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Franco-Echevarría E, Nielsen M, Schulten A, Cheema J, Morgan TE, Bienz M, Dean C. Distinct accessory roles of Arabidopsis VEL proteins in Polycomb silencing. Genes Dev 2023; 37:801-817. [PMID: 37734835 PMCID: PMC7615239 DOI: 10.1101/gad.350814.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/31/2023] [Indexed: 09/23/2023]
Abstract
Polycomb repressive complex 2 (PRC2) mediates epigenetic silencing of target genes in animals and plants. In Arabidopsis, PRC2 is required for the cold-induced epigenetic silencing of the FLC floral repressor locus to align flowering with spring. During this process, PRC2 relies on VEL accessory factors, including the constitutively expressed VRN5 and the cold-induced VIN3. The VEL proteins are physically associated with PRC2, but their individual functions remain unclear. Here, we show an intimate association between recombinant VRN5 and multiple components within a reconstituted PRC2, dependent on a compact conformation of VRN5 central domains. Key residues mediating this compact conformation are conserved among VRN5 orthologs across the plant kingdom. In contrast, VIN3 interacts with VAL1, a transcriptional repressor that binds directly to FLC These associations differentially affect their role in H3K27me deposition: Both proteins are required for H3K27me3, but only VRN5 is necessary for H3K27me2. Although originally defined as vernalization regulators, VIN3 and VRN5 coassociate with many targets in the Arabidopsis genome that are modified with H3K27me3. Our work therefore reveals the distinct accessory roles for VEL proteins in conferring cold-induced silencing on FLC, with broad relevance for PRC2 targets generally.
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Affiliation(s)
- Elsa Franco-Echevarría
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Mathias Nielsen
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Anna Schulten
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Jitender Cheema
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Tomos E Morgan
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Mariann Bienz
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
| | - Caroline Dean
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
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2
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Interaction Analysis between the Arabidopsis Transcription Repressor VAL1 and Transcription Coregulators SIN3-LIKEs (SNLs). Int J Mol Sci 2022; 23:ijms23136987. [PMID: 35805982 PMCID: PMC9266683 DOI: 10.3390/ijms23136987] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 01/19/2023] Open
Abstract
VIVIPAROUS1/ABSCISIC ACID INSENSITIVE3-LIKE1 (VAL1) encodes a DNA-binding B3 domain protein and plays essential roles in seed maturation and flowering transition by repressing genes through epigenetic silencing in Arabidopsis. SWI-INDEPENDENT3 (SIN3)-LIKEs (SNLs), which encode scaffold proteins for the assembly of histone deacetylase complexes and have six SIN3 homologues (SNL1–SNL6) in Arabidopsis thaliana, directly repress gene expression to regulate seed maturation and flowering transition. However, it remains unclear whether VAL1 and SNLs work together in repressing the expression of related genes. In this study, yeast two-hybrid and firefly luciferase complementation imaging assays revealed that VAL1 interacts with SNLs, which can be attributed to its own zinc-finger CW (conserved Cys (C) and Trp (W) residues) domain and the PAH (Paired Amphipathic Helices) domains of SNLs. Furthermore, pull-down experiments confirmed that the CW domain of VAL1 interacts with both intact protein and the PAH domains of SNLs proteins, and the co-immunoprecipitation assays also confirmed the interaction between VAL1 and SNLs. In addition, quantitative real-time PCR (qRT-PCR) analysis showed that VAL1 and SNLs were expressed in seedlings, and transient expression assays showed that VAL1 and SNLs were localized in the nucleus. Considered together, these results reveal that VAL1 physically interacts with SNLs both in vitro and in vivo, and suggest that VAL1 and SNLs may work together to repress the expression of genes related to seed maturation and flowering transition in Arabidopsis.
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Joshi S, Paul P, Hartman JM, Perry SE. AGL15 Promotion of Somatic Embryogenesis: Role and Molecular Mechanism. FRONTIERS IN PLANT SCIENCE 2022; 13:861556. [PMID: 35419012 PMCID: PMC8996056 DOI: 10.3389/fpls.2022.861556] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Plants have amazing regenerative properties with single somatic cells, or groups of cells able to give rise to fully formed plants. One means of regeneration is somatic embryogenesis, by which an embryonic structure is formed that "converts" into a plantlet. Somatic embryogenesis has been used as a model for zygotic processes that are buried within layers of maternal tissues. Understanding mechanisms of somatic embryo induction and development are important as a more accessible model for seed development. We rely on seed development not only for most of our caloric intake, but also as a delivery system for engineered crops to meet agricultural challenges. Regeneration of transformed cells is needed for this applied work as well as basic research to understand gene function. Here we focus on a MADS-domain transcription factor, AGAMOUS-Like15 (AGL15) that shows a positive correlation between accumulation levels and capacity for somatic embryogenesis. We relate AGL15 function to other transcription factors, hormones, and epigenetic modifiers involved in somatic embryo development.
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Affiliation(s)
- Sanjay Joshi
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, United States
| | - Priyanka Paul
- Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, United States
| | - Jeanne M. Hartman
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, United States
| | - Sharyn E. Perry
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, United States
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Godwin J, Farrona S. The Importance of Networking: Plant Polycomb Repressive Complex 2 and Its Interactors. EPIGENOMES 2022; 6:epigenomes6010008. [PMID: 35323212 PMCID: PMC8948837 DOI: 10.3390/epigenomes6010008] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/13/2022] Open
Abstract
Polycomb Repressive Complex 2 (PRC2) is arguably the best-known plant complex of the Polycomb Group (PcG) pathway, formed by a group of proteins that epigenetically represses gene expression. PRC2-mediated deposition of H3K27me3 has amply been studied in Arabidopsis and, more recently, data from other plant model species has also been published, allowing for an increasing knowledge of PRC2 activities and target genes. How PRC2 molecular functions are regulated and how PRC2 is recruited to discrete chromatin regions are questions that have brought more attention in recent years. A mechanism to modulate PRC2-mediated activity is through its interaction with other protein partners or accessory proteins. Current evidence for PRC2 interactors has demonstrated the complexity of its protein network and how far we are from fully understanding the impact of these interactions on the activities of PRC2 core subunits and on the formation of new PRC2 versions. This review presents a list of PRC2 interactors, emphasizing their mechanistic action upon PRC2 functions and their effects on transcriptional regulation.
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5
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Yuan L, Song X, Zhang L, Yu Y, Liang Z, Lei Y, Ruan J, Tan B, Liu J, Li C. The transcriptional repressors VAL1 and VAL2 recruit PRC2 for genome-wide Polycomb silencing in Arabidopsis. Nucleic Acids Res 2021; 49:98-113. [PMID: 33270882 PMCID: PMC7797069 DOI: 10.1093/nar/gkaa1129] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 10/19/2020] [Accepted: 11/07/2020] [Indexed: 12/11/2022] Open
Abstract
The Polycomb repressive complex 2 (PRC2) catalyzes histone H3 Lys27 trimethylation (H3K27me3) to repress gene transcription in multicellular eukaryotes. Despite its importance in gene silencing and cellular differentiation, how PRC2 is recruited to target loci is still not fully understood. Here, we report genome-wide evidence for the recruitment of PRC2 by the transcriptional repressors VIVIPAROUS1/ABI3-LIKE1 (VAL1) and VAL2 in Arabidopsis thaliana. We show that the val1 val2 double mutant possesses somatic embryonic phenotypes and a transcriptome strikingly similar to those of the swn clf double mutant, which lacks the PRC2 catalytic subunits SWINGER (SWN) and CURLY LEAF (CLF). We further show that VAL1 and VAL2 physically interact with SWN and CLF in vivo. Genome-wide binding profiling demonstrated that they colocalize with SWN and CLF at PRC2 target loci. Loss of VAL1/2 significantly reduces SWN and CLF enrichment at PRC2 target loci and leads to a genome-wide redistribution of H3K27me3 that strongly affects transcription. Finally, we provide evidence that the VAL1/VAL2-RY regulatory system is largely independent of previously identified modules for Polycomb silencing in plants. Together, our work demonstrates an extensive genome-wide interaction between VAL1/2 and PRC2 and provides mechanistic insights into the establishment of Polycomb silencing in plants.
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Affiliation(s)
- Liangbing Yuan
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Xin Song
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Lu Zhang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China.,Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Yaoguang Yu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhenwei Liang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yawen Lei
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jiuxiao Ruan
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Bin Tan
- Guangdong Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou 510624, China
| | - Jun Liu
- Guangdong Provincial Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Chenlong Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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6
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Chen N, Wang H, Abdelmageed H, Veerappan V, Tadege M, Allen RD. HSI2/VAL1 and HSL1/VAL2 function redundantly to repress DOG1 expression in Arabidopsis seeds and seedlings. THE NEW PHYTOLOGIST 2020; 227:840-856. [PMID: 32201955 PMCID: PMC7383879 DOI: 10.1111/nph.16559] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/16/2020] [Indexed: 05/21/2023]
Abstract
DELAY OF GERMINATION1 (DOG1) is a primary regulator of seed dormancy. Accumulation of DOG1 in seeds leads to deep dormancy and delayed germination in Arabidopsis. B3 domain-containing transcriptional repressors HSI2/VAL1 and HSL1/VAL2 silence seed dormancy and enable the subsequent germination and seedling growth. However, the roles of HSI2 and HSL1 in regulation of DOG1 expression and seed dormancy remain elusive. Seed dormancy was analysed by measurement of maximum germination percentage of freshly harvested Arabidopsis seeds. In vivo protein-protein interaction analysis, ChIP-qPCR and EMSA were performed and suggested that HSI2 and HSL1 can form dimers to directly regulate DOG1. HSI2 and HSL1 dimers interact with RY elements at DOG1 promoter. Both B3 and PHD-like domains are required for enrichment of HSI2 and HSL1 at the DOG1 promoter. HSI2 and HSL1 recruit components of polycomb-group proteins, including CURLY LEAF (CLF) and LIKE HETERCHROMATIN PROTEIN 1 (LHP1), for consequent deposition of H3K27me3 marks, leading to repression of DOG1 expression. Our findings suggest that HSI2- and HSL1-dependent histone methylation plays critical roles in regulation of seed dormancy during seed germination and early seedling growth.
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Affiliation(s)
- Naichong Chen
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwater74078OKUSA
| | - Hui Wang
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
| | - Haggag Abdelmageed
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
- Department of Agricultural BotanyFaculty of AgricultureCairo UniversityGiza12613Egypt
| | | | - Million Tadege
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
- Department of Plant and Soil SciencesOklahoma State UniversityStillwaterOKUSA
| | - Randy D. Allen
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwater74078OKUSA
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7
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Luo X, He Y. Experiencing winter for spring flowering: A molecular epigenetic perspective on vernalization. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:104-117. [PMID: 31829495 DOI: 10.1111/jipb.12896] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 12/10/2019] [Indexed: 05/17/2023]
Abstract
Many over-wintering plants, through vernalization, overcome a block to flowering and thus acquire competence to flower in the following spring after experiencing prolonged cold exposure or winter cold. The vernalization pathways in different angiosperm lineages appear to have convergently evolved to adapt to temperate climates. Molecular and epigenetic mechanisms for vernalization regulation have been well studied in the crucifer model plant Arabidopsis thaliana. Here, we review recent progresses on the vernalization pathway in Arabidopsis. In addition, we summarize current molecular and genetic understandings of vernalization regulation in temperate grasses including wheat and Brachypodium, two monocots from Pooideae, followed by a brief discussion on divergence of the vernalization pathways between Brassicaceae and Pooideae.
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Affiliation(s)
- Xiao Luo
- National Key Laboratory of Plant Molecular Genetics & Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
| | - Yuehui He
- National Key Laboratory of Plant Molecular Genetics & Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
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8
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Lin CT, Xu T, Xing SL, Zhao L, Sun RZ, Liu Y, Moore JP, Deng X. Weighted Gene Co-expression Network Analysis (WGCNA) Reveals the Hub Role of Protein Ubiquitination in the Acquisition of Desiccation Tolerance in Boea hygrometrica. PLANT & CELL PHYSIOLOGY 2019; 60:2707-2719. [PMID: 31410481 DOI: 10.1093/pcp/pcz160] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 08/06/2019] [Indexed: 05/28/2023]
Abstract
Boea hygrometrica can survive extreme drought conditions and has been used as a model to study desiccation tolerance. A genome-wide transcriptome analysis of B. hygrometrica showed that the plant can survive rapid air-drying after experiencing a slow soil-drying acclimation phase. In addition, a weighted gene co-expression network analysis was used to study the transcriptomic datasets. A network comprising 22 modules was constructed, and seven modules were found to be significantly related to desiccation response using an enrichment analysis. Protein ubiquitination was observed to be a common process linked to hub genes in all the seven modules. Ubiquitin-modified proteins with diversified functions were identified using immunoprecipitation coupled with mass spectrometry. The lowest level of ubiquitination was noted at the full soil drying priming stage, which coincided the accumulation of dehydration-responsive gene BhLEA2. The highly conserved RY motif (CATGCA) was identified from the promoters of ubiquitin-related genes that were downregulated in the desiccated samples. An in silico gene expression analysis showed that the negative regulation of ubiquitin-related genes is potentially mediated via a B3 domain-containing transcription repressor VAL1. This study suggests that priming may involve the transcriptional regulation of several major processes, and the transcriptional regulation of genes in protein ubiquitination may play a hub role to deliver acclimation signals to posttranslational level in the acquisition of desiccation tolerance in B. hygrometrica.
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Affiliation(s)
- Chih-Ta Lin
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Tao Xu
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Shi-Lai Xing
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Li Zhao
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Run-Ze Sun
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Yang Liu
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - John Paul Moore
- Department of Viticulture and Oenology, Institute for Wine Biotechnology, Stellenbosch University, Matieland 7602, South Africa
| | - Xin Deng
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
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9
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Wang L, Ruan C, Liu L, Du W, Bao A. Comparative RNA-Seq Analysis of High- and Low-Oil Yellow Horn During Embryonic Development. Int J Mol Sci 2018; 19:ijms19103071. [PMID: 30297676 PMCID: PMC6212864 DOI: 10.3390/ijms19103071] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/01/2018] [Accepted: 10/03/2018] [Indexed: 11/16/2022] Open
Abstract
Yellow horn (Xanthoceras sorbifolium Bunge) is an endemic oil-rich shrub that has been widely cultivated in northern China for bioactive oil production. However, little is known regarding the molecular mechanisms that contribute to oil content in yellow horn. Herein, we measured the oil contents of high- and low-oil yellow horn embryo tissues at four developmental stages and investigated the global gene expression profiles through RNA-seq. The results found that at 40, 54, 68, and 81 days after anthesis, a total of 762, 664, 599, and 124 genes, respectively, were significantly differentially expressed between the high- and low-oil lines. Gene ontology (GO) enrichment analysis revealed some critical GO terms related to oil accumulation, including acyl-[acyl-carrier-protein] desaturase activity, pyruvate kinase activity, acetyl-CoA carboxylase activity, and seed oil body biogenesis. The identified differentially expressed genes also included several transcription factors, such as, AP2-EREBP family members, B3 domain proteins and C2C2-Dof proteins. Several genes involved in fatty acid (FA) biosynthesis, glycolysis/gluconeogenesis, and pyruvate metabolism were also up-regulated in the high-oil line at different developmental stages. Our findings indicate that the higher oil accumulation in high-oil yellow horn could be mostly driven by increased FA biosynthesis and carbon supply, i.e. a source effect.
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Affiliation(s)
- Li Wang
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Institute of Plant Resources, Dalian Minzu University, Dalian 116600, China.
| | - Chengjiang Ruan
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Institute of Plant Resources, Dalian Minzu University, Dalian 116600, China.
| | - Lingyue Liu
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Institute of Plant Resources, Dalian Minzu University, Dalian 116600, China.
| | - Wei Du
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Institute of Plant Resources, Dalian Minzu University, Dalian 116600, China.
| | - Aomin Bao
- Institute of economic forest, Tongliao Academy of Forestry Science and Technology, Tongliao 028000, China.
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10
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Lepiniec L, Devic M, Roscoe TJ, Bouyer D, Zhou DX, Boulard C, Baud S, Dubreucq B. Molecular and epigenetic regulations and functions of the LAFL transcriptional regulators that control seed development. PLANT REPRODUCTION 2018; 31:291-307. [PMID: 29797091 DOI: 10.1007/s00497-018-0337-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 05/10/2018] [Indexed: 05/20/2023]
Abstract
The LAFL (i.e. LEC1, ABI3, FUS3, and LEC2) master transcriptional regulators interact to form different complexes that induce embryo development and maturation, and inhibit seed germination and vegetative growth in Arabidopsis. Orthologous genes involved in similar regulatory processes have been described in various angiosperms including important crop species. Consistent with a prominent role of the LAFL regulators in triggering and maintaining embryonic cell fate, their expression appears finely tuned in different tissues during seed development and tightly repressed in vegetative tissues by a surprisingly high number of genetic and epigenetic factors. Partial functional redundancies and intricate feedback regulations of the LAFL have hampered the elucidation of the underpinning molecular mechanisms. Nevertheless, genetic, genomic, cellular, molecular, and biochemical analyses implemented during the last years have greatly improved our knowledge of the LALF network. Here we summarize and discuss recent progress, together with current issues required to gain a comprehensive insight into the network, including the emerging function of LEC1 and possibly LEC2 as pioneer transcription factors.
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Affiliation(s)
- L Lepiniec
- IJPB (Institut Jean-Pierre Bourgin), INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France.
| | - M Devic
- Régulations Epigénétiques et Développement de la Graine, ERL 5300 CNRS-IRD UMR DIADE, IRD centre de Montpellier, 911 Avenue Agropolis, BP 64501, 34394, Montpellier, France
- Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS UMR 7621, 66650, Banyuls-sur-Mer, France
| | - T J Roscoe
- Régulations Epigénétiques et Développement de la Graine, ERL 5300 CNRS-IRD UMR DIADE, IRD centre de Montpellier, 911 Avenue Agropolis, BP 64501, 34394, Montpellier, France
- Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS UMR 7621, 66650, Banyuls-sur-Mer, France
| | - D Bouyer
- Institut de Biologie de l'ENS, CNRS UMR8197, Ecole Normale Supérieure, 46 rue d'Ulm, 75230, Paris Cedex 05, France
| | - D-X Zhou
- Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris Sud 11, Université Paris-Saclay, 91405, Orsay, France
| | - C Boulard
- IJPB (Institut Jean-Pierre Bourgin), INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
| | - S Baud
- IJPB (Institut Jean-Pierre Bourgin), INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
| | - B Dubreucq
- IJPB (Institut Jean-Pierre Bourgin), INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
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11
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Vachon G, Engelhorn J, Carles CC. Interactions between transcription factors and chromatin regulators in the control of flower development. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2461-2471. [PMID: 29506187 DOI: 10.1093/jxb/ery079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/22/2018] [Indexed: 06/08/2023]
Abstract
Chromatin modifiers and remodelers are involved in generating dynamic changes at the chromatin, which allow differential and specific readouts of the genome. While genetic evidence indicates that several chromatin factors play a key role in controlling basic developmental programs for inflorescence and flower morphogenesis, it remained unknown until recently how they exert their specificity toward gene expression, both temporally and spatially. An emerging topic is the recruitment or eviction of chromatin factors through the activity of sequence-specific DNA-binding domains, present in the chromatin factors themselves or in partnering transcription factors. Here we summarize recent progress that has been made in this regard in the model plant Arabidopsis thaliana. We further outline the different possible modes through which chromatin complexes specifically target genes involved in flower development.
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Affiliation(s)
- Gilles Vachon
- LPCV, CNRS, CEA, INRA, Université Grenoble Alpes, BIG, Grenoble, France
| | - Julia Engelhorn
- LPCV, CNRS, CEA, INRA, Université Grenoble Alpes, BIG, Grenoble, France
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12
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Chen N, Veerappan V, Abdelmageed H, Kang M, Allen RD. HSI2/VAL1 Silences AGL15 to Regulate the Developmental Transition from Seed Maturation to Vegetative Growth in Arabidopsis. THE PLANT CELL 2018; 30:600-619. [PMID: 29475938 PMCID: PMC5894832 DOI: 10.1105/tpc.17.00655] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/30/2018] [Accepted: 02/20/2018] [Indexed: 05/18/2023]
Abstract
Gene expression during seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from seed maturation to germination and seedling growth requires the transcriptional silencing of these seed maturation-specific factors leading to downregulation of structural genes including those that encode seed storage proteins, oleosins, and dehydrins. During seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major seed maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the seed maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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Affiliation(s)
- Naichong Chen
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74074
| | - Vijaykumar Veerappan
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401
- Department of Biology, Eastern Connecticut State University, Willimantic, Connecticut 06226
| | - Haggag Abdelmageed
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401
- Department of Agricultural Botany, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
| | - Miyoung Kang
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74074
| | - Randy D Allen
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74074
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13
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Carbonero P, Iglesias-Fernández R, Vicente-Carbajosa J. The AFL subfamily of B3 transcription factors: evolution and function in angiosperm seeds. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:871-880. [PMID: 28007955 DOI: 10.1093/jxb/erw458] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Seed development follows zygotic embryogenesis; during the maturation phase reserves accumulate and desiccation tolerance is acquired. This is tightly regulated at the transcriptional level and the AFL (ABI3/FUS3/LEC2) subfamily of B3 transcription factors (TFs) play a central role. They alter hormone biosynthesis, mainly in regards to abscisic acid and gibberellins, and also regulate the expression of other TFs and/or modulate their downstream activity via protein-protein interactions. This review deals with the origin of AFL TFs, which can be traced back to non-vascular plants such as Physcomitrella patens and achieves foremost expansion in the angiosperms. In green algae, like the unicellular Chlamydomonas reinhardtii or the pluricellular Klebsormidium flaccidum, a single B3 gene and four B3 paralogous genes are annotated, respectively. However, none of them present with the structural features of the AFL subfamily, with the exception of the B3 DNA-binding domain. Phylogenetic analysis groups the AFL TFs into four Major Clusters of Ortologous Genes (MCOGs). The origin and function of these genes is discussed in view of their expression patterns and in the context of major regulatory interactions in seeds of monocotyledonous and dicotyledonous species.
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Affiliation(s)
- Pilar Carbonero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, 28223-Madrid, Spain
| | - Raquel Iglesias-Fernández
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, 28223-Madrid, Spain
| | - Jesús Vicente-Carbajosa
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, 28223-Madrid, Spain
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14
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Yuan W, Luo X, Li Z, Yang W, Wang Y, Liu R, Du J, He Y. A cis cold memory element and a trans epigenome reader mediate Polycomb silencing of FLC by vernalization in Arabidopsis. Nat Genet 2016; 48:1527-1534. [DOI: 10.1038/ng.3712] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/07/2016] [Indexed: 12/16/2022]
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15
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Manan S, Chen B, She G, Wan X, Zhao J. Transport and transcriptional regulation of oil production in plants. Crit Rev Biotechnol 2016; 37:641-655. [DOI: 10.1080/07388551.2016.1212185] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sehrish Manan
- National Key Laboratory for Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Beibei Chen
- National Key Laboratory for Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Guangbiao She
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Jian Zhao
- National Key Laboratory for Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
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16
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Chhun T, Chong SY, Park BS, Wong ECC, Yin JL, Kim M, Chua NH. HSI2 Repressor Recruits MED13 and HDA6 to Down-Regulate Seed Maturation Gene Expression Directly During Arabidopsis Early Seedling Growth. PLANT & CELL PHYSIOLOGY 2016; 57:1689-706. [PMID: 27335347 DOI: 10.1093/pcp/pcw095] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/01/2016] [Indexed: 05/25/2023]
Abstract
Arabidopsis HSI2 (HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE 2) which carries a EAR (ERF-associated amphiphilic repression) motif acts as a repressor of seed maturation genes and lipid biosynthesis, whereas MEDIATOR (MED) is a conserved multiprotein complex linking DNA-bound transcription factors to RNA polymerase II transcription machinery. How HSI2 executes its repressive function through MED is hitherto unknown. Here, we show that HSI2 and its homolog, HSI2-lik (HSL1), are able to form homo- and heterocomplexes. Both factors bind to the TRAP240 domain of MED13, a subunit of the MED CDK8 module. Mutant alleles of the med13 mutant show elevated seed maturation gene expression and increased lipid accumulation in cotyledons; in contrast, HSI2- or MED13-overexpressing plants display the opposite phenotypes. The overexpression phenotypes of HSI2 and MED13 are abolished in med13 and hsi2 hsl1, respectively, indicating that HSI2 and MED13 together are required for these functions. The HSI2 C-terminal region interacts with HDA6, whose overexpression also reduces seed maturation gene expression and lipid accumulation. Moreover, HSI2, MED13 and HDA6 bind to the proximal promoter and 5'-coding regions of seed maturation genes. Taken together, our results suggest that HSI2 recruits MED13 and HDA6 to suppress directly a subset of seed maturation genes post-germination.
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Affiliation(s)
- Tory Chhun
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Suet Yen Chong
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Bong Soo Park
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Eriko Chi Cheng Wong
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Jun-Lin Yin
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Mijung Kim
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
| | - Nam-Hai Chua
- Laboratory of Plant Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065-6399, USA
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17
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Schneider A, Aghamirzaie D, Elmarakeby H, Poudel AN, Koo AJ, Heath LS, Grene R, Collakova E. Potential targets of VIVIPAROUS1/ABI3-LIKE1 (VAL1) repression in developing Arabidopsis thaliana embryos. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:305-19. [PMID: 26678037 DOI: 10.1111/tpj.13106] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/28/2015] [Accepted: 12/01/2015] [Indexed: 05/06/2023]
Abstract
Developing Arabidopsis seeds accumulate oils and seed storage proteins synthesized by the pathways of primary metabolism. Seed development and metabolism are positively regulated by transcription factors belonging to the LAFL (LEC1, AB13, FUSCA3 and LEC2) regulatory network. The VAL gene family encodes repressors of the seed maturation program in germinating seeds, although they are also expressed during seed maturation. The possible regulatory role of VAL1 in seed development has not been studied to date. Reverse genetics revealed that val1 mutant seeds accumulated elevated levels of proteins compared with the wild type, suggesting that VAL1 functions as a repressor of seed metabolism; however, in the absence of VAL1, the levels of metabolites, ABA, auxin and jasmonate derivatives did not change significantly in developing embryos. Two VAL1 splice variants were identified through RNA sequencing analysis: a full-length form and a truncated form lacking the plant homeodomain-like domain associated with epigenetic repression. None of the transcripts encoding the core LAFL network transcription factors were affected in val1 embryos. Instead, activation of VAL1 by FUSCA3 appears to result in the repression of a subset of seed maturation genes downstream of core LAFL regulators, as 39% of transcripts in the FUSCA3 regulon were derepressed in the val1 mutant. The LEC1 and LEC2 regulons also responded, but to a lesser extent. Additional 832 transcripts that were not LAFL targets were derepressed in val1 mutant embryos. These transcripts are candidate targets of VAL1, acting through epigenetic and/or transcriptional repression.
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Affiliation(s)
- Andrew Schneider
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Delasa Aghamirzaie
- Genetics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Haitham Elmarakeby
- Department of Computer Science, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Arati N Poudel
- Division of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Abraham J Koo
- Division of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Lenwood S Heath
- Department of Computer Science, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Ruth Grene
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Eva Collakova
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, 24061, USA
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