1
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Lu B, Wang S, Feng H, Wang J, Zhang K, Li Y, Wu P, Zhang M, Xia Y, Peng C, Li C. FERONIA-mediated TIR1/AFB2 oxidation stimulates auxin signaling in Arabidopsis. MOLECULAR PLANT 2024; 17:772-787. [PMID: 38581129 DOI: 10.1016/j.molp.2024.04.002] [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: 01/08/2024] [Revised: 03/13/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
The phytohormone auxin plays a pivotal role in governing plant growth and development. Although the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX (TIR1/AFB) receptors function in both the nucleus and cytoplasm, the mechanism governing the distribution of TIR1/AFBs between these cellular compartments remains unknown. In this study, we demonstrate that auxin-mediated oxidation of TIR1/AFB2 is essential for their targeting to the nucleus. We showed that small active molecules, reactive oxygen species (ROS) and nitric oxide (NO), are indispensable for the nucleo-cytoplasmic distribution of TIR1/AFB2 in trichoblasts and root hairs. Further studies revealed that this process is regulated by the FERONIA receptor kinase-NADPH oxidase signaling pathway. Interestingly, ROS and NO initiate oxidative modifications in TIR1C140/516 and AFB2C135/511, facilitating their subsequent nuclear import. The oxidized forms of TIR1C140/516 and AFB2C135/511 play a crucial role in enhancing the function of TIR1 and AFB2 in transcriptional auxin responses. Collectively, our study reveals a novel mechanism by which auxin stimulates the transport of TIR1/AFB2 from the cytoplasm to the nucleus, orchestrated by the FERONIA-ROS signaling pathway.
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Affiliation(s)
- Baiyan Lu
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Shengnan Wang
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Hanqian Feng
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jing Wang
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Kaixing Zhang
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Yilin Li
- National Facility for Protein Science Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Ping Wu
- National Facility for Protein Science Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Minmin Zhang
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Yanshu Xia
- School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Chao Peng
- National Facility for Protein Science Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Chao Li
- School of Life Sciences, East China Normal University, Shanghai 200241, China.
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2
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Sheen J. The new horizon of plant auxin signaling via cell-surface co-receptors. Cell Res 2024; 34:343-344. [PMID: 38182889 PMCID: PMC11061107 DOI: 10.1038/s41422-023-00921-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2024] Open
Affiliation(s)
- Jen Sheen
- Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA.
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3
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Cohen JD, Strader LC. An auxin research odyssey: 1989-2023. THE PLANT CELL 2024; 36:1410-1428. [PMID: 38382088 PMCID: PMC11062468 DOI: 10.1093/plcell/koae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/23/2024] [Accepted: 02/07/2024] [Indexed: 02/23/2024]
Abstract
The phytohormone auxin is at times called the master regulator of plant processes and has been shown to be a central player in embryo development, the establishment of the polar axis, early aspects of seedling growth, as well as growth and organ formation during later stages of plant development. The Plant Cell has been key, since the inception of the journal, to developing an understanding of auxin biology. Auxin-regulated plant growth control is accomplished by both changes in the levels of active hormones and the sensitivity of plant tissues to these concentration changes. In this historical review, we chart auxin research as it has progressed in key areas and highlight the role The Plant Cell played in these scientific developments. We focus on understanding auxin-responsive genes, transcription factors, reporter constructs, perception, and signal transduction processes. Auxin metabolism is discussed from the development of tryptophan auxotrophic mutants, the molecular biology of conjugate formation and hydrolysis, indole-3-butyric acid metabolism and transport, and key steps in indole-3-acetic acid biosynthesis, catabolism, and transport. This progress leads to an expectation of a more comprehensive understanding of the systems biology of auxin and the spatial and temporal regulation of cellular growth and development.
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Affiliation(s)
- Jerry D Cohen
- Department of Horticultural Science and the Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - Lucia C Strader
- Department of Biology, Duke University, Durham, NC 27008, USA
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4
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Kulich I, Schmid J, Teplova A, Qi L, Friml J. Rapid translocation of NGR proteins driving polarization of PIN-activating D6 protein kinase during root gravitropism. eLife 2024; 12:RP91523. [PMID: 38441122 PMCID: PMC10942638 DOI: 10.7554/elife.91523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024] Open
Abstract
Root gravitropic bending represents a fundamental aspect of terrestrial plant physiology. Gravity is perceived by sedimentation of starch-rich plastids (statoliths) to the bottom of the central root cap cells. Following gravity perception, intercellular auxin transport is redirected downwards leading to an asymmetric auxin accumulation at the lower root side causing inhibition of cell expansion, ultimately resulting in downwards bending. How gravity-induced statoliths repositioning is translated into asymmetric auxin distribution remains unclear despite PIN auxin efflux carriers and the Negative Gravitropic Response of roots (NGR) proteins polarize along statolith sedimentation, thus providing a plausible mechanism for auxin flow redirection. In this study, using a functional NGR1-GFP construct, we visualized the NGR1 localization on the statolith surface and plasma membrane (PM) domains in close proximity to the statoliths, correlating with their movements. We determined that NGR1 binding to these PM domains is indispensable for NGR1 functionality and relies on cysteine acylation and adjacent polybasic regions as well as on lipid and sterol PM composition. Detailed timing of the early events following graviperception suggested that both NGR1 repolarization and initial auxin asymmetry precede the visible PIN3 polarization. This discrepancy motivated us to unveil a rapid, NGR-dependent translocation of PIN-activating AGCVIII kinase D6PK towards lower PMs of gravity-perceiving cells, thus providing an attractive model for rapid redirection of auxin fluxes following gravistimulation.
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Affiliation(s)
- Ivan Kulich
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Julia Schmid
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | | | - Linlin Qi
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Jiří Friml
- Institute of Science and Technology AustriaKlosterneuburgAustria
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5
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Kubalová M, Müller K, Dobrev PI, Rizza A, Jones AM, Fendrych M. Auxin co-receptor IAA17/AXR3 controls cell elongation in Arabidopsis thaliana root solely by modulation of nuclear auxin pathway. THE NEW PHYTOLOGIST 2024; 241:2448-2463. [PMID: 38308183 DOI: 10.1111/nph.19557] [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: 04/14/2023] [Accepted: 01/06/2024] [Indexed: 02/04/2024]
Abstract
The nuclear TIR1/AFB-Aux/IAA auxin pathway plays a crucial role in regulating plant growth and development. Specifically, the IAA17/AXR3 protein participates in Arabidopsis thaliana root development, response to auxin and gravitropism. However, the mechanism by which AXR3 regulates cell elongation is not fully understood. We combined genetical and cell biological tools with transcriptomics and determination of auxin levels and employed live cell imaging and image analysis to address how the auxin response pathways influence the dynamics of root growth. We revealed that manipulations of the TIR1/AFB-Aux/IAA pathway rapidly modulate root cell elongation. While inducible overexpression of the AXR3-1 transcriptional inhibitor accelerated growth, overexpression of the dominant activator form of ARF5/MONOPTEROS inhibited growth. In parallel, AXR3-1 expression caused loss of auxin sensitivity, leading to transcriptional reprogramming, phytohormone signaling imbalance and increased levels of auxin. Furthermore, we demonstrated that AXR3-1 specifically perturbs nuclear auxin signaling, while the rapid auxin response remains functional. Our results shed light on the interplay between the nuclear and cytoplasmic auxin pathways in roots, revealing their partial independence but also the dominant role of the nuclear auxin pathway during the gravitropic response of Arabidopsis thaliana roots.
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Affiliation(s)
- Monika Kubalová
- Department of Experimental Plant Biology, Charles University, Prague, 12844, Czech Republic
| | - Karel Müller
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Petre Ivanov Dobrev
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Annalisa Rizza
- Sainsbury Laboratory, Cambridge University, Cambridge, CB2 1LR, UK
| | | | - Matyáš Fendrych
- Department of Experimental Plant Biology, Charles University, Prague, 12844, Czech Republic
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6
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Li X, Zhao R, Liu J, Li Z, Chen A, Xu S, Sheng X. Dynamic changes in calcium signals during root gravitropism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 208:108481. [PMID: 38447424 DOI: 10.1016/j.plaphy.2024.108481] [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: 01/11/2024] [Revised: 02/17/2024] [Accepted: 02/28/2024] [Indexed: 03/08/2024]
Abstract
Gravitropism is a vital mechanism through which plants adapt to their environment. Previous studies indicated that Ca2+ may play an important role in plant gravitropism. However, our understanding of the calcium signals in root gravitropism is still largely limited. Using a vertical stage confocal and transgenic Arabidopsis R-GECO1, our data showed that gravity stimulation enhances the occurrence of calcium spikes and increases the Ca2+ concentration in the lower side of the root cap. Furthermore, a close correlation was observed in the asymmetry of calcium signals with the inclination angles at which the roots were oriented. The frequency of calcium spikes on the lower side of 90°-rotated root decreases rapidly over time, whereas the asymmetric distribution of auxin readily strengthens for up to 3 h, indicating that the calcium spikes, promoted by gravity stimulation, may precede auxin as one of the early signals. In addition, the root gravitropism of starchless mutants is severely impaired. Correspondingly, no significant increase in calcium spike occurrence was observed in the root caps of these mutants within 15 min following a 90° rotation, indicating the involvement of starch grains in the formation of calcium spikes. However, between 30 and 45 min after a 90° rotation, asymmetric calcium spikes were indeed observed in the root of starchless mutants, suggesting that starch grains are not indispensable for the formation of calcium spikes. Besides, co-localization analysis suggests that the ER may function as calcium stores during the occurrence of calcium spikes. These findings provide further insights into plant gravitropism.
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Affiliation(s)
- Xinyu Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ruoxin Zhao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Jiahui Liu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ziwei Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ai Chen
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Shi Xu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Xianyong Sheng
- College of Life Sciences, Capital Normal University, Beijing 100048, China.
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7
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Kuhn A, Roosjen M, Mutte S, Dubey SM, Carrillo Carrasco VP, Boeren S, Monzer A, Koehorst J, Kohchi T, Nishihama R, Fendrych M, Sprakel J, Friml J, Weijers D. RAF-like protein kinases mediate a deeply conserved, rapid auxin response. Cell 2024; 187:130-148.e17. [PMID: 38128538 PMCID: PMC10783624 DOI: 10.1016/j.cell.2023.11.021] [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: 11/25/2022] [Revised: 06/29/2023] [Accepted: 11/18/2023] [Indexed: 12/23/2023]
Abstract
The plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism. We recently identified a fast, proteome-wide phosphorylation response to auxin. Here, we show that this response occurs across 5 land plant and algal species and converges on a core group of shared targets. We found conserved rapid physiological responses to auxin in the same species and identified rapidly accelerated fibrosarcoma (RAF)-like protein kinases as central mediators of auxin-triggered phosphorylation across species. Genetic analysis connects this kinase to both auxin-triggered protein phosphorylation and rapid cellular response, thus identifying an ancient mechanism for fast auxin responses in the green lineage.
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Affiliation(s)
- Andre Kuhn
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands
| | - Mark Roosjen
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands
| | - Sumanth Mutte
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands
| | - Shiv Mani Dubey
- Department of Experimental Plant Biology, Charles University, Prague, Czech Republic
| | | | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands
| | - Aline Monzer
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Jasper Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Ryuichi Nishihama
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Matyáš Fendrych
- Department of Experimental Plant Biology, Charles University, Prague, Czech Republic
| | - Joris Sprakel
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands
| | - Jiří Friml
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands.
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8
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Pierre PM, Preyanka M, Zachary H, Zhang L, Lukas B, Matias GF, Kian F, Callum G, Wolfgang B. Root Walker: an automated pipeline for large scale quantification of early root growth responses at high spatial and temporal resolution. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:632-646. [PMID: 37871136 PMCID: PMC10841685 DOI: 10.1111/tpj.16493] [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: 08/25/2023] [Accepted: 09/22/2023] [Indexed: 10/25/2023]
Abstract
Plants are sessile organisms that constantly adapt to their changing environment. The root is exposed to numerous environmental signals ranging from nutrients and water to microbial molecular patterns. These signals can trigger distinct responses including the rapid increase or decrease of root growth. Consequently, using root growth as a readout for signal perception can help decipher which external cues are perceived by roots, and how these signals are integrated. To date, studies measuring root growth responses using large numbers of roots have been limited by a lack of high-throughput image acquisition, poor scalability of analytical methods, or low spatiotemporal resolution. Here, we developed the Root Walker pipeline, which uses automated microscopes to acquire time-series images of many roots exposed to controlled treatments with high spatiotemporal resolution, in conjunction with fast and automated image analysis software. We demonstrate the power of Root Walker by quantifying root growth rate responses at different time and throughput scales upon treatment with natural auxin and two mitogen-associated protein kinase cascade inhibitors. We find a concentration-dependent root growth response to auxin and reveal the specificity of one MAPK inhibitor. We further demonstrate the ability of Root Walker to conduct genetic screens by performing a genome-wide association study on 260 accessions in under 2 weeks, revealing known and unknown root growth regulators. Root Walker promises to be a useful toolkit for the plant science community, allowing large-scale screening of root growth dynamics for a variety of purposes, including genetic screens for root sensing and root growth response mechanisms.
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Affiliation(s)
- Platre Matthieu Pierre
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Mehta Preyanka
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Halvorson Zachary
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Ling Zhang
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Brent Lukas
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Gleason F. Matias
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Faizi Kian
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Goulding Callum
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Busch Wolfgang
- Salk Institute for Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
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9
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Jobert F, Yadav S, Robert S. Auxin as an architect of the pectin matrix. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6933-6949. [PMID: 37166384 PMCID: PMC10690733 DOI: 10.1093/jxb/erad174] [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: 03/10/2023] [Accepted: 05/10/2023] [Indexed: 05/12/2023]
Abstract
Auxin is a versatile plant growth regulator that triggers multiple signalling pathways at different spatial and temporal resolutions. A plant cell is surrounded by the cell wall, a complex and dynamic network of polysaccharides. The cell wall needs to be rigid to provide mechanical support and protection and highly flexible to allow cell growth and shape acquisition. The modification of the pectin components, among other processes, is a mechanism by which auxin activity alters the mechanical properties of the cell wall. Auxin signalling precisely controls the transcriptional output of several genes encoding pectin remodelling enzymes, their local activity, pectin deposition, and modulation in different developmental contexts. This review examines the mechanism of auxin activity in regulating pectin chemistry at organ, cellular, and subcellular levels across diverse plant species. Moreover, we ask questions that remain to be addressed to fully understand the interplay between auxin and pectin in plant growth and development.
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Affiliation(s)
- François Jobert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
- CRRBM, Université de Picardie Jules Verne, 80000, Amiens, France
| | - Sandeep Yadav
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
| | - Stéphanie Robert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
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10
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Del Bianco M, Friml J, Strader L, Kepinski S. Auxin research: creating tools for a greener future. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6889-6892. [PMID: 38038239 PMCID: PMC10690723 DOI: 10.1093/jxb/erad420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Affiliation(s)
| | - Jiří Friml
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Lucia Strader
- Department of Biology, Duke University, Durham, NC, USA
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11
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Huang M, Chen J, Yang X, Zheng Y, Ma Y, Sun K, Han N, Bian H, Qiu T, Wang J. A unique mutation in PIN-FORMED1 and a genetic pathway for reduced sensitivity of Arabidopsis roots to N-1-naphthylphthalamic acid. PHYSIOLOGIA PLANTARUM 2023; 175:e14120. [PMID: 38148206 DOI: 10.1111/ppl.14120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 12/28/2023]
Abstract
The small chemical N-1-naphthylphthalamic acid (NPA) has long been used as a polar auxin transport inhibitor. Recent biochemical and structural investigations have revealed that this molecule competes with the auxin IAA (indole-3-acetic acid) inside the PIN-FORMED auxin efflux carriers. However, the existence of any mutations in PIN family proteins capable of uncoupling the docking of IAA from NPA remains unclear. We report that Arabidopsis thaliana seedlings overexpressing SMALL AUXIN UP RNA 41 were hypersensitive to NPA-induced root elongation inhibition. We mutagenized this line to improve the genetic screening efficiency for NPA hyposensitivity mutants. Using bulked segregation analysis and mapping-by-sequencing assessment of these mutants, we identified a core genetic pathway for NPA-induced root elongation inhibition, including genes required for auxin biosynthesis, transportation, and signaling. To evaluate specific changes of auxin signaling activity in mutant roots before and after NPA treatment, the DR5::GFP/DR5::YFP markers were introduced and observed. Most importantly, we discovered a unique mutation in the PIN1 protein, substituting a proline residue with leucine at position 584, leading to a loss of NPA sensitivity while keeping the auxin efflux capacity. Transforming the null mutant pin1-201 with the PIN1::PIN1P584L -GFP fusion construct rescued the PIN1 function and provided NPA hyposensitivity. The proline residue is predicted to be adjacent to a hinge in the middle region of the ninth transmembrane helix of PIN1 and is conserved from moss to higher plants. Our work may bring new insights into the engineering of NPA-resistant PINs for auxin biology studies.
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Affiliation(s)
- Minhua Huang
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jie Chen
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Xinxing Yang
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yanyan Zheng
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yuan Ma
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Kai Sun
- School of Pharmacy, Hangzhou Normal University, Hangzhou, China
| | - Ning Han
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Hongwu Bian
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Ting Qiu
- School of Pharmacy, Hangzhou Normal University, Hangzhou, China
| | - Junhui Wang
- Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
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12
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Fiedler L, Friml J. Rapid auxin signaling: Unknowns old and new. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102443. [PMID: 37666097 DOI: 10.1016/j.pbi.2023.102443] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/06/2023]
Abstract
To respond to auxin, the chief orchestrator of their multicellularity, plants evolved multiple receptor systems and signal transduction cascades. Despite decades of research, however, we are still lacking a satisfactory synthesis of various auxin signaling mechanisms. The chief discrepancy and historical controversy of the field is that of rapid and slow auxin effects on plant physiology and development. How is it possible that ions begin to trickle across the plasma membrane as soon as auxin enters the cell, even though the best-characterized transcriptional auxin pathway can take effect only after tens of minutes? Recently, unexpected progress has been made in understanding this and other unknowns of auxin signaling. We provide a perspective on these exciting developments and concepts whose general applicability might have ramifications beyond auxin signaling.
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Affiliation(s)
- Lukáš Fiedler
- Institute of Science and Technology Austria (ISTA), 3400, Klosterneuburg, Austria
| | - Jiří Friml
- Institute of Science and Technology Austria (ISTA), 3400, Klosterneuburg, Austria.
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