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Schippers JHM, von Bongartz K, Laritzki L, Frohn S, Frings S, Renziehausen T, Augstein F, Winkels K, Sprangers K, Sasidharan R, Vertommen D, Van Breusegem F, Hartman S, Beemster GTS, Mhamdi A, van Dongen JT, Schmidt-Schippers RR. ERFVII-controlled hypoxia responses are in part facilitated by MEDIATOR SUBUNIT 25 in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 39259461 DOI: 10.1111/tpj.17018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 08/20/2024] [Accepted: 08/27/2024] [Indexed: 09/13/2024]
Abstract
Flooding impairs plant growth through oxygen deprivation, which activates plant survival and acclimation responses. Transcriptional responses to low oxygen are generally associated with the activation of group VII ETHYLENE-RESPONSE FACTOR (ERFVII) transcription factors. However, the exact mechanisms and molecular components by which ERFVII factors initiate gene expression are not fully elucidated. Here, we show that the ERFVII factors RELATED TO APETALA 2.2 (RAP2.2) and RAP2.12 cooperate with the Mediator complex subunit AtMED25 to coordinate gene expression under hypoxia in Arabidopsis thaliana. Respective med25 knock-out mutants display reduced low-oxygen stress tolerance. AtMED25 physically associates with a distinct set of hypoxia core genes and its loss partially impairs transcription under hypoxia due to decreased RNA polymerase II recruitment. Association of AtMED25 with target genes requires the presence of ERFVII transcription factors. Next to ERFVII protein stabilisation, also the composition of the Mediator complex including AtMED25 is potentially affected by hypoxia stress as shown by protein-complex pulldown assays. The dynamic response of the Mediator complex to hypoxia is furthermore supported by the fact that two subunits, AtMED8 and AtMED16, are not involved in the establishment of hypoxia tolerance, whilst both act in coordination with AtMED25 under other environmental conditions. We furthermore show that AtMED25 function under hypoxia is independent of ethylene signalling. Finally, functional conservation at the molecular level was found for the MED25-ERFVII module between A. thaliana and the monocot species Oryza sativa, pointing to a potentially universal role of MED25 in coordinating ERFVII-dependent transcript responses to hypoxia in plants.
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Affiliation(s)
- Jos H M Schippers
- Department of Molecular Genetics, Seed Development, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstraße 3, Gatersleben, Seeland, 06466, Germany
| | - Kira von Bongartz
- Institute of Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Lisa Laritzki
- Institute of Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Stephanie Frohn
- Department of Molecular Genetics, Seed Development, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstraße 3, Gatersleben, Seeland, 06466, Germany
| | - Stephanie Frings
- Plant Biotechnology, Faculty of Biology, University of Bielefeld, Universitätsstraße 25, Bielefeld, 33615, Germany
- Center for Biotechnology, University of Bielefeld, Universitätsstraße 27, Bielefeld, 33615, Germany
| | - Tilo Renziehausen
- Plant Biotechnology, Faculty of Biology, University of Bielefeld, Universitätsstraße 25, Bielefeld, 33615, Germany
- Center for Biotechnology, University of Bielefeld, Universitätsstraße 27, Bielefeld, 33615, Germany
| | - Frauke Augstein
- Department of Organismal Biology, Physiological Botany, and Linnean Centre for Plant Biology, Uppsala University, Ullsv. 24E, Uppsala, SE-75651, Sweden
| | - Katharina Winkels
- Institute of Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Katrien Sprangers
- IMPRES Research Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, G.U.613, Antwerpen, 2020, Belgium
| | - Rashmi Sasidharan
- Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Didier Vertommen
- de Duve Institute and MASSPROT platform, Université Catholique de Louvain, Avenue Hippocrate 75, Brussels, 1200, Belgium
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- Vlaams Instituut voor Biotechnologie (VIB), Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Sjon Hartman
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, Freiburg, 79104, Germany
- Plant Environmental Signalling and Development, Faculty of Biology, University of Freiburg, Schänzlestraße 1, Freiburg, 79104, Germany
| | - Gerrit T S Beemster
- IMPRES Research Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, G.U.613, Antwerpen, 2020, Belgium
| | - Amna Mhamdi
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- Vlaams Instituut voor Biotechnologie (VIB), Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Joost T van Dongen
- Institute of Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Romy R Schmidt-Schippers
- Plant Biotechnology, Faculty of Biology, University of Bielefeld, Universitätsstraße 25, Bielefeld, 33615, Germany
- Center for Biotechnology, University of Bielefeld, Universitätsstraße 27, Bielefeld, 33615, Germany
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Yuan C, Hu Y, Liu Q, Xu J, Zhou W, Yu H, Shen L, Qin C. MED8 regulates floral transition in Arabidopsis by interacting with FPA. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1234-1247. [PMID: 37565662 DOI: 10.1111/tpj.16419] [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: 05/18/2023] [Revised: 07/04/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023]
Abstract
Success in plant reproduction is highly dependent on the correct timing of the floral transition, which is tightly regulated by the flowering pathways. In the model plant Arabidopsis thaliana, the central flowering repressor FLOWERING LOCUS C (FLC) is precisely regulated by multiple flowering time regulators in the vernalization pathway and autonomous pathway, including FPA. Here we report that Arabidopsis MEDIATOR SUBUNIT 8 (MED8) promotes floral transition in Arabidopsis by recruiting FPA to the FLC locus to repress FLC expression. Loss of MED8 function leads to a significant late-flowering phenotype due to increased FLC expression. We further show that MED8 directly interacts with FPA in the nucleus and recruits FPA to the FLC locus. Moreover, MED8 is indispensable for FPA's function in controlling flowering time and regulating FLC expression. Our study thus reveals a flowering mechanism by which the Mediator subunit MED8 represses FLC expression by facilitating the binding of FPA to the FLC locus to ensure appropriate timing of flowering for reproductive success.
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Affiliation(s)
- Chen Yuan
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Yikai Hu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Qinggang Liu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Jingya Xu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Wei Zhou
- Temasek Life Sciences Laboratory, National University of Singapore, 117604, Singapore
| | - Hao Yu
- Temasek Life Sciences Laboratory, National University of Singapore, 117604, Singapore
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 117543, Singapore
| | - Lisha Shen
- Temasek Life Sciences Laboratory, National University of Singapore, 117604, Singapore
| | - Cheng Qin
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
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3
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Shapulatov U, van Zanten M, van Hoogdalem M, Meisenburg M, van Hall A, Kappers I, Fasano C, Facella P, Loh CC, Perrella G, van der Krol A. The Mediator complex subunit MED25 interacts with HDA9 and PIF4 to regulate thermomorphogenesis. PLANT PHYSIOLOGY 2023; 192:582-600. [PMID: 36537119 PMCID: PMC10152658 DOI: 10.1093/plphys/kiac581] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 05/03/2023]
Abstract
Thermomorphogenesis is, among other traits, characterized by enhanced hypocotyl elongation due to the induction of auxin biosynthesis genes like YUCCA8 by transcription factors, most notably PHYTOCHROME INTERACTING FACTOR 4 (PIF4). Efficient binding of PIF4 to the YUCCA8 locus under warmth depends on HISTONE DEACETYLASE 9 (HDA9) activity, which mediates histone H2A.Z depletion at the YUCCA8 locus. However, HDA9 lacks intrinsic DNA-binding capacity, and how HDA9 is recruited to YUCCA8, and possibly other PIF4-target sites, is currently not well understood. The Mediator complex functions as a bridge between transcription factors bound to specific promoter sequences and the basal transcription machinery containing RNA polymerase II. Mutants of Mediator component Mediator25 (MED25) exhibit reduced hypocotyl elongation and reduced expression of YUCCA8 at 27°C. In line with a proposed role for MED25 in thermomorphogenesis in Arabidopsis (Arabidopsis thaliana), we demonstrated an enhanced association of MED25 to the YUCCA8 locus under warmth and interaction of MED25 with both PIF4 and HDA9. Genetic analysis confirmed that MED25 and HDA9 operate in the same pathway. Intriguingly, we also showed that MED25 destabilizes HDA9 protein. Based on our findings, we propose that MED25 recruits HDA9 to the YUCCA8 locus by binding to both PIF4 and HDA9.
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Affiliation(s)
- Umidjon Shapulatov
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Temasek Life Science Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Martijn van Zanten
- Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Mark van Hoogdalem
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Mara Meisenburg
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Alexander van Hall
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Iris Kappers
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Carlo Fasano
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Trisaia Research Centre, S.S. Ionica, km 419.5, 75026 Rotondella (Matera), Italy
| | - Paolo Facella
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Trisaia Research Centre, S.S. Ionica, km 419.5, 75026 Rotondella (Matera), Italy
| | - Chi Cheng Loh
- Temasek Life Science Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Giorgio Perrella
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Trisaia Research Centre, S.S. Ionica, km 419.5, 75026 Rotondella (Matera), Italy
| | - Alexander van der Krol
- Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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Abstract
Plant architecture fundamentally differs from that of other multicellular organisms in that individual cells serve as osmotic bricks, defined by the equilibrium between the internal turgor pressure and the mechanical resistance of the surrounding cell wall, which constitutes the interface between plant cells and their environment. The state and integrity of the cell wall are constantly monitored by cell wall surveillance pathways, which relay information to the cell interior. A recent surge of discoveries has led to significant advances in both mechanistic and conceptual insights into a multitude of cell wall response pathways that play diverse roles in the development, defense, stress response, and maintenance of structural integrity of the cell. However, these advances have also revealed the complexity of cell wall sensing, and many more questions remain to be answered, for example, regarding the mechanisms of cell wall perception, the molecular players in this process, and how cell wall-related signals are transduced and integrated into cellular behavior. This review provides an overview of the mechanistic and conceptual insights obtained so far and highlights areas for future discoveries in this exciting area of plant biology.
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Affiliation(s)
- Sebastian Wolf
- Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), Eberhard-Karls University, Tübingen, Germany;
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5
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Chen Q, Zhang J, Li G. Dynamic epigenetic modifications in plant sugar signal transduction. TRENDS IN PLANT SCIENCE 2022; 27:379-390. [PMID: 34865981 DOI: 10.1016/j.tplants.2021.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 09/28/2021] [Accepted: 10/22/2021] [Indexed: 05/21/2023]
Abstract
In eukaryotes, dynamic chromatin states are closely related to changes in gene expression. Epigenetic modifications help plants adapt to their ever-changing environment by modulating gene expression via covalent modification at specific sites on DNA or histones. Sugars provide energy, but also function as signaling molecules to control plant growth and development. Various epigenetic modifications participate in sensing and transmitting sugar signals. Here we summarize recent progress in uncovering the epigenetic mechanisms involved in sugar signal transduction, including histone acetylation and deacetylation, histone methylation and demethylation, and DNA methylation. We also highlight changes in chromatin marks when crosstalk occurs between sugar signaling and the light, temperature, and phytohormone signaling pathways, and describe potential questions and approaches for future research.
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Affiliation(s)
- Qingshuai Chen
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, Shandong, China; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Jing Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Gang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China.
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Meyer RC, Weigelt-Fischer K, Knoch D, Heuermann M, Zhao Y, Altmann T. Temporal dynamics of QTL effects on vegetative growth in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:476-490. [PMID: 33080013 DOI: 10.1093/jxb/eraa490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
We assessed early vegetative growth in a population of 382 accessions of Arabidopsis thaliana using automated non-invasive high-throughput phenotyping. All accessions were imaged daily from 7 d to 18 d after sowing in three independent experiments and genotyped using the Affymetrix 250k SNP array. Projected leaf area (PLA) was derived from image analysis and used to calculate relative growth rates (RGRs). In addition, initial seed size was determined. The generated datasets were used jointly for a genome-wide association study that identified 238 marker-trait associations (MTAs) individually explaining up to 8% of the total phenotypic variation. Co-localization of MTAs occurred at 33 genomic positions. At 21 of these positions, sequential co-localization of MTAs for 2-9 consecutive days was observed. The detected MTAs for PLA and RGR could be grouped according to their temporal expression patterns, emphasizing that temporal variation of MTA action can be observed even during the vegetative growth phase, a period of continuous formation and enlargement of seemingly similar rosette leaves. This indicates that causal genes may be differentially expressed in successive periods. Analyses of the temporal dynamics of biological processes are needed to gain important insight into the molecular mechanisms of growth-controlling processes in plants.
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Affiliation(s)
- Rhonda C Meyer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Molecular Genetics, Research Group Heterosis, OT Gatersleben, Corrensstraße, Seeland, Germany
| | - Kathleen Weigelt-Fischer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Molecular Genetics, Research Group Heterosis, OT Gatersleben, Corrensstraße, Seeland, Germany
| | - Dominic Knoch
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Molecular Genetics, Research Group Heterosis, OT Gatersleben, Corrensstraße, Seeland, Germany
| | - Marc Heuermann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Molecular Genetics, Research Group Heterosis, OT Gatersleben, Corrensstraße, Seeland, Germany
| | - Yusheng Zhao
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Breeding Research, Research Group Quantitative Genetics, OT Gatersleben, Corrensstraße, Seeland, Germany
| | - Thomas Altmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Department of Molecular Genetics, Research Group Heterosis, OT Gatersleben, Corrensstraße, Seeland, Germany
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7
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Harun S, Abdullah-Zawawi MR, Goh HH, Mohamed-Hussein ZA. A Comprehensive Gene Inventory for Glucosinolate Biosynthetic Pathway in Arabidopsis thaliana. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:7281-7297. [PMID: 32551569 DOI: 10.1021/acs.jafc.0c01916] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Glucosinolates (GSLs) are plant secondary metabolites comprising sulfur and nitrogen mainly found in plants from the order of Brassicales, such as broccoli, cabbage, and Arabidopsis thaliana. The activated forms of GSL play important roles in fighting against pathogens and have health benefits to humans. The increasing amount of data on A. thaliana generated from various omics technologies can be investigated more deeply in search of new genes or compounds involved in GSL biosynthesis and metabolism. This review describes a comprehensive inventory of A. thaliana GSLs identified from published literature and databases such as KNApSAcK, KEGG, and AraCyc. A total of 113 GSL genes encoding for 23 transcription components, 85 enzymes, and five protein transporters were experimentally characterized in the past two decades. Continuous efforts are still on going to identify all molecules related to the production of GSLs. A manually curated database known as SuCCombase (http://plant-scc.org) was developed to serve as a comprehensive GSL inventory. Realizing lack of information on the regulation of GSL biosynthesis and degradation mechanisms, this review also includes relevant information and their connections with crosstalk among various factors, such as light, sulfur metabolism, and nitrogen metabolism, not only in A. thaliana but also in other crucifers.
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Affiliation(s)
- Sarahani Harun
- Centre for Bioinformatics Research, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Muhammad-Redha Abdullah-Zawawi
- Centre for Bioinformatics Research, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Hoe-Han Goh
- Centre for Plant Biotechnology, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Zeti-Azura Mohamed-Hussein
- Centre for Bioinformatics Research, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
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Mao X, Weake VM, Chapple C. Mediator function in plant metabolism revealed by large-scale biology. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5995-6003. [PMID: 31504746 DOI: 10.1093/jxb/erz372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/07/2019] [Indexed: 05/16/2023]
Abstract
Mediator is a multisubunit transcriptional co-regulator that is involved in the regulation of an array of processes including plant metabolism. The pathways regulated by Mediator-dependent processes include those for the synthesis of phenylpropanoids (MED5), cellulose (MED16), lipids (MED15 and CDK8), and the regulation of iron homeostasis (MED16 and MED25). Traditional genetic and biochemical approaches laid the foundation for our understanding of Mediator function, but recent transcriptomic and metabolomic studies have provided deeper insights into how specific subunits cooperate in the regulation of plant metabolism. In this review, we highlight recent developments in the investigation of Mediator and plant metabolism, with particular emphasis on the large-scale biology studies of med mutants.
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Affiliation(s)
- Xiangying Mao
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Clint Chapple
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
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9
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Zhao C, Zayed O, Zeng F, Liu C, Zhang L, Zhu P, Hsu CC, Tuncil YE, Tao WA, Carpita NC, Zhu JK. Arabinose biosynthesis is critical for salt stress tolerance in Arabidopsis. THE NEW PHYTOLOGIST 2019; 224:274-290. [PMID: 31009077 DOI: 10.1111/nph.15867] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 04/16/2019] [Indexed: 05/21/2023]
Abstract
The capability to maintain cell wall integrity is critical for plants to adapt to unfavourable conditions. l-Arabinose (Ara) is a constituent of several cell wall polysaccharides and many cell wall-localised glycoproteins, but so far the contribution of Ara metabolism to abiotic stress tolerance is still poorly understood. Here, we report that mutations in the MUR4 (also known as HSR8) gene, which is required for the biosynthesis of UDP-Arap in Arabidopsis, led to reduced root elongation under high concentrations of NaCl, KCl, NaNO3 , or KNO3 . The short root phenotype of the mur4/hsr8 mutants under high salinity is rescued by exogenous Ara or gum arabic, a commercial product of arabinogalactan proteins (AGPs) from Acacia senegal. Mutation of the MUR4 gene led to abnormal cell-cell adhesion under salt stress. MUR4 forms either a homodimer or heterodimers with its isoforms. Analysis of the higher order mutants of MUR4 with its three paralogues, MURL, DUR, MEE25, reveals that the paralogues of MUR4 also contribute to the biosynthesis of UDP-Ara and are critical for root elongation. Taken together, our work revealed the importance of the Ara metabolism in salt stress tolerance and also provides new insights into the enzymes involved in the UDP-Ara biosynthesis in plants.
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Affiliation(s)
- Chunzhao Zhao
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
| | - Omar Zayed
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
| | - Fansuo Zeng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, 150040, China
| | - Chaoxian Liu
- Maize Research Institute, Southwest University, Chongqing, 400715, China
| | - Ling Zhang
- Jilin Provincial Key laboratory of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, Jilin, 130033, China
| | - Peipei Zhu
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Chuan-Chih Hsu
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Yunus E Tuncil
- Food Engineering Department, Ordu University, Ordu, 52200, Turkey
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Nicholas C Carpita
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Jian-Kang Zhu
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
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10
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Chen Q, Xu X, Xu D, Zhang H, Zhang C, Li G. WRKY18 and WRKY53 Coordinate with HISTONE ACETYLTRANSFERASE1 to Regulate Rapid Responses to Sugar. PLANT PHYSIOLOGY 2019; 180:2212-2226. [PMID: 31182557 PMCID: PMC6670108 DOI: 10.1104/pp.19.00511] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 06/01/2019] [Indexed: 05/18/2023]
Abstract
Sugars provide a source of energy; they also function as signaling molecules that regulate gene expression, affect metabolism, and alter growth in plants. Rapid responses to sugar signaling and metabolism are essential for optimal growth and fitness, but the regulatory mechanisms underlying these are largely unknown. In this study, we found that the rapid induction of sugar responses in Arabidopsis (Arabidopsis thaliana) requires the W-box cis-elements in the promoter region of GLC 6-PHOSPHATE/PHOSPHATE TRANSLOCATOR2, a well-studied sugar response marker gene. The transcription factors WRKY18 and WRKY53 directly bind to the W-Box cis-elements in the promoter region of sugar response genes and activate their expression. In addition, HISTONE ACETYLTRANSFERASE 1 (HAC1) is recruited to the WRKY18 and WRKY53 complex that resides on the promoters. In this complex, HAC1 facilitates the acetylation of histone 3 Lys 27 (H3K27ac) on the sugar-responsive genes. Taken together, our findings demonstrate a mechanism by which sugar regulates chromatin modification and gene expression, thus helping plants to adjust their growth in response to environmental changes.
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Affiliation(s)
- Qingshuai Chen
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Xiyu Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Di Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Haisen Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Cankui Zhang
- Department of Agronomy, Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana
| | - Gang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
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Transcriptome Analysis of Four Arabidopsis thaliana Mediator Tail Mutants Reveals Overlapping and Unique Functions in Gene Regulation. G3-GENES GENOMES GENETICS 2018; 8:3093-3108. [PMID: 30049745 PMCID: PMC6118316 DOI: 10.1534/g3.118.200573] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The Mediator complex is a central component of transcriptional regulation in Eukaryotes. The complex is structurally divided into four modules known as the head, middle, tail and kinase modules, and in Arabidopsis thaliana, comprises 28-34 subunits. Here, we explore the functions of four Arabidopsis Mediator tail subunits, MED2, MED5a/b, MED16, and MED23, by comparing the impact of mutations in each on the Arabidopsis transcriptome. We find that these subunits affect both unique and overlapping sets of genes, providing insight into the functional and structural relationships between them. The mutants primarily exhibit changes in the expression of genes related to biotic and abiotic stress. We find evidence for a tissue specific role for MED23, as well as in the production of alternative transcripts. Together, our data help disentangle the individual contributions of these MED subunits to global gene expression and suggest new avenues for future research into their functions.
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Edqvist J, Blomqvist K, Nieuwland J, Salminen TA. Plant lipid transfer proteins: are we finally closing in on the roles of these enigmatic proteins? J Lipid Res 2018; 59:1374-1382. [PMID: 29555656 PMCID: PMC6071764 DOI: 10.1194/jlr.r083139] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 01/23/2018] [Indexed: 12/22/2022] Open
Abstract
The nonspecific lipid transfer proteins (LTPs) are small compact proteins folded around a tunnel-like hydrophobic cavity, making them suitable for lipid binding and transport. LTPs are encoded by large gene families in all land plants, but they have not been identified in algae or any other organisms. Thus, LTPs are considered key proteins for plant survival on and colonization of land. LTPs are abundantly expressed in most plant tissues, both above and below ground. They are usually localized to extracellular spaces outside the plasma membrane. Although the in vivo functions of LTPs remain unclear, accumulating evidence suggests a role for LTPs in the transfer and deposition of monomers required for assembly of the waterproof lipid barriers, such as cutin and cuticular wax, suberin, and sporopollenin, formed on many plant surfaces. Some LTPs may be involved in other processes, such as signaling during pathogen attacks. Here, we present the current status of LTP research with a focus on the role of these proteins in lipid barrier deposition and cell expansion. We suggest that LTPs facilitate extracellular transfer of barrier materials and adhesion between barriers and extracellular materials. A growing body of research may uncover the true role of LTPs in plants.
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Affiliation(s)
| | | | - Jeroen Nieuwland
- Faculty of Computing, Engineering, and Science, University of South Wales, CF37 1DL Pontypridd, United Kingdom
| | - Tiina A Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20520 Turku, Finland
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The Arabidopsis thaliana Mediator subunit MED8 regulates plant immunity to Botrytis Cinerea through interacting with the basic helix-loop-helix (bHLH) transcription factor FAMA. PLoS One 2018. [PMID: 29513733 PMCID: PMC5841781 DOI: 10.1371/journal.pone.0193458] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The Mediator complex is at the core of transcriptional regulation and plays a central role in plant immunity. The MEDIATOR25 (MED25) subunit of Arabidopsis thaliana regulates jasmonate-dependent resistance to Botrytis cinerea through interacting with the basic helix-loop-helix (bHLH) transcription factor of jasmonate signaling, MYC2. Another Mediator subunit, MED8, acts independently or together with MED25 in plant immunity. However, unlike MED25, the underlying action mechanisms of MED8 in regulating B. cinerea resistance are still unknown. Here, we demonstrated that MED8 regulated plant immunity to B. cinerea through interacting with another bHLH transcription factor, FAMA, which was previously shown to control the final proliferation/differentiation switch during stomatal development. Our research demonstrates that FAMA is also an essential component of B. cinerea resistance. The fama loss-of-function mutants (fama-1 and fama-2) increased susceptibility to B. cinerea infection and reduced defense-gene expression. On the contrary, transgenic lines constitutively overexpressing FAMA showed opposite B. cinerea responses compared with the fama loss-of-function mutants. FAMA-overexpressed plants displayed enhanced resistance to B. cinerea infection and increased expression levels of defensin genes following B. cinerea treatment. Genetic analysis of MED8 and FAMA suggested that FAMA-regulated pathogen resistance was dependent on MED8. In addition, MED8 and FAMA were both associated with the G-box region in the promoter of ORA59. Our findings indicate that the MED8 subunit of the A. thaliana Mediator regulates plant immunity to B. cinerea through interacting with the transcription factor FAMA, which was discovered to be a key component in B. cinerea resistance.
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Dolan WL, Dilkes BP, Stout JM, Bonawitz ND, Chapple C. Mediator Complex Subunits MED2, MED5, MED16, and MED23 Genetically Interact in the Regulation of Phenylpropanoid Biosynthesis. THE PLANT CELL 2017; 29:3269-3285. [PMID: 29203634 PMCID: PMC5757269 DOI: 10.1105/tpc.17.00282] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/26/2017] [Accepted: 11/29/2017] [Indexed: 05/19/2023]
Abstract
The phenylpropanoid pathway is a major global carbon sink and is important for plant fitness and the engineering of bioenergy feedstocks. In Arabidopsis thaliana, disruption of two subunits of the transcriptional regulatory Mediator complex, MED5a and MED5b, results in an increase in phenylpropanoid accumulation. By contrast, the semidominant MED5b mutation reduced epidermal fluorescence4-3 (ref4-3) results in dwarfism and constitutively repressed phenylpropanoid accumulation. Here, we report the results of a forward genetic screen for suppressors of ref4-3. We identified 13 independent lines that restore growth and/or phenylpropanoid accumulation in the ref4-3 background. Two of the suppressors restore growth without restoring soluble phenylpropanoid accumulation, indicating that the growth and metabolic phenotypes of the ref4-3 mutant can be genetically disentangled. Whole-genome sequencing revealed that all but one of the suppressors carry mutations in MED5b or other Mediator subunits. RNA-seq analysis showed that the ref4-3 mutation causes widespread changes in gene expression, including the upregulation of negative regulators of the phenylpropanoid pathway, and that the suppressors reverse many of these changes. Together, our data highlight the interdependence of individual Mediator subunits and provide greater insight into the transcriptional regulation of phenylpropanoid biosynthesis by the Mediator complex.
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Affiliation(s)
- Whitney L Dolan
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, West Lafayette, Indiana 47907
| | - Brian P Dilkes
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, West Lafayette, Indiana 47907
| | - Jake M Stout
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, West Lafayette, Indiana 47907
| | - Nicholas D Bonawitz
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, West Lafayette, Indiana 47907
| | - Clint Chapple
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, West Lafayette, Indiana 47907
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15
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Raya-González J, López-Bucio JS, Prado-Rodríguez JC, Ruiz-Herrera LF, Guevara-García ÁA, López-Bucio J. The MEDIATOR genes MED12 and MED13 control Arabidopsis root system configuration influencing sugar and auxin responses. PLANT MOLECULAR BIOLOGY 2017; 95:141-156. [PMID: 28780645 DOI: 10.1007/s11103-017-0647-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 07/27/2017] [Indexed: 05/23/2023]
Abstract
Arabidopsis med12 and med13 mutants exhibit shoot and root phenotypes related to an altered auxin homeostasis. Sucrose supplementation reactivates both cell division and elongation in primary roots as well as auxin-responsive and stem cell niche gene expression in these mutants. An analysis of primary root growth of WT, med12, aux1-7 and med12 aux1 single and double mutants in response to sucrose and/or N-1-naphthylphthalamic acid (NPA) placed MED12 upstream of auxin transport for the sugar modulation of root growth. The MEDIATOR (MED) complex plays diverse functions in plant development, hormone signaling and biotic and abiotic stress tolerance through coordination of transcription. Here, we performed genetic, developmental, molecular and pharmacological analyses to characterize the role of MED12 and MED13 on the configuration of root architecture and its relationship with auxin and sugar responses. Arabidopsis med12 and med13 single mutants exhibit shoot and root phenotypes consistent with altered auxin homeostasis including altered primary root growth, lateral root development, and root hair elongation. MED12 and MED13 were required for activation of cell division and elongation in primary roots, as well as auxin-responsive and stem cell niche gene expression. Remarkably, most of these mutant phenotypes were rescued by supplying sucrose to the growth medium. The growth response of primary roots of WT, med12, aux1-7 and med12 aux1 single and double mutants to sucrose and application of auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) revealed the correlation of med12 phenotype with the activity of the auxin intake permease and suggests that MED12 acts upstream of AUX1 in the root growth response to sugar. These data provide compelling evidence that MEDIATOR links sugar sensing to auxin transport and distribution during root morphogenesis.
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Affiliation(s)
- Javier Raya-González
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | | | - José Carlos Prado-Rodríguez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | - León Francisco Ruiz-Herrera
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | | | - José López-Bucio
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico.
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Kazan K. The Multitalented MEDIATOR25. FRONTIERS IN PLANT SCIENCE 2017; 8:999. [PMID: 28659948 PMCID: PMC5467580 DOI: 10.3389/fpls.2017.00999] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/26/2017] [Indexed: 05/19/2023]
Abstract
The multi-subunit Mediator complex, which links DNA-bound transcription factors to RNA Pol II during transcription, is an essential regulator of gene expression in all eukaryotes. Individual subunits of the Mediator complex integrate numerous endogenous and exogenous signals. In this paper, diverse regulatory functions performed by MEDIATOR25 (MED25), one of the subunits of the plant Mediator complex are reviewed. MED25 was first identified as a regulator of flowering time and named PHYTOCHROME AND FLOWERING TIME1 (PFT1). Since then, MED25 has been implicated in a range of other plant functions that vary from hormone signaling (JA, ABA, ethylene, and IAA) to biotic and abiotic stress tolerance and plant development. MED25 physically interacts with transcriptional activators (e.g., AP2/ERFs, MYCs, and ARFs), repressors (e.g., JAZs and Aux/IAAs), and other Mediator subunits (MED13 and MED16). In addition, various genetic and epigenetic interactions involving MED25 have been reported. These features make MED25 one of the most multifunctional Mediator subunits and provide new insights into the transcriptional control of gene expression in plants.
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Affiliation(s)
- Kemal Kazan
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, BrisbaneQLD, Australia
- Queensland Alliance for Agriculture and Food Innovation, Queensland Bioscience Precinct, The University of Queensland, BrisbaneQLD, Australia
- *Correspondence: Kemal Kazan,
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