1
|
Corrigendum to C-terminal conformational changes in SCF-D3/MAX2 ubiquitin ligase are required for KAI2-mediated signaling. THE NEW PHYTOLOGIST 2024; 243:495-496. [PMID: 38757549 DOI: 10.1111/nph.19819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 05/18/2024]
|
2
|
Ganapathy J, Hand KA, Shabek N. Analysis of 26S Proteasome Activity across Arabidopsis Tissues. PLANTS (BASEL, SWITZERLAND) 2024; 13:1696. [PMID: 38931128 PMCID: PMC11207565 DOI: 10.3390/plants13121696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024]
Abstract
Plants utilize the ubiquitin proteasome system (UPS) to orchestrate numerous essential cellular processes, including the rapid responses required to cope with abiotic and biotic stresses. The 26S proteasome serves as the central catalytic component of the UPS that allows for the proteolytic degradation of ubiquitin-conjugated proteins in a highly specific manner. Despite the increasing number of studies employing cell-free degradation assays to dissect the pathways and target substrates of the UPS, the precise extraction methods of highly potent tissues remain unexplored. Here, we utilize a fluorogenic reporting assay using two extraction methods to survey proteasomal activity in different Arabidopsis thaliana tissues. This study provides new insights into the enrichment of activity and varied presence of proteasomes in specific plant tissues.
Collapse
Affiliation(s)
| | | | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA; (J.G.); (K.A.H.)
| |
Collapse
|
3
|
Daignan-Fornier S, Keita A, Boyer FD. Chemistry of Strigolactones, Key Players in Plant Communication. Chembiochem 2024; 25:e202400133. [PMID: 38607659 DOI: 10.1002/cbic.202400133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/12/2024] [Accepted: 04/12/2024] [Indexed: 04/13/2024]
Abstract
Today, the use of artificial pesticides is questionable and the adaptation to global warming is a necessity. The promotion of favorable natural interactions in the rhizosphere offers interesting perspectives for changing the type of agriculture. Strigolactones (SLs), the latest class of phytohormones to be discovered, are also chemical mediators in the rhizosphere. We present in this review the diversity of natural SLs, their analogs, mimics, and probes essential for the biological studies of this class of compounds. Their biosynthesis and access by organic synthesis are highlighted especially concerning noncanonical SLs, the more recently discovered natural SLs. Organic synthesis of analogs, stable isotope-labeled standards, mimics, and probes are also reviewed here. In the last part, the knowledge about the SL perception is described as well as the different inhibitors of SL receptors that have been developed.
Collapse
Affiliation(s)
- Suzanne Daignan-Fornier
- Institut de Chimie des Substances Naturelles, UPR 2301, Université Paris-Saclay, CNRS, 91198, Gif-sur-Yvette, France
| | - Antoinette Keita
- Institut de Chimie des Substances Naturelles, UPR 2301, Université Paris-Saclay, CNRS, 91198, Gif-sur-Yvette, France
| | - François-Didier Boyer
- Institut de Chimie des Substances Naturelles, UPR 2301, Université Paris-Saclay, CNRS, 91198, Gif-sur-Yvette, France
| |
Collapse
|
4
|
Zeng L, Gomez Mendez MF, Guo J, Jiang J, Zhang B, Chen H, Le B, Ke H, Dehesh K. Activation of stress-response genes by retrograde signaling-mediated destabilization of nuclear importin IMPα-9 and its interactor TPR2. MOLECULAR PLANT 2024; 17:884-899. [PMID: 38693693 DOI: 10.1016/j.molp.2024.04.008] [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: 12/22/2023] [Revised: 01/26/2024] [Accepted: 04/21/2024] [Indexed: 05/03/2024]
Abstract
Stress-induced retrograde signal transmission from the plastids to the nucleus has long puzzled plant biologists. To address this, we performed a suppressor screen of the ceh1 mutant, which contains elevated 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate (MEcPP) levels, and identified the gain-of-function mutant impα-9, which shows reversed dwarfism and suppressed expression of stress-response genes in the ceh1 background despite heightened MEcPP. Subsequent genetic and biochemical analyses established that the accumulation of MEcPP initiates an upsurge in Arabidopsis SKP1-like 1 (ASK1) abundance, a pivotal component in the proteasome degradation pathway. This increase in ASK1 prompts the degradation of IMPα-9. Moreover, we uncovered a protein-protein interaction between IMPα-9 and TPR2, a transcriptional co-suppressor and found that a reduction in IMPα-9 levels coincides with a decrease in TPR2 abundance. Significantly, the interaction between IMPα-9 and TPR2 was disrupted in impα-9 mutants, highlighting the critical role of a single amino acid alteration in maintaining their association. Disruption of their interaction results in the reversal of MEcPP-associated phenotypes. Chromatin immunoprecipitation coupled with sequencing analyses revealed that TPR2 binds globally to stress-response genes and suggested that IMPα-9 associates with the chromatin. They function together to suppress the expression of stress-response genes under normal conditions, but this suppression is alleviated in response to stress through the degradation of the suppressing machinery. The biological relevance of our discoveries was validated under high light stress, marked by MEcPP accumulation, elevated ASK1 levels, IMPα-9 degredation, reduced TPR2 abundance, and subsequent activation of a network of stress-response genes. In summary, our study collectively unveils fresh insights into plant adaptive mechanisms, highlighting intricate interactions among retrograde signaling, the proteasome, and nuclear transport machinery.
Collapse
Affiliation(s)
- Liping Zeng
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Maria Fernanda Gomez Mendez
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Jingzhe Guo
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Jishan Jiang
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Bailong Zhang
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA; School of Medicine, University of California, Riverside, Riverside, CA 92521, USA
| | - Hao Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Brandon Le
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Haiyan Ke
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Katayoon Dehesh
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
5
|
Morales-Herrera S, Paul MJ, Van Dijck P, Beeckman T. SnRK1/TOR/T6P: three musketeers guarding energy for root growth. TRENDS IN PLANT SCIENCE 2024:S1360-1385(24)00062-1. [PMID: 38580543 DOI: 10.1016/j.tplants.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/28/2024] [Accepted: 03/08/2024] [Indexed: 04/07/2024]
Abstract
Sugars derived from photosynthesis, specifically sucrose, are the primary source of plant energy. Sucrose is produced in leaves and transported to the roots through the phloem, serving as a vital energy source. Environmental conditions can result in higher or lower photosynthesis, promoting anabolism or catabolism, respectively, thereby influencing the sucrose budget available for roots. Plants can adjust their root system to optimize the search for soil resources and to ensure the plant's adaptability to diverse environmental conditions. Recently, emerging research indicates that SNF1-RELATED PROTEIN KINASE 1 (SnRK1), trehalose 6-phosphate (T6P), and TARGET OF RAPAMYCIN (TOR) collectively serve as fundamental regulators of root development, together forming a signaling module to interpret the nutritional status of the plant and translate this to growth adjustments in the below ground parts.
Collapse
Affiliation(s)
- S Morales-Herrera
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; VIB Center for Plant Systems Biology, Ghent, Belgium; Laboratory of Molecular Cell Biology, KU Leuven, Kasteelpark Arenberg, Leuven, Belgium
| | - M J Paul
- Sustainable Soils and Crops, Rothamsted Research, Harpenden, UK
| | - P Van Dijck
- Laboratory of Molecular Cell Biology, KU Leuven, Kasteelpark Arenberg, Leuven, Belgium; KU Leuven Plant Institute (LPI), Leuven, Belgium
| | - T Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; VIB Center for Plant Systems Biology, Ghent, Belgium.
| |
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
|
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
|
8
|
Bai J, Guo H, Xiong H, Xie Y, Gu J, Zhao L, Zhao S, Ding Y, Liu L. Strigolactone and abscisic acid synthesis and signaling pathways are enhanced in the wheat oligo-tillering mutant ot1. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2024; 44:12. [PMID: 38313680 PMCID: PMC10837411 DOI: 10.1007/s11032-024-01450-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/10/2024] [Indexed: 02/06/2024]
Abstract
Tiller number greatly contributes to grain yield in wheat. Using ethylmethanesulfonate mutagenesis, we previously discovered the oligo-tillering mutant ot1. The tiller number was significantly lower in ot1 than in the corresponding wild type from the early tillering stage until the heading stage. Compared to the wild type, the thousand-grain weight and grain length were increased by 15.41% and 31.44%, respectively, whereas the plant height and spike length were decreased by 26.13% and 37.25%, respectively. Transcriptomic analysis was conducted at the regreening and jointing stages to identify differential expressed genes (DEGs). Functional enrichment analysis with the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases showed differential expression of genes associated with ADP binding, transmembrane transport, and transcriptional regulation during tiller development. Differences in tiller number in ot1 led to the upregulation of genes in the strigolactone (SL) and abscisic acid (ABA) pathways. Specifically, the SL biosynthesis genes DWARF (D27), D17, D10, and MORE AXILLARY GROWTH 1 (MAX1) were upregulated by 3.37- to 8.23-fold; the SL signal transduction genes D14 and D53 were upregulated by 1.81- and 1.32-fold, respectively; the ABA biosynthesis genes 9-CIS-EPOXICAROTENOID DIOXIGENASE 3 (NCED3) and NCED5 were upregulated by 1.66- and 3.4-fold, respectively; and SNF1-REGULATED PROTEIN KINASE2 (SnRK2) and PROTEIN PHOSPHATASE 2C (PP2C) genes were upregulated by 1.30- to 4.79-fold. This suggested that the tiller number reduction in ot1 was due to alterations in plant hormone pathways. Genes known to promote tillering growth were upregulated, whereas those known to inhibit tillering growth were downregulated. For example, PIN-FORMED 9 (PIN9), which promotes tiller development, was upregulated by 8.23-fold in ot1; Ideal Plant Architecture 1 (IPA1), which inhibits tiller development, was downregulated by 1.74-fold. There were no significant differences in the expression levels of TILLER NUMBER 1 (TN1) or TEOSINTE BRANCHED 1 (TB1), indicating that the tiller reduction in ot1 was not controlled by known genes. Our findings provide valuable data for subsequent research into the genetic bases and regulatory mechanisms of wheat tillering. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-024-01450-3.
Collapse
Affiliation(s)
- Jiaxing Bai
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huijun Guo
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hongchun Xiong
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yongdun Xie
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiayu Gu
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Linshu Zhao
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shirong Zhao
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuping Ding
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Luxiang Liu
- State Key Laboratory of Crop Gene Resources and Breeding, National Engineering Laboratory of Crop Molecular Breeding, National Center of Space Mutagenesis for Crop Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
9
|
Chen J, Dean TJ, Shukla D. Contribution of Signaling Partner Association to Strigolactone Receptor Selectivity. J Phys Chem B 2024; 128:698-705. [PMID: 38194306 DOI: 10.1021/acs.jpcb.3c06940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The parasitic plant witchweed, Striga hermonthica, results in agricultural losses of billions of dollars per year. It perceives its host via plant hormones called strigolactones, which act as germination stimulants for witchweed. Strigolactone signaling involves substrate binding to the strigolactone receptor, followed by substrate hydrolysis and a conformational change from an inactive, or open state, to an active, or closed state. In the active state, the receptor associates with a signaling partner, MAX2. Recently, it was shown that this MAX2 association process acts as a strong contributor to the uniquely high signaling activity observed in ShHTL7; however, it is unknown why ShHTL7 has enhanced MAX2 association affinity. Using an umbrella sampling molecular dynamics approach, we characterized the association processes of AtD14, ShHTL7, a mutant of ShHTL7, and ShHTL6 with MAX2 homologue OsD3. From these results, we show that ShHTL7 has an enhanced standard binding free energy of OsD3 compared to those of the other receptors. Additionally, our results suggest that the overall topology of the T2/T3 helix region is likely an important modulator of MAX2 binding. Thus, differences in MAX2 association, modulated by differences in the T2/T3 helix region, are a contributor to differences in signaling activity between different strigolactone receptors.
Collapse
Affiliation(s)
- Jiming Chen
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Tanner J Dean
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
10
|
Göbel M, Fichtner F. Functions of sucrose and trehalose 6-phosphate in controlling plant development. JOURNAL OF PLANT PHYSIOLOGY 2023; 291:154140. [PMID: 38007969 DOI: 10.1016/j.jplph.2023.154140] [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: 07/23/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 11/28/2023]
Abstract
Plants exhibit enormous plasticity in regulating their architecture to be able to adapt to a constantly changing environment and carry out vital functions such as photosynthesis, anchoring, and nutrient uptake. Phytohormones play a role in regulating these responses, but sugar signalling mechanisms are also crucial. Sucrose is not only an important source of carbon and energy fuelling plant growth, but it also functions as a signalling molecule that influences various developmental processes. Trehalose 6-phosphate (Tre6P), a sucrose-specific signalling metabolite, is emerging as an important regulator in plant metabolism and development. Key players involved in sucrose and Tre6P signalling pathways, including MAX2, SnRK1, bZIP11, and TOR, have been implicated in processes such as flowering, branching, and root growth. We will summarize our current knowledge of how these pathways shape shoot and root architecture and highlight how sucrose and Tre6P signalling are integrated with known signalling networks in shaping plant growth.
Collapse
Affiliation(s)
- Moritz Göbel
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute of Plant Biochemistry, Germany; Cluster of Excellences on Plant Sciences (CEPLAS), Heinrich Heine University Düsseldorf, Germany
| | - Franziska Fichtner
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute of Plant Biochemistry, Germany; Cluster of Excellences on Plant Sciences (CEPLAS), Heinrich Heine University Düsseldorf, Germany.
| |
Collapse
|
11
|
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
|
12
|
Dun EA, Brewer PB, Gillam EMJ, Beveridge CA. Strigolactones and Shoot Branching: What Is the Real Hormone and How Does It Work? PLANT & CELL PHYSIOLOGY 2023; 64:967-983. [PMID: 37526426 PMCID: PMC10504579 DOI: 10.1093/pcp/pcad088] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/02/2023]
Abstract
There have been substantial advances in our understanding of many aspects of strigolactone regulation of branching since the discovery of strigolactones as phytohormones. These include further insights into the network of phytohormones and other signals that regulate branching, as well as deep insights into strigolactone biosynthesis, metabolism, transport, perception and downstream signaling. In this review, we provide an update on recent advances in our understanding of how the strigolactone pathway co-ordinately and dynamically regulates bud outgrowth and pose some important outstanding questions that are yet to be resolved.
Collapse
Affiliation(s)
- Elizabeth A Dun
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland, St Lucia, QLD 4072, Australia
- School of Agriculture and Food Sustainability, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Philip B Brewer
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland, St Lucia, QLD 4072, Australia
- Waite Research Institute, School of Agriculture Food & Wine, The University of Adelaide, Adelaide, SA 5064, Australia
| | - Elizabeth M J Gillam
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Christine A Beveridge
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland, St Lucia, QLD 4072, Australia
- School of Agriculture and Food Sustainability, The University of Queensland, St Lucia, QLD 4072, Australia
| |
Collapse
|
13
|
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
|
14
|
Barbier F, Fichtner F, Beveridge C. The strigolactone pathway plays a crucial role in integrating metabolic and nutritional signals in plants. NATURE PLANTS 2023; 9:1191-1200. [PMID: 37488268 DOI: 10.1038/s41477-023-01453-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/24/2023] [Indexed: 07/26/2023]
Abstract
Strigolactones are rhizosphere signals and phytohormones that play crucial roles in plant development. They are also well known for their role in integrating nitrate and phosphate signals to regulate shoot and root development. More recently, sugars and citrate (an intermediate of the tricarboxylic acid cycle) were reported to inhibit the strigolactone response, with dramatic effects on shoot architecture. This Review summarizes the discoveries recently made concerning the mechanisms through which the strigolactone pathway integrates sugar, metabolite and nutrient signals. We highlight here that strigolactones and MAX2-dependent signalling play crucial roles in mediating the impacts of nutritional and metabolic cues on plant development and metabolism. We also discuss and speculate concerning the role of these interactions in plant evolution and adaptation to their environment.
Collapse
Affiliation(s)
- Francois Barbier
- School of Biological Sciences, University of Queensland, St Lucia, Queensland, Australia.
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, University of Queensland, St Lucia, Queensland, Australia.
| | - Franziska Fichtner
- Institute of Plant Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christine Beveridge
- School of Biological Sciences, University of Queensland, St Lucia, Queensland, Australia
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
15
|
Zhang T, Peng JT, Klair A, Dickinson AJ. Non-canonical and developmental roles of the TCA cycle in plants. CURRENT OPINION IN PLANT BIOLOGY 2023; 74:102382. [PMID: 37210789 PMCID: PMC10524895 DOI: 10.1016/j.pbi.2023.102382] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/23/2023]
Abstract
Over recent years, our understanding of the tricarboxylic acid cycle (TCAC) in living organisms has expanded beyond its canonical role in cellular energy production. In plants, TCAC metabolites and related enzymes have important roles in physiology, including vacuolar function, chelation of metals and nutrients, photorespiration, and redox regulation. Research in other organisms, including animals, has demonstrated unexpected functions of the TCAC metabolites in a number of biological processes, including signaling, epigenetic regulation, and cell differentiation. Here, we review the recent progress in discovery of non-canonical roles of the TCAC. We then discuss research on these metabolites in the context of plant development, with a focus on research related to tissue-specific functions of the TCAC. Additionally, we review research describing connections between TCAC metabolites and phytohormone signaling pathways. Overall, we discuss the opportunities and challenges in discovering new functions of TCAC metabolites in plants.
Collapse
Affiliation(s)
- Tao Zhang
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Jesus T Peng
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Amman Klair
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Alexandra J Dickinson
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
16
|
Arellano-Saab A, Skarina T, Xu Z, McErlean CSP, Savchenko A, Lumba S, Stogios PJ, McCourt P. Structural analysis of a hormone-bound Striga strigolactone receptor. NATURE PLANTS 2023; 9:883-888. [PMID: 37264151 DOI: 10.1038/s41477-023-01423-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 04/25/2023] [Indexed: 06/03/2023]
Abstract
Strigolactones (SLs) regulate many aspects of plant development, but ambiguities remain about how this hormone is perceived because SL-complexed receptor structures do not exist. We find that when SL binds the Striga receptor, ShHTL5, a series of conformational changes relative to the unbound state occur, but these events are not sufficient for signalling. Ligand-complexed receptors, however, form internal tunnels that posit an explanation for how SL exits its receptor after hydrolysis.
Collapse
Affiliation(s)
- Amir Arellano-Saab
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Zhenhua Xu
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | | | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Shelley Lumba
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.
| | - Peter McCourt
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.
| |
Collapse
|
17
|
Zhang T, Noll SE, Peng JT, Klair A, Tripka A, Stutzman N, Cheng C, Zare RN, Dickinson AJ. Chemical imaging reveals diverse functions of tricarboxylic acid metabolites in root growth and development. Nat Commun 2023; 14:2567. [PMID: 37142569 PMCID: PMC10160030 DOI: 10.1038/s41467-023-38150-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 04/18/2023] [Indexed: 05/06/2023] Open
Abstract
Understanding how plants grow is critical for agriculture and fundamental for illuminating principles of multicellular development. Here, we apply desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to the chemical mapping of the developing maize root. This technique reveals a range of small molecule distribution patterns across the gradient of stem cell differentiation in the root. To understand the developmental logic of these patterns, we examine tricarboxylic acid (TCA) cycle metabolites. In both Arabidopsis and maize, we find evidence that elements of the TCA cycle are enriched in developmentally opposing regions. We find that these metabolites, particularly succinate, aconitate, citrate, and α-ketoglutarate, control root development in diverse and distinct ways. Critically, the developmental effects of certain TCA metabolites on stem cell behavior do not correlate with changes in ATP production. These results present insights into development and suggest practical means for controlling plant growth.
Collapse
Affiliation(s)
- Tao Zhang
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Sarah E Noll
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Department of Chemistry, Pomona College, Claremont, CA, 91711, USA
| | - Jesus T Peng
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Amman Klair
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Abigail Tripka
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Nathan Stutzman
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Casey Cheng
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.
| | - Alexandra J Dickinson
- Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
| |
Collapse
|
18
|
Chen J, Shukla D. Effect of histidine covalent modification on strigolactone receptor activation and selectivity. Biophys J 2023; 122:1219-1228. [PMID: 36798027 PMCID: PMC10111262 DOI: 10.1016/j.bpj.2023.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 01/17/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
The parasitic weed Striga has led to billions of dollars' worth of agricultural productivity loss worldwide. Striga detects host plants using compounds of the strigolactone class of phytohormones. Early steps in the strigolactone signaling pathway involve substrate binding and hydrolysis followed by a conformational change to an "active" or "closed" state, after which it associates with a MAX2-family downstream signaling partner. The structures of the inactive and active states of strigolactone receptors are known through X-ray crystallography, and the transition pathway from the inactive to active state in apo receptors has previously been characterized using molecular dynamics simulations. However, it also has been suggested that a covalent butenolide modification of the receptor on the catalytic histidine through substrate hydrolysis promotes formation of the active state. Using molecular dynamics simulations, we show that the presence of the covalent butenolide enhances activation in both AtD14, a receptor found in Arabidopsis, and ShHTL7, a receptor found in Striga, but the enhancement is ∼50 times greater in ShHTL7. We also show that several conserved interactions with the covalent butenolide modification promote transition to the active state in both AtD14 (non-parasite) and ShHTL7 (parasite). Finally, we demonstrate that the enhanced activation of ShHTL7 likely results from disruption of ShHTL7-specific histidine interactions that inhibited activation in the apo case. These results provide a possible explanation for difference in strigolactone sensitivity seen between different strigolactone-sensitive proteins and can be used to aid the design of selective modulators to control Striga parasites.
Collapse
Affiliation(s)
- Jiming Chen
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois; Department of Plant Biology, University of Illinois Urbana-Champaign, Urbana, Illinois; Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, Illinois.
| |
Collapse
|
19
|
Guercio AM, Palayam M, Shabek N. Strigolactones: diversity, perception, and hydrolysis. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2023; 22:339-360. [PMID: 37201177 PMCID: PMC10191409 DOI: 10.1007/s11101-023-09853-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 01/03/2023] [Indexed: 05/20/2023]
Abstract
Strigolactones (SLs) are a unique and novel class of phytohormones that regulate numerous processes of growth and development in plants. Besides their endogenous functions as hormones, SLs are exuded by plant roots to stimulate critical interactions with symbiotic fungi but can also be exploited by parasitic plants to trigger their seed germination. In the past decade, since their discovery as phytohormones, rapid progress has been made in understanding the SL biosynthesis and signaling pathway. Of particular interest are the diversification of natural SLs and their exact mode of perception, selectivity, and hydrolysis by their dedicated receptors in plants. Here we provide an overview of the emerging field of SL perception with a focus on the diversity of canonical, non-canonical, and synthetic SL probes. Moreover, this review offers useful structural insights into SL perception, the precise molecular adaptations that define receptor-ligand specificities, and the mechanisms of SL hydrolysis and its attenuation by downstream signaling components.
Collapse
Affiliation(s)
- Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA 95616, USA
| | - Malathy Palayam
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA 95616, USA
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California - Davis, Davis, CA 95616, USA
| |
Collapse
|
20
|
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
|
21
|
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
|
22
|
Trasoletti M, Visentin I, Campo E, Schubert A, Cardinale F. Strigolactones as a hormonal hub for the acclimation and priming to environmental stress in plants. PLANT, CELL & ENVIRONMENT 2022; 45:3611-3630. [PMID: 36207810 PMCID: PMC9828678 DOI: 10.1111/pce.14461] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/29/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Strigolactones are phytohormones with many attributed roles in development, and more recently in responses to environmental stress. We will review evidence of the latter in the frame of the classic distinction among the three main stress acclimation strategies (i.e., avoidance, tolerance and escape), by taking osmotic stress in its several facets as a non-exclusive case study. The picture we will sketch is that of a hormonal family playing important roles in each of the mechanisms tested so far, and influencing as well the build-up of environmental memory through priming. Thus, strigolactones appear to be backstage operators rather than frontstage players, setting the tune of acclimation responses by fitting them to the plant individual history of stress experience.
Collapse
Affiliation(s)
| | | | - Eva Campo
- DISAFA, PlantStressLabTurin UniversityTurinItaly
| | | | | |
Collapse
|