously inhibit the activity of NHXs and CLC-a transporters, whose coordinated action can play an important role in the water balance of plant cells.
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Affiliation(s)
- Antonella Gradogna
- Institute of Biophysics, National Research Council , Via De Marini 6 , 16149 Genova , Italy
| | - José M. Pardo
- Institute of Plant Biochemistry and Photosynthesis, Consejo Superior de Investigaciones Cientificas and University of Seville , Seville 41092 , Spain
| | - Armando Carpaneto
- Department of Earth, Environment and Life Sciences (DISTAV) – University of Genoa , Viale Benedetto XV 5 , 16132 Genova , Italy
- Institute of Biophysics, National Research Council , Via De Marini 6 , 16149 Genova , Italy
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13
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Current Methods to Unravel the Functional Properties of Lysosomal Ion Channels and Transporters. Cells 2022; 11:cells11060921. [PMID: 35326372 PMCID: PMC8946281 DOI: 10.3390/cells11060921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 02/07/2023] Open
Abstract
A distinct set of channels and transporters regulates the ion fluxes across the lysosomal membrane. Malfunctioning of these transport proteins and the resulting ionic imbalance is involved in various human diseases, such as lysosomal storage disorders, cancer, as well as metabolic and neurodegenerative diseases. As a consequence, these proteins have stimulated strong interest for their suitability as possible drug targets. A detailed functional characterization of many lysosomal channels and transporters is lacking, mainly due to technical difficulties in applying the standard patch-clamp technique to these small intracellular compartments. In this review, we focus on current methods used to unravel the functional properties of lysosomal ion channels and transporters, stressing their advantages and disadvantages and evaluating their fields of applicability.
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D’Amore A, Gradogna A, Palombi F, Minicozzi V, Ceccarelli M, Carpaneto A, Filippini A. The Discovery of Naringenin as Endolysosomal Two-Pore Channel Inhibitor and Its Emerging Role in SARS-CoV-2 Infection. Cells 2021; 10:1130. [PMID: 34067054 PMCID: PMC8150892 DOI: 10.3390/cells10051130] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/01/2021] [Accepted: 05/04/2021] [Indexed: 12/23/2022] Open
Abstract
The flavonoid naringenin (Nar), present in citrus fruits and tomatoes, has been identified as a blocker of an emerging class of human intracellular channels, namely the two-pore channel (TPC) family, whose role has been established in several diseases. Indeed, Nar was shown to be effective against neoangiogenesis, a process essential for solid tumor progression, by specifically impairing TPC activity. The goal of the present review is to illustrate the rationale that links TPC channels to the mechanism of coronavirus infection, and how their inhibition by Nar could be an efficient pharmacological strategy to fight the current pandemic plague COVID-19.
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Affiliation(s)
- Antonella D’Amore
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
| | - Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genova, Italy
| | - Fioretta Palombi
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
| | - Velia Minicozzi
- INFN and Department of Physics, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma, Italy;
| | - Matteo Ceccarelli
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy;
- IOM-CNR Unità di Cagliari, Cittadella Universitaria, 09042 Monserrato, Italy
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, 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
| | - Antonio Filippini
- Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy; (A.D.); (F.P.)
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