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Dubey SM, Fendrych M, Serre NB. Relative Membrane Potential Measurements Using DISBAC 2(3) Fluorescence in Arabidopsis thaliana Primary Roots. Bio Protoc 2023; 13:e4778. [PMID: 37497461 PMCID: PMC10367083 DOI: 10.21769/bioprotoc.4778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/20/2023] [Accepted: 06/12/2023] [Indexed: 07/28/2023] Open
Abstract
In vivo microscopy of plants with high-frequency imaging allows observation and characterization of the dynamic responses of plants to stimuli. It provides access to responses that could not be observed by imaging at a given time point. Such methods are particularly suitable for the observation of fast cellular events such as membrane potential changes. Classical measurement of membrane potential by probe impaling gives quantitative and precise measurements. However, it is invasive, requires specialized equipment, and only allows measurement of one cell at a time. To circumvent some of these limitations, we developed a method to relatively quantify membrane potential variations in Arabidopsis thaliana roots using the fluorescence of the voltage reporter DISBAC2(3). In this protocol, we describe how to prepare experiments for agar media and microfluidics, and we detail the image analysis. We take an example of the rapid plasma membrane depolarization induced by the phytohormone auxin to illustrate the method. Relative membrane potential measurements using DISBAC2(3) fluorescence increase the spatio-temporal resolution of the measurements and are non-invasive and suitable for live imaging of growing roots. Studying membrane potential with a more flexible method allows to efficiently combine mature electrophysiology literature and new molecular knowledge to achieve a better understanding of plant behaviors. Key features Non-invasive method to relatively quantify membrane potential in plant roots. Method suitable for imaging seedlings root in agar or liquid medium. Straightforward quantification.
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Affiliation(s)
- Shiv Mani Dubey
- Department of Experimental Plant Biology, Charles University, Prague, Czech Republic
| | - Matyáš Fendrych
- Department of Experimental Plant Biology, Charles University, Prague, Czech Republic
| | - Nelson Bc Serre
- Department of Experimental Plant Biology, Charles University, Prague, Czech Republic
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, École normale supérieure de Lyon, Centre national de la recherche scientifique (CNRS), Institut National de la Recherche Agronomique (INRAE), Lyon, France
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El Houari I, Klíma P, Baekelandt A, Staswick PE, Uzunova V, Del Genio CI, Steenackers W, Dobrev PI, Filepová R, Novák O, Napier R, Petrášek J, Inzé D, Boerjan W, Vanholme B. Non-specific effects of the CINNAMATE-4-HYDROXYLASE inhibitor piperonylic acid. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023. [PMID: 37036146 DOI: 10.1111/tpj.16237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 03/25/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Chemical inhibitors are often implemented for the functional characterization of genes to overcome the limitations associated with genetic approaches. Although it is well established that the specificity of the compound is key to success of a pharmacological approach, off-target effects are often overlooked or simply neglected in a complex biological setting. Here we illustrate the cause and implications of such secondary effects by focusing on piperonylic acid (PA), an inhibitor of CINNAMATE-4-HYDROXYLASE (C4H) that is frequently used to investigate the involvement of lignin during plant growth and development. When supplied to plants, we found that PA is recognized as a substrate by GRETCHEN HAGEN 3.6 (GH3.6), an amido synthetase involved in the formation of the indole-3-acetic acid (IAA) conjugate IAA-Asp. By competing for the same enzyme, PA interferes with IAA conjugation, resulting in an increase in IAA concentrations in the plant. In line with the broad substrate specificity of the GH3 family of enzymes, treatment with PA increased not only IAA levels but also those of other GH3-conjugated phytohormones, namely jasmonic acid and salicylic acid. Finally, we found that interference with the endogenous function of GH3s potentially contributes to phenotypes previously observed upon PA treatment. We conclude that deregulation of phytohormone homeostasis by surrogate occupation of the conjugation machinery in the plant is likely a general phenomenon when using chemical inhibitors. Our results hereby provide a novel and important basis for future reference in studies using chemical inhibitors.
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Affiliation(s)
- Ilias El Houari
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
| | - Petr Klíma
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Alexandra Baekelandt
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
| | - Paul E Staswick
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Veselina Uzunova
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Charo I Del Genio
- Centre for Fluid and Complex Systems, School of Computing, Electronics and Mathematics, Coventry University, Prior Street, Coventry, CV1 5FB, UK
| | - Ward Steenackers
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
| | - Petre I Dobrev
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Roberta Filepová
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Ondrej Novák
- Laboratory of Growth Regulators, Faculty of Science of Palacký University & Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Richard Napier
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Jan Petrášek
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43, Prague 2, Czech Republic
| | - Dirk Inzé
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
| | - Wout Boerjan
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
| | - Bartel Vanholme
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, B-9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, B-9052, Ghent, Belgium
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Abstract
Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here, we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa histidine kinase-1 (HK1) as well as the auxin influx carrier gene OsAUX1 as essential regulators of this process in rice. Robophysical modeling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics, and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.
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Abstract
Auxin regulates the transcription of auxin-responsive genes by the TIR1/AFBs-Aux/IAA-ARF signaling pathway, and in this way facilitates plant growth and development. However, rapid, nontranscriptional responses to auxin that cannot be explained by this pathway have been reported. In this review, we focus on several examples of rapid auxin responses: (1) the triggering of changes in plasma membrane potential in various plant species and tissues, (2) inhibition of root growth, which also correlates with membrane potential changes, cytosolic Ca2+ spikes, and a rise of apoplastic pH, (3) the influence on endomembrane trafficking of PIN proteins and other membrane cargoes, and (4) activation of ROPs (Rho of plants) and their downstream effectors such as the cytoskeleton or vesicle trafficking. In most cases, the signaling pathway triggering the response is poorly understood. A role for the TIR1/AFBs in rapid root growth regulation is emerging, as well as the involvement of transmembrane kinases (TMKs) in the activation of ROPs. We discuss similarities and differences among these rapid responses and focus on their physiological significance, which remains an enigma in most cases.
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Tan S, Di Donato M, Glanc M, Zhang X, Klíma P, Liu J, Bailly A, Ferro N, Petrášek J, Geisler M, Friml J. Non-steroidal Anti-inflammatory Drugs Target TWISTED DWARF1-Regulated Actin Dynamics and Auxin Transport-Mediated Plant Development. Cell Rep 2020; 33:108463. [PMID: 33264621 DOI: 10.1016/j.celrep.2020.108463] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/18/2020] [Accepted: 11/10/2020] [Indexed: 12/28/2022] Open
Abstract
The widely used non-steroidal anti-inflammatory drugs (NSAIDs) are derivatives of the phytohormone salicylic acid (SA). SA is well known to regulate plant immunity and development, whereas there have been few reports focusing on the effects of NSAIDs in plants. Our studies here reveal that NSAIDs exhibit largely overlapping physiological activities to SA in the model plant Arabidopsis. NSAID treatments lead to shorter and agravitropic primary roots and inhibited lateral root organogenesis. Notably, in addition to the SA-like action, which in roots involves binding to the protein phosphatase 2A (PP2A), NSAIDs also exhibit PP2A-independent effects. Cell biological and biochemical analyses reveal that many NSAIDs bind directly to and inhibit the chaperone activity of TWISTED DWARF1, thereby regulating actin cytoskeleton dynamics and subsequent endosomal trafficking. Our findings uncover an unexpected bioactivity of human pharmaceuticals in plants and provide insights into the molecular mechanism underlying the cellular action of this class of anti-inflammatory compounds.
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Affiliation(s)
- Shutang Tan
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Martin Di Donato
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Matouš Glanc
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400 Klosterneuburg, Austria; Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43 Prague 2, Czech Republic
| | - Xixi Zhang
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400 Klosterneuburg, Austria; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Petr Klíma
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Jie Liu
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Aurélien Bailly
- Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Noel Ferro
- University of Bonn, Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, 53115 Bonn, Germany
| | - Jan Petrášek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43 Prague 2, Czech Republic; The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Markus Geisler
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Jiří Friml
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400 Klosterneuburg, Austria.
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Jia L, Xie Y, Wang Z, Luo L, Zhang C, Pélissier PM, Parizot B, Qi W, Zhang J, Hu Z, Motte H, Luo L, Xu G, Beeckman T, Xuan W. Rice plants respond to ammonium stress by adopting a helical root growth pattern. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1023-1037. [PMID: 32890411 DOI: 10.1111/tpj.14978] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/28/2020] [Accepted: 08/19/2020] [Indexed: 05/26/2023]
Abstract
High levels of ammonium nutrition reduce plant growth and different plant species have developed distinct strategies to maximize ammonium acquisition while alleviating ammonium toxicity through modulating root growth. To date, the mechanisms underlying plant tolerance or sensitivity towards ammonium remain unclear. Rice (Oryza sativa) uses ammonium as its main N source. Here we show that ammonium supply restricts rice root elongation and induces a helical growth pattern, which is attributed to root acidification resulting from ammonium uptake. Ammonium-induced low pH triggers the asymmetric distribution of auxin in rice root tips through changes in auxin signaling, thereby inducing a helical growth response. Blocking auxin signaling completely inhibited this root response. In contrast, this root response is not activated in ammonium-treated Arabidopsis. Acidification of Arabidopsis roots leads to the protonation of indole-3-acetic acid and dampening of the intracellular auxin signaling levels that are required for maintaining root growth. Our study suggests a different mode of action by ammonium on the root pattern and auxin response machinery in rice versus Arabidopsis, and the rice-specific helical root response towards ammonium is an expression of the ability of rice to moderate auxin signaling and root growth to utilize ammonium while confronting acidic stress.
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Affiliation(s)
- Letian Jia
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuanming Xie
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhen Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Long Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chi Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Pierre-Mathieu Pélissier
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, B-9052, Belgium
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, Ghent, B-9052, Belgium
| | - Boris Parizot
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, B-9052, Belgium
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, Ghent, B-9052, Belgium
| | - Weicong Qi
- Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Jing Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhubing Hu
- Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Hans Motte
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, B-9052, Belgium
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, Ghent, B-9052, Belgium
| | - Le Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, B-9052, Belgium
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, Ghent, B-9052, Belgium
| | - Wei Xuan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
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