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Manosalva Pérez N, Ferrari C, Engelhorn J, Depuydt T, Nelissen H, Hartwig T, Vandepoele K. MINI-AC: inference of plant gene regulatory networks using bulk or single-cell accessible chromatin profiles. Plant J 2024; 117:280-301. [PMID: 37788349 DOI: 10.1111/tpj.16483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/13/2023] [Accepted: 09/16/2023] [Indexed: 10/05/2023]
Abstract
Gene regulatory networks (GRNs) represent the interactions between transcription factors (TF) and their target genes. Plant GRNs control transcriptional programs involved in growth, development, and stress responses, ultimately affecting diverse agricultural traits. While recent developments in accessible chromatin (AC) profiling technologies make it possible to identify context-specific regulatory DNA, learning the underlying GRNs remains a major challenge. We developed MINI-AC (Motif-Informed Network Inference based on Accessible Chromatin), a method that combines AC data from bulk or single-cell experiments with TF binding site (TFBS) information to learn GRNs in plants. We benchmarked MINI-AC using bulk AC datasets from different Arabidopsis thaliana tissues and showed that it outperforms other methods to identify correct TFBS. In maize, a crop with a complex genome and abundant distal AC regions, MINI-AC successfully inferred leaf GRNs with experimentally confirmed, both proximal and distal, TF-target gene interactions. Furthermore, we showed that both AC regions and footprints are valid alternatives to infer AC-based GRNs with MINI-AC. Finally, we combined MINI-AC predictions from bulk and single-cell AC datasets to identify general and cell-type specific maize leaf regulators. Focusing on C4 metabolism, we identified diverse regulatory interactions in specialized cell types for this photosynthetic pathway. MINI-AC represents a powerful tool for inferring accurate AC-derived GRNs in plants and identifying known and novel candidate regulators, improving our understanding of gene regulation in plants.
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Affiliation(s)
- Nicolás Manosalva Pérez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium
| | - Camilla Ferrari
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium
| | - Julia Engelhorn
- Molecular Physiology Department, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
| | - Thomas Depuydt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium
| | - Hilde Nelissen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium
| | - Thomas Hartwig
- Molecular Physiology Department, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
- Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Klaas Vandepoele
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, 9052, Ghent, Belgium
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Hartwig T, Banf M, Prietsch GP, Zhu JY, Mora-Ramírez I, Schippers JHM, Snodgrass SJ, Seetharam AS, Huettel B, Kolkman JM, Yang J, Engelhorn J, Wang ZY. Hybrid allele-specific ChIP-seq analysis identifies variation in brassinosteroid-responsive transcription factor binding linked to traits in maize. Genome Biol 2023; 24:108. [PMID: 37158941 PMCID: PMC10165856 DOI: 10.1186/s13059-023-02909-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 03/23/2023] [Indexed: 05/10/2023] Open
Abstract
BACKGROUND Genetic variation in regulatory sequences that alter transcription factor (TF) binding is a major cause of phenotypic diversity. Brassinosteroid is a growth hormone that has major effects on plant phenotypes. Genetic variation in brassinosteroid-responsive cis-elements likely contributes to trait variation. Pinpointing such regulatory variations and quantitative genomic analysis of the variation in TF-target binding, however, remains challenging. How variation in transcriptional targets of signaling pathways such as the brassinosteroid pathway contributes to phenotypic variation is an important question to be investigated with innovative approaches. RESULTS Here, we use a hybrid allele-specific chromatin binding sequencing (HASCh-seq) approach and identify variations in target binding of the brassinosteroid-responsive TF ZmBZR1 in maize. HASCh-seq in the B73xMo17 F1s identifies thousands of target genes of ZmBZR1. Allele-specific ZmBZR1 binding (ASB) has been observed for 18.3% of target genes and is enriched in promoter and enhancer regions. About a quarter of the ASB sites correlate with sequence variation in BZR1-binding motifs and another quarter correlate with haplotype-specific DNA methylation, suggesting that both genetic and epigenetic variations contribute to the high level of variation in ZmBZR1 occupancy. Comparison with GWAS data shows linkage of hundreds of ASB loci to important yield and disease-related traits. CONCLUSION Our study provides a robust method for analyzing genome-wide variations of TF occupancy and identifies genetic and epigenetic variations of the brassinosteroid response transcription network in maize.
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Affiliation(s)
- Thomas Hartwig
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA.
- Heinrich-Heine University, Universitätsstraße 1, Düsseldorf, NRW, 40225, Germany.
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, NRW, 50829, Germany.
| | - Michael Banf
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Gisele Passaia Prietsch
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Jia-Ying Zhu
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, Seeland, SA, 06466, Germany
| | - Isabel Mora-Ramírez
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, Seeland, SA, 06466, Germany
| | - Jos H M Schippers
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, Seeland, SA, 06466, Germany
| | - Samantha J Snodgrass
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 339A Bessey Hall, Ames, IA, 50011, USA
| | - Arun S Seetharam
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 339A Bessey Hall, Ames, IA, 50011, USA
| | - Bruno Huettel
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, NRW, 50829, Germany
| | - Judith M Kolkman
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, 413 Bradfield Hall, Ithaca, NY, 14853, USA
| | - Jinliang Yang
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, 363 Keim Hall, Lincoln, NE, 68583, USA
| | - Julia Engelhorn
- Heinrich-Heine University, Universitätsstraße 1, Düsseldorf, NRW, 40225, Germany
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, NRW, 50829, Germany
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA.
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Myers ZA, Wootan CM, Liang Z, Zhou P, Engelhorn J, Hartwig T, Nathan SM. Conserved and variable heat stress responses of the Heat Shock Factor transcription factor family in maize and Setaria viridis. Plant Direct 2023; 7:e489. [PMID: 37124872 PMCID: PMC10133983 DOI: 10.1002/pld3.489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 01/31/2023] [Accepted: 02/24/2023] [Indexed: 05/03/2023]
Abstract
The Heat Shock Factor (HSF) transcription factor family is a central and required component of plant heat stress responses and acquired thermotolerance. The HSF family has dramatically expanded in plant lineages, often including a repertoire of 20 or more genes. Here we assess and compare the composition, heat responsiveness, and chromatin profiles of the HSF families in maize and Setaria viridis (Setaria), two model C4 panicoid grasses. Both species encode a similar number of HSFs, and examples of both conserved and variable expression responses to a heat stress event were observed between the two species. Chromatin accessibility and genome-wide DNA-binding profiles were generated to assess the chromatin of HSF family members with distinct responses to heat stress. We observed significant variability for both chromatin accessibility and promoter occupancy within similarly regulated sets of HSFs between Setaria and maize, as well as between syntenic pairs of maize HSFs retained following its most recent genome duplication event. Additionally, we observed the widespread presence of TF binding at HSF promoters in control conditions, even at HSFs that are only expressed in response to heat stress. TF-binding peaks were typically near putative HSF-binding sites in HSFs upregulated in response to heat stress, but not in stable or not expressed HSFs. These observations collectively support a complex scenario of expansion and subfunctionalization within this transcription factor family and suggest that within-family HSF transcriptional regulation is a conserved, defining feature of the family.
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Affiliation(s)
- Zachary A. Myers
- Department of Plant and Microbial BiologyUniversity of MinnesotaMinneapolisMNUSA
| | - Clair M. Wootan
- Department of Plant and Microbial BiologyUniversity of MinnesotaMinneapolisMNUSA
| | - Zhikai Liang
- Department of Plant and Microbial BiologyUniversity of MinnesotaMinneapolisMNUSA
| | - Peng Zhou
- Chinese Academy of Agricultural SciencesInstitute of Crop SciencesBeijingChina
| | - Julia Engelhorn
- Heinrich‐Heine UniversityDüsseldorfGermany
- Max Planck Institute for Plant Breeding ResearchCologneGermany
| | - Thomas Hartwig
- Heinrich‐Heine UniversityDüsseldorfGermany
- Max Planck Institute for Plant Breeding ResearchCologneGermany
| | - Springer M. Nathan
- Department of Plant and Microbial BiologyUniversity of MinnesotaMinneapolisMNUSA
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Liang Z, Myers ZA, Petrella D, Engelhorn J, Hartwig T, Springer NM. Mapping responsive genomic elements to heat stress in a maize diversity panel. Genome Biol 2022; 23:234. [PMID: 36345007 PMCID: PMC9639295 DOI: 10.1186/s13059-022-02807-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/29/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Many plant species exhibit genetic variation for coping with environmental stress. However, there are still limited approaches to effectively uncover the genomic region that regulates distinct responsive patterns of the gene across multiple varieties within the same species under abiotic stress. RESULTS By analyzing the transcriptomes of more than 100 maize inbreds, we reveal many cis- and trans-acting eQTLs that influence the expression response to heat stress. The cis-acting eQTLs in response to heat stress are identified in genes with differential responses to heat stress between genotypes as well as genes that are only expressed under heat stress. The cis-acting variants for heat stress-responsive expression likely result from distinct promoter activities, and the differential heat responses of the alleles are confirmed for selected genes using transient expression assays. Global footprinting of transcription factor binding is performed in control and heat stress conditions to document regions with heat-enriched transcription factor binding occupancies. CONCLUSIONS Footprints enriched near proximal regions of characterized heat-responsive genes in a large association panel can be utilized for prioritizing functional genomic regions that regulate genotype-specific responses under heat stress.
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Affiliation(s)
- Zhikai Liang
- grid.17635.360000000419368657Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108 USA
| | - Zachary A. Myers
- grid.17635.360000000419368657Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108 USA
| | - Dominic Petrella
- grid.17635.360000000419368657Department of Horticulture, University of Minnesota, Saint Paul, MN 55108 USA ,grid.261331.40000 0001 2285 7943Present address: Agricultural Technical Institute, The Ohio State University, Wooster, OH 44691 USA
| | - Julia Engelhorn
- grid.419498.90000 0001 0660 6765Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany ,grid.411327.20000 0001 2176 9917Heinrich-Heine University, 40225 Dusseldorf, Germany
| | - Thomas Hartwig
- grid.419498.90000 0001 0660 6765Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany ,grid.411327.20000 0001 2176 9917Heinrich-Heine University, 40225 Dusseldorf, Germany
| | - Nathan M. Springer
- grid.17635.360000000419368657Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108 USA
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Comelli P, Glowa D, Frerichs A, Engelhorn J, Chandler JW, Werr W. Functional dissection of the DORNRÖSCHEN-LIKE enhancer 2 during embryonic and phyllotactic patterning. Planta 2020; 251:90. [PMID: 32236749 DOI: 10.1007/s00425-020-03381-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
The Arabidopsis DORNRÖSCHEN-LIKE enhancer 2 comprises a high-occupancy target region in the IM periphery that integrates signals for the spiral phyllotactic pattern and cruciferous arrangement of sepals. Transcription of the DORNRÖSCHEN-LIKE (DRNL) gene marks lateral organ founder cells (LOFCs) in the peripheral zone of the inflorescence meristem (IM) and enhancer 2 (En2) in the DRNL promoter upstream region essentially contributes to this phyllotactic transcription pattern. Further analysis focused on the phylogenetically highly conserved 100-bp En2core element, which was sufficient to promote the phyllotactic pattern, but was recalcitrant to further shortening. Here, we show that En2core functions independent of orientation and create a series of mutations to study consequences on the transcription pattern. Their analysis shows that, first, in addition to in the inflorescence apex, En2core acts in the embryo; second, cis-regulatory target sequences are distributed throughout the 100-bp element, although substantial differences exist in their function between embryo and IM. Third, putative core auxin response elements (AuxREs) spatially activate or restrict DRNL expression, and fourth, according to chromatin configuration data, En2core enhancer activity in LOFCs correlates with an open chromatin structure at the DRNL transcription start. In combination, mutational and chromatin analyses imply that En2core comprises a high-occupancy target (HOT) region for transcription factors, which implements phyllotactic information for the spiral LOFC pattern in the IM periphery and coordinates the cruciferous array of floral sepals. Our data disfavor a contribution of activating auxin response factors (ARFs) but do not exclude auxin as a morphogenetic signal.
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Affiliation(s)
- Petra Comelli
- Developmental Biology, Biocenter, University of Cologne, Zülpicher Str 47b, 50674, Cologne, Germany
| | - Dorothea Glowa
- Developmental Biology, Biocenter, University of Cologne, Zülpicher Str 47b, 50674, Cologne, Germany
| | - Anneke Frerichs
- Developmental Biology, Biocenter, University of Cologne, Zülpicher Str 47b, 50674, Cologne, Germany
| | - Julia Engelhorn
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
- Institute for Molecular Physiology, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - John W Chandler
- Developmental Biology, Biocenter, University of Cologne, Zülpicher Str 47b, 50674, Cologne, Germany
| | - Wolfgang Werr
- Developmental Biology, Biocenter, University of Cologne, Zülpicher Str 47b, 50674, Cologne, Germany.
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Frerichs A, Engelhorn J, Altmüller J, Gutierrez-Marcos J, Werr W. Specific chromatin changes mark lateral organ founder cells in the Arabidopsis inflorescence meristem. J Exp Bot 2019; 70:3867-3879. [PMID: 31037302 PMCID: PMC6685650 DOI: 10.1093/jxb/erz181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/18/2019] [Indexed: 05/20/2023]
Abstract
Fluorescence-activated cell sorting (FACS) and assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) were combined to analyse the chromatin state of lateral organ founder cells (LOFCs) in the peripheral zone of the Arabidopsis apetala1-1 cauliflower-1 double mutant inflorescence meristem. On a genome-wide level, we observed a striking correlation between transposase hypersensitive sites (THSs) detected by ATAC-seq and DNase I hypersensitive sites (DHSs). The mostly expanded DHSs were often substructured into several individual THSs, which correlated with phylogenetically conserved DNA sequences or enhancer elements. Comparing chromatin accessibility with available RNA-seq data, THS change configuration was reflected by gene activation or repression and chromatin regions acquired or lost transposase accessibility in direct correlation with gene expression levels in LOFCs. This was most pronounced immediately upstream of the transcription start, where genome-wide THSs were abundant in a complementary pattern to established H3K4me3 activation or H3K27me3 repression marks. At this resolution, the combined application of FACS/ATAC-seq is widely applicable to detect chromatin changes during cell-type specification and facilitates the detection of regulatory elements in plant promoters.
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Affiliation(s)
- Anneke Frerichs
- Developmental Biology, Department of Biology, Biocenter, University of Cologne, Cologne, Germany
| | - Julia Engelhorn
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg, Cologne, Germany
- Institute for Molecular Physiology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, Weyertal Cologne, Germany
| | | | - Wolfgang Werr
- Developmental Biology, Department of Biology, Biocenter, University of Cologne, Cologne, Germany
- Correspondence:
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Frerichs A, Engelhorn J, Altmüller J, Gutierrez-Marcos J, Werr W. Corrigendum to: Specific chromatin changes mark lateral organ founder cells in the Arabidopsis inflorescence meristem. J Exp Bot 2019; 70:4065-4066. [PMID: 31251340 PMCID: PMC6685654 DOI: 10.1093/jxb/erz277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Anneke Frerichs
- Developmental Biology, Department of Biology, Biocenter, University of Cologne, Cologne, Germany
| | - Julia Engelhorn
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Institute for Molecular Physiology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, Weyertal, Germany
| | | | - Wolfgang Werr
- Developmental Biology, Department of Biology, Biocenter, University of Cologne, Cologne, Germany
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Yan W, Chen D, Schumacher J, Durantini D, Engelhorn J, Chen M, Carles CC, Kaufmann K. Dynamic control of enhancer activity drives stage-specific gene expression during flower morphogenesis. Nat Commun 2019; 10:1705. [PMID: 30979870 PMCID: PMC6461659 DOI: 10.1038/s41467-019-09513-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 03/13/2019] [Indexed: 12/20/2022] Open
Abstract
Enhancers are critical for developmental stage-specific gene expression, but their dynamic regulation in plants remains poorly understood. Here we compare genome-wide localization of H3K27ac, chromatin accessibility and transcriptomic changes during flower development in Arabidopsis. H3K27ac prevalently marks promoter-proximal regions, suggesting that H3K27ac is not a hallmark for enhancers in Arabidopsis. We provide computational and experimental evidence to confirm that distal DNase І hypersensitive sites are predictive of enhancers. The predicted enhancers are highly stage-specific across flower development, significantly associated with SNPs for flowering-related phenotypes, and conserved across crucifer species. Through the integration of genome-wide transcription factor (TF) binding datasets, we find that floral master regulators and stage-specific TFs are largely enriched at developmentally dynamic enhancers. Finally, we show that enhancer clusters and intronic enhancers significantly associate with stage-specific gene regulation by floral master TFs. Our study provides insights into the functional flexibility of enhancers during plant development, as well as hints to annotate plant enhancers. Enhancer elements can control spatial and temporal patterns of gene expression. Here the authors profile chromatin accessibility, histone modifications and gene expression during Arabidopsis flower development providing evidence for sets of distal enhancers acting in a highly stage-specific manner.
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Affiliation(s)
- Wenhao Yan
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Dijun Chen
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany. .,Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany.
| | - Julia Schumacher
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.,Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Diego Durantini
- Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany.,Ernst Benary Samenzucht GmbH, Friedrich-Benary-Weg, 134346, Hann, Muenden, Germany
| | - Julia Engelhorn
- Université Grenoble Alpes (UGA), CNRS, CEA, INRA, IRIG-LPCV, 38000 Grenoble, France, 38000, Grenoble, France.,Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany/Institute for Molecular Physiology, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Cristel C Carles
- Université Grenoble Alpes (UGA), CNRS, CEA, INRA, IRIG-LPCV, 38000 Grenoble, France, 38000, Grenoble, France
| | - Kerstin Kaufmann
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
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Yan W, Chen D, Smaczniak C, Engelhorn J, Liu H, Yang W, Graf A, Carles CC, Zhou DX, Kaufmann K. Dynamic and spatial restriction of Polycomb activity by plant histone demethylases. Nat Plants 2018; 4:681-689. [PMID: 30104650 DOI: 10.1038/s41477-018-0219-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 07/12/2018] [Indexed: 05/23/2023]
Abstract
Targeted changes in chromatin state at thousands of genes are central to eukaryotic development. RELATIVE OF EARLY FLOWERING 6 (REF6) is a Jumonji-type histone demethylase that counteracts Polycomb repressive complex 2 (PRC2)-mediated gene silencing in plants and was reported to select its binding sites in a direct, sequence-specific manner1-3. Here we show that REF6 and its two close paralogues determine spatial 'boundaries' of the repressive histone H3K27me3 mark in the genome and control the tissue-specific release from PRC2-mediated gene repression. Targeted mutagenesis revealed that these histone demethylases display pleiotropic, redundant functions in plant development, several of which depend on trans factor-mediated recruitment. Thus, Jumonji-type histone demethylases restrict repressive chromatin domains and contribute to tissue-specific gene activation via complementary targeting mechanisms.
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Affiliation(s)
- Wenhao Yan
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Dijun Chen
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Cezary Smaczniak
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Julia Engelhorn
- LPCV, CNRS, CEA, INRA, Université Grenoble Alpes, Grenoble, France
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Haiyang Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Wenjing Yang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Alexander Graf
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - Cristel C Carles
- LPCV, CNRS, CEA, INRA, Université Grenoble Alpes, Grenoble, France
| | - Dao-Xiu Zhou
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- Institute Plant Science Paris-Saclay (IPS2), CNRS, INRA, Université Paris-sud 11, Université Paris-Saclay, Orsay, France
| | - Kerstin Kaufmann
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany.
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10
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Vachon G, Engelhorn J, Carles CC. Interactions between transcription factors and chromatin regulators in the control of flower development. J Exp Bot 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Engelhorn J, Wellmer F, Carles CC. Profiling Histone Modifications in Synchronized Floral Tissues for Quantitative Resolution of Chromatin and Transcriptome Dynamics. Methods Mol Biol 2018; 1675:271-296. [PMID: 29052197 DOI: 10.1007/978-1-4939-7318-7_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Covalent histone modifications and their effects on chromatin state and accessibility play a key role in the regulation of gene expression in eukaryotes. To gain insights into their functions during plant growth and development, the distribution of histone modifications can be analyzed at a genome-wide scale through chromatin immunoprecipitation assays followed by sequencing of the isolated genomic DNA. Here, we present a protocol for systematic analysis of the distribution and dynamic changes of selected histone modifications, during flower development in the model plant Arabidopsis thaliana. This protocol utilizes a previously established floral induction system to synchronize flower development, which allows the collection of sufficient plant material for analysis by genomic technologies. In this chapter, we describe how to use this system to study, from the same set of samples, chromatin and transcriptome dynamics during early stages of flower formation.
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Affiliation(s)
- Julia Engelhorn
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France
- School of Life Science, University of Warwick, Coventry, CV4 7AL, UK
| | - Frank Wellmer
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Cristel C Carles
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France.
- Laboratoire Physiologie Cellulaire Végétale, BIG, CEA, 17 rue des Martyrs, bât. C2 - Bureau 227B, 38054, GRENOBLE Cedex 9, France.
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Engelhorn J, Moreau F, Fletcher JC, Carles CC. ULTRAPETALA1 and LEAFY pathways function independently in specifying identity and determinacy at the Arabidopsis floral meristem. Ann Bot 2014; 114:1497-505. [PMID: 25288633 PMCID: PMC4204788 DOI: 10.1093/aob/mcu185] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/14/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS The morphological variability of the flower in angiosperms, combined with its relatively simple structure, makes it an excellent model to study cell specification and the establishment of morphogenetic patterns. Flowers are the products of floral meristems, which are determinate structures that generate four different types of floral organs before terminating. The precise organization of the flower in whorls, each defined by the identity and number of organs it contains, is controlled by a multi-layered network involving numerous transcriptional regulators. In particular, the AGAMOUS (AG) MADS domain-containing transcription factor plays a major role in controlling floral determinacy in Arabidopsis thaliana in addition to specifying reproductive organ identity. This study aims to characterize the genetic interactions between the ULTRAPETALA1 (ULT1) and LEAFY (LFY) transcriptional regulators during flower morphogenesis, with a focus on AG regulation. METHODS Genetic and molecular approaches were used to address the question of redundancy and reciprocal interdependency for the establishment of flower meristem initiation, identity and termination. In particular, the effects of loss of both ULT1 and LFY function were determined by analysing flower developmental phenotypes of double-mutant plants. The dependency of each factor on the other for activating developmental genes was also investigated in gain-of-function experiments. KEY RESULTS The ULT1 and LFY pathways, while both activating AG expression in the centre of the flower meristem, functioned independently in floral meristem determinacy. Ectopic transcriptional activation by ULT1 of AG and AP3, another gene encoding a MADS domain-containing flower architect, did not depend on LFY function. Similarly, LFY did not require ULT1 function to ectopically determine floral fate. CONCLUSIONS The results indicate that the ULT1 and LFY pathways act separately in regulating identity and determinacy at the floral meristem. In particular, they independently induce AG expression in the centre of the flower to terminate meristem activity. A model is proposed whereby these independent contributions bring about a switch at the AG locus from an inactive to an active transcriptional state at the correct time and place during flower development.
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Affiliation(s)
- Julia Engelhorn
- Université Grenoble Alpes, UMR5168, F-38041 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire Physiologie Cellulaire et Végétale, F-38054 Grenoble, France INRA, F-38054 Grenoble, France
| | - Fanny Moreau
- Université Grenoble Alpes, UMR5168, F-38041 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire Physiologie Cellulaire et Végétale, F-38054 Grenoble, France INRA, F-38054 Grenoble, France
| | - Jennifer C Fletcher
- Plant Gene Expression Center, USDA-ARS/University of California, Berkeley, 800 Buchanan Street, Albany, CA 94710, USA
| | - Cristel C Carles
- Université Grenoble Alpes, UMR5168, F-38041 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire Physiologie Cellulaire et Végétale, F-38054 Grenoble, France INRA, F-38054 Grenoble, France
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Engelhorn J, Blanvillain R, Carles CC. Gene activation and cell fate control in plants: a chromatin perspective. Cell Mol Life Sci 2014; 71:3119-37. [PMID: 24714879 DOI: 10.1007/s00018-014-1609-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 01/02/2023]
Abstract
In plants, environment-adaptable organogenesis extends throughout the lifespan, and iterative development requires repetitive rounds of activation and repression of several sets of genes. Eukaryotic genome compaction into chromatin forms a physical barrier for transcription; therefore, induction of gene expression requires alteration in chromatin structure. One of the present great challenges in molecular and developmental biology is to understand how chromatin is brought from a repressive to permissive state on specific loci and in a very specific cluster of cells, as well as how this state is further maintained and propagated through time and cell division in a cell lineage. In this review, we report recent discoveries implementing our knowledge on chromatin dynamics that modulate developmental gene expression. We also discuss how new data sets highlight plant specificities, likely reflecting requirement for a highly dynamic chromatin.
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Affiliation(s)
- Julia Engelhorn
- Université Grenoble Alpes, UMR5168, 38041, Grenoble, France,
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Dong X, Reimer J, Göbel U, Engelhorn J, He F, Schoof H, Turck F. Natural variation of H3K27me3 distribution between two Arabidopsis accessions and its association with flanking transposable elements. Genome Biol 2012; 13:R117. [PMID: 23253144 PMCID: PMC4056368 DOI: 10.1186/gb-2012-13-12-r117] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 12/19/2012] [Indexed: 01/05/2023] Open
Abstract
Background Histone H3 lysine 27 tri-methylation and lysine 9 di-methylation are independent repressive chromatin modifications in Arabidopsis thaliana. H3K27me3 is established and maintained by Polycomb repressive complexes whereas H3K9me2 is catalyzed by SUVH histone methyltransferases. Both modifications can spread to flanking regions after initialization and were shown to be mutually exclusive in Arabidopsis. Results We analyzed the extent of natural variation of H3K27me3 in the two accessions Landsberg erecta (Ler) and Columbia (Col) and their F1 hybrids. The majority of H3K27me3 target genes in Col were unchanged in Ler and F1 hybrids. A small number of Ler-specific targets were detected and confirmed. Consistent with a cis-regulatory mechanism for establishing H3K27me3, differential targets showed allele-specific H3K27me3 in hybrids. Five Ler-specific targets showed the active mark H3K4me3 in Col and for this group, differential H3K27me3 enrichment accorded to expression variation. On the other hand, the majority of Ler-specific targets were not expressed in Col, Ler or 17 other accessions. Instead of H3K27me3, the antagonistic mark H3K9me2 and other heterochromatic features were observed at these loci in Col. These loci were frequently flanked by transposable elements, which were often missing in the Ler genome assembly. Conclusion There is little variation in H3K27me3 occupancy within the species, although H3K27me3 targets were previously shown as overrepresented among differentially expressed genes. The existing variation in H3K27me3 seems mostly explained by flanking polymorphic transposable elements. These could nucleate heterochromatin, which then spreads into neighboring H3K27me3 genes, thus converting them to H3K9me2 targets.
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Engelhorn J, Reimer JJ, Leuz I, Göbel U, Huettel B, Farrona S, Turck F. Development-related PcG target in the apex 4 controls leaf margin architecture in Arabidopsis thaliana. Development 2012; 139:2566-75. [PMID: 22675210 DOI: 10.1242/dev.078618] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In a reverse genetics screen based on a group of genes enriched for development-related Polycomb group targets in the apex (DPAs), we isolated DPA4 as a novel regulator of leaf margin shape. T-DNA insertion lines in the DPA4 locus display enhanced leaf margin serrations and enlarged petals, whereas overexpression of DPA4 results in smooth margins. DPA4 encodes a putative RAV (Related to ABI3/VP1) transcriptional repressor and is expressed in the lateral organ boundary region and in the sinus of leaf serrations. DPA4 expression domains overlap with those of the known leaf shape regulator CUP-SHAPED COTYLEDON 2 (CUC2) and we provide evidence that DPA4 negatively regulates CUC2 expression independently of MIR164A, an established regulator of CUC2. Taken together, the data suggest DPA4 as a newly identified player in the signalling network that controls leaf serrations in Arabidopsis thaliana.
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Affiliation(s)
- Julia Engelhorn
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829 Köln, Germany
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Farrona S, Thorpe FL, Engelhorn J, Adrian J, Dong X, Sarid-Krebs L, Goodrich J, Turck F. Tissue-specific expression of FLOWERING LOCUS T in Arabidopsis is maintained independently of polycomb group protein repression. Plant Cell 2011; 23:3204-14. [PMID: 21917549 PMCID: PMC3203448 DOI: 10.1105/tpc.111.087809] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The Polycomb Group (PcG) pathway represses transcription through a mechanism conserved among plants and animals. PcG-mediated repression can determine spatial territories of gene expression, but it remains unclear whether PcG-mediated repression is a regulatory requirement for all targets. Here, we show the role of PcG proteins in the spatial regulation of FLOWERING LOCUS T (FT), a main activator of flowering in Arabidopsis thaliana exclusively expressed in the vasculature. Strikingly, the loss of PcG repression causes down-regulation of FT. In addition, our results show how the effect of PcG-mediated regulation differs for target genes and that, for FT expression, it relies primarily on tissue differentiation.
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Affiliation(s)
- Sara Farrona
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Frazer L. Thorpe
- Institute for Molecular Plant Sciences, University of Edinburgh, Edinburgh EH9 3JH, United Kingdom
| | - Julia Engelhorn
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Jessika Adrian
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Xue Dong
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Liron Sarid-Krebs
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Justin Goodrich
- Institute for Molecular Plant Sciences, University of Edinburgh, Edinburgh EH9 3JH, United Kingdom
| | - Franziska Turck
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Address correspondence to
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Abstract
Genome-wide analysis of histone modifications via ChIP-chip (chromatin immunoprecipitation followed by whole genome tiling array hybridization) may generate lists of up to several thousand potential target genes. In the case of the model organism Arabidopsis thaliana, several databases are available to alleviate further characterization and classification of genomic data sets. The term metaanalysis has been coined for this type of multidatabase comparison. In this chapter, we describe open source software and web tools that perform transcriptional and functional analysis of target genes. Sources of transcription data and clustering tools to subdivide genes according to their expression pattern are described. The user is guided through all necessary steps, including data download and formatting. In addition, the Gene Ontology (GO) vocabulary and methods to uncover over- or underrepresented functions among target genes are introduced. Genomic targets of the histone H3K27me3 modification are presented as a case study to demonstrate that metaanalysis can uncover novel functions that were hidden in genomic data sets.
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Affiliation(s)
- Julia Engelhorn
- Max Planck Institute for Plant Breeding Research, Köln, Germany
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Berkner H, Engelhorn J, Liscombe DK, Schweimer K, Wöhrl BM, Facchini PJ, Rösch P, Matecko I. High-yield expression and purification of isotopically labeled norcoclaurine synthase, a Bet v 1-homologous enzyme, from Thalictrum flavum for NMR studies. Protein Expr Purif 2007; 56:197-204. [PMID: 17900926 DOI: 10.1016/j.pep.2007.07.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 07/16/2007] [Accepted: 07/23/2007] [Indexed: 11/18/2022]
Abstract
The enzyme norcoclaurine synthase (NCS) found in the common meadow rue, Thalictrum flavum, and other plants shows sequence homology to members of the class 10 of pathogenesis related (PR 10) proteins that contains allergens such as the major birch pollen allergen Bet v 1, the major cherry allergen Pru av 1, and the major apple allergen Mal d 1. The enzyme is involved in the plant's secondary metabolism and is required for the production of bioactive secondary metabolites like morphine. Whereas the physiological function of PR 10 class allergens is still unknown, NCS activity has been studied in detail. Investigation of the structural properties of NCS by NMR spectroscopy can thus not only provide new information concerning the reaction mechanism of the enzyme, but is also expected to help clarify the long standing and heavily debated question on the physiological function as well as the reasons for the allergenic potential of members of this protein family. As the first important step towards the three-dimensional solution structure, we optimized expression of recombinant NCS in Escherichia coli and established an efficient purification protocol yielding high amounts of pure isotopically labeled active enzyme. The identity of NCS was confirmed by electrospray ionization mass spectrometry, and activity of the purified enzyme was determined by an assay detecting the radiolabeled reaction product. Spectroscopic analysis by NMR spectroscopy showed that the protein was properly folded with well defined tertiary structure.
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Affiliation(s)
- Hanna Berkner
- Department of Biopolymers and Research Center for Bio-Macromolecules, Universität Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
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