1
|
Guercio AM, Gilio AK, Pawlak J, Shabek N. Structural insights into rice KAI2 receptor provide functional implications for perception and signal transduction. J Biol Chem 2024; 300:107593. [PMID: 39032651 DOI: 10.1016/j.jbc.2024.107593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 07/10/2024] [Accepted: 07/12/2024] [Indexed: 07/23/2024] Open
Abstract
KAI2 receptors, classified as plant α/β hydrolase enzymes, are capable of perceiving smoke-derived butenolide signals and endogenous yet unidentified KAI2-ligands (KLs). While the number of functional KAI2 receptors varies among land plant species, rice has only one KAI2 gene. Rice, a significant crop and representative of grasses, relies on KAI2-mediated Arbuscular mycorrhiza (AM) symbioses to flourish in traditionally arid and nutrient-poor environments. This study presents the first crystal structure of an active rice (Oryza sativa, Os) KAI2 hydrolase receptor. Our structural and biochemical analyses uncover grass-unique pocket residues influencing ligand sensitivity and hydrolytic activity. Through structure-guided analysis, we identify a specific residue whose mutation enables the increase or decrease of ligand perception, catalytic activity, and signal transduction. Furthermore, we investigate OsKAI2-mediated signaling by examining its ability to form a complex with its binding partner, the F-box protein DWARF3 (D3) ubiquitin ligase and subsequent degradation of the target substrate OsSMAX1, demonstrating the significant role of hydrophobic interactions in the OsKAI2-D3 interface. This study provides new insights into the diverse and pivotal roles of the OsKAI2 signaling pathway in the plant kingdom, particularly in grasses.
Collapse
Affiliation(s)
- Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, California, USA
| | - Amelia K Gilio
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, California, USA
| | - Jacob Pawlak
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, California, USA
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, California, USA.
| |
Collapse
|
2
|
Chang W, Qiao Q, Li Q, Li X, Li Y, Huang X, Wang Y, Li J, Wang B, Wang L. Non-transcriptional regulatory activity of SMAX1 and SMXL2 mediates karrikin-regulated seedling response to red light in Arabidopsis. MOLECULAR PLANT 2024; 17:1054-1072. [PMID: 38807366 DOI: 10.1016/j.molp.2024.05.007] [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: 07/25/2023] [Revised: 04/09/2024] [Accepted: 05/26/2024] [Indexed: 05/30/2024]
Abstract
Karrikins and strigolactones govern plant development and environmental responses through closely related signaling pathways. The transcriptional repressor proteins SUPPRESSOR OF MAX2 1 (SMAX1), SMAX1-like2 (SMXL2), and D53-like SMXLs mediate karrikin and strigolactone signaling by directly binding downstream genes or by inhibiting the activities of transcription factors. In this study, we characterized the non-transcriptional regulatory activities of SMXL proteins in Arabidopsis. We discovered that SMAX1 and SMXL2 with mutations in their ethylene-response factor-associated amphiphilic repression (EAR) motif had undetectable or weak transcriptional repression activities but still partially rescued the hypocotyl elongation defects and fully reversed the cotyledon epinasty defects of the smax1 smxl2 mutant. SMAX1 and SMXL2 directly interact with PHYTOCHROME INTERACTION FACTOR 4 (PIF4) and PIF5 to enhance their protein stability by interacting with phytochrome B (phyB) and suppressing the association of phyB with PIF4 and PIF5. The karrikin-responsive genes were then identified by treatment with GR24ent-5DS, a GR24 analog showing karrikin activity. Interestingly, INDOLE-3-ACETIC ACID INDUCIBLE 29 (IAA29) expression was repressed by GR24ent-5DS treatment in a PIF4- and PIF5-dependent and EAR-independent manner, whereas KARRIKIN UPREGULATED F-BOX 1 (KUF1) expression was induced in a PIF4- and PIF5-independent and EAR-dependent manner. Furthermore, the non-transcriptional regulatory activity of SMAX1, which is independent of the EAR motif, had a global effect on gene expression. Taken together, these results indicate that non-transcriptional regulatory activities of SMAX1 and SMXL2 mediate karrikin-regulated seedling response to red light.
Collapse
Affiliation(s)
- Wenwen Chang
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiao Qiao
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingtian Li
- Yazhouwan National Laboratory, Sanya, Hainan 572024, China
| | - Xin Li
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanyan Li
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
| | - Xiahe Huang
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yingchun Wang
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiayang Li
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; Yazhouwan National Laboratory, Sanya, Hainan 572024, China
| | - Bing Wang
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lei Wang
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
3
|
Guillory A, Lopez-Obando M, Bouchenine K, Le Bris P, Lécureuil A, Pillot JP, Steinmetz V, Boyer FD, Rameau C, de Saint Germain A, Bonhomme S. SUPPRESSOR OF MAX2 1-LIKE (SMXL) homologs are MAX2-dependent repressors of Physcomitrium patens growth. THE PLANT CELL 2024; 36:1655-1672. [PMID: 38242840 PMCID: PMC11062456 DOI: 10.1093/plcell/koae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/21/2024]
Abstract
SUPPRESSOR OF MAX2 (SMAX)1-LIKE (SMXL) proteins are a plant-specific clade of type I HSP100/Clp-ATPases. SMXL genes are present in virtually all land plant genomes. However, they have mainly been studied in angiosperms. In Arabidopsis (Arabidopsis thaliana), 3 functional SMXL subclades have been identified: SMAX1/SMXL2, SMXL345, and SMXL678. Of these, 2 subclades ensure endogenous phytohormone signal transduction. SMAX1/SMXL2 proteins are involved in KAI2 ligand (KL) signaling, while SMXL678 proteins are involved in strigolactone (SL) signaling. Many questions remain regarding the mode of action of these proteins, as well as their ancestral roles. We addressed these questions by investigating the functions of the 4 SMXL genes in the moss Physcomitrium patens. We demonstrate that PpSMXL proteins are involved in the conserved ancestral MAX2-dependent KL signaling pathway and negatively regulate growth. However, PpSMXL proteins expressed in Arabidopsis cannot replace SMAX1 or SMXL2 function in KL signaling, whereas they can functionally replace SMXL4 and SMXL5 and restore root growth. Therefore, the molecular functions of SMXL proteins are conserved, but their interaction networks are not. Moreover, the PpSMXLC/D clade positively regulates SL signal transduction in P. patens. Overall, our data reveal that SMXL proteins in moss mediate crosstalk between the SL and KL signaling pathways.
Collapse
Affiliation(s)
- Ambre Guillory
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan 31326, France
| | - Mauricio Lopez-Obando
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
- Institut de biologie moléculaire des plantes (IBMP), CNRS, University of Strasbourg, 12 rue du Général Zimmer, 67000 Strasbourg, France
| | - Khalissa Bouchenine
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Philippe Le Bris
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Alain Lécureuil
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Jean-Paul Pillot
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Vincent Steinmetz
- CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - François-Didier Boyer
- CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Catherine Rameau
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Alexandre de Saint Germain
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Sandrine Bonhomme
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| |
Collapse
|
4
|
Wu J, Fu X, Zhao L, Lv J, Lv S, Shang J, Lv J, Du S, Guo H, Ma F. Biochar as a partner of plants and beneficial microorganisms to assist in-situ bioremediation of heavy metal contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171442. [PMID: 38453085 DOI: 10.1016/j.scitotenv.2024.171442] [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: 12/28/2023] [Revised: 02/19/2024] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Synergistic remediation of heavy metal (HM) contaminated soil using beneficial microorganisms (BM) and plants is a common and effective in situ bioremediation method. However, the shortcomings of this approach are the low colonisation of BM under high levels of heavy metal stress (HMS) and the poor state of plant growth. Previous studies have overlooked the potential of biochar to mitigate the above problems and aid in-situ remediation. Therefore, this paper describes the characteristics and physicochemical properties of biochar. It is proposed that biochar enhances plant resistance to HMS and aids in situ bioremediation by increasing colonisation of BM and HM stability. On this basis, the paper focuses on the following possible mechanisms: specific biochar-derived organic matter regulates the transport of HMs in plants and promotes mycorrhizal colonisation via the abscisic acid signalling pathway and the karrikin signalling pathway; promotes the growth-promoting pathway of indole-3-acetic acid and increases expression of the nodule-initiating gene NIN; improvement of soil HM stability by ion exchange, electrostatic adsorption, redox and complex precipitation mechanisms. And this paper summarizes guidelines on how to use biochar-assisted remediation based on current research for reference. Finally, the paper identifies research gaps in biochar in the direction of promoting beneficial microbial symbiotic mechanisms, recognition and function of organic molecules, and factors affecting practical applications.
Collapse
Affiliation(s)
- Jieting Wu
- School of Environmental Science, Liaoning University, Shenyang 110036, China.
| | - Xiaofan Fu
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Lei Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jin Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Sidi Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Jing Shang
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Jiaxuan Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Shuxuan Du
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Haijuan Guo
- School of Environmental Science, Liaoning University, Shenyang 110036, China.
| | - Fang Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| |
Collapse
|
5
|
Park YJ, Nam BE, Park CM. Environmentally adaptive reshaping of plant photomorphogenesis by karrikin and strigolactone signaling. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:865-882. [PMID: 38116738 DOI: 10.1111/jipb.13602] [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: 08/06/2023] [Revised: 12/09/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating environments. Plant morphogenic responses to light and warm temperatures, termed photomorphogenesis and thermomorphogenesis, respectively, have been extensively studied in recent decades. During photomorphogenesis, plants actively reshape their growth and developmental patterns to cope with changes in light regimes. Accordingly, photomorphogenesis is closely associated with diverse growth hormonal cues. Notably, accumulating evidence indicates that light-directed morphogenesis is profoundly affected by two recently identified phytochemicals, karrikins (KARs) and strigolactones (SLs). KARs and SLs are structurally related butenolides acting as signaling molecules during a variety of developmental steps, including seed germination. Their receptors and signaling mediators have been identified, and associated working mechanisms have been explored using gene-deficient mutants in various plant species. Of particular interest is that the KAR and SL signaling pathways play important roles in environmental responses, among which their linkages with photomorphogenesis are most comprehensively studied during seedling establishment. In this review, we focus on how the phytochemical and light signals converge on the optimization of morphogenic fitness. We also discuss molecular mechanisms underlying the signaling crosstalks with an aim of developing potential ways to improve crop productivity under climate changes.
Collapse
Affiliation(s)
- Young-Joon Park
- Department of Smart Farm Science, Kyung Hee University, Yongin, 17104, Korea
| | - Bo Eun Nam
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Chung-Mo Park
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| |
Collapse
|
6
|
Li Q, Yu H, Chang W, Chang S, Guzmán M, Faure L, Wallner ES, Yan H, Greb T, Wang L, Yao R, Nelson DC. SMXL5 attenuates strigolactone signaling in Arabidopsis thaliana by inhibiting SMXL7 degradation. MOLECULAR PLANT 2024; 17:631-647. [PMID: 38475994 DOI: 10.1016/j.molp.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 01/10/2024] [Accepted: 03/07/2024] [Indexed: 03/14/2024]
Abstract
Hormone-activated proteolysis is a recurring theme of plant hormone signaling mechanisms. In strigolactone signaling, the enzyme receptor DWARF14 (D14) and an F-box protein, MORE AXILLARY GROWTH2 (MAX2), mark SUPPRESSOR OF MAX2 1-LIKE (SMXL) family proteins SMXL6, SMXL7, and SMXL8 for rapid degradation. Removal of these transcriptional corepressors initiates downstream growth responses. The homologous proteins SMXL3, SMXL4, and SMXL5, however, are resistant to MAX2-mediated degradation. We discovered that the smxl4 smxl5 mutant has enhanced responses to strigolactone. SMXL5 attenuates strigolactone signaling by interfering with AtD14-SMXL7 interactions. SMXL5 interacts with AtD14 and SMXL7, providing two possible ways to inhibit SMXL7 degradation. SMXL5 function is partially dependent on an ethylene-responsive-element binding-factor-associated amphiphilic repression (EAR) motif, which typically mediates interactions with the TOPLESS family of transcriptional corepressors. However, we found that loss of the EAR motif reduces SMXL5-SMXL7 interactions and the attenuation of strigolactone signaling by SMXL5. We hypothesize that integration of SMXL5 into heteromeric SMXL complexes reduces the susceptibility of SMXL6/7/8 proteins to strigolactone-activated degradation and that the EAR motif promotes the formation or stability of these complexes. This mechanism may provide a way to spatially or temporally fine-tune strigolactone signaling through the regulation of SMXL5 expression or translation.
Collapse
Affiliation(s)
- Qingtian Li
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA; Yazhouwan National Laboratory, Sanya 572025, China; Hainan Seed Industry Laboratory, Sanya 57205, China.
| | - Haiyang Yu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China
| | - Wenwen Chang
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sunhyun Chang
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Michael Guzmán
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Lionel Faure
- School of the Sciences, Biology Division, Texas Woman's University, Denton, TX 76204, USA
| | - Eva-Sophie Wallner
- Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Heqin Yan
- Yazhouwan National Laboratory, Sanya 572025, China
| | - Thomas Greb
- Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Lei Wang
- Key Laboratory of Seed Innovation, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
| | - Ruifeng Yao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
| | - David C Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
7
|
Stirling SA, Guercio AM, Patrick RM, Huang XQ, Bergman ME, Dwivedi V, Kortbeek RWJ, Liu YK, Sun F, Tao WA, Li Y, Boachon B, Shabek N, Dudareva N. Volatile communication in plants relies on a KAI2-mediated signaling pathway. Science 2024; 383:1318-1325. [PMID: 38513014 DOI: 10.1126/science.adl4685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/08/2024] [Indexed: 03/23/2024]
Abstract
Plants are constantly exposed to volatile organic compounds (VOCs) that are released during plant-plant communication, within-plant self-signaling, and plant-microbe interactions. Therefore, understanding VOC perception and downstream signaling is vital for unraveling the mechanisms behind information exchange in plants, which remain largely unexplored. Using the hormone-like function of volatile terpenoids in reproductive organ development as a system with a visual marker for communication, we demonstrate that a petunia karrikin-insensitive receptor, PhKAI2ia, stereospecifically perceives the (-)-germacrene D signal, triggering a KAI2-mediated signaling cascade and affecting plant fitness. This study uncovers the role(s) of the intermediate clade of KAI2 receptors, illuminates the involvement of a KAI2ia-dependent signaling pathway in volatile communication, and provides new insights into plant olfaction and the long-standing question about the nature of potential endogenous KAI2 ligand(s).
Collapse
Affiliation(s)
- Shannon A Stirling
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
| | - Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Ryan M Patrick
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Xing-Qi Huang
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Matthew E Bergman
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Varun Dwivedi
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Ruy W J Kortbeek
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Yi-Kai Liu
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Fuai Sun
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Ying Li
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Benoît Boachon
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
- Université Jean Monnet Saint-Etienne, CNRS, LBVpam UMR 5079, F-42023 Saint-Etienne, France
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Natalia Dudareva
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
8
|
Kamran M, Melville KT, Waters MT. Karrikin signalling: impacts on plant development and abiotic stress tolerance. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1174-1186. [PMID: 38001035 PMCID: PMC10860534 DOI: 10.1093/jxb/erad476] [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: 07/28/2023] [Accepted: 11/23/2023] [Indexed: 11/26/2023]
Abstract
Plants rely upon a diverse range of metabolites to control growth and development, and to overcome stress that results from suboptimal conditions. Karrikins (KARs) are a class of butenolide compounds found in smoke that stimulate seed germination and regulate various developmental processes in plants. KARs are perceived via a plant α/β-hydrolase called KARRIKIN INSENSITIVE2 (KAI2), which also functions as a receptor for a postulated phytohormone, provisionally termed KAI2 ligand (KL). Considered natural analogues of KL, KARs have been extensively studied for their effects on plant growth and their crosstalk with plant hormones. The perception and response pathway for KAR-KL signalling is closely related to that of strigolactones, another class of butenolides with numerous functions in regulating plant growth. KAR-KL signalling influences seed germination, seedling photomorphogenesis, root system architecture, abiotic stress responses, and arbuscular mycorrhizal symbiosis. Here, we summarize current knowledge of KAR-KL signalling, focusing on its role in plant development, its effects on stress tolerance, and its interaction with other signalling mechanisms.
Collapse
Affiliation(s)
- Muhammad Kamran
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Kim T Melville
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Mark T Waters
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| |
Collapse
|
9
|
Melville KT, Kamran M, Yao J, Costa M, Holland M, Taylor NL, Fritz G, Flematti GR, Waters MT. Perception of butenolides by Bacillus subtilis via the α/β hydrolase RsbQ. Curr Biol 2024; 34:623-631.e6. [PMID: 38183985 DOI: 10.1016/j.cub.2023.12.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/06/2023] [Accepted: 12/12/2023] [Indexed: 01/08/2024]
Abstract
The regulation of behavioral and developmental decisions by small molecules is common to all domains of life. In plants, strigolactones and karrikins are butenolide growth regulators that influence several aspects of plant growth and development, as well as interactions with symbiotic fungi.1,2,3 DWARF14 (D14) and KARRIKIN INSENSITIVE2 (KAI2) are homologous enzyme-receptors that perceive strigolactones and karrikins, respectively, and that require hydrolase activity to effect signal transduction.4,5,6,7 RsbQ, a homolog of D14 and KAI2 from the gram-positive bacterium Bacillus subtilis, regulates growth responses to nutritional stress via the alternative transcription factor SigmaB (σB).8,9 However, the molecular function of RsbQ is unknown. Here, we show that RsbQ perceives butenolide compounds that are bioactive in plants. RsbQ is thermally destabilized by the synthetic strigolactone GR24 and its desmethyl butenolide equivalent dGR24. We show that, like D14 and KAI2, RsbQ is a functional butenolide hydrolase that undergoes covalent modification of the catalytic histidine residue. Exogenous application of both GR24 and dGR24 inhibited the endogenous signaling function of RsbQ in vivo, with dGR24 being 10-fold more potent. Application of dGR24 to B. subtilis phenocopied loss-of-function rsbQ mutations and led to a significant downregulation of σB-regulated transcripts. We also discovered that exogenous butenolides promoted the transition from planktonic to biofilm growth. Our results suggest that butenolides may serve as inter-kingdom signaling compounds between plants and bacteria to help shape rhizosphere communities.
Collapse
Affiliation(s)
- Kim T Melville
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Muhammad Kamran
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Jiaren Yao
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Marianne Costa
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Madeleine Holland
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Nicolas L Taylor
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia; Institute of Agriculture, The University of Western Australia, Perth WA 6009, Australia
| | - Georg Fritz
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Gavin R Flematti
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia
| | - Mark T Waters
- School of Molecular Sciences, The University of Western Australia, Perth WA 6009, Australia.
| |
Collapse
|
10
|
Ni F, Shah FA, Ren J. Identification and characterization of the karrikins signaling gene SsSMAX1 in Sapium sebiferum. PeerJ 2023; 11:e16610. [PMID: 38089914 PMCID: PMC10712317 DOI: 10.7717/peerj.16610] [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: 05/31/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023] Open
Abstract
SUPPRESSOR OF MAX2 LIKE 1 (SMAX1) is a member of the SUPPRESSOR of MAX2 1‑LIKE family of genes and is known as a target protein of KARRIKIN INSENSITIVE2 (KAI2)-MORE AXILLARY BRANCHES2 (MAX2), which mediates karrikin signaling in Arabidopsis. SMAX1 plays a significant role in seed germination, hypocotyl elongation, and root hair development in Arabidopsis. SMAX1 has not yet been identified and characterized in woody plants. This study identified and characterized SsSMAX1 in Sapium sebiferum and found that SsSMAX1 was highly expressed in the seed, hypocotyl, and root tips of S. sebiferum. SsSMAX1 was functionally characterized by ectopic expression in Arabidopsis. SsSMAX1 overexpression lines of Arabidopsis showed significantly delayed seed germination and produced seedlings with longer hypocotyl and roots than wild-type and Atsmax1 functional mutants. SsSMAX1 overexpression lines of Arabidopsis also had broader and longer leaves and petioles than wild-type and Atsmax1, suggesting that SsSMAX1 is functionally conserved. This study characterizes the SMAX1 gene in a woody and commercially valuable bioenergy plant, Sapium sebiferum. The results of this study are beneficial to future research on the molecular biology of woody plants.
Collapse
Affiliation(s)
- Fang Ni
- Anhui Wenda University of Information Engineering, Hefei, Anhui, China
| | - Faheem Afzal Shah
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, Anhui, China
| | - Jie Ren
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, Anhui, China
| |
Collapse
|
11
|
Basso MF, Contaldi F, Lo Celso F, Baratto CM, Grossi-de-Sa MF, Barone G, Ferrante A, Martinelli F. Identification and expression profile of the SMAX/SMXL family genes in chickpea and lentil provide important players of biotechnological interest involved in plant branching. PLANTA 2023; 259:1. [PMID: 37966555 PMCID: PMC10651550 DOI: 10.1007/s00425-023-04277-y] [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: 08/17/2023] [Accepted: 10/28/2023] [Indexed: 11/16/2023]
Abstract
MAIN CONCLUSION SMAX/SMXL family genes were successfully identified and characterized in the chickpea and lentil and gene expression data revealed several genes associated with the modulation of plant branching and powerful targets for use in transgenesis and genome editing. Strigolactones (SL) play essential roles in plant growth, rooting, development, and branching, and are associated with plant resilience to abiotic and biotic stress conditions. Likewise, karrikins (KAR) are "plant smoke-derived molecules" that act in a hormonal signaling pathway similar to SL playing an important role in seed germination and hairy root elongation. The SMAX/SMXL family genes are part of these two signaling pathways, in addition to some of these members acting in a still little known SL- and KAR-independent signaling pathway. To date, the identification and functional characterization of the SMAX/SMXL family genes has not been performed in the chickpea and lentil. In this study, nine SMAX/SMXL genes were systematically identified and characterized in the chickpea and lentil, and their expression profiles were explored under different unstressless or different stress conditions. After a comprehensive in silico characterization of the genes, promoters, proteins, and protein-protein interaction network, the expression profile for each gene was determined using a meta-analysis from the RNAseq datasets and complemented with real-time PCR analysis. The expression profiles of the SMAX/SMXL family genes were very dynamic in different chickpea and lentil organs, with some genes assuming a tissue-specific expression pattern. In addition, these genes were significantly modulated by different stress conditions, indicating that SMAX/SMXL genes, although working in three distinct signaling pathways, can act to modulate plant resilience. Most CaSMAX/SMXL and partner genes such as CaTiE1 and CaLAP1, have a positive correlation with the plant branching level, while most LcSMAX/SMXL genes were less correlated with the plant branching level. The SMXL6, SMXL7, SMXL8, TiE1, LAP1, BES1, and BRC1 genes were highlighted as powerful targets for use in transgenesis and genome editing aiming to develop chickpea and lentil cultivars with improved architecture. Therefore, this study presented a detailed characterization of the SMAX/SMXL genes in the chickpea and lentil, and provided new insights for further studies focused on each SMAX/SMXL gene.
Collapse
Affiliation(s)
| | - Felice Contaldi
- Department of Biology, University of Florence, 50019, Sesto Fiorentino, Italy
| | - Fabrizio Lo Celso
- Department of Physics and Chemical, University of Palermo, Viale Delle Scienze, Edificio 17, 90128, Palermo, Italy
| | - César Milton Baratto
- University of Western Santa Catarina, Biotechnological Center, UNOESC, Videira, SC, 89566-252, Brazil
| | | | - Giampaolo Barone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale Delle Scienze, Edificio 17, 90128, Palermo, Italy
| | - Antonio Ferrante
- Department of Agricultural and Environmental Sciences, University of Milan, Via Festa del Perdono, 20122, Milan, Italy
| | - Federico Martinelli
- Department of Biology, University of Florence, 50019, Sesto Fiorentino, Italy.
| |
Collapse
|
12
|
Temmerman A, De Keyser A, Boyer FD, Struk S, Goormachtig S. Histone Deacetylases Regulate MORE AXILLARY BRANCHED 2-Dependent Germination of Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2023; 64:1008-1020. [PMID: 37279553 DOI: 10.1093/pcp/pcad047] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/21/2023] [Accepted: 05/29/2023] [Indexed: 06/08/2023]
Abstract
Under specific conditions, the germination of Arabidopsis thaliana is dependent on the activation of the KARRIKIN INSENSITIVE 2 (KAI2) signaling pathway by the KAI2-dependent perception of karrikin or the artificial strigolactone analogue, rac-GR24. To regulate the induction of germination, the KAI2 signaling pathway relies on MORE AXILLARY BRANCHED 2- (MAX2-)dependent ubiquitination and proteasomal degradation of the repressor protein SUPPRESSOR OF MAX2 1 (SMAX1). It is not yet known how the degradation of SMAX1 proteins eventually results in the regulation of seed germination, but it has been hypothesized that SMAX1-LIKE generally functions as transcriptional repressors through the recruitment of co-repressors TOPLESS (TPL) and TPL-related, which in turn interact with histone deacetylases. In this article, we show the involvement of histone deacetylases HDA6, HDA9, HDA19 and HDT1 in MAX2-dependent germination of Arabidopsis, and more specifically, that HDA6 is required for the induction of DWARF14-LIKE2 expression in response to rac-GR24 treatment.
Collapse
Affiliation(s)
- Arne Temmerman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Gent 9052, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark 71, Gent 9052, Belgium
| | - Annick De Keyser
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Gent 9052, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark 71, Gent 9052, Belgium
| | - François-Didier Boyer
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, UPR2301, Université Paris-Sud, Université Paris-Saclay, Aveue de la Terrasse 1, Gif-sur-Yvette 91198, France
| | - Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Gent 9052, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark 71, Gent 9052, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Gent 9052, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark 71, Gent 9052, Belgium
| |
Collapse
|
13
|
Yap JX, Tsuchiya Y. Gibberellins Promote Seed Conditioning by Up-Regulating Strigolactone Receptors in the Parasitic Plant Striga hermonthica. PLANT & CELL PHYSIOLOGY 2023; 64:1021-1033. [PMID: 37300550 DOI: 10.1093/pcp/pcad056] [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: 02/14/2023] [Revised: 05/24/2023] [Accepted: 06/08/2023] [Indexed: 06/12/2023]
Abstract
Dormant seeds of the root parasitic plant Striga hermonthica sense strigolactones from host plants as environmental cues for germination. This process is mediated by a diversified member of the strigolactone receptors encoded by HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE2 genes. It is known that warm and moist treatment during seed conditioning gradually makes dormant Striga seeds competent to respond to strigolactones, although the mechanism behind it is poorly understood. In this report, we show that plant hormone gibberellins increase strigolactone competence by up-regulating mRNA expression of the major strigolactone receptors during the conditioning period. This idea was supported by a poor germination phenotype in which gibberellin biosynthesis was depleted by paclobutrazol during conditioning. Moreover, live imaging with a fluorogenic strigolactone mimic, yoshimulactone green W, revealed that paclobutrazol treatment during conditioning caused aberrant dynamics of strigolactone perception after germination. These observations revealed an indirect role of gibberellins in seed germination in Striga, which contrasts with their roles as dominant germination-stimulating hormones in non-parasitic plants. We propose a model of how the role of gibberellins became indirect during the evolution of parasitism in plants. Our work also highlights the potential role for gibberellins in field applications, for instance, in elevating the sensitivity of seeds toward strigolactones in the current suicidal germination approach to alleviate the agricultural threats caused by this parasite in Africa.
Collapse
Affiliation(s)
- Jia Xin Yap
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Yuichiro Tsuchiya
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
- Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| |
Collapse
|
14
|
Varshney K, Gutjahr C. KAI2 Can Do: Karrikin Receptor Function in Plant Development and Response to Abiotic and Biotic Factors. PLANT & CELL PHYSIOLOGY 2023; 64:984-995. [PMID: 37548562 PMCID: PMC10504578 DOI: 10.1093/pcp/pcad077] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/02/2023] [Accepted: 07/14/2023] [Indexed: 08/08/2023]
Abstract
The α/β hydrolase KARRIKIN INSENSITIVE 2 (KAI2) functions as a receptor for a yet undiscovered phytohormone, provisionally termed KAI2 ligand (KL). In addition, it perceives karrikin, a butenolide compound found in the smoke of burnt plant material. KAI2-mediated signaling is involved in regulating seed germination and in shaping seedling and adult plant morphology, both above and below ground. It also governs responses to various abiotic stimuli and stresses and shapes biotic interactions. KAI2-mediated signaling is being linked to an elaborate cross-talk with other phytohormone pathways such as auxin, gibberellin, abscisic acid, ethylene and salicylic acid signaling, in addition to light and nutrient starvation signaling. Further connections will likely be revealed in the future. This article summarizes recent advances in unraveling the function of KAI2-mediated signaling and its interaction with other signaling pathways.
Collapse
Affiliation(s)
- Kartikye Varshney
- Department of Root Biology and Symbiosis, Max Planck Institute of Molecular Plant Physiology, Potsdam Science Park, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| | - Caroline Gutjahr
- Department of Root Biology and Symbiosis, Max Planck Institute of Molecular Plant Physiology, Potsdam Science Park, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| |
Collapse
|
15
|
Liu S, Wang J, Song B, Gong X, Liu H, Hu Q, Zhang J, Li Q, Zheng J, Wang H, Xu HE, Li J, Wang B. Conformational Dynamics of the D53-D3-D14 Complex in Strigolactone Signaling. PLANT & CELL PHYSIOLOGY 2023; 64:1046-1056. [PMID: 37384578 PMCID: PMC10858650 DOI: 10.1093/pcp/pcad067] [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: 02/21/2023] [Revised: 06/19/2023] [Accepted: 06/25/2023] [Indexed: 07/01/2023]
Abstract
Strigolactones (SLs) play fundamental roles in regulating plant architecture, which is a major factor determining crop yield. The perception and signal transduction of SLs require the formation of a complex containing the receptor DWARF14 (D14), an F-box protein D3 and a transcriptional regulator D53 in an SL-dependent manner. Structural and biochemical analyses of D14 and its orthologs DAD2 and AtD14, D3 and the complexes of ASK1-D3-AtD14 and D3CTH-D14 have made great contributions to understanding the mechanisms of SL perception. However, structural analyses of D53 and the D53-D3-D14 holo-complex are challenging, and the biochemical mechanism underlying the complex assembly remains poorly understood. Here, we found that apo-D53 was rather flexible and reconstituted the holo-complex containing D53, S-phase kinase-associated protein 1 (SKP1), D3 and D14 with rac-GR24. The cryo-electron microscopy (cryo-EM) structure of SKP1-D3-D14 in the presence of D53 was analyzed and superimposed on the crystal structure of ASK1-D3-AtD14 without D53. No large conformational rearrangement was observed, but a 9Å rotation appeared between D14 and AtD14. Using hydrogen-deuterium exchange monitored by mass spectrometry, we analyzed dynamic motifs of D14, D3 and D53 in the D53-SKP1-D3-D14 complex assembly process and further identified two potential interfaces in D53 that are located in the N and D2 domains, respectively. Together, our results uncovered the dynamic conformational changes and built a model of the holo-complex D53-SKP1-D3-D14, offering valuable information for the biochemical and genetic mechanisms of SL perception and signal transduction.
Collapse
Affiliation(s)
| | - Jia Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bin Song
- The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xinqi Gong
- Institute for Mathematical Sciences, Renmin University of China, Beijing 100872, China
| | - Huihui Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qingliang Hu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Junhui Zhang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qianqian Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jie Zheng
- The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hongwei Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research and the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jiayang Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Yazhouwan National Laboratory, Sanya 572025, China
| | - Bing Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
16
|
Huizinga S, Bouwmeester HJ. Role of Strigolactones in the Host Specificity of Broomrapes and Witchweeds. PLANT & CELL PHYSIOLOGY 2023; 64:936-954. [PMID: 37319019 PMCID: PMC10504575 DOI: 10.1093/pcp/pcad058] [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: 05/11/2023] [Revised: 06/05/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023]
Abstract
Root parasitic plants of the Orobanchaceae, broomrapes and witchweeds, pose a severe problem to agriculture in Europe, Asia and especially Africa. These parasites are totally dependent on their host for survival, and therefore, their germination is tightly regulated by host presence. Indeed, their seeds remain dormant in the soil until a host root is detected through compounds called germination stimulants. Strigolactones (SLs) are the most important class of germination stimulants. They play an important role in planta as a phytohormone and, upon exudation from the root, function in the recruitment of symbiotic arbuscular mycorrhizal fungi. Plants exude mixtures of various different SLs, possibly to evade detection by these parasites and still recruit symbionts. Vice versa, parasitic plants must only respond to the SL composition that is exuded by their host, or else risk germination in the presence of non-hosts. Therefore, parasitic plants have evolved an entire clade of SL receptors, called HTL/KAI2s, to perceive the SL cues. It has been demonstrated that these receptors each have a distinct sensitivity and specificity to the different known SLs, which possibly allows them to recognize the SL-blend characteristic of their host. In this review, we will discuss the molecular basis of SL sensitivity and specificity in these parasitic plants through HTL/KAI2s and review the evidence that these receptors contribute to host specificity of parasitic plants.
Collapse
Affiliation(s)
- Sjors Huizinga
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Harro J Bouwmeester
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| |
Collapse
|
17
|
Kodama K, Xie X, Kyozuka J. The D14 and KAI2 Orthologs of Gymnosperms Sense Strigolactones and KL Mimics, Respectively, and the Signals Are Transduced to Control Downstream Genes. PLANT & CELL PHYSIOLOGY 2023; 64:1057-1065. [PMID: 37489639 DOI: 10.1093/pcp/pcad072] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/21/2023] [Accepted: 07/02/2023] [Indexed: 07/26/2023]
Abstract
Strigolactones (SLs), lactone-containing carotenoid derivatives, function as signaling molecules in the rhizosphere, inducing symbiosis with arbuscular mycorrhizal. In addition, as a class of plant hormones, SLs control plant growth and development in flowering plants (angiosperms). Recent studies show that the ancestral function of SLs, which precede terrestrialization of plants, is as rhizosphere signaling molecules. SLs were then recruited as a class of plant hormones through the step-by-step acquisition of signaling components. The D14 gene encoding the SL receptor arose by gene duplication of KARRIKIN INSENSITIVE2 (KAI2), the receptor of karrikins and KAI2 ligand (KL), an unknown ligand, in the common ancestor of seed plants. KL signaling targets SMAX1, a repressor protein. On the other hand, the SL signaling targets SMXL78 subclade repressors, which arose by duplication of SMAX1 in angiosperms. Thus, gymnosperms contain the SL receptor D14 but not SMXL78, the SL signaling-specific repressor proteins. We studied two gymnosperm species, ginkgo (Ginkgo biloba) and Japanese umbrella pine (Sciadopitys verticillata), to clarify whether SLs are perceived and the signals are transduced in gymnosperms. We show that D14 and KAI2 of ginkgo and Japanese umbrella pine specifically perceive an SL analog and KL mimic, respectively. Furthermore, our results suggest that both SL signaling and KL signaling target SMAX1, and the specific localization of the receptor may result in the specificity of the signaling in gymnosperms.
Collapse
Affiliation(s)
- Kyoichi Kodama
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577 Japan
| | - Xiaonan Xie
- Center for Bioscience Research and Education, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi, 321-8505 Japan
| | - Junko Kyozuka
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577 Japan
| |
Collapse
|
18
|
Ma B, Zhu J, Huang X. Diversification of plant SUPPRESSOR OF MAX2 1 (SMAX1)-like genes and genome-wide identification and characterization of cotton SMXL gene family. BMC PLANT BIOLOGY 2023; 23:419. [PMID: 37691127 PMCID: PMC10494346 DOI: 10.1186/s12870-023-04421-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/25/2023] [Indexed: 09/12/2023]
Abstract
BACKGROUND Strigolactones (SLs) are a recently discovered class of plant hormones. SUPPRESSOR OF MAX2 1 (SMAX1)-like proteins, key component of the SL signaling pathway, have been studied extensively for their roles in regulating plant growth and development, such as plant branching. However, systematic identification and functional characterization of SMXL genes in cotton (Gossypium sp.), an important fiber and oil crop, has rarely been conducted. RESULTS We identified 210 SMXL genes from 21 plant genomes and examined their evolutionary relationships. The structural characteristics of the SMXL genes and their encoded proteins exhibited both consistency and diversity. All plant SMXL proteins possess a conserved Clp-N domain, P-loop NTPase, and EAR motif. We identified 63 SMXL genes in cotton and classified these into four evolutionary branches. Gene expression analysis revealed tissue-specific expression patterns of GhSMXL genes, with some upregulated in response to GR24 treatment. Protein co-expression network analysis showed that GhSMXL6, GhSMXL7-1, and GhSMXL7-2 mainly interact with proteins functioning in growth and development, while virus-induced gene silencing revealed that GhSMAX1-1 and GhSMAX1-2 suppress the growth and development of axillary buds. CONCLUSIONS SMXL gene family members show evolutionary diversification through the green plant lineage. GhSMXL6/7-1/7-2 genes play critical roles in the SL signaling pathway, while GhSMXL1-1 and GhSMXL1-2 function redundantly in growth of axillary buds. Characterization of the cotton SMXL gene family provides new insights into their roles in responding to SL signals and in plant growth and development. Genes identified in this study could be used as the candidate genes for improvement of plant architecture and crop yield.
Collapse
Affiliation(s)
- Bin Ma
- College of Life Sciences, Shihezi University, Shihezi, 832003, China
- Center for Crop Biotechnology, College of Agriculture, Anhui Science and Technology University, Fengyang, 233100, China
| | - Jianbo Zhu
- College of Life Sciences, Shihezi University, Shihezi, 832003, China
| | - Xianzhong Huang
- Center for Crop Biotechnology, College of Agriculture, Anhui Science and Technology University, Fengyang, 233100, China.
| |
Collapse
|
19
|
Tal L, Guercio AM, Varshney K, Young A, Gutjahr C, Shabek N. C-terminal conformational changes in SCF-D3/MAX2 ubiquitin ligase are required for KAI2-mediated signaling. THE NEW PHYTOLOGIST 2023; 239:2067-2075. [PMID: 37376727 DOI: 10.1111/nph.19101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023]
Affiliation(s)
- Lior Tal
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, 95616, USA
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, 95616, USA
| | - Kartikye Varshney
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), 85354, Freising, Germany
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam Science Park, 14476, Potsdam-Golm, Germany
| | - Aleczander Young
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, 95616, USA
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), 85354, Freising, Germany
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam Science Park, 14476, Potsdam-Golm, Germany
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, 95616, USA
| |
Collapse
|
20
|
Kameoka H, Shimazaki S, Mashiguchi K, Watanabe B, Komatsu A, Yoda A, Mizuno Y, Kodama K, Okamoto M, Nomura T, Yamaguchi S, Kyozuka J. DIENELACTONE HYDROLASE LIKE PROTEIN1 negatively regulates the KAI2-ligand pathway in Marchantia polymorpha. Curr Biol 2023; 33:3505-3513.e5. [PMID: 37480853 DOI: 10.1016/j.cub.2023.06.083] [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: 12/01/2022] [Revised: 05/25/2023] [Accepted: 06/29/2023] [Indexed: 07/24/2023]
Abstract
Karrikins are smoke-derived butenolides that induce seed germination and photomorphogenesis in a wide range of plants.1,2,3 KARRIKIN INSENSITIVE2 (KAI2), a paralog of a strigolactone receptor, perceives karrikins or their metabolized products in Arabidopsis thaliana.4,5,6,7 Furthermore, KAI2 is thought to perceive an unidentified plant hormone, called KAI2 ligand (KL).8,9 KL signal is transduced via the interaction between KAI2, MORE AXILLARY GROWTH2 (MAX2), and SUPPRESSOR of MORE AXILLARY GROWTH2 1 LIKE family proteins (SMXLs), followed by the degradation of SMXLs.4,7,10,11,12,13,14 This signaling pathway is conserved both in A. thaliana and the bryophyte Marchantia polymorpha.14 Although the KL signaling pathway is well characterized, the KL metabolism pathways remain poorly understood. Here, we show that DIENELACTONE HYDROLASE LIKE PROTEIN1 (DLP1) is a negative regulator of the KL pathway in M. polymorpha. The KL signal induces DLP1 expression. DLP1 overexpression lines phenocopied the Mpkai2a and Mpmax2 mutants, while dlp1 mutants phenocopied the Mpsmxl mutants. Mutations in the KL signaling genes largely suppressed these phenotypes, indicating that DLP1 acts upstream of the KL signaling pathway, although DLP1 also has KL pathway-independent functions. DLP1 exhibited enzymatic activity toward a potential substrate, suggesting the possibility that DLP1 works through KL inactivation. Investigation of DLP1 homologs in A. thaliana revealed that they do not play a major role in the KL pathway, suggesting different mechanisms for the KL signal regulation. Our findings provide new insights into the regulation of the KL signal in M. polymorpha and the evolution of the KL pathway in land plants.
Collapse
Affiliation(s)
- Hiromu Kameoka
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
| | - Shota Shimazaki
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Kiyoshi Mashiguchi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Bunta Watanabe
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Aino Komatsu
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Akiyoshi Yoda
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Yohei Mizuno
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Kyoichi Kodama
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Masanori Okamoto
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| | - Takahito Nomura
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Shinjiro Yamaguchi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Junko Kyozuka
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.
| |
Collapse
|
21
|
Seo PJ, Lee HG, Choi HY, Lee S, Park CM. Complexity of SMAX1 signaling during seedling establishment. TRENDS IN PLANT SCIENCE 2023; 28:902-912. [PMID: 37069002 DOI: 10.1016/j.tplants.2023.03.014] [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: 08/19/2022] [Revised: 03/12/2023] [Accepted: 03/18/2023] [Indexed: 06/19/2023]
Abstract
Karrikins (KARs) are small butenolide compounds identified in the smoke of burning vegetation. Along with the stimulating effects on seed germination, KARs also regulate seedling vigor and adaptive behaviors, such as seedling morphogenesis, root hair development, and stress acclimation. The pivotal KAR signaling repressor, SUPPRESSOR OF MAX2 1 (SMAX1), plays central roles in these developmental and morphogenic processes through an extensive signaling network that governs seedling responses to endogenous and environmental cues. Here, we summarize the versatile roles of SMAX1 reported in recent years and discuss how SMAX1 integrates multiple growth hormone signals into optimizing seedling establishment. We also discuss the evolutionary relevance of the SMAX1-mediated signaling pathways during the colonization of aqueous plants to terrestrial environments.
Collapse
Affiliation(s)
- Pil Joon Seo
- Department of Chemistry, Seoul National University, Seoul 08826, Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.
| | - Hong Gil Lee
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea
| | - Hye-Young Choi
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Sangmin Lee
- Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju 61003, Korea
| | - Chung-Mo Park
- Department of Chemistry, Seoul National University, Seoul 08826, Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.
| |
Collapse
|
22
|
Korek M, Marzec M. Strigolactones and abscisic acid interactions affect plant development and response to abiotic stresses. BMC PLANT BIOLOGY 2023; 23:314. [PMID: 37308831 DOI: 10.1186/s12870-023-04332-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 06/06/2023] [Indexed: 06/14/2023]
Abstract
Strigolactones (SL) are the youngest group of plant hormones responsible for shaping plant architecture, especially the branching of shoots. However, recent studies provided new insights into the functioning of SL, confirming their participation in regulating the plant response to various types of abiotic stresses, including water deficit, soil salinity and osmotic stress. On the other hand, abscisic acid (ABA), commonly referred as a stress hormone, is the molecule that crucially controls the plant response to adverse environmental conditions. Since the SL and ABA share a common precursor in their biosynthetic pathways, the interaction between both phytohormones has been largely studied in the literature. Under optimal growth conditions, the balance between ABA and SL content is maintained to ensure proper plant development. At the same time, the water deficit tends to inhibit SL accumulation in the roots, which serves as a sensing mechanism for drought, and empowers the ABA production, which is necessary for plant defense responses. The SL-ABA cross-talk at the signaling level, especially regarding the closing of the stomata under drought conditions, still remains poorly understood. Enhanced SL content in shoots is likely to stimulate the plant sensitivity to ABA, thus reducing the stomatal conductance and improving the plant survival rate. Besides, it was proposed that SL might promote the closing of stomata in an ABA-independent way. Here, we summarize the current knowledge regarding the SL and ABA interactions by providing new insights into the function, perception and regulation of both phytohormones during abiotic stress response of plants, as well as revealing the gaps in the current knowledge of SL-ABA cross-talk.
Collapse
Affiliation(s)
- Magdalena Korek
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, Katowice, 40-032, Poland.
| | - Marek Marzec
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, Katowice, 40-032, Poland
| |
Collapse
|
23
|
Waters MT, Nelson DC. Karrikin perception and signalling. THE NEW PHYTOLOGIST 2023; 237:1525-1541. [PMID: 36333982 DOI: 10.1111/nph.18598] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Karrikins (KARs) are a class of butenolide compounds found in smoke that were first identified as seed germination stimulants for fire-following species. Early studies of KARs classified the germination and postgermination responses of many plant species and investigated crosstalk with plant hormones that regulate germination. The discovery that Arabidopsis thaliana responds to KARs laid the foundation for identifying mutants with altered KAR responses. Genetic analysis of KAR signalling revealed an unexpected link to strigolactones (SLs), a class of carotenoid-derived plant hormones. Substantial progress has since been made towards understanding how KARs are perceived and regulate plant growth, in no small part due to advances in understanding SL perception. KAR and SL signalling systems are evolutionarily related and retain a high degree of similarity. There is strong evidence that KARs are natural analogues of an endogenous signal(s), KAI2 ligand (KL), which remains unknown. KAR/KL signalling regulates many developmental processes in plants including germination, seedling photomorphogenesis, and root and root hair growth. KAR/KL signalling also affects abiotic stress responses and arbuscular mycorrhizal symbiosis. Here, we summarise the current knowledge of KAR/KL signalling and discuss current controversies and unanswered questions in this field.
Collapse
Affiliation(s)
- Mark T Waters
- School of Molecular Sciences, University of Western Australia, Perth, WA, 6009, Australia
| | - David C Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA
| |
Collapse
|
24
|
Komatsu A, Kodama K, Mizuno Y, Fujibayashi M, Naramoto S, Kyozuka J. Control of vegetative reproduction in Marchantiapolymorpha by the KAI2-ligand signaling pathway. Curr Biol 2023; 33:1196-1210.e4. [PMID: 36863344 DOI: 10.1016/j.cub.2023.02.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/29/2022] [Accepted: 02/06/2023] [Indexed: 03/04/2023]
Abstract
In vegetative reproduction of Marchantia polymorpha (M. polymorpha), propagules, called gemmae, are formed in gemma cups. Despite its significance for survival, control of gemma and gemma cup formation by environmental cues is not well understood. We show here that the number of gemmae formed in a gemma cup is a genetic trait. Gemma formation starts from the central region of the floor of the gemma cup, proceeds to the periphery, and terminates when the appropriate number of gemmae is initiated. The MpKARRIKIN INSENSITIVE2 (MpKAI2)-dependent signaling pathway promotes gemma cup formation and gemma initiation. The number of gemmae in a cup is controlled by modulating the ON/OFF switch of the KAI2-dependent signaling. Termination of the signaling results in the accumulation of MpSMXL, a suppressor protein. In the Mpsmxl mutants, gemma initiation continues, leading to the formation of a highly increased number of gemmae in a cup. Consistent with its function, the MpKAI2-dependent signaling pathway is active in gemma cups where gemmae initiate, as well as in the notch region of the mature gemma and midrib of the ventral side of the thallus. In this work, we also show that GEMMA CUP-ASSOCIATED MYB1 works downstream of this signaling pathway to promote gemma cup formation and gemma initiation. We also found that the availability of potassium affects gemma cup formation independently from the KAI2-dependent signaling pathway in M. polymorpha. We propose that the KAI2-dependent signaling pathway functions to optimize vegetative reproduction by adapting to the environment in M. polymorpha.
Collapse
Affiliation(s)
- Aino Komatsu
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Kyoichi Kodama
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Yohei Mizuno
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Mizuki Fujibayashi
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Satoshi Naramoto
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Junko Kyozuka
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.
| |
Collapse
|
25
|
Sun M, Wang D, Liu C, Liu Y, Niu M, Wang J, Li J. Genome-wide identification and analysis of the SUPPRESSOR of MAX2 1-LIKE gene family and its interaction with DWARF14 in poplar. BMC PLANT BIOLOGY 2023; 23:105. [PMID: 36814183 PMCID: PMC9945404 DOI: 10.1186/s12870-023-04118-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Strigolactones (SLs) are important phytohormones that can regulate branch development in plants. Although SUPPRESSOR of MAX2 1-LIKE proteins (SMXLs) play a crucial role in SL signaling transduction, the SMXL gene family has not been well characterized in poplar. RESULTS In this study, 12 members of the poplar SMXL gene family were identified and phylogenetically classified into four clades. Motif and 3D structural analyses revealed that PtSMXL proteins are structurally very conserved; however, the P-loop NTPase domain at the C-terminal was found to vary substantially among clades. A genomic collinearity analysis indicated that PtSMXL gene family members have expanded during recent genome doubling events in poplar, with all gene pairs subsequently undergoing purifying selection. According to a Cis-element analysis, PtSMXL promoters contain many light-responsive elements. In an expression pattern analysis, all 12 PtSMXL genes displayed tissue-specific expression, especially PtSMXL8a. PtSMXL7b expression was significantly downregulated after axillary bud growth begins. In addition, the expressions of PtSMXL7b and PtSMXL8a were highly induced by 2 μM GR24, a synthetic SL analog, thus suggesting that these genes are involved in SL-regulated axillary bud growth. In a yeast two-hybrid assay, only PtSMXL7b in clade II was able to interact with the SL receptor PtD14a in an SL dependent manner, which indicates that PtSMXL7b may be the functional homolog of D53/SMXL6/7/8 in poplar. Finally, we established its ability to affect axillary bud growth by constructing poplar overexpressing the PtSMXL7b gene. CONCLUSIONS Our findings may inform future research on the functions of SMXLs in poplar, especially with respect to branch development.
Collapse
Affiliation(s)
- Maotong Sun
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China
| | - Dongyue Wang
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China
| | - Cuishuang Liu
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China
| | - Yuan Liu
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China
| | - Muge Niu
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China
| | - Jinnan Wang
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China.
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China.
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China.
| | - Jihong Li
- College of Forestry, Shandong Agricultural University, Taian, 271018, Shangdong, China.
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, Shandong Agricultural University, Taian, 271018, Shangdong, China.
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Taian, 271018, Shangdong, China.
| |
Collapse
|
26
|
Zheng X, Liu F, Yang X, Li W, Chen S, Yue X, Jia Q, Sun X. The MAX2-KAI2 module promotes salicylic acid-mediated immune responses in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023. [PMID: 36738234 DOI: 10.1111/jipb.13463] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Arabidopsis MORE AXILLARY GROWTH2 (MAX2) is a key component in the strigolactone (SL) and karrikin (KAR) signaling pathways and regulates the degradation of SUPPRESSOR OF MAX2 1/SMAX1-like (SMAX1/SMXL) proteins, which are transcriptional co-repressors that regulate plant architecture, as well as abiotic and biotic stress responses. The max2 mutation reduces resistance against Pseudomonas syringae pv. tomato (Pst). To uncover the mechanism of MAX2-mediated resistance, we evaluated the resistance of various SL and KAR signaling pathway mutants. The resistance of SL-deficient mutants and of dwarf 14 (d14) was similar to that of the wild-type, whereas the resistance of the karrikin insensitive 2 (kai2) mutant was compromised, demonstrating that the KAR signaling pathway, not the SL signaling pathway, positively regulates the immune response. We measured the resistance of smax1 and smxl mutants, as well as the double, triple, and quadruple mutants with max2, which revealed that both the smax1 mutant and smxl6/7/8 triple mutant rescue the low resistance phenotype of max2 and that SMAX1 accumulation diminishes resistance. The susceptibility of smax1D, containing a degradation-insensitive form of SMAX1, further confirmed the SMAX1 function in the resistance. The relationship between the accumulation of SMAX1/SMXLs and disease resistance suggested that the inhibitory activity of SMAX1 to resistance requires SMXL6/7/8. Moreover, the exogenous application of KAR2 enhanced resistance against Pst, but KAR-induced resistance depended on salicylic acid (SA) signaling. Inhibition of karrikin signaling delayed SA-mediated defense responses and inhibited pathogen-induced protein biosynthesis. Together, we propose that the MAX2-KAI2-SMAX1 complex regulates resistance with the assistance of SMXL6/7/8 and SA signaling and that SMAX1/SMXLs possibly form a multimeric complex with their target transcription factors to fine tune immune responses.
Collapse
Affiliation(s)
- Xiujuan Zheng
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Fangqian Liu
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Xianfeng Yang
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Weiqiang Li
- Jilin Da'an Agro-ecosystem National Observation Research Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Sique Chen
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Xinwu Yue
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Qi Jia
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Xinli Sun
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| |
Collapse
|
27
|
Abdelrahman M, Mostofa MG, Tran CD, El-Sayed M, Li W, Sulieman S, Tanaka M, Seki M, Tran LSP. The Karrikin Receptor Karrikin Insensitive2 Positively Regulates Heat Stress Tolerance in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2023; 63:1914-1926. [PMID: 35880749 DOI: 10.1093/pcp/pcac112] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 06/23/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
In this study, we investigated the potential role of the karrikin receptor KARRIKIN INSENSITIVE2 (KAI2) in the response of Arabidopsis seedlings to high-temperature stress. We performed phenotypic, physiological and transcriptome analyses of Arabidopsis kai2 mutants and wild-type (WT) plants under control (kai2_C and WT_C, respectively) and 6- and 24-h heat stress conditions (kai2_H6, kai2_H24, WT_H6 and WT_H24, respectively) to understand the basis for KAI2-regulated heat stress tolerance. We discovered that the kai2 mutants exhibited hypersensitivity to high-temperature stress relative to WT plants, which might be associated with a more highly increased leaf surface temperature and cell membrane damage in kai2 mutant plants. Next, we performed comparative transcriptome analysis of kai2_C, kai2_H6, kai2_H24, WT_C, WT_H6 and WT_H24 to identify transcriptome differences between WT and kai2 mutants in response to heat stress. K-mean clustering of normalized gene expression separated the investigated genotypes into three clusters based on heat-treated and non-treated control conditions. Within each cluster, the kai2 mutants were separated from WT plants, implying that kai2 mutants exhibited distinct transcriptome profiles relative to WT plants. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed a repression in 'misfolded protein binding', 'heat shock protein binding', 'unfolded protein binding' and 'protein processing in endoplasmic reticulum' pathways, which was consistent with the downregulation of several genes encoding heat shock proteins and heat shock transcription factors in the kai2 mutant versus WT plants under control and heat stress conditions. Our findings suggest that chemical or genetic manipulation of KAI2 signaling may provide a novel way to improve heat tolerance in plants.
Collapse
Affiliation(s)
- Mostafa Abdelrahman
- Faculty of Science, Galala University, Suez, El Sokhna 43511, Egypt
- Botany Department, Faculty of Science, Aswan University, Aswan 81528, Egypt
| | - Mohammad Golam Mostofa
- Department of Plant and Soil Science, Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX 79409, USA
| | - Cuong Duy Tran
- Genetic Engineering Department, Agricultural Genetics Institute, Vietnamese Academy of Agricultural Science, Pham Van Dong Street, Hanoi 100000, Viet Nam
| | - Magdi El-Sayed
- Faculty of Science, Galala University, Suez, El Sokhna 43511, Egypt
| | - Weiqiang Li
- Jilin Da'an Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, Kaifeng 475001, China
| | - Saad Sulieman
- Department of Agronomy, Faculty of Agriculture, University of Khartoum, Shambat, Khartoum North 13314, Sudan
| | - Maho Tanaka
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Saitama, 351-0198 Japan
| | - Motoaki Seki
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Saitama, 351-0198 Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, 244-0813 Japan
| | - Lam-Son Phan Tran
- Department of Plant and Soil Science, Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX 79409, USA
| |
Collapse
|
28
|
Feng Z, Liang X, Tian H, Watanabe Y, Nguyen KH, Tran CD, Abdelrahman M, Xu K, Mostofa MG, Ha CV, Mochida K, Tian C, Tanaka M, Seki M, Liang Z, Miao Y, Tran LSP, Li W. SUPPRESSOR of MAX2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) Negatively Regulate Drought Resistance in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2023; 63:1900-1913. [PMID: 35681253 DOI: 10.1093/pcp/pcac080] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/13/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Recent investigations in Arabidopsis thaliana suggest that SUPPRESSOR of MORE AXILLARY GROWTH 2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) are negative regulators of karrikin (KAR) and strigolactone (SL) signaling during plant growth and development, but their functions in drought resistance and related mechanisms of action remain unclear. To understand the roles and mechanisms of SMAX1 and SMXL2 in drought resistance, we investigated the drought-resistance phenotypes and transcriptome profiles of smax1 smxl2 (s1,2) double-mutant plants in response to drought stress. The s1,2 mutant plants showed enhanced drought-resistance and lower leaf water loss when compared with wild-type (WT) plants. Transcriptome comparison of rosette leaves from the s1,2 mutant and the WT under normal and dehydration conditions suggested that the mechanism related to cuticle formation was involved in drought resistance. This possibility was supported by enhanced cuticle formation in the rosette leaves of the s1,2 mutant. We also found that the s1,2 mutant plants were more sensitive to abscisic acid in assays of stomatal closure, cotyledon opening, chlorophyll degradation and growth inhibition, and they showed a higher reactive oxygen species detoxification capacity than WT plants. In addition, the s1,2 mutant plants had longer root hairs and a higher root-to-shoot ratio than the WT plants, suggesting that the mutant had a greater capacity for water absorption than the WT. Taken together, our results indicate that SMAX1 and SMXL2 negatively regulate drought resistance, and disruption of these KAR- and SL-signaling-related genes may therefore provide a novel means for improving crop drought resistance.
Collapse
Affiliation(s)
- Zhonghui Feng
- Jilin Daan Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, No. 4888 Shengbei Street, Changchun 130102, China
- College of Life Science, Baicheng Normal University, No. 57, Zhongxing West Road, Taobei District, Baicheng 137000, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Xiaohan Liang
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Hongtao Tian
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Yasuko Watanabe
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, 230-0045 Japan
| | - Kien Huu Nguyen
- National Key Laboratory for Plant Cell Biotechnology, Agricultural Genetics Institute, Vietnam Academy of Agricultural Science, Pham Van Dong Street, Hanoi 100000, Vietnam
| | - Cuong Duy Tran
- Genetic Engineering Department, Agricultural Genetics Institute, Vietnamese Academy of Agricultural Science, Pham Van Dong Street, Hanoi 100000, Vietnam
| | - Mostafa Abdelrahman
- Botany Department, Faculty of Science, Aswan University, Aswan 81528, Egypt
- Molecular Biotechnology Program, Faculty of Science, Galala University, Suze, New Galala 43511, Egypt
| | - Kun Xu
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Mohammad Golam Mostofa
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, 1006 Canton Ave, Lubbock, TX 79409, USA
| | - Chien Van Ha
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, 1006 Canton Ave, Lubbock, TX 79409, USA
| | - Keiichi Mochida
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, 230-0045 Japan
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-tyo, Totsuka, Yokohama, 244-0813 Japan
- RIKEN Baton Zone Program, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, 230-0045 Japan
- School of Information and Data Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521 Japan
| | - Chunjie Tian
- Jilin Daan Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, No. 4888 Shengbei Street, Changchun 130102, China
| | - Maho Tanaka
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, 230-0045 Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Motoaki Seki
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, 230-0045 Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Zhengwei Liang
- Jilin Daan Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, No. 4888 Shengbei Street, Changchun 130102, China
| | - Yuchen Miao
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Lam-Son Phan Tran
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, 1006 Canton Ave, Lubbock, TX 79409, USA
| | - Weiqiang Li
- Jilin Daan Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, No. 4888 Shengbei Street, Changchun 130102, China
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| |
Collapse
|
29
|
Xu P, Jinbo H, Cai W. Karrikin signaling regulates hypocotyl shade avoidance response by modulating auxin homeostasis in Arabidopsis. THE NEW PHYTOLOGIST 2022; 236:1748-1761. [PMID: 36068957 DOI: 10.1111/nph.18459] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Shade affects all aspects of plant growth and development, including seed germination, hypocotyl elongation, petiole growth, leaf hyponasty, and flowering time. Here, we found that mutations in the key Arabidopsis karrikins signal perception-associated KARRIKIN INSENSITIVE 2 (KAI2) gene, encoding an α/β-fold hydrolase, and the MORE AXILLARY GROWTH 2 (MAX2) gene, encoding an F-box protein, led to greater hypocotyl elongation under shade avoidance conditions. We further verified that these phenotypes were caused by perception of the endogenous KAI2-ligands (KLs), and that this phenotype is independent of strigolactone biosynthetic or signaling pathways. Upon perception of a KL, it is probable that the target protein forms a complex with the KAI2/MAX2 proteins, which are degraded through the action of the 26S proteasome. We demonstrated that SUPPRESSOR OF MAX2-1 (SMAX1) is the degradation target for the KAI2/MAX2 complex in the context of shade avoidance. KAI2 and MAX2 require SMAX1 to limit the hypocotyl growth associated with shade avoidance. Treatment with l-kynurenine, an inhibitor of auxin accumulation, partially restored elongation of kai2 mutant hypocotyls under simulated shade. Furthermore, KAI2 is involved in regulating auxin accumulation and polar auxin transport, which may contribute to the hypocotyl shade response. In addition, SMAX1 gene overexpression promoted the hypocotyl shade response. RNA-sequencing analysis revealed that SMAX1-overexpression affected the expression of many auxin homeostasis genes, especially under simulated shade. Altogether, our data support the conclusion that KL signaling regulates shade avoidance by modulating auxin homeostasis in the hypocotyl.
Collapse
Affiliation(s)
- Peipei Xu
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hu Jinbo
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Weiming Cai
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| |
Collapse
|
30
|
Tian H, Watanabe Y, Nguyen KH, Tran CD, Abdelrahman M, Liang X, Xu K, Sepulveda C, Mostofa MG, Van Ha C, Nelson DC, Mochida K, Tian C, Tanaka M, Seki M, Miao Y, Tran LSP, Li W. KARRIKIN UPREGULATED F-BOX 1 negatively regulates drought tolerance in Arabidopsis. PLANT PHYSIOLOGY 2022; 190:2671-2687. [PMID: 35822606 PMCID: PMC9706471 DOI: 10.1093/plphys/kiac336] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 06/26/2022] [Indexed: 06/15/2023]
Abstract
The karrikin (KAR) receptor and several related signaling components have been identified by forward genetic screening, but only a few studies have reported on upstream and downstream KAR signaling components and their roles in drought tolerance. Here, we characterized the functions of KAR UPREGULATED F-BOX 1 (KUF1) in drought tolerance using a reverse genetics approach in Arabidopsis (Arabidopsis thaliana). We observed that kuf1 mutant plants were more tolerant to drought stress than wild-type (WT) plants. To clarify the mechanisms by which KUF1 negatively regulates drought tolerance, we performed physiological, transcriptome, and morphological analyses. We found that kuf1 plants limited leaf water loss by reducing stomatal aperture and cuticular permeability. In addition, kuf1 plants showed increased sensitivity of stomatal closure, seed germination, primary root growth, and leaf senescence to abscisic acid (ABA). Genome-wide transcriptome comparisons of kuf1 and WT rosette leaves before and after dehydration showed that the differences in various drought tolerance-related traits were accompanied by differences in the expression of genes associated with stomatal closure (e.g. OPEN STOMATA 1), lipid and fatty acid metabolism (e.g. WAX ESTER SYNTHASE), and ABA responsiveness (e.g. ABA-RESPONSIVE ELEMENT 3). The kuf1 mutant plants had higher root/shoot ratios and root hair densities than WT plants, suggesting that they could absorb more water than WT plants. Together, these results demonstrate that KUF1 negatively regulates drought tolerance by modulating various physiological traits, morphological adjustments, and ABA responses and that the genetic manipulation of KUF1 in crops is a potential means of enhancing their drought tolerance.
Collapse
Affiliation(s)
- Hongtao Tian
- Jilin Da’an Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Yasuko Watanabe
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
| | - Kien Huu Nguyen
- National Key Laboratory for Plant Cell Biotechnology, Agricultural Genetics Institute, Vietnam Academy of Agricultural Science, Pham-Van-Dong Str., Hanoi, 100000, Vietnam
| | - Cuong Duy Tran
- National Key Laboratory for Plant Cell Biotechnology, Agricultural Genetics Institute, Vietnam Academy of Agricultural Science, Pham-Van-Dong Str., Hanoi, 100000, Vietnam
| | - Mostafa Abdelrahman
- Botany Department, Faculty of Science, Aswan University, Aswan 81528, Egypt
- Molecular Biotechnology Program, Faculty of Science, Galala University, Suze, New Galala 43511, Egypt
| | - Xiaohan Liang
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Kun Xu
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | - Claudia Sepulveda
- Department of Botany & Plant Sciences, University of California, Riverside, California 92521, USA
| | - Mohammad Golam Mostofa
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, Texas 79409, USA
| | - Chien Van Ha
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, Texas 79409, USA
| | - David C Nelson
- Department of Botany & Plant Sciences, University of California, Riverside, California 92521, USA
| | - Keiichi Mochida
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
- School of Information and Data Sciences, Nagasaki University, Nagasaki, Japan
| | - Chunjie Tian
- Jilin Da’an Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Maho Tanaka
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Wako, Japan
| | - Motoaki Seki
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Wako, Japan
| | - Yuchen Miao
- State Key Laboratory of Cotton Biology, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, No. 85 Jinming Road, Kaifeng 475004, China
| | | | - Weiqiang Li
- Author for correspondence: or (W.L.), (L.-S.P.T.)
| |
Collapse
|
31
|
Temmerman A, Marquez-Garcia B, Depuydt S, Bruznican S, De Cuyper C, De Keyser A, Boyer FD, Vereecke D, Struk S, Goormachtig S. MAX2-dependent competence for callus formation and shoot regeneration from Arabidopsis thaliana root explants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6272-6291. [PMID: 35738874 DOI: 10.1093/jxb/erac281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/23/2022] [Indexed: 05/21/2023]
Abstract
Although the division of the pericycle cells initiates both lateral root development and root-derived callus formation, these developmental processes are affected differently in the strigolactone and karrikin/KARRIKIN INSENSITIVE 2 (KAI2) ligand signalling mutant more axillary growth 2 (max2). Whereas max2 produces more lateral roots than the wild type, it is defective in the regeneration of shoots from root explants. We suggest that the decreased shoot regeneration of max2 originates from delayed formation of callus primordium, yielding less callus material to regenerate shoots. Indeed, when incubated on callus-inducing medium, the pericycle cell division was reduced in max2 and the early gene expression varied when compared with the wild type, as determined by a transcriptomics analysis. Furthermore, the expression of the LATERAL ORGAN BOUNDARIES DOMAIN genes and of callus-induction genes was modified in correlation with the max2 phenotype, suggesting a role for MAX2 in the regulation of the interplay between cytokinin, auxin, and light signalling in callus initiation. Additionally, we found that the in vitro shoot regeneration phenotype of max2 might be caused by a defect in KAI2, rather than in DWARF14, signalling. Nevertheless, the shoot regeneration assays revealed that the strigolactone biosynthesis mutants max3 and max4 also play a minor role.
Collapse
Affiliation(s)
- Arne Temmerman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - Belen Marquez-Garcia
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - Stephen Depuydt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
- Laboratory of Plant Growth Analysis, Ghent University Global Campus, Songdomunhwa-Ro, Yeonsu-Gu, Incheon, Korea
| | - Silvia Bruznican
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - Carolien De Cuyper
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - Annick De Keyser
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - François-Didier Boyer
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Avenue de la Terrasse, Gif-sur-Yvette, France
| | - Danny Vereecke
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Valentin Vaerwyckweg, Ghent, Belgium
| | - Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium
| |
Collapse
|
32
|
Martinez SE, Conn CE, Guercio AM, Sepulveda C, Fiscus CJ, Koenig D, Shabek N, Nelson DC. A KARRIKIN INSENSITIVE2 paralog in lettuce mediates highly sensitive germination responses to karrikinolide. PLANT PHYSIOLOGY 2022; 190:1440-1456. [PMID: 35809069 PMCID: PMC9516758 DOI: 10.1093/plphys/kiac328] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Karrikins (KARs) are chemicals in smoke that can enhance germination of many plants. Lettuce (Lactuca sativa) cv. Grand Rapids germinates in response to nanomolar karrikinolide (KAR1). Lettuce is much less responsive to KAR2 or a mixture of synthetic strigolactone analogs, rac-GR24. We investigated the molecular basis of selective and sensitive KAR1 perception in lettuce. The lettuce genome contains two copies of KARRIKIN INSENSITIVE2 (KAI2), which in Arabidopsis (Arabidopsis thaliana) encodes a receptor that is required for KAR responses. LsKAI2b is more highly expressed than LsKAI2a in dry achenes and during early stages of imbibition. Through cross-species complementation assays in Arabidopsis, we found that an LsKAI2b transgene confers robust responses to KAR1, but LsKAI2a does not. Therefore, LsKAI2b likely mediates KAR1 responses in lettuce. We compared homology models of KAI2 proteins from lettuce and a fire-follower, whispering bells (Emmenanthe penduliflora). This identified pocket residues 96, 124, 139, and 161 as candidates that influence the ligand specificity of KAI2. Further support for the importance of these residues was found through a broader comparison of pocket residues among 281 KAI2 proteins from 184 asterid species. Almost all KAI2 proteins had either Tyr or Phe identity at position 124. Genes encoding Y124-type KAI2 are more broadly distributed in asterids than in F124-type KAI2. Substitutions at residues 96, 124, 139, and 161 in Arabidopsis KAI2 produced a broad array of responses to KAR1, KAR2, and rac-GR24. This suggests that the diverse ligand preferences observed among KAI2 proteins in plants could have evolved through relatively few mutations.
Collapse
Affiliation(s)
- Stephanie E Martinez
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | - Caitlin E Conn
- Department of Biology, Berry College, Mount Berry, Georgia 30149, USA
| | - Angelica M Guercio
- Department of Plant Biology, University of California, Davis, California 95616, USA
| | - Claudia Sepulveda
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | - Christopher J Fiscus
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | - Daniel Koenig
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | - Nitzan Shabek
- Department of Plant Biology, University of California, Davis, California 95616, USA
| | - David C Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| |
Collapse
|
33
|
Ogawa S, Cui S, White ARF, Nelson DC, Yoshida S, Shirasu K. Strigolactones are chemoattractants for host tropism in Orobanchaceae parasitic plants. Nat Commun 2022; 13:4653. [PMID: 35970835 PMCID: PMC9378612 DOI: 10.1038/s41467-022-32314-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/26/2022] [Indexed: 12/17/2022] Open
Abstract
Parasitic plants are worldwide threats that damage major agricultural crops. To initiate infection, parasitic plants have developed the ability to locate hosts and grow towards them. This ability, called host tropism, is critical for parasite survival, but its underlying mechanism remains mostly unresolved. To characterise host tropism, we used the model facultative root parasite Phtheirospermum japonicum, a member of the Orobanchaceae. Here, we show that strigolactones (SLs) function as host-derived chemoattractants. Chemotropism to SLs is also found in Striga hermonthica, a parasitic member of the Orobanchaceae, but not in non-parasites. Intriguingly, chemotropism to SLs in P. japonicum is attenuated in ammonium ion-rich conditions, where SLs are perceived, but the resulting asymmetrical accumulation of the auxin transporter PIN2 is diminished. P. japonicum encodes putative receptors that sense exogenous SLs, whereas expression of a dominant-negative form reduces its chemotropic ability. We propose a function for SLs as navigators for parasite roots.
Collapse
Affiliation(s)
- Satoshi Ogawa
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan
| | - Songkui Cui
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| | - Alexandra R F White
- Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA
| | - David C Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA
| | - Satoko Yoshida
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan
| | - Ken Shirasu
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan. .,Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan.
| |
Collapse
|
34
|
Liu H, Liu S, Yu H, Huang X, Wang Y, Jiang L, Meng X, Liu G, Chen M, Jing Y, Yu F, Wang B, Li J. An engineered platform for reconstituting functional multisubunit SCF E3 ligase in vitro. MOLECULAR PLANT 2022; 15:1285-1299. [PMID: 35751381 DOI: 10.1016/j.molp.2022.06.011] [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: 08/10/2021] [Revised: 03/13/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Multisubunit SKP1/Cullin1/F-box (SCF) E3 ligases play essential roles in regulating the stability of crucial regulatory factors and controlling growth and development in eukaryotes. Detecting E3 ligase activity in vitro is important for exploring the molecular mechanism of protein ubiquitination. However, in vitro ubiquitination assay systems for multisubunit E3 ligases remain difficult to achieve, especially in plants, mainly owing to difficulties in achieving active components of multisubunit E3 ligases with high purity and characterizing specific E2 and E3 pairs. In this study, we characterized components of the rice SCFDWARF3 (SCFD3) E3 ligase, screened the coordinated E2, and reconstituted active SCFD3 E3 ligase in vitro. We further engineered SCFD3 E3 ligase using a fused SKP1-Cullin1-RBX1 (eSCR) protein and found that both the wild-type SCFD3 E3 ligase and the engineered SCFD3 E3 ligase catalyzed ubiquitination of the substrate D53, which is the key transcriptional repressor in strigolactone signaling. Finally, we replaced D3 with other F-box proteins from rice and humans and reconstituted active eSCF E3 ligases, including eSCFGID2, eSCFFBXL18, and eSCFCDC4 E3 ligases. Our work reconstitutes functional SCF E3 ligases in vitro and generates an engineered system with interchangeable F-box proteins, providing a powerful platform for studying the mechanisms of multisubunit SCF E3 ligases in eukaryotes.
Collapse
Affiliation(s)
- Huihui Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Simiao Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong Yu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiahe Huang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yingchun Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Jiang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiangbing Meng
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Guifu Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Mingjiang Chen
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanhui Jing
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Feifei Yu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Bing Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
| | - Jiayang Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
35
|
Bonhomme S, Guillory A. Synthesis and signalling of strigolactone and KAI2-ligand signals in bryophytes. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4487-4495. [PMID: 35524989 DOI: 10.1093/jxb/erac186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
Strigolactones (SLs), long known as butenolide rhizospheric signals, have been recognized since 2008 as a class of hormones regulating many aspects of plant development. Many authors also anticipate 'KAI2-ligand' (KL) as a novel class of phytohormones; however, this ligand remains elusive. Core genes of SL and KL pathways, first described in angiosperms, are found in all land plants and some even in green algae. This review reports current knowledge of these pathways in bryophytes. Data on the pathways mostly come from two models: the moss Physcomitrium patens and the liverwort Marchantia. Gene targeting methods have allowed functional analyses of both models. Recent work in Marchantia suggests that SLs' ancestral role was to recruit beneficial microbes as arbuscular mycorrhizal fungi. In contrast, the hormonal role of SLs observed in P. patens is probably a result of convergent evolution. Evidence for a functional KL pathway in both bryophyte models is very recent. Nevertheless, many unknowns remain and warrant a more extensive investigation of SL and KL pathways in various land plant lineages.
Collapse
Affiliation(s)
- Sandrine Bonhomme
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Ambre Guillory
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
- Laboratoire des Interactions Plantes - Microbes - Environnement (LIPME), Université de Toulouse, INRAE, CNRS, 24 Chemin de Borde Rouge, 31320 Castanet-Tolosan, France
| |
Collapse
|
36
|
Kim JY, Park YJ, Lee JH, Park CM. SMAX1 Integrates Karrikin and Light Signals into GA-Mediated Hypocotyl Growth during Seedling Establishment. PLANT & CELL PHYSIOLOGY 2022; 63:932-943. [PMID: 35477800 DOI: 10.1093/pcp/pcac055] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/13/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Morphogenic adaptation of young seedlings to light environments is a critical developmental process that ensures plant survival and propagation, as they emerge from the soil. Photomorphogenic responses are facilitated by a network of light and growth hormonal signals, such as auxin and gibberellic acid (GA). Karrikins (KARs), a group of butenolide compounds produced from burning plant materials in wildfires, are known to stimulate seed germination in fire-prone plant species. Notably, recent studies support that they also regulate seedling growth, while underlying molecular mechanisms have been unexplored yet. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), a negative regulator of KAR signaling, integrates light and KAR signals into GA-DELLA pathways that regulate hypocotyl growth during seedling establishment. We found that SMAX1 facilitates degradation of DELLA proteins in the hypocotyls. Interestingly, light induces the accumulation of SMAX1 proteins, and SMAX1-mediated degradation of DELLA is elevated in seedling establishment during the dark-to-light transition. Our observations indicate that SMAX1-mediated integration of light and KAR signals into GA pathways elaborately modulates seedling establishment.
Collapse
Affiliation(s)
- Jae Young Kim
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
| | - Young-Joon Park
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
| | - June-Hee Lee
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
| | - Chung-Mo Park
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, South Korea
| |
Collapse
|
37
|
Park YJ, Kim JY, Park CM. SMAX1 potentiates phytochrome B-mediated hypocotyl thermomorphogenesis. THE PLANT CELL 2022; 34:2671-2687. [PMID: 35478037 PMCID: PMC9252492 DOI: 10.1093/plcell/koac124] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/16/2022] [Indexed: 05/19/2023]
Abstract
Plant thermosensors help optimize plant development and architecture for ambient temperatures, and morphogenic adaptation to warm temperatures has been extensively studied in recent years. Phytochrome B (phyB)-mediated thermosensing and the gene regulatory networks governing thermomorphogenic responses are well understood at the molecular level. However, it is unknown how plants manage their responsiveness to fluctuating temperatures in inducing thermomorphogenic behaviors. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), known as a karrikin signaling repressor, enhances the thermosensitivity of hypocotyl morphogenesis in Arabidopsis thaliana. Hypocotyl thermomorphogenesis was largely disrupted in SMAX1-deficient mutants. SMAX1 interacts with phyB to alleviate its suppressive effects on the transcription factor activity of PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), promoting hypocotyl thermomorphogenesis. Interestingly, the SMAX1 protein is slowly destabilized at warm temperatures, preventing hypocotyl overgrowth. Our findings indicate that the thermodynamic control of SMAX1 abundance serves as a molecular gatekeeper for phyB function in thermosensitizing PIF4-mediated hypocotyl morphogenesis.
Collapse
Affiliation(s)
- Young-Joon Park
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Jae Young Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | | |
Collapse
|
38
|
Hamon‐Josse M, Villaécija‐Aguilar JA, Ljung K, Leyser O, Gutjahr C, Bennett T. KAI2 regulates seedling development by mediating light-induced remodelling of auxin transport. THE NEW PHYTOLOGIST 2022; 235:126-140. [PMID: 35313031 PMCID: PMC9320994 DOI: 10.1111/nph.18110] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/05/2022] [Indexed: 05/13/2023]
Abstract
Photomorphogenic remodelling of seedling growth is a key developmental transition in the plant life cycle. The α/β-hydrolase signalling protein KARRIKIN-INSENSITIVE2 (KAI2), a close homologue of the strigolactone receptor DWARF14 (D14), is involved in this process, but it is unclear how the effects of KAI2 on development are mediated. Here, using a combination of physiological, pharmacological, genetic and imaging approaches in Arabidopsis thaliana (Heynh.) we show that kai2 phenotypes arise because of a failure to downregulate auxin transport from the seedling shoot apex towards the root system, rather than a failure to respond to light per se. We demonstrate that KAI2 controls the light-induced remodelling of the PIN-mediated auxin transport system in seedlings, promoting a reduction in PIN7 abundance in older tissues, and an increase of PIN1/PIN2 abundance in the root meristem. We show that removing PIN3, PIN4 and PIN7 from kai2 mutants, or pharmacological inhibition of auxin transport and synthesis, is sufficient to suppress most kai2 seedling phenotypes. We conclude that KAI2 regulates seedling morphogenesis by its effects on the auxin transport system. We propose that KAI2 is not required for the light-mediated changes in PIN gene expression but is required for the appropriate changes in PIN protein abundance within cells.
Collapse
Affiliation(s)
- Maxime Hamon‐Josse
- School of BiologyFaculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
| | | | - Karin Ljung
- Department of Forest Genetics and Plant PhysiologyUmeå Plant Science CentreSwedish University of Agricultural SciencesSE‐901 83UmeåSweden
| | - Ottoline Leyser
- Sainsbury Laboratory Cambridge UniversityBateman StreetCambridgeCB2 1LRUK
| | - Caroline Gutjahr
- Plant GeneticsTUM School of Life SciencesTechnical University of Munich (TUM)Emil Ramann Str. 485354FreisingGermany
- GeneticsFaculty of BiologyLMU MunichGrosshaderner St. 482152MartinsriedGermany
| | - Tom Bennett
- School of BiologyFaculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
- Sainsbury Laboratory Cambridge UniversityBateman StreetCambridgeCB2 1LRUK
| |
Collapse
|
39
|
Tal L, Palayam M, Ron M, Young A, Britt A, Shabek N. A conformational switch in the SCF-D3/MAX2 ubiquitin ligase facilitates strigolactone signalling. NATURE PLANTS 2022; 8:561-573. [PMID: 35484202 DOI: 10.1038/s41477-022-01145-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/28/2022] [Indexed: 05/22/2023]
Abstract
Strigolactones (SLs) are a class of plant hormones that regulate numerous processes of growth and development. SL perception and signal activation involves interaction between F-box E3 ubiquitin ligase D3/MAX2 and DWARF14 (D14) α/β-hydrolase in a SL-dependent manner and targeting of D53/SMXL6/7/8 transcriptional repressors (SMXLs) for proteasome-mediated degradation. D3/MAX2 has been shown to exist in multiple conformational states in which the C-terminal helix (CTH) undergoes a closed-to-open dynamics and regulates D14 binding and SL perception. Despite the multiple modes of D3-D14 interactions found in vitro, the residues that regulate the conformational switch of D3/MAX2 CTH in targeting D53/SMXLs and the subsequent effect on SL signalling remain unclear. Here we elucidate the functional dynamics of ASK1-D3/MAX2 in SL signalling by leveraging conformational switch mutants in vitro and in plants. We report the crystal structure of a dislodged CTH of the ASK1-D3 mutant and demonstrate that disruptions in CTH plasticity via either CRISPR-Cas9 genome editing or expression of point mutation mutants result in impairment of SL signalling. We show that the conformational switch in ASK1-D3/MAX2 CTH directly regulates ubiquitin-mediated protein degradation. A dislodged conformation involved in D53/SMXLs SL-dependent recruitment and ubiquitination and an engaged conformation are required for the release of polyubiquitinated D53/SMXLs and subsequently D14 for proteasomal degradation. Finally, we uncovered an organic acid metabolite that can directly trigger the D3/MAX2 CTH conformational switch. Our findings unravel a new regulatory function of a SKP1-CUL1-F-box ubiquitin ligase in plant signalling.
Collapse
Affiliation(s)
- Lior Tal
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA
| | - Malathy Palayam
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA
| | - Mily Ron
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA
| | - Aleczander Young
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA
| | - Anne Britt
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA, USA.
| |
Collapse
|
40
|
Sepulveda C, Guzmán MA, Li Q, Villaécija-Aguilar JA, Martinez SE, Kamran M, Khosla A, Liu W, Gendron JM, Gutjahr C, Waters MT, Nelson DC. KARRIKIN UP-REGULATED F-BOX 1 (KUF1) imposes negative feedback regulation of karrikin and KAI2 ligand metabolism in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2022; 119:e2112820119. [PMID: 35254909 PMCID: PMC8931227 DOI: 10.1073/pnas.2112820119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/28/2022] [Indexed: 12/13/2022] Open
Abstract
SignificanceKarrikins are chemicals in smoke that stimulate regrowth of many plants after fire. However, karrikin responses are not limited to species from fire-prone environments and can affect growth after germination. Putatively, this is because karrikins mimic an unknown signal in plants, KAI2 ligand (KL). Karrikins likely require modification in plants to become bioactive. We identify a gene, KUF1, that appears to negatively regulate biosynthesis of KL and metabolism of a specific karrikin. KUF1 expression increases in response to karrikin or KL signaling, thus forming a negative feedback loop that limits further activation of the signaling pathway. This discovery will advance understanding of how karrikins are perceived and how smoke-activated germination evolved. It will also aid identification of the elusive KL.
Collapse
Affiliation(s)
- Claudia Sepulveda
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| | - Michael A. Guzmán
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| | - Qingtian Li
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| | | | - Stephanie E. Martinez
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| | - Muhammad Kamran
- School of Molecular Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Aashima Khosla
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| | - Wei Liu
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511
| | - Joshua M. Gendron
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich, Freising, 85354 Germany
| | - Mark T. Waters
- School of Molecular Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - David C. Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
| |
Collapse
|
41
|
Li Q, Martín-Fontecha ES, Khosla A, White AR, Chang S, Cubas P, Nelson DC. The strigolactone receptor D14 targets SMAX1 for degradation in response to GR24 treatment and osmotic stress. PLANT COMMUNICATIONS 2022; 3:100303. [PMID: 35529949 PMCID: PMC9073322 DOI: 10.1016/j.xplc.2022.100303] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/15/2021] [Accepted: 01/25/2022] [Indexed: 05/25/2023]
Abstract
The effects of the phytohormone strigolactone (SL) and smoke-derived karrikins (KARs) on plants are generally distinct, despite the fact that they are perceived through very similar mechanisms. The homologous receptors DWARF14 (D14) and KARRIKIN-INSENSITIVE2 (KAI2), together with the F-box protein MORE AXILLARY GROWTH2 (MAX2), mediate SL and KAR responses, respectively, by targeting different SMAX1-LIKE (SMXL) family proteins for degradation. These mechanisms are putatively well-insulated, with D14-MAX2 targeting SMXL6, SMXL7, and SMXL8 and KAI2-MAX2 targeting SMAX1 and SMXL2 in Arabidopsis thaliana. Recent evidence challenges this model. We investigated whether D14 can target SMAX1 and whether this occurs naturally. Genetic analysis indicates that the SL analog GR24 promotes D14-SMAX1 crosstalk. Although D14 shows weaker interactions with SMAX1 than with SMXL2 or SMXL7, D14 mediates GR24-induced degradation of SMAX1 in plants. Osmotic stress triggers SMAX1 degradation, which is protective, through SL biosynthesis and signaling genes. Thus, D14-SMAX1 crosstalk may be beneficial and not simply a vestige of the evolution of the SL pathway.
Collapse
Affiliation(s)
- Qingtian Li
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Elena Sánchez Martín-Fontecha
- Plant Molecular Genetics Department, Centro Nacional de Biotecnología/CSIC, Campus Universidad Autόnoma de Madrid, Madrid, Spain
| | - Aashima Khosla
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Alexandra R.F. White
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Sunhyun Chang
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Pilar Cubas
- Plant Molecular Genetics Department, Centro Nacional de Biotecnología/CSIC, Campus Universidad Autόnoma de Madrid, Madrid, Spain
| | - David C. Nelson
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| |
Collapse
|
42
|
White ARF, Mendez JA, Khosla A, Nelson DC. Rapid analysis of strigolactone receptor activity in a Nicotiana benthamiana dwarf14 mutant. PLANT DIRECT 2022; 6:e389. [PMID: 35355884 PMCID: PMC8948499 DOI: 10.1002/pld3.389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 12/03/2021] [Accepted: 02/17/2022] [Indexed: 05/29/2023]
Abstract
DWARF14 (D14) is an ɑ/β-hydrolase and receptor for the plant hormone strigolactone (SL) in angiosperms. Upon SL perception, D14 works with MORE AXILLARY GROWTH2 (MAX2) to trigger polyubiquitination and degradation of DWARF53(D53)-type proteins in the SUPPRESSOR OF MAX2 1-LIKE (SMXL) family. We used CRISPR-Cas9 to generate knockout alleles of the two homoeologous D14 genes in the Nicotiana benthamiana genome. The Nbd14a,b double mutant had several phenotypes that are consistent with the loss of SL perception in other plants, including increased axillary bud outgrowth, reduced height, shortened petioles, and smaller leaves. A ratiometric fluorescent reporter system was used to monitor degradation of SMXL7 from Arabidopsis thaliana (AtSMXL7) after transient expression in N. benthamiana and treatment with the strigolactone analog GR24. AtSMXL7 was degraded after treatment with GR245DS, which has the stereochemical configuration of natural SLs, as well as its enantiomer GR24 ent-5DS. In Nbd14a,b leaves, AtSMXL7 abundance was unaffected by rac-GR24 or either GR24 stereoisomer. Transient coexpression of AtD14 with the AtSMXL7 reporter in Nbd14a,b restored the degradation response to rac-GR24, but required an active catalytic triad. We used this platform to evaluate the ability of several AtD14 mutants that had not been characterized in plants to target AtSMXL7 for degradation.
Collapse
Affiliation(s)
- Alexandra R. F. White
- Department of Botany and Plant SciencesUniversity of CaliforniaRiversideCaliforniaUSA
| | - Jose A. Mendez
- Department of Botany and Plant SciencesUniversity of CaliforniaRiversideCaliforniaUSA
| | - Aashima Khosla
- Department of Botany and Plant SciencesUniversity of CaliforniaRiversideCaliforniaUSA
| | - David C. Nelson
- Department of Botany and Plant SciencesUniversity of CaliforniaRiversideCaliforniaUSA
| |
Collapse
|
43
|
Meng Y, Varshney K, Incze N, Badics E, Kamran M, Davies SF, Oppermann LMF, Magne K, Dalmais M, Bendahmane A, Sibout R, Vogel J, Laudencia-Chingcuanco D, Bond CS, Soós V, Gutjahr C, Waters MT. KARRIKIN INSENSITIVE2 regulates leaf development, root system architecture and arbuscular-mycorrhizal symbiosis in Brachypodium distachyon. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:1559-1574. [PMID: 34953105 DOI: 10.1111/tpj.15651] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
KARRIKIN INSENSITIVE2 (KAI2) is an α/β-hydrolase required for plant responses to karrikins, which are abiotic butenolides that can influence seed germination and seedling growth. Although represented by four angiosperm species, loss-of-function kai2 mutants are phenotypically inconsistent and incompletely characterised, resulting in uncertainties about the core functions of KAI2 in plant development. Here we characterised the developmental functions of KAI2 in the grass Brachypodium distachyon using molecular, physiological and biochemical approaches. Bdkai2 mutants exhibit increased internode elongation and reduced leaf chlorophyll levels, but only a modest increase in water loss from detached leaves. Bdkai2 shows increased numbers of lateral roots and reduced root hair growth, and fails to support normal root colonisation by arbuscular-mycorrhizal (AM) fungi. The karrikins KAR1 and KAR2 , and the strigolactone (SL) analogue rac-GR24, each elicit overlapping but distinct changes to the shoot transcriptome via BdKAI2. Finally, we show that BdKAI2 exhibits a clear ligand preference for desmethyl butenolides and weak responses to methyl-substituted SL analogues such as GR24. Our findings suggest that KAI2 has multiple roles in shoot development, root system development and transcriptional regulation in grasses. Although KAI2-dependent AM symbiosis is likely conserved within monocots, the magnitude of the effect of KAI2 on water relations may vary across angiosperms.
Collapse
Affiliation(s)
- Yongjie Meng
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kartikye Varshney
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich, Freising, 85354, Germany
| | - Norbert Incze
- Department of Biological Resources, Agricultural Institute, Centre for Agricultural Research, Martonvásár, 2462, Hungary
- Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest, 1117, Hungary
| | - Eszter Badics
- Department of Biological Resources, Agricultural Institute, Centre for Agricultural Research, Martonvásár, 2462, Hungary
- Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest, 1117, Hungary
| | - Muhammad Kamran
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Sabrina F Davies
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Larissa M F Oppermann
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Kévin Magne
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
- Université de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
| | - Marion Dalmais
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
- Université de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
| | - Abdel Bendahmane
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
- Université de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, 91405, France
| | - Richard Sibout
- Institut Jean-Pierre Bourgin, UMR1318 INRAE-AgroParisTech, Versailles Cedex, F-78026, France
- UR1268 BIA, INRAE, Nantes, 44300, France
| | - John Vogel
- DOE Joint Genome Institute, Berkeley, California, 94720, USA
| | | | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Vilmos Soós
- Department of Biological Resources, Agricultural Institute, Centre for Agricultural Research, Martonvásár, 2462, Hungary
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich, Freising, 85354, Germany
| | - Mark T Waters
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| |
Collapse
|
44
|
Struk S, Braem L, Matthys C, Walton A, Vangheluwe N, Van Praet S, Jiang L, Baster P, De Cuyper C, Boyer FD, Stes E, Beeckman T, Friml J, Gevaert K, Goormachtig S. Transcriptional Analysis in the Arabidopsis Roots Reveals New Regulators that Link rac-GR24 Treatment with Changes in Flavonol Accumulation, Root Hair Elongation and Lateral Root Density. PLANT & CELL PHYSIOLOGY 2022; 63:104-119. [PMID: 34791413 DOI: 10.1093/pcp/pcab149] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/06/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
The synthetic strigolactone (SL) analog, rac-GR24, has been instrumental in studying the role of SLs as well as karrikins because it activates the receptors DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2) of their signaling pathways, respectively. Treatment with rac-GR24 modifies the root architecture at different levels, such as decreasing the lateral root density (LRD), while promoting root hair elongation or flavonol accumulation. Previously, we have shown that the flavonol biosynthesis is transcriptionally activated in the root by rac-GR24 treatment, but, thus far, the molecular players involved in that response have remained unknown. To get an in-depth insight into the changes that occur after the compound is perceived by the roots, we compared the root transcriptomes of the wild type and the more axillary growth2 (max2) mutant, affected in both SL and karrikin signaling pathways, with and without rac-GR24 treatment. Quantitative reverse transcription (qRT)-PCR, reporter line analysis and mutant phenotyping indicated that the flavonol response and the root hair elongation are controlled by the ELONGATED HYPOCOTYL 5 (HY5) and MYB12 transcription factors, but HY5, in contrast to MYB12, affects the LRD as well. Furthermore, we identified the transcription factors TARGET OF MONOPTEROS 5 (TMO5) and TMO5 LIKE1 as negative and the Mediator complex as positive regulators of the rac-GR24 effect on LRD. Altogether, hereby, we get closer toward understanding the molecular mechanisms that underlay the rac-GR24 responses in the root.
Collapse
Affiliation(s)
- Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Lukas Braem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
- Department of Biomolecular Medicine, Ghent University, Technologiepark 75, Ghent 9052, Belgium
- Center for Medical Biotechnology, VIB, Technologiepark 75, Ghent 9052, Belgium
| | - Cedrick Matthys
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Alan Walton
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
- Department of Biomolecular Medicine, Ghent University, Technologiepark 75, Ghent 9052, Belgium
- Center for Medical Biotechnology, VIB, Technologiepark 75, Ghent 9052, Belgium
| | - Nick Vangheluwe
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Stan Van Praet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
- Laboratory of Plant Growth Analysis, Ghent University Global Campus, 119 Songdomunhwa-Ro, Yeonsu-Gu, Incheon 21985, Republic of Korea
| | - Lingxiang Jiang
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Pawel Baster
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Carolien De Cuyper
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - François-Didier Boyer
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, Route de Saint-Cyr, Versailles 78026, France
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, UPR2301, Université Paris-Sud, Université Paris-Saclay, 1 Avenue de la Terrasse, Gif-sur-Yvette 91198, France
| | - Elisabeth Stes
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
- Department of Biomolecular Medicine, Ghent University, Technologiepark 75, Ghent 9052, Belgium
- Center for Medical Biotechnology, VIB, Technologiepark 75, Ghent 9052, Belgium
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| | - Jiří Friml
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
- Institute of Science and Technology (IST) Austria, Cell Biology Laboratory, Am Campus 1, Klosterneuburg 3400, Austria
| | - Kris Gevaert
- Department of Biomolecular Medicine, Ghent University, Technologiepark 75, Ghent 9052, Belgium
- Center for Medical Biotechnology, VIB, Technologiepark 75, Ghent 9052, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- Center of Plant Systems Biology, VIB, Technologiepark 71, Ghent 9052, Belgium
| |
Collapse
|
45
|
Song C, Zhao J, Guichard M, Shi D, Grossmann G, Schmitt C, Jouannet V, Greb T. Strigo-D2-a bio-sensor for monitoring spatio-temporal strigolactone signaling patterns in intact plants. PLANT PHYSIOLOGY 2022; 188:97-110. [PMID: 34718781 PMCID: PMC8774841 DOI: 10.1093/plphys/kiab504] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/09/2021] [Indexed: 05/29/2023]
Abstract
Strigolactones (SLs) are a class of plant hormones that mediate biotic interactions and modulate developmental programs in response to endogenous and exogenous stimuli. However, a comprehensive view on the spatio-temporal pattern of SL signaling has not been established, and tools for a systematic in planta analysis do not exist. Here, we present Strigo-D2, a genetically encoded ratiometric SL signaling sensor that enables the examination of SL signaling distribution at cellular resolution and is capable of rapid response to altered SL levels in intact Arabidopsis (Arabidopsis thaliana) plants. By monitoring the abundance of a truncated and fluorescently labeled SUPPRESSOR OF MAX2 1-LIKE 6 (SMXL6) protein, a proteolytic target of the SL signaling machinery, we show that all cell types investigated have the capacity to respond to changes in SL levels but with very different dynamics. In particular, SL signaling is pronounced in vascular cells but low in guard cells and the meristematic region of the root. We also show that other hormones leave Strigo-D2 activity unchanged, indicating that initial SL signaling steps work in isolation from other hormonal signaling pathways. The specificity and spatio-temporal resolution of Strigo-D2 underline the value of the sensor for monitoring SL signaling in a broad range of biological contexts with highly instructive analytical depth.
Collapse
Affiliation(s)
- Changzheng Song
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Jiao Zhao
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Marjorie Guichard
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
- Institute of Cell and Interaction Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Dongbo Shi
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
- RIKEN Center for Sustainable Resource Science (CSRS), 1-7-22 Suehiro-cho, Tsurumi-Yokohama 230-0045, Japan
| | - Guido Grossmann
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
- Institute of Cell and Interaction Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Christian Schmitt
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Virginie Jouannet
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Thomas Greb
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| |
Collapse
|
46
|
Temmerman A, Guillory A, Bonhomme S, Goormachtig S, Struk S. Masks Start to Drop: Suppressor of MAX2 1-Like Proteins Reveal Their Many Faces. FRONTIERS IN PLANT SCIENCE 2022; 13:887232. [PMID: 35645992 PMCID: PMC9133912 DOI: 10.3389/fpls.2022.887232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/25/2022] [Indexed: 05/11/2023]
Abstract
Although the main players of the strigolactone (SL) signaling pathway have been characterized genetically, how they regulate plant development is still poorly understood. Of central importance are the SUPPRESSOR OF MAX2 1-LIKE (SMXL) proteins that belong to a family of eight members in Arabidopsis thaliana, of which one subclade is involved in SL signaling and another one in the pathway of the chemically related karrikins. Through proteasomal degradation of these SMXLs, triggered by either DWARF14 (D14) or KARRIKIN INSENSITIVE2 (KAI2), several physiological processes are controlled, such as, among others, shoot and root architecture, seed germination, and seedling photomorphogenesis. Yet another clade has been shown to be involved in vascular development, independently of the D14 and KAI2 actions and not relying on proteasomal degradation. Despite their role in several aspects of plant development, the exact molecular mechanisms by which SMXLs regulate them are not completely unraveled. To fill the major knowledge gap in understanding D14 and KAI2 signaling, SMXLs are intensively studied, making it challenging to combine all the insights into a coherent characterization of these important proteins. To this end, this review provides an in-depth exploration of the recent data regarding their physiological function, evolution, structure, and molecular mechanism. In addition, we propose a selection of future perspectives, focusing on the apparent localization of SMXLs in subnuclear speckles, as observed in transient expression assays, which we couple to recent advances in the field of biomolecular condensates and liquid-liquid phase separation.
Collapse
Affiliation(s)
- Arne Temmerman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-Center for Plant Systems Biology, Ghent, Belgium
| | - Ambre Guillory
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Sandrine Bonhomme
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-Center for Plant Systems Biology, Ghent, Belgium
| | - Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-Center for Plant Systems Biology, Ghent, Belgium
- *Correspondence: Sylwia Struk,
| |
Collapse
|
47
|
Hu A, Zhao Q, Chen L, Zhao J, Wang Y, Feng K, Wu L, Xie M, Zhou X, Xiao L, Ming Z, Zhang M, Yao R. Identification of Conserved and Divergent Strigolactone Receptors in Sugarcane Reveals a Key Residue Crucial for Plant Branching Control. FRONTIERS IN PLANT SCIENCE 2021; 12:747160. [PMID: 34858455 PMCID: PMC8632500 DOI: 10.3389/fpls.2021.747160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/12/2021] [Indexed: 05/29/2023]
Abstract
Strigolactones (SLs) are a class of important plant hormones mainly regulating plant architecture such as branching, which is crucial for crop yield. It is valuable to study SL signaling pathway and its physiological function in sugarcane, the most important sugar crop, for further molecular breeding. Here, two putative SL receptors SsD14a/b and the interacting F-box protein SsMAX2 were identified in Saccharum spontaneum. SL induced both SsD14a and SsD14b to interact with SsMAX2 in yeast. SsD14a, but not SsD14b, could bind with AtMAX2 and AtSMXL7/SsSMXL7. Overexpression of SsD14a or SsMAX2 rescued the increased branching phenotypes of Arabidopsis thaliana d14-1 or max2-3 mutants, respectively. Moreover, the crystal structure of N-terminal truncated SsD14a was solved, with an overall structure identical to AtD14 and OsD14 in the open state, consistent with its conserved branching suppression capacity in Arabidopsis. In line with the biochemical observations, SsD14b could not completely complement in d14-1 although these two SsD14 proteins have almost identical primary sequences except for very few residues. Complement with the combination of SsD14b and SsMAX2 still failed to rescue the d14-1 max2-3 double mutant multi-branching phenotype, indicating SsD14b-AtSMXL7 complex formation is required for regulating branching. Mutagenesis analyses revealed that residue R310 at α10 helix of SsD14a was crucial for the binding with SsSMXL7/AtSMXL7 but not SsMAX2. The site-equivalent single-residue P304R substitution enabled SsD14b to bind with AtMAX2 and AtSMXL7/SsSMXL7 and to rescue the phenotype of d14-1 max2-3 together with SsMAX2. Moreover, this conserved Arg residue across species including rice and Arabidopsis determined the activity of SL receptors through maintaining their interaction with SMXL repressors. Taken together, our work identified conserved and divergent strigolactone receptors in sugarcane core SL signaling pathway and revealed a key residue crucial for plant branching control.
Collapse
Affiliation(s)
- Anqi Hu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Qiaoqiao Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio Resources, Guangxi Key Laboratory for Sugarcane Biology, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Jinping Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
- Hunan Province Key Laboratory of Phytohormones and Growth Development, Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, China
| | - Yuehua Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Kuiliang Feng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Ling Wu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Miao Xie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Xuemei Zhou
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Langtao Xiao
- Hunan Province Key Laboratory of Phytohormones and Growth Development, Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, China
| | - Zhenhua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio Resources, Guangxi Key Laboratory for Sugarcane Biology, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Meng Zhang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| | - Ruifeng Yao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China
| |
Collapse
|
48
|
Villaécija-Aguilar JA, Körösy C, Maisch L, Hamon-Josse M, Petrich A, Magosch S, Chapman P, Bennett T, Gutjahr C. KAI2 promotes Arabidopsis root hair elongation at low external phosphate by controlling local accumulation of AUX1 and PIN2. Curr Biol 2021; 32:228-236.e3. [PMID: 34758285 DOI: 10.1016/j.cub.2021.10.044] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/17/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Root hair (RH) growth to increase the absorptive root surface area is a key adaptation of plants to limiting phosphate availability in soils. Despite the importance of this trait, especially for seedling survival, little is known about the molecular events connecting phosphate starvation sensing and RH growth regulation. KARRIKIN INSENSITIVE2 (KAI2), an α/β-hydrolase receptor of a yet-unknown plant hormone ("KAI2-ligand" [KL]), is required for RH elongation.1 KAI2 interacts with the F-box protein MORE AXILLIARY BRANCHING2 (MAX2) to target regulatory proteins of the SUPPRESSOR of MAX2 1 (SMAX1) family for degradation.2 Here, we demonstrate that Pi starvation increases KL signaling in Arabidopsis roots through transcriptional activation of KAI2 and MAX2. Both genes are required for RH elongation under these conditions, while smax1 smxl2 mutants have constitutively long RHs, even at high Pi availability. Attenuated RH elongation in kai2 mutants is explained by reduced shootward auxin transport from the root tip resulting in reduced auxin signaling in the RH zone, caused by an inability to increase localized accumulation of the auxin importer AUXIN TRANSPORTER PROTEIN1 (AUX1) and the auxin exporter PIN-FORMED2 (PIN2) upon Pi starvation. Consistent with AUX1 and PIN2 accumulation being mediated via ethylene signaling,3 expression of 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 7 (ACS7) is increased at low Pi in a KAI2-dependent manner, and treatment with an ethylene precursor restores RH elongation of acs7, but not of aux1 and pin2. Thus, KAI2 signaling is increased by phosphate starvation to trigger an ethylene- AUX1/PIN2-auxin cascade required for RH elongation.
Collapse
Affiliation(s)
- José Antonio Villaécija-Aguilar
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Caroline Körösy
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Lukas Maisch
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Maxime Hamon-Josse
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Andrea Petrich
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Sonja Magosch
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Philipp Chapman
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany
| | - Tom Bennett
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354 Freising, Germany.
| |
Collapse
|
49
|
Lopez-Obando M, Guillory A, Boyer FD, Cornu D, Hoffmann B, Le Bris P, Pouvreau JB, Delavault P, Rameau C, de Saint Germain A, Bonhomme S. The Physcomitrium (Physcomitrella) patens PpKAI2L receptors for strigolactones and related compounds function via MAX2-dependent and -independent pathways. THE PLANT CELL 2021; 33:3487-3512. [PMID: 34459915 PMCID: PMC8662777 DOI: 10.1093/plcell/koab217] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 08/24/2021] [Indexed: 05/20/2023]
Abstract
In angiosperms, the α/β hydrolase DWARF14 (D14), along with the F-box protein MORE AXILLARY GROWTH2 (MAX2), perceives strigolactones (SL) to regulate developmental processes. The key SL biosynthetic enzyme CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) is present in the moss Physcomitrium patens, and PpCCD8-derived compounds regulate moss extension. The PpMAX2 homolog is not involved in the SL response, but 13 PpKAI2LIKE (PpKAI2L) genes homologous to the D14 ancestral paralog KARRIKIN INSENSITIVE2 (KAI2) encode candidate SL receptors. In Arabidopsis thaliana, AtKAI2 perceives karrikins and the elusive endogenous KAI2-Ligand (KL). Here, germination assays of the parasitic plant Phelipanche ramosa suggested that PpCCD8-derived compounds are likely noncanonical SLs. (+)-GR24 SL analog is a good mimic for PpCCD8-derived compounds in P. patens, while the effects of its enantiomer (-)-GR24, a KL mimic in angiosperms, are minimal. Interaction and binding assays of seven PpKAI2L proteins pointed to the stereoselectivity toward (-)-GR24 for a single clade of PpKAI2L (eu-KAI2). Enzyme assays highlighted the peculiar behavior of PpKAI2L-H. Phenotypic characterization of Ppkai2l mutants showed that eu-KAI2 genes are not involved in the perception of PpCCD8-derived compounds but act in a PpMAX2-dependent pathway. In contrast, mutations in PpKAI2L-G, and -J genes abolished the response to the (+)-GR24 enantiomer, suggesting that PpKAI2L-G, and -J proteins are receptors for moss SLs.
Collapse
Affiliation(s)
- Mauricio Lopez-Obando
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
- Department of Plant Biology, Swedish University of Agricultural Sciences, The
Linnean Centre for Plant Biology in Uppsala, SE-750 07 Uppsala, Sweden
- VEDAS Corporación de Investigación e Innovación (VEDASCII),
050024 Medellín, Colombia
| | - Ambre Guillory
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
| | - François-Didier Boyer
- Institut de Chimie des Substances Naturelles, CNRS, Université
Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - David Cornu
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université
Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Beate Hoffmann
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
| | - Philippe Le Bris
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
| | - Jean-Bernard Pouvreau
- Laboratoire de Biologie et Pathologie Végétales, LBPV, Université de
Nantes, 44000 Nantes, France
| | - Philippe Delavault
- Laboratoire de Biologie et Pathologie Végétales, LBPV, Université de
Nantes, 44000 Nantes, France
| | - Catherine Rameau
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
| | - Alexandre de Saint Germain
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
- Author for correspondence:
(S.B.),
(A.d.S.G.)
| | - Sandrine Bonhomme
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, 78000 Versailles, France
- Author for correspondence:
(S.B.),
(A.d.S.G.)
| |
Collapse
|
50
|
Bunsick M, McCullough R, McCourt P, Lumba S. Plant hormone signaling: Is upside down right side up? CURRENT OPINION IN PLANT BIOLOGY 2021; 63:102070. [PMID: 34166978 DOI: 10.1016/j.pbi.2021.102070] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/29/2021] [Accepted: 05/20/2021] [Indexed: 06/13/2023]
Abstract
Since the early days of plant biology, small molecule hormones have held a central place in our understanding of development. A key feature of plant hormone action is the ability to regulate multiple developmental processes. Despite this pleiotropy, decades of genetic and molecular studies have shown that plant hormone signaling is often canalized through a core pathway. This raises the difficult question of how one signaling pathway produces different outputs in different tissues. Drawing on examples from gibberellin and strigolactone signaling pathways, we propose this conceptual problem arises from an upside-down perspective of hormone signaling. Recent studies have revealed hormone and core pathway-independent mechanisms of regulating downstream signaling components, which could explain multiple developmental responses to the same hormone.
Collapse
Affiliation(s)
- Michael Bunsick
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada
| | - Rachel McCullough
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada
| | - Peter McCourt
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada
| | - Shelley Lumba
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada.
| |
Collapse
|