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Xiao K, Qiao K, Cui W, Xu X, Pan H, Wang F, Wang S, Yang F, Xuan Y, Li A, Han X, Song Z, Liu J. Comparative transcriptome profiling reveals the importance of GmSWEET15 in soybean susceptibility to Sclerotinia sclerotiorum. Front Microbiol 2023; 14:1119016. [PMID: 36778863 PMCID: PMC9909833 DOI: 10.3389/fmicb.2023.1119016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/05/2023] [Indexed: 01/27/2023] Open
Abstract
Soybean sclerotinia stem rot (SSR) is a disease caused by Sclerotinia sclerotiorum that causes incalculable losses in soybean yield each year. Considering the lack of effective resistance resources and the elusive resistance mechanisms, we are urged to develop resistance genes and explore their molecular mechanisms. Here, we found that loss of GmSWEET15 enhanced the resistance to S. sclerotiorum, and we explored the molecular mechanisms by which gmsweet15 mutant exhibit enhanced resistance to S. sclerotiorum by comparing transcriptome. At the early stage of inoculation, the wild type (WT) showed moderate defense response, whereas gmsweet15 mutant exhibited more extensive and intense transcription reprogramming. The gmsweet15 mutant enriched more biological processes, including the secretory pathway and tetrapyrrole metabolism, and it showed stronger changes in defense response, protein ubiquitination, MAPK signaling pathway-plant, plant-pathogen interaction, phenylpropanoid biosynthesis, and photosynthesis. The more intense and abundant transcriptional reprogramming of gmsweet15 mutant may explain how it effectively delayed colonization by S. sclerotiorum. In addition, we identified common and specific differentially expressed genes between WT and gmsweet15 mutant after inoculation with S. sclerotiorum, and gene sets and genes related to gmsweet15_24 h were identified through Gene Set Enrichment Analysis. Moreover, we constructed the protein-protein interaction network and gene co-expression networks and identified several groups of regulatory networks of gmsweet15 mutant in response to S. sclerotiorum, which will be helpful for the discovery of candidate functional genes. Taken together, our results elucidate molecular mechanisms of delayed colonization by S. sclerotiorum after loss of GmSWEET15 in soybean, and we propose novel resources for improving resistance to SSR.
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Affiliation(s)
- Kunqin Xiao
- College of Plant Sciences, Jilin University, Changchun, China
| | - Kaibin Qiao
- College of Plant Sciences, Jilin University, Changchun, China
| | - Wenjing Cui
- College of Plant Sciences, Jilin University, Changchun, China
| | - Xun Xu
- College of Plant Sciences, Jilin University, Changchun, China
| | - Hongyu Pan
- College of Plant Sciences, Jilin University, Changchun, China
| | - Fengting Wang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Shoudong Wang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Feng Yang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Yuanhu Xuan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Anmo Li
- College of Plant Sciences, Jilin University, Changchun, China
| | - Xiao Han
- College of Plant Sciences, Jilin University, Changchun, China
| | - Zhuojian Song
- College of Plant Sciences, Jilin University, Changchun, China
| | - Jinliang Liu
- College of Plant Sciences, Jilin University, Changchun, China,*Correspondence: Jinliang Liu,
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2
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Barros J, Shrestha HK, Serrani-Yarce JC, Engle NL, Abraham PE, Tschaplinski TJ, Hettich RL, Dixon RA. Proteomic and metabolic disturbances in lignin-modified Brachypodium distachyon. THE PLANT CELL 2022; 34:3339-3363. [PMID: 35670759 PMCID: PMC9421481 DOI: 10.1093/plcell/koac171] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/23/2022] [Indexed: 05/30/2023]
Abstract
Lignin biosynthesis begins with the deamination of phenylalanine and tyrosine (Tyr) as a key branch point between primary and secondary metabolism in land plants. Here, we used a systems biology approach to investigate the global metabolic responses to lignin pathway perturbations in the model grass Brachypodium distachyon. We identified the lignin biosynthetic protein families and found that ammonia-lyases (ALs) are among the most abundant proteins in lignifying tissues in grasses. Integrated metabolomic and proteomic data support a link between lignin biosynthesis and primary metabolism mediated by the ammonia released from ALs that is recycled for the synthesis of amino acids via glutamine. RNA interference knockdown of lignin genes confirmed that the route of the canonical pathway using shikimate ester intermediates is not essential for lignin formation in Brachypodium, and there is an alternative pathway from Tyr via sinapic acid for the synthesis of syringyl lignin involving yet uncharacterized enzymatic steps. Our findings support a model in which plant ALs play a central role in coordinating the allocation of carbon for lignin synthesis and the nitrogen available for plant growth. Collectively, these data also emphasize the value of integrative multiomic analyses to advance our understanding of plant metabolism.
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Affiliation(s)
| | - Him K Shrestha
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37916, USA
| | - Juan C Serrani-Yarce
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201, USA
| | - Nancy L Engle
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Paul E Abraham
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Timothy J Tschaplinski
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Robert L Hettich
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
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3
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Chen J, Yang S, Fan B, Zhu C, Chen Z. The Mediator Complex: A Central Coordinator of Plant Adaptive Responses to Environmental Stresses. Int J Mol Sci 2022; 23:ijms23116170. [PMID: 35682844 PMCID: PMC9181133 DOI: 10.3390/ijms23116170] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/22/2022] [Accepted: 05/28/2022] [Indexed: 01/25/2023] Open
Abstract
As sessile organisms, plants are constantly exposed to a variety of environmental stresses and have evolved adaptive mechanisms, including transcriptional reprogramming, in order to survive or acclimate under adverse conditions. Over the past several decades, a large number of gene-specific transcription factors have been identified in the transcriptional regulation of plant adaptive responses. The Mediator complex plays a key role in transducing signals from gene-specific transcription factors to the transcription machinery to activate or repress target gene expression. Since its first purification about 15 years ago, plant Mediator complex has been extensively analyzed for its composition and biological functions. Mutants of many plant Mediator subunits are not lethal but are compromised in growth, development and response to biotic and abiotic stress, underscoring a particularly important role in plant adaptive responses. Plant Mediator subunits also interact with partners other than transcription factors and components of the transcription machinery, indicating the complexity of the regulation of gene expression by plant Mediator complex. Here, we present a comprehensive discussion of recent analyses of the structure and function of plant Mediator complex, with a particular focus on its roles in plant adaptive responses to a wide spectrum of environmental stresses and associated biological processes.
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Affiliation(s)
- Jialuo Chen
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China; (J.C.); (S.Y.)
| | - Su Yang
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China; (J.C.); (S.Y.)
| | - Baofang Fan
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA;
| | - Cheng Zhu
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China; (J.C.); (S.Y.)
- Correspondence: (C.Z.); (Z.C.); Tel.: +86-571-8683-6090 (C.Z.); +1-765-494-4657 (Z.C.)
| | - Zhixiang Chen
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China; (J.C.); (S.Y.)
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA;
- Correspondence: (C.Z.); (Z.C.); Tel.: +86-571-8683-6090 (C.Z.); +1-765-494-4657 (Z.C.)
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Khan MSS, Islam F, Chen H, Chang M, Wang D, Liu F, Fu ZQ, Chen J. Transcriptional Coactivators: Driving Force of Plant Immunity. FRONTIERS IN PLANT SCIENCE 2022; 13:823937. [PMID: 35154230 PMCID: PMC8831314 DOI: 10.3389/fpls.2022.823937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/10/2022] [Indexed: 05/03/2023]
Abstract
Salicylic acid (SA) is a plant defense signal that mediates local and systemic immune responses against pathogen invasion. However, the underlying mechanism of SA-mediated defense is very complex due to the involvement of various positive and negative regulators to fine-tune its signaling in diverse pathosystems. Upon pathogen infections, elevated level of SA promotes massive transcriptional reprogramming in which Non-expresser of PR genes 1 (NPR1) acts as a central hub and transcriptional coactivator in defense responses. Recent findings show that Enhanced Disease Susceptibility 1 (EDS1) also functions as a transcriptional coactivator and stimulates the expression of PR1 in the presence of NPR1 and SA. Furthermore, EDS1 stabilizes NPR1 protein level, while NPR1 sustains EDS1 expression during pathogenic infection. The interaction of NPR1 and EDS1 coactivators initiates transcriptional reprogramming by recruiting cyclin-dependent kinase 8 in the Mediator complex to control immune responses. In this review, we highlight the recent breakthroughs that considerably advance our understanding on how transcriptional coactivators interact with their functional partners to trigger distinct pathways to facilitate immune responses, and how SA accumulation induces dynamic changes in NPR1 structure for transcriptional reprogramming. In addition, the functions of different Mediator subunits in SA-mediated plant immunity are also discussed in light of recent discoveries. Taken together, the available evidence suggests that transcriptional coactivators are essential and potent regulators of plant defense pathways and play crucial roles in coordinating plant immune responses during plant-pathogen interactions.
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Affiliation(s)
| | - Faisal Islam
- Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, China
| | - Huan Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
| | - Ming Chang
- The Key Laboratory of Bio-interactions and Plant Health, College of Life Science, Nanjing Agricultural University, Nanjing, China
| | - Daowen Wang
- State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- *Correspondence: Fengquan Liu,
| | - Zheng Qing Fu
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
- Zheng Qing Fu,
| | - Jian Chen
- International Genome Center, Jiangsu University, Zhenjiang, China
- Jian Chen,
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5
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He H, Denecker J, Van Der Kelen K, Willems P, Pottie R, Phua SY, Hannah MA, Vertommen D, Van Breusegem F, Mhamdi A. The Arabidopsis mediator complex subunit 8 regulates oxidative stress responses. THE PLANT CELL 2021; 33:2032-2057. [PMID: 33713138 PMCID: PMC8290281 DOI: 10.1093/plcell/koab079] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/10/2021] [Indexed: 05/13/2023]
Abstract
Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.
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Affiliation(s)
- Huaming He
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Jordi Denecker
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
- Present address: Illumina Cambridge Ltd, Cambridge, CB21 6DF, UK; Present address: Sciensano, 1050 Brussels, Belgium
| | - Katrien Van Der Kelen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
- Present address: Illumina Cambridge Ltd, Cambridge, CB21 6DF, UK; Present address: Sciensano, 1050 Brussels, Belgium
| | - Patrick Willems
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Robin Pottie
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Su Yin Phua
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Matthew A Hannah
- BASF Belgium Coordination Center, Innovation Center Gent, 9052 Gent, Belgium
| | - Didier Vertommen
- de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Amna Mhamdi
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
- Author for correspondence: (A.M.)
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6
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Ha CM, Rao X, Saxena G, Dixon RA. Growth-defense trade-offs and yield loss in plants with engineered cell walls. THE NEW PHYTOLOGIST 2021; 231:60-74. [PMID: 33811329 DOI: 10.1111/nph.17383] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/29/2021] [Indexed: 05/18/2023]
Abstract
As a major component of plant secondary cell walls, lignin provides structural integrity and rigidity, and contributes to primary defense by providing a physical barrier to pathogen ingress. Genetic modification of lignin biosynthesis has been adopted to reduce the recalcitrance of lignified cell walls to improve biofuel production, tree pulping properties and forage digestibility. However, lignin-modification is often, but unpredictably, associated with dwarf phenotypes. Hypotheses suggested to explain this include: collapsed vessels leading to defects in water and solute transport; accumulation of molecule(s) that are inhibitory to plant growth or deficiency of metabolites that are critical for plant growth; activation of defense pathways linked to cell wall integrity sensing. However, there is still no commonly accepted underlying mechanism for the growth defects. Here, we discuss recent data on transcriptional reprogramming in plants with modified lignin content and their corresponding suppressor mutants, and evaluate growth-defense trade-offs as a factor underlying the growth phenotypes. New approaches will be necessary to estimate how gross changes in transcriptional reprogramming may quantitatively affect growth. Better understanding of the basis for yield drag following cell wall engineering is important for the biotechnological exploitation of plants as factories for fuels and chemicals.
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Affiliation(s)
- Chan Man Ha
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Xiaolan Rao
- College of Life Sciences, Hubei University, No. 28 Nanli Road, Hong-shan District, Wuchang, Wuhan, Hubei Province, 430068, China
| | - Garima Saxena
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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7
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Signal Integration by Cyclin-Dependent Kinase 8 (CDK8) Module and Other Mediator Subunits in Biotic and Abiotic Stress Responses. Int J Mol Sci 2020; 22:ijms22010354. [PMID: 33396301 PMCID: PMC7795602 DOI: 10.3390/ijms22010354] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022] Open
Abstract
Environmental stresses have driven plants to develop various mechanisms to acclimate in adverse conditions. Extensive studies have demonstrated that a significant reprogramming occurs in the plant transcriptome in response to biotic and abiotic stresses. The highly conserved and large multi-subunit transcriptional co-activator of eukaryotes, known as the Mediator, has been reported to play a substantial role in the regulation of important genes that help plants respond to environmental perturbances. CDK8 module is a relatively new component of the Mediator complex that has been shown to contribute to plants' defense, development, and stress responses. Previous studies reported that CDK8 module predominantly acts as a transcriptional repressor in eukaryotic cells by reversibly associating with core Mediator. However, growing evidence has demonstrated that depending on the type of biotic and abiotic stress, the CDK8 module may perform a contrasting regulatory role. This review will summarize the current knowledge of CDK8 module as well as other previously documented Mediator subunits in plant cell signaling under stress conditions.
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8
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Zhu Y, Huang P, Guo P, Chong L, Yu G, Sun X, Hu T, Li Y, Hsu CC, Tang K, Zhou Y, Zhao C, Gao W, Tao WA, Mengiste T, Zhu JK. CDK8 is associated with RAP2.6 and SnRK2.6 and positively modulates abscisic acid signaling and drought response in Arabidopsis. THE NEW PHYTOLOGIST 2020; 228:1573-1590. [PMID: 32619295 DOI: 10.1111/nph.16787] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/20/2020] [Indexed: 06/11/2023]
Abstract
CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions of CDK8 in plant abiotic stress responses remain largely unexplored. Here, we demonstrated CDK8 as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways in Arabidopsis. Compared to wild-type, cdk8 mutants showed reduced sensitivity to ABA, impaired stomatal apertures and hypersensitivity to drought stress. Transcriptomic and chromatin immunoprecipitation analysis revealed that CDK8 positively regulates the transcription of several ABA-responsive genes, probably through promoting the recruitment of RNA polymerase II to their promoters. We discovered that both CDK8 and SnRK2.6 interact physically with an ERF/AP2 transcription factor RAP2.6, which can directly bind to the promoters of RD29A and COLD-REGULATED 15A (COR15A) with GCC or DRE elements, thereby promoting their expression. Importantly, we also showed that CDK8 is essential for the ABA-induced expression of RAP2.6 and RAP2.6-mediated upregulation of ABA-responsive genes, indicating that CDK8 could link the SnRK2.6-mediated ABA signaling to RNA polymerase II to promote immediate transcriptional response to ABA and drought signals. Overall, our data provide new insights into the roles of CDK8 in modulating ABA signaling and drought responses.
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Affiliation(s)
- Yingfang Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Pengcheng Huang
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Pengcheng Guo
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Leelyn Chong
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Gaobo Yu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, 163711, China
| | - Xiaoli Sun
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, 163711, China
| | - Tao Hu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Yuan Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Chuan-Chih Hsu
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Kai Tang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Chunzhao Zhao
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Wei Gao
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Tesfaye Mengiste
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Jian-Kang Zhu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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Chen J, Clinton M, Qi G, Wang D, Liu F, Fu ZQ. Reprogramming and remodeling: transcriptional and epigenetic regulation of salicylic acid-mediated plant defense. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5256-5268. [PMID: 32060527 DOI: 10.1093/jxb/eraa072] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/11/2020] [Indexed: 05/13/2023]
Abstract
As a plant hormone, salicylic acid (SA) plays essential roles in plant defense against biotrophic and hemibiotrophic pathogens. Significant progress has been made in understanding the SA biosynthesis pathways and SA-mediated defense signaling networks in the past two decades. Plant defense responses involve rapid and massive transcriptional reprogramming upon the recognition of pathogens. Plant transcription factors and their co-regulators are critical players in establishing a transcription regulatory network and boosting plant immunity. A multitude of transcription factors and epigenetic regulators have been discovered, and their roles in SA-mediated defense responses have been reported. However, our understanding of plant transcriptional networks is still limited. As such, novel genomic tools and bioinformatic techniques will be necessary if we are to fully understand the mechanisms behind plant immunity. Here, we discuss current knowledge, provide an update on the SA biosynthesis pathway, and describe the transcriptional and epigenetic regulation of SA-mediated plant immune responses.
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Affiliation(s)
- Jian Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, P. R. China
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Michael Clinton
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Guang Qi
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou, P. R. China
| | - Daowen Wang
- State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou, P. R. China
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, P. R. China
| | - Zheng Qing Fu
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
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10
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The Important Function of Mediator Complex in Controlling the Developmental Transitions in Plants. Int J Mol Sci 2020; 21:ijms21082733. [PMID: 32326439 PMCID: PMC7215822 DOI: 10.3390/ijms21082733] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/09/2020] [Accepted: 04/11/2020] [Indexed: 12/24/2022] Open
Abstract
Developmental transitions in plants are tightly associated with changes in the transcriptional regulation of gene expression. One of the most important regulations is conferred by cofactors of RNA polymerase II including the mediator complex, a large complex with a modular organization. The mediator complex recruits transcription factors to bind to the specific sites of genes including protein-coding genes and non-coding RNA genes to promote or repress the transcription initiation and elongation using a protein-protein interaction module. Mediator complex subunits have been isolated and identified in plants and the function of most mediator subunits in whole life cycle plants have been revealed. Studies have shown that the Mediator complex is indispensable for the regulation of plant developmental transitions by recruiting age-, flowering-, or hormone-related transcription factors. Here, we first overviewed the Mediator subunits in plants, and then we summarized the specific Mediator subunits involved in developmental transitions, including vegetative phase change and floral transition. Finally, we proposed the future directions to further explore their roles in plants. The link between Mediator subunits and developmental transitions implies the necessity to explore targets of this complex as a potential application in developing high quality crop varieties.
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11
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Specific functions for Mediator complex subunits from different modules in the transcriptional response of Arabidopsis thaliana to abiotic stress. Sci Rep 2020; 10:5073. [PMID: 32193425 PMCID: PMC7081235 DOI: 10.1038/s41598-020-61758-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/26/2020] [Indexed: 11/22/2022] Open
Abstract
Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization.
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Wang XC, Wu J, Guan ML, Zhao CH, Geng P, Zhao Q. Arabidopsis MYB4 plays dual roles in flavonoid biosynthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:637-652. [PMID: 31626358 DOI: 10.1111/tpj.14570] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/21/2019] [Accepted: 10/08/2019] [Indexed: 05/18/2023]
Abstract
Flavonoids are major secondary metabolites derived from the plant phenylpropanoid pathway that play important roles in plant development and also have benefits for human health. So-called MBW ternary complexes involving R2R3-MYB and basic helix-loop-helix (bHLH) transcription factors along with WD-repeat proteins have been reported to regulate expression of the biosynthetic genes in the flavonoid pathway. MYB4 and its closest homolog MYB7 have been suggested to function as repressors of phenylpropanoid metabolism. However, the detailed mechanism by which they act has not been fully elucidated. Here, we show that Arabidopsis thaliana MYB4 and its homologs MYB7 and MYB32 interact with the bHLH transcription factors TT8, GL3 and EGL3 and thereby interfere with the transcriptional activity of the MBW complexes. In addition, MYB4 can also inhibit flavonoid accumulation by repressing expression of the gene encoding Arogenate Dehydratase 6 (ADT6), which catalyzes the final step in the biosynthesis of phenylalanine, the precursor for flavonoid biosynthesis. MYB4 potentially represses not only the conventional ADT6 encoding the plastidial enzyme but also the alternative isoform encoding the cytosolic enzyme. We suggest that MYB4 plays dual roles in modulating the flavonoid biosynthetic pathway in Arabidopsis.
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Affiliation(s)
- Xiao-Chen Wang
- Joint Center for Life Sciences, Tsinghua University-Peking University, Beijing, 100084, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jie Wu
- Joint Center for Life Sciences, Tsinghua University-Peking University, Beijing, 100084, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Meng-Ling Guan
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Cui-Huan Zhao
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Pan Geng
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiao Zhao
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
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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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