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Matyášek R, Kalfusová R, Kuderová A, Řehůřková K, Sochorová J, Kovařík A. Transcriptional Silencing of 35S rDNA in Tragopogon porrifolius Correlates with Cytosine Methylation in Sequence-Specific Manner. Int J Mol Sci 2024; 25:7540. [PMID: 39062783 PMCID: PMC11276851 DOI: 10.3390/ijms25147540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/21/2024] [Accepted: 07/04/2024] [Indexed: 07/28/2024] Open
Abstract
Despite the widely accepted involvement of DNA methylation in the regulation of rDNA transcription, the relative participation of different cytosine methylation pathways is currently described only for a few model plants. Using PacBio, Bisulfite, and RNA sequencing; PCR; Southern hybridizations; and FISH, the epigenetic consequences of rDNA copy number variation were estimated in two T. porrifolius lineages, por1 and por2, the latter with more than twice the rDNA copy numbers distributed approximately equally between NORs on chromosomes A and D. The lower rDNA content in por1 correlated with significantly reduced (>90%) sizes of both D-NORs. Moreover, two (L and S) prominent rDNA variants, differing in the repetitive organization of intergenic spacers, were detected in por2, while only the S-rDNA variant was detected in por1. Transcriptional activity of S-rDNA in por1 was associated with secondary constriction of both A-NORs. In contrast, silencing of S-rDNA in por2 was accompanied by condensation of A-NORs, secondary constriction on D-NORs, and L-rDNA transcriptional activity, suggesting (i) bidirectional nucleolar dominance and (ii) association of S-rDNAs with A-NORs and L-rDNAs with D-NORs in T. porrifolius. Each S- and L-rDNA array was formed of several sub-variants differentiating both genetically (specific SNPs) and epigenetically (transcriptional efficiency and cytosine methylation). The most significant correlations between rDNA silencing and methylation were detected for symmetric CWG motifs followed by CG motifs. No correlations were detected for external cytosine in CCGs or asymmetric CHHs, where methylation was rather position-dependent, particularly for AT-rich variants. We conclude that variations in rDNA copy numbers in plant diploids can be accompanied by prompt epigenetic responses to maintain an appropriate number of active rDNAs. The methylation dynamics of CWGs are likely to be the most responsible for regulating silent and active rDNA states.
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Affiliation(s)
- Roman Matyášek
- Institute of Biophysics of the Czech Academy of Sciences, 612 65 Brno, Czech Republic; (R.K.); (A.K.); (K.Ř.); (J.S.); (A.K.)
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Zhang Y, Jang H, Luo Z, Dong Y, Xu Y, Kantamneni Y, Schmitz RJ. Dynamic evolution of the heterochromatin sensing histone demethylase IBM1. PLoS Genet 2024; 20:e1011358. [PMID: 38991029 PMCID: PMC11265718 DOI: 10.1371/journal.pgen.1011358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 07/23/2024] [Accepted: 07/01/2024] [Indexed: 07/13/2024] Open
Abstract
Heterochromatin is critical for maintaining genome stability, especially in flowering plants, where it relies on a feedback loop involving the H3K9 methyltransferase, KRYPTONITE (KYP), and the DNA methyltransferase CHROMOMETHYLASE3 (CMT3). The H3K9 demethylase INCREASED IN BONSAI METHYLATION 1 (IBM1) counteracts the detrimental consequences of KYP-CMT3 activity in transcribed genes. IBM1 expression in Arabidopsis is uniquely regulated by methylation of the 7th intron, allowing it to monitor global H3K9me2 levels. We show the methylated intron is prevalent across flowering plants and its underlying sequence exhibits dynamic evolution. We also find extensive genetic and expression variations in KYP, CMT3, and IBM1 across flowering plants. We identify Arabidopsis accessions resembling weak ibm1 mutants and Brassicaceae species with reduced IBM1 expression or deletions. Evolution towards reduced IBM1 activity in some flowering plants could explain the frequent natural occurrence of diminished or lost CMT3 activity and loss of gene body DNA methylation, as cmt3 mutants in A. thaliana mitigate the deleterious effects of IBM1.
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Affiliation(s)
- Yinwen Zhang
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Hosung Jang
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Ziliang Luo
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Yinxin Dong
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Yangyang Xu
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Yamini Kantamneni
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Robert J. Schmitz
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
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Yabe K, Kamio A, Oya S, Kakutani T, Hirayama M, Tanaka Y, Inagaki S. H3K9 methylation regulates heterochromatin silencing through incoherent feedforward loops. SCIENCE ADVANCES 2024; 10:eadn4149. [PMID: 38924413 PMCID: PMC11204290 DOI: 10.1126/sciadv.adn4149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
Histone H3 lysine-9 methylation (H3K9me) is a hallmark of the condensed and transcriptionally silent heterochromatin. It remains unclear how H3K9me controls transcription silencing and how cells delimit H3K9me domains to avoid silencing essential genes. Here, using Arabidopsis genetic systems that induce H3K9me2 in genes and transposons de novo, we show that H3K9me2 accumulation paradoxically also causes the deposition of the euchromatic mark H3K36me3 by a SET domain methyltransferase, ASHH3. ASHH3-induced H3K36me3 confers anti-silencing by preventing the demethylation of H3K4me1 by LDL2, which mediates transcriptional silencing downstream of H3K9me2. These results demonstrate that H3K9me2 not only facilitates but orchestrates silencing by actuating antagonistic silencing and anti-silencing pathways, providing insights into the molecular basis underlying proper partitioning of chromatin domains and the creation of metastable epigenetic variation.
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Affiliation(s)
| | | | - Satoyo Oya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | - Mami Hirayama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuriko Tanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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Fan D, Wang X, Liu T, Liu H, Peng Y, Tang X, Ye X, Sun K, Yue Y, Xu D, Li C, Luo K. Epigenetic regulation of high light-induced anthocyanin biosynthesis by histone demethylase IBM1 in Arabidopsis. THE NEW PHYTOLOGIST 2024; 242:2570-2585. [PMID: 38708492 DOI: 10.1111/nph.19789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 03/27/2024] [Indexed: 05/07/2024]
Abstract
In plant species, anthocyanin accumulation is specifically regulated by light signaling. Although the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) complex is known to control anthocyanin biosynthesis in response to light, the precise mechanism underlying this process remains largely unknown. Here, we report that Increase in BONSAI Methylation 1 (IBM1), a JmjC domain-containing histone demethylase, participates in the regulation of light-induced anthocyanin biosynthesis in Arabidopsis. The expression of IBM1 was induced by high light (HL) stress, and loss-of-function mutations in IBM1 led to accelerated anthocyanin accumulation under HL conditions. We further identified that IBM1 is directly associated with SPA1/3/4 chromatin in vivo to establish a hypomethylation status on H3K9 and DNA non-CG at these loci under HL, thereby releasing their expression. Genetic analysis showed that quadruple mutants of IBM1 and SPA1/3/4 resemble spa134 mutants. Overexpression of SPA1 in ibm1 mutants complements the mutant phenotype. Our results elucidate the significance and mechanism of IBM1 histone demethylase in the epigenetic regulation of anthocyanin biosynthesis in Arabidopsis under HL conditions.
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Affiliation(s)
- Di Fan
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xianqiang Wang
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Tingting Liu
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Huimin Liu
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Yingying Peng
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiaofeng Tang
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiao Ye
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Kuan Sun
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Yuchen Yue
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Dan Xu
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Chaofeng Li
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Keming Luo
- Chongqing Key Laboratory of Innovative and Utilization of Tree Germplasm Resources, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
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Mori S, Oya S, Takahashi M, Takashima K, Inagaki S, Kakutani T. Cotranscriptional demethylation induces global loss of H3K4me2 from active genes in Arabidopsis. EMBO J 2023; 42:e113798. [PMID: 37849386 PMCID: PMC10690457 DOI: 10.15252/embj.2023113798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 09/20/2023] [Accepted: 09/25/2023] [Indexed: 10/19/2023] Open
Abstract
Based on studies of animals and yeasts, methylation of histone H3 lysine 4 (H3K4me1/2/3, for mono-, di-, and tri-methylation, respectively) is regarded as the key epigenetic modification of transcriptionally active genes. In plants, however, H3K4me2 correlates negatively with transcription, and the regulatory mechanisms of this counterintuitive H3K4me2 distribution in plants remain largely unexplored. A previous genetic screen for factors regulating plant regeneration identified Arabidopsis LYSINE-SPECIFIC DEMETHYLASE 1-LIKE 3 (LDL3), which is a major H3K4me2 demethylase. Here, we show that LDL3-mediated H3K4me2 demethylation depends on the transcription elongation factor Paf1C and phosphorylation of the C-terminal domain (CTD) of RNA polymerase II (RNAPII). In addition, LDL3 binds to phosphorylated RNAPII. These results suggest that LDL3 is recruited to transcribed genes by binding to elongating RNAPII and demethylates H3K4me2 cotranscriptionally. Importantly, the negative correlation between H3K4me2 and transcription is significantly attenuated in the ldl3 mutant, demonstrating the genome-wide impacts of the transcription-driven LDL3 pathway to control H3K4me2 in plants. Our findings implicate H3K4me2 demethylation in plants as chromatin records of transcriptional activity, which ensures robust gene control.
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Affiliation(s)
- Shusei Mori
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
| | - Satoyo Oya
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
| | | | | | - Soichi Inagaki
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
| | - Tetsuji Kakutani
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
- National Institute of GeneticsShizuokaJapan
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Goeldel C, Johannes F. Stochasticity in gene body methylation. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102436. [PMID: 37597469 DOI: 10.1016/j.pbi.2023.102436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/30/2023] [Accepted: 07/10/2023] [Indexed: 08/21/2023]
Abstract
Gene body methylation (gbM) is a widely conserved epigenetic feature of plant genomes. Efforts to delineate the mechanisms by which gbM contributes to transcriptional regulation remain largely inconclusive, and its evolutionary significance continues to be debated. Curiously, although steady-state gbM levels are remarkably stable across mitotic and meiotic cell divisions, the methylation status of individual CG dinucleotides in gbM genes is highly stochastic. How can these two seemingly contradictory observations be reconciled? Here, we discuss how stochastic processes relate to gbM maintenance dynamics. We show that a quantitative understanding of these processes can shed deeper insights into the molecular and evolutionary biology of this enigmatic epigenetic trait.
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Affiliation(s)
| | - Frank Johannes
- Plant Epigenomics, Technical University of Munich, Germany.
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7
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Liu ZW, Liu J, Liu F, Zhong X. Depositing centromere repeats induces heritable intragenic heterochromatin establishment and spreading in Arabidopsis. Nucleic Acids Res 2023; 51:6039-6054. [PMID: 37094065 PMCID: PMC10325890 DOI: 10.1093/nar/gkad306] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 04/10/2023] [Accepted: 04/19/2023] [Indexed: 04/26/2023] Open
Abstract
Stable transmission of non-DNA-sequence-based epigenetic information contributes to heritable phenotypic variants and thus to biological diversity. While studies on spontaneous natural epigenome variants have revealed an association of epialleles with a wide range of biological traits in both plants and animals, the function, transmission mechanism, and stability of an epiallele over generations in a locus-specific manner remain poorly investigated. Here, we invented a DNA sequence deposition strategy to generate a locus-specific epiallele by depositing CEN180 satellite repeats into a euchromatic target locus in Arabidopsis. Using CRISPR/Cas9-mediated knock-in system, we demonstrated that depositing CEN180 repeats can induce heterochromatin nucleation accompanied by DNA methylation, H3K9me2, and changes in the nucleosome occupancy at the insertion sites. Interestingly, both DNA methylation and H3K9me2 are restricted within the depositing sites and depletion of an H3K9me2 demethylase IBM1 enables the outward heterochromatin propagation into the neighboring regions, leading to inheritable target gene silencing to persist for at least five generations. Together, these results demonstrate the promise of employing a cis-engineering system for the creation of stable and site-specific epialleles and provide important insights into functional epigenome studies and locus-specific transgenerational epigenetic inheritance.
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Affiliation(s)
- Zhang-Wei Liu
- Department of Biology, Washington University in St Louis, St Louis, MO 63130, USA
- Wisconsin Institute for Discovery & Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jie Liu
- Department of Biology, Washington University in St Louis, St Louis, MO 63130, USA
- Wisconsin Institute for Discovery & Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China
| | - Xuehua Zhong
- Department of Biology, Washington University in St Louis, St Louis, MO 63130, USA
- Wisconsin Institute for Discovery & Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
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Berthelier J, Furci L, Asai S, Sadykova M, Shimazaki T, Shirasu K, Saze H. Long-read direct RNA sequencing reveals epigenetic regulation of chimeric gene-transposon transcripts in Arabidopsis thaliana. Nat Commun 2023; 14:3248. [PMID: 37277361 DOI: 10.1038/s41467-023-38954-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 05/21/2023] [Indexed: 06/07/2023] Open
Abstract
Transposable elements (TEs) are accumulated in both intergenic and intragenic regions in plant genomes. Intragenic TEs often act as regulatory elements of associated genes and are also co-transcribed with genes, generating chimeric TE-gene transcripts. Despite the potential impact on mRNA regulation and gene function, the prevalence and transcriptional regulation of TE-gene transcripts are poorly understood. By long-read direct RNA sequencing and a dedicated bioinformatics pipeline, ParasiTE, we investigated the transcription and RNA processing of TE-gene transcripts in Arabidopsis thaliana. We identified a global production of TE-gene transcripts in thousands of A. thaliana gene loci, with TE sequences often being associated with alternative transcription start sites or transcription termination sites. The epigenetic state of intragenic TEs affects RNAPII elongation and usage of alternative poly(A) signals within TE sequences, regulating alternative TE-gene isoform production. Co-transcription and inclusion of TE-derived sequences into gene transcripts impact regulation of RNA stability and environmental responses of some loci. Our study provides insights into TE-gene interactions that contributes to mRNA regulation, transcriptome diversity, and environmental responses in plants.
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Grants
- JP20H02995 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP22H00364 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP20H05909 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP20H05913 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
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Affiliation(s)
- Jérémy Berthelier
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
| | - Leonardo Furci
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Shuta Asai
- Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
| | - Munissa Sadykova
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Tomoe Shimazaki
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Ken Shirasu
- Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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Hayashi K, Alseekh S, Fernie AR. Genetic and epigenetic control of the plant metabolome. Proteomics 2023:e2200104. [PMID: 36781168 DOI: 10.1002/pmic.202200104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/15/2023]
Abstract
Plant metabolites are mainly produced through chemical reactions catalysed by enzymes encoded in the genome. Mutations in enzyme-encoding or transcription factor-encoding genes can alter the metabolome by changing the enzyme's catalytic activity or abundance, respectively. Insertion of transposable elements into non-coding regions has also been reported to affect transcription and ultimately metabolite content. In addition to genetic mutations, transgenerational epigenetic variations have also been found to affect metabolic content by controlling the transcription of metabolism-related genes. However, the majority of cases reported so far, in which epigenetic mechanisms are associated with metabolism, are non-transgenerational, and are triggered by developmental signals or environmental stress. Although, accumulating research has provided evidence of strong genetic control of the metabolome, epigenetic control has been largely untouched. Here, we provide a review of the genetic and epigenetic control of metabolism with a focus on epigenetics. We discuss both transgenerational and non-transgenerational epigenetic marks regulating metabolism as well as prospects of the field of metabolic control where intricate interactions between genetics and epigenetics are involved.
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Affiliation(s)
- Koki Hayashi
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.,Center for Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.,Center for Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
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Fukagawa T, Kakutani T. Transgenerational epigenetic control of constitutive heterochromatin, transposons, and centromeres. Curr Opin Genet Dev 2023; 78:102021. [PMID: 36716679 DOI: 10.1016/j.gde.2023.102021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/20/2022] [Accepted: 01/04/2023] [Indexed: 01/30/2023]
Abstract
Epigenetic mechanisms are important not only for development but also for genome stability and chromosome dynamics. The latter types of epigenetic controls can often be transgenerational. Here, we review recent progress in two examples of transgenerational epigenetic control: i) the control of constitutive heterochromatin and transposable elements and ii) epigenetic mechanisms that regulate centromere specification and functions. We also discuss the biological significance of enigmatic associations among centromeres, transposons, and constitutive heterochromatin.
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Affiliation(s)
- Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan. https://twitter.com/tatsuofukagawa1
| | - Tetsuji Kakutani
- Department of Biological Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
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11
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Morgan BL, Donohue K. Parental methylation mediates how progeny respond to environments of parents and of progeny themselves. ANNALS OF BOTANY 2022; 130:883-899. [PMID: 36201313 PMCID: PMC9758305 DOI: 10.1093/aob/mcac125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND AIMS Environments experienced by both parents and offspring influence progeny traits, but the epigenetic mechanisms that regulate the balance of parental vs. progeny control of progeny phenotypes are not known. We tested whether DNA methylation in parents and/or progeny mediates responses to environmental cues experienced in both generations. METHODS Using Arabidopsis thaliana, we manipulated parental and progeny DNA methylation both chemically, via 5-azacytidine, and genetically, via mutants of methyltransferase genes, then measured progeny germination responses to simulated canopy shade in parental and progeny generations. KEY RESULTS We first found that germination of offspring responded to parental but not seed demethylation. We further found that parental demethylation reversed the parental effect of canopy in seeds with low (Cvi-1) to intermediate (Col) dormancy, but it obliterated the parental effect in seeds with high dormancy (Cvi-0). Demethylation did so by either suppressing germination of seeds matured under white-light (Cvi-1) or under canopy (Cvi-0), or by increasing the germination of seeds matured under canopy (Col). Disruption of parental methylation also prevented seeds from responding to their own light environment in one genotype (Cvi-0, most dormant), but it enabled seeds to respond to their own environment in another genotype (Cvi-1, least dormant). Using mutant genotypes, we found that both CG and non-CG DNA methylation were involved in parental effects on seed germination. CONCLUSIONS Parental methylation state influences seed germination more strongly than does the progeny's own methylation state, and it influences how seeds respond to environments of parents and progeny in a genotype-specific manner.
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Affiliation(s)
- Britany L Morgan
- University Program in Ecology Duke University, Durham, NC 27705, USA
- Center for Agricultural Synthetic Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Kathleen Donohue
- University Program in Ecology Duke University, Durham, NC 27705, USA
- Biology Department, Duke University, Durham, NC 27705, USA
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12
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Wang Y, Le BH, Wang J, You C, Zhao Y, Galli M, Xu Y, Gallavotti A, Eulgem T, Mo B, Chen X. ZMP recruits and excludes Pol IV-mediated DNA methylation in a site-specific manner. SCIENCE ADVANCES 2022; 8:eadc9454. [PMID: 36427317 PMCID: PMC9699677 DOI: 10.1126/sciadv.adc9454] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
In plants, RNA-directed DNA methylation (RdDM) uses small interfering RNAs (siRNAs) to target transposable elements (TEs) but usually avoids genes. RNA polymerase IV (Pol IV) shapes the landscape of DNA methylation through its pivotal role in siRNA biogenesis. However, how Pol IV is recruited to specific loci, particularly how it avoids genes, is poorly understood. Here, we identified a Pol IV-interacting protein, ZMP (zinc finger, mouse double-minute/switching complex B, Plus-3 protein), which exerts a dual role in regulating siRNA biogenesis and DNA methylation at specific genomic regions. ZMP is required for siRNA biogenesis at some pericentromeric regions and prevents Pol IV from targeting a subset of TEs and genes at euchromatic loci. As a chromatin-associated protein, ZMP prefers regions with depleted histone H3 lysine 4 (H3K4) methylation abutted by regions with H3K4 methylation, probably monitoring changes in local H3K4 methylation status to regulate Pol IV's chromatin occupancy. Our findings uncover a mechanism governing the specificity of RdDM.
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Affiliation(s)
- Yuan Wang
- Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Institute of Innovative Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, 518060 Shenzhen, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, 518060 Shenzhen, China
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Brandon H. Le
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Jianqiang Wang
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Chenjiang You
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Institute of Plant Biology, Fudan University, Shanghai 200438, China
| | - Yonghui Zhao
- Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Mary Galli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854-8020, USA
| | - Ye Xu
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Andrea Gallavotti
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854-8020, USA
| | - Thomas Eulgem
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Beixin Mo
- Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Institute of Innovative Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, 518060 Shenzhen, China
| | - Xuemei Chen
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
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13
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Knaack SA, Conde D, Chakraborty S, Balmant KM, Irving TB, Maia LGS, Triozzi PM, Dervinis C, Pereira WJ, Maeda J, Schmidt HW, Ané JM, Kirst M, Roy S. Temporal change in chromatin accessibility predicts regulators of nodulation in Medicago truncatula. BMC Biol 2022; 20:252. [DOI: 10.1186/s12915-022-01450-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/25/2022] [Indexed: 11/11/2022] Open
Abstract
Abstract
Background
Symbiotic associations between bacteria and leguminous plants lead to the formation of root nodules that fix nitrogen needed for sustainable agricultural systems. Symbiosis triggers extensive genome and transcriptome remodeling in the plant, yet an integrated understanding of the extent of chromatin changes and transcriptional networks that functionally regulate gene expression associated with symbiosis remains poorly understood. In particular, analyses of early temporal events driving this symbiosis have only captured correlative relationships between regulators and targets at mRNA level. Here, we characterize changes in transcriptome and chromatin accessibility in the model legume Medicago truncatula, in response to rhizobial signals that trigger the formation of root nodules.
Results
We profiled the temporal chromatin accessibility (ATAC-seq) and transcriptome (RNA-seq) dynamics of M. truncatula roots treated with bacterial small molecules called lipo-chitooligosaccharides that trigger host symbiotic pathways of nodule development. Using a novel approach, dynamic regulatory module networks, we integrated ATAC-seq and RNA-seq time courses to predict cis-regulatory elements and transcription factors that most significantly contribute to transcriptomic changes associated with symbiosis. Regulators involved in auxin (IAA4-5, SHY2), ethylene (EIN3, ERF1), and abscisic acid (ABI5) hormone response, as well as histone and DNA methylation (IBM1), emerged among those most predictive of transcriptome dynamics. RNAi-based knockdown of EIN3 and ERF1 reduced nodule number in M. truncatula validating the role of these predicted regulators in symbiosis between legumes and rhizobia.
Conclusions
Our transcriptomic and chromatin accessibility datasets provide a valuable resource to understand the gene regulatory programs controlling the early stages of the dynamic process of symbiosis. The regulators identified provide potential targets for future experimental validation, and the engineering of nodulation in species is unable to establish that symbiosis naturally.
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14
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Sasaki E, Gunis J, Reichardt-Gomez I, Nizhynska V, Nordborg M. Conditional GWAS of non-CG transposon methylation in Arabidopsis thaliana reveals major polymorphisms in five genes. PLoS Genet 2022; 18:e1010345. [PMID: 36084135 PMCID: PMC9491579 DOI: 10.1371/journal.pgen.1010345] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/21/2022] [Accepted: 07/16/2022] [Indexed: 11/19/2022] Open
Abstract
Genome-wide association studies (GWAS) have revealed that the striking natural variation for DNA CHH-methylation (mCHH; H is A, T, or C) of transposons has oligogenic architecture involving major alleles at a handful of known methylation regulators. Here we use a conditional GWAS approach to show that CHG-methylation (mCHG) has a similar genetic architecture-once mCHH is statistically controlled for. We identify five key trans-regulators that appear to modulate mCHG levels, and show that they interact with a previously identified modifier of mCHH in regulating natural transposon mobilization.
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Affiliation(s)
- Eriko Sasaki
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Joanna Gunis
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Ilka Reichardt-Gomez
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Viktoria Nizhynska
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Magnus Nordborg
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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15
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To TK, Kakutani T. Crosstalk among pathways to generate DNA methylome. CURRENT OPINION IN PLANT BIOLOGY 2022; 68:102248. [PMID: 35724481 DOI: 10.1016/j.pbi.2022.102248] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/19/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Cytosine is methylated in both CpG and non-CpG contexts (mCG and mCH, respectively) in plant genomes. Although mCG and mCH are almost independent in regard to their "maintenance," recent studies uncovered crosstalk between them during their "establishment," which unexpectedly functions in both RNAi-dependent and -independent pathways. In addition, the importance of linker histone H1 and variants of histone H2A to DNA methylation dynamics is starting to be understood. We summarize these new aspects of mechanisms to generate DNA methylomes and discuss future prospects.
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Affiliation(s)
- Taiko Kim To
- Department of Biological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tetsuji Kakutani
- Department of Biological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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16
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Histone demethylase IBM1-mediated meiocyte gene expression ensures meiotic chromosome synapsis and recombination. PLoS Genet 2022; 18:e1010041. [PMID: 35192603 PMCID: PMC8896719 DOI: 10.1371/journal.pgen.1010041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/04/2022] [Accepted: 01/17/2022] [Indexed: 11/19/2022] Open
Abstract
Histone methylation and demethylation play important roles in plant growth and development, but the involvement of histone demethylation during meiosis is poorly understood. Here we show that disruption of Arabidopsis thaliana INCREASE IN BONSAI METHYLATION 1 (IBM1) causes incomplete synapsis, chromosome entanglement and reduction of recombination during meiosis, leading to sterility. Interestingly, these ibm1 meiotic defects are rescued by mutations in either SUVH4/KYP or CMT3. Using transcriptomic analyses we show that mutation of IBM1 down-regulates thousands of genes expressed in meiocytes, and that expression of about 38% of these genes are restored to wild type levels in ibm1 cmt3 double mutants. Changes in the expression of 437 of these, including the ARABIDOPSIS MEI2-LIKE AML3-5 genes, are correlated with a significant reduction of gene body CHG methylation. Consistently, the aml3 aml4 aml5 triple have defects in synapsis and chromosome entanglement similar to ibm1. Genetic analysis shows that aml3 aml4 aml5 ibm1 quadruple mutants resembles the ibm1 single mutant. Strikingly, over expression of AML5 in ibm1 can partially rescue the ibm1 meiotic defects. Taken together, our results demonstrate that histone demethylase IBM1 is required for meiosis likely via coordinated regulation of meiocyte gene expression during meiosis.
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17
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Local and global crosstalk among heterochromatin marks drives DNA methylome patterning in Arabidopsis. Nat Commun 2022; 13:861. [PMID: 35165291 PMCID: PMC8844080 DOI: 10.1038/s41467-022-28468-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 01/26/2022] [Indexed: 12/13/2022] Open
Abstract
Transposable elements (TEs) are robustly silenced by multiple epigenetic marks, but dynamics of crosstalk among these marks remains enigmatic. In Arabidopsis, TEs are silenced by cytosine methylation in both CpG and non-CpG contexts (mCG and mCH) and histone H3 lysine 9 methylation (H3K9me). While mCH and H3K9me are mutually dependent for their maintenance, mCG and mCH/H3K9me are independently maintained. Here, we show that establishment, rather than maintenance, of mCH depends on mCG, accounting for the synergistic colocalization of these silent marks in TEs. When mCG is lost, establishment of mCH is abolished in TEs. mCG also guides mCH in active genes, though the resulting mCH/H3K9me is removed thereafter. Unexpectedly, targeting efficiency of mCH depends on relative, rather than absolute, levels of mCG within the genome, suggesting underlying global negative controls. We propose that local positive feedback in heterochromatin dynamics, together with global negative feedback, drive robust and balanced DNA methylome patterning. In plant genomes, both mCG and H3K9me2/mCH are important for silencing transposable elements (TEs). Here, the authors show that establishment of mCH is abolished in both TE and active genes when mCG is lost and targeting efficiency of mCH depends on relative levels of mCG within the genome.
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18
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Choi J, Lyons DB, Zilberman D. Histone H1 prevents non-CG methylation-mediated small RNA biogenesis in Arabidopsis heterochromatin. eLife 2021; 10:72676. [PMID: 34850679 PMCID: PMC8828055 DOI: 10.7554/elife.72676] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 11/30/2021] [Indexed: 11/27/2022] Open
Abstract
Flowering plants utilize small RNA (sRNA) molecules to guide DNA methyltransferases to genomic sequences. This RNA-directed DNA methylation (RdDM) pathway preferentially targets euchromatic transposable elements. However, RdDM is thought to be recruited by methylation of histone H3 at lysine 9 (H3K9me), a hallmark of heterochromatin. How RdDM is targeted to euchromatin despite an affinity for H3K9me is unclear. Here, we show that loss of histone H1 enhances heterochromatic RdDM, preferentially at nucleosome linker DNA. Surprisingly, this does not require SHH1, the RdDM component that binds H3K9me. Furthermore, H3K9me is dispensable for RdDM, as is CG DNA methylation. Instead, we find that non-CG methylation is specifically associated with sRNA biogenesis, and without H1 sRNA production quantitatively expands to non-CG-methylated loci. Our results demonstrate that H1 enforces the separation of euchromatic and heterochromatic DNA methylation pathways by excluding the sRNA-generating branch of RdDM from non-CG-methylated heterochromatin. Cells adapt to different roles by turning different groups of genes on and off. One way cells control which genes are on or off is by creating regions of active and inactive DNA, which are created and maintained by different groups of proteins. Genes in active DNA regions can be turned on, while genes in inactive regions are switched off or silenced. Silenced DNA regions also turn off ‘transposable elements’: pieces of DNA that can copy themselves and move to other regions of the genome if they become active. Transposons can be dangerous if they are activated, because they can disrupt genes or regulatory sequences when they move. There are different types of active and inactive DNA, but it is not always clear why these differences exist, or how they are maintained over time. In plants, such as the commonly-studied weed Arabidopsis thaliana, there are two types of inactive DNA, called E and H, that can silence transposons. In both types, DNA has small chemicals called methyl groups attached to it, which help inactivate the DNA. Type E DNA is methylated by a process called RNA-directed DNA methylation (RdDM), but RdDM is rarely seen in type H DNA. Choi, Lyons and Zilberman showed that RdDM is attracted to E and H regions by previously existing methylated DNA. However, in the H regions, a protein called histone H1 blocks RdDM from attaching methyl groups. This helps focus RdDM onto E regions where it is most needed, because E regions contain the types of transposons RdDM is best suited to silence. When Choi, Lyons and Zilberman examined genetically modified A. thaliana plants that do not produce histone H1, they found that RdDM happened in both E and H regions. There are many more H regions than E regions, so stretching RdDM across both made it less effective at silencing DNA. This work shows how different DNA silencing processes are focused onto specific genetic regions, helping explain why there are different types of active and inactive DNA within cells. RdDM has been studied as a way to affect crop growth and yield by altering DNA methylation. These results may help such studies by explaining how RdDM is naturally targeted.
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Affiliation(s)
- Jaemyung Choi
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - David B Lyons
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Daniel Zilberman
- Department of Cell and Developmental Biology, John Innes Centre, Klosterneuburg, Austria
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19
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Zhang Y, Jang H, Xiao R, Kakoulidou I, Piecyk RS, Johannes F, Schmitz RJ. Heterochromatin is a quantitative trait associated with spontaneous epiallele formation. Nat Commun 2021; 12:6958. [PMID: 34845222 PMCID: PMC8630088 DOI: 10.1038/s41467-021-27320-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 11/15/2021] [Indexed: 11/09/2022] Open
Abstract
Epialleles are meiotically heritable variations in expression states that are independent from changes in DNA sequence. Although they are common in plant genomes, their molecular origins are unknown. Here we show, using mutant and experimental populations, that epialleles in Arabidopsis thaliana that result from ectopic hypermethylation are due to feedback regulation of pathways that primarily function to maintain DNA methylation at heterochromatin. Perturbations to maintenance of heterochromatin methylation leads to feedback regulation of DNA methylation in genes. Using single base resolution methylomes from epigenetic recombinant inbred lines (epiRIL), we show that epiallelic variation is abundant in euchromatin, yet, associates with QTL primarily in heterochromatin regions. Mapping three-dimensional chromatin contacts shows that genes that are hotspots for ectopic hypermethylation have increases in contact frequencies with regions possessing H3K9me2. Altogether, these data show that feedback regulation of pathways that have evolved to maintain heterochromatin silencing leads to the origins of spontaneous hypermethylated epialleles.
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Affiliation(s)
- Yinwen Zhang
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Hosung Jang
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Rui Xiao
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Ioanna Kakoulidou
- Department of Plant Sciences, Technical University of Munich, Freising, Germany
| | - Robert S Piecyk
- Department of Plant Sciences, Technical University of Munich, Freising, Germany
| | - Frank Johannes
- Department of Plant Sciences, Technical University of Munich, Freising, Germany.
- Institute for Advanced Study (IAS), Technical University of Munich, Garching, Germany.
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA, USA.
- Institute for Advanced Study (IAS), Technical University of Munich, Garching, Germany.
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20
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Inagaki S. Silencing and anti-silencing mechanisms that shape the epigenome in plants. Genes Genet Syst 2021; 96:217-228. [PMID: 34719532 DOI: 10.1266/ggs.21-00041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Epigenome information mediates genome function and maintenance by regulating gene expression and chromatin organization. Because the epigenome pattern can change in response to internal and external environments, it may underlie an adaptive genome response that modulates phenotypes during development and in changing environments. Here I summarize recent progress in our understanding of how epigenome patterns are shaped and modulated by concerted actions of silencing and anti-silencing factors mainly in Arabidopsis thaliana. I discuss the dynamic nature of epigenome regulation, which is realized by cooperation and counteraction among silencing and anti-silencing factors, and how the dynamic epigenome mediates robust and plastic responses of plants to fluctuating environments.
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Affiliation(s)
- Soichi Inagaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo.,PRESTO, Japan Science and Technology Agency
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21
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Shang JY, Lu YJ, Cai XW, Su YN, Feng C, Li L, Chen S, He XJ. COMPASS functions as a module of the INO80 chromatin remodeling complex to mediate histone H3K4 methylation in Arabidopsis. THE PLANT CELL 2021; 33:3250-3271. [PMID: 34270751 PMCID: PMC8505878 DOI: 10.1093/plcell/koab187] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 07/11/2021] [Indexed: 05/26/2023]
Abstract
In the INO80 chromatin remodeling complex, all of the accessory subunits are assembled on the following three domains of INO80: N-terminal domain (NTD), HSA domain, and ATPase domain. Although the ATPase and HSA domains and their interacting accessory subunits are known to be responsible for chromatin remodeling, it is largely unknown how the accessory subunits that interact with the INO80 NTD regulate chromatin status. Here, we identify both conserved and nonconserved accessory subunits that interact with the three domains in the INO80 complex in Arabidopsis thaliana. While the accessory subunits that interact with all the three INO80 domains can mediate transcriptional repression, the INO80 NTD and the accessory subunits interact with it can contribute to transcriptional activation even when the ATPase domain is absent, suggesting that INO80 has an ATPase-independent role. A subclass of the COMPASS histone H3K4 methyltransferase complexes interact with the INO80 NTD in the INO80 complex and function together with the other accessory subunits that interact with the INO80 NTD, thereby facilitating H3K4 trimethylation and transcriptional activation. This study suggests that the opposite effects of the INO80 complex on transcription are required for the balance between vegetative growth and flowering under diverse environmental conditions.
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Affiliation(s)
| | | | - Xue-Wei Cai
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Yin-Na Su
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Chao Feng
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 100084, China
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22
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Wang Q, Liu P, Jing H, Zhou XF, Zhao B, Li Y, Jin JB. JMJ27-mediated histone H3K9 demethylation positively regulates drought-stress responses in Arabidopsis. THE NEW PHYTOLOGIST 2021; 232:221-236. [PMID: 34197643 DOI: 10.1111/nph.17593] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Dimethylation of histone H3 at lysine 9 (H3K9me2) is associated with heterochromatinization and transcriptional gene silencing in plants. The activation of sets of genes by drought stress is correlated with reduced H3K9me2 levels, but the role of H3K9 methylation in the regulation of drought-stress responses remains elusive. Here, we show that the Jumonji domain-containing H3K9 demethylase JMJ27 positively regulates drought-stress responses through its histone demethylase activity. RNA-seq analysis identified JMJ27-regulated genes, including positive regulators of drought stress GALACTINOL SYNTHASE 2 (GOLS2) and RESPONSE TO DESICCATION 20 (RD20). Genetic analysis demonstrated that JMJ27 positively regulates drought-stress responses at least partly through GOLS2 and RD20. JMJ27 directly associated with GOLS2 and RD20, and protected these loci from silencing by reducing H3K9me2 levels under normal conditions. REGULATORY PARTICLE NON-ATPASE 1a (RPN1a), a subunit of the 26S proteasome, interacted with JMJ27 and negatively regulated JMJ27 accumulation. Drought stress diminished RPN1a abundance, resulting in increased JMJ27 abundance. The drought stress-promoted occupancy of JMJ27 at GOLS2 and RD20 chromatin may reinforce their transcriptional induction by locally reducing the H3K9me2 levels. These results indicate that the RPN1a-JMJ27 module precisely regulates dynamic H3K9me2 deposition plasticity, ensuring proper adaptation to drought stress in Arabidopsis.
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Affiliation(s)
- Qiongli Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Peng Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hua Jing
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao Feng Zhou
- Department of Ornamental Horticulture, China Agricultural University, Beijing, 100193, China
| | - Bo Zhao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yuan Li
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jing Bo Jin
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
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23
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Sato H, Santos-González J, Köhler C. Combinations of maternal-specific repressive epigenetic marks in the endosperm control seed dormancy. eLife 2021; 10:e64593. [PMID: 34427186 PMCID: PMC8456740 DOI: 10.7554/elife.64593] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 08/23/2021] [Indexed: 12/20/2022] Open
Abstract
Polycomb Repressive Complex 2 (PRC2)-mediated trimethylation of histone H3 on lysine 27 (H3K27me3) and methylation of histone 3 on lysine 9 (H3K9me) are two repressive epigenetic modifications that are typically localized in distinct regions of the genome. For reasons unknown, however, they co-occur in some organisms and special tissue types. In this study, we show that maternal alleles marked by H3K27me3 in the Arabidopsis endosperm were targeted by the H3K27me3 demethylase REF6 and became activated during germination. In contrast, maternal alleles marked by H3K27me3, H3K9me2, and CHG methylation (CHGm) are likely to be protected from REF6 targeting and remained silenced. Our study unveils that combinations of different repressive epigenetic modifications time a key adaptive trait by modulating access of REF6.
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Affiliation(s)
- Hikaru Sato
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant BiologyUppsalaSweden
| | - Juan Santos-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant BiologyUppsalaSweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant BiologyUppsalaSweden
- Max Planck Institute of Molecular Plant PhysiologyPotsdam-GolmGermany
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24
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Papareddy RK, Páldi K, Smolka AD, Hüther P, Becker C, Nodine MD. Repression of CHROMOMETHYLASE 3 prevents epigenetic collateral damage in Arabidopsis. eLife 2021; 10:e69396. [PMID: 34296996 PMCID: PMC8352596 DOI: 10.7554/elife.69396] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/21/2021] [Indexed: 01/14/2023] Open
Abstract
DNA methylation has evolved to silence mutagenic transposable elements (TEs) while typically avoiding the targeting of endogenous genes. Mechanisms that prevent DNA methyltransferases from ectopically methylating genes are expected to be of prime importance during periods of dynamic cell cycle activities including plant embryogenesis. However, virtually nothing is known regarding how DNA methyltransferase activities are precisely regulated during embryogenesis to prevent the induction of potentially deleterious and mitotically stable genic epimutations. Here, we report that microRNA-mediated repression of CHROMOMETHYLASE 3 (CMT3) and the chromatin features that CMT3 prefers help prevent ectopic methylation of thousands of genes during embryogenesis that can persist for weeks afterwards. Our results are also consistent with CMT3-induced ectopic methylation of promoters or bodies of genes undergoing transcriptional activation reducing their expression. Therefore, the repression of CMT3 prevents epigenetic collateral damage on endogenous genes. We also provide a model that may help reconcile conflicting viewpoints regarding the functions of gene-body methylation that occurs in nearly all flowering plants.
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Affiliation(s)
- Ranjith K Papareddy
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
| | - Katalin Páldi
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
| | - Anna D Smolka
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
| | - Patrick Hüther
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
- Genetics, LMU Biocenter, Ludwig-Maximilians UniversityMartinsriedGermany
| | - Claude Becker
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
- Genetics, LMU Biocenter, Ludwig-Maximilians UniversityMartinsriedGermany
| | - Michael D Nodine
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3ViennaAustria
- Laboratory of Molecular Biology, Wageningen UniversityWageningenNetherlands
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25
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He K, Cao X, Deng X. Histone methylation in epigenetic regulation and temperature responses. CURRENT OPINION IN PLANT BIOLOGY 2021; 61:102001. [PMID: 33508540 DOI: 10.1016/j.pbi.2021.102001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/21/2020] [Accepted: 01/04/2021] [Indexed: 05/26/2023]
Abstract
Methylation of histones on different lysine residues is dynamically added by distinct writer enzymes, interpreted by reader proteins, and removed by eraser enzymes. This epigenetic mark has widespread, dynamic roles in plant development and environmental responses. For example, histone methylation plays a key role in mediating plant responses to temperature, including alterations of flowering time. In this review, we summarize recent advances in understanding the mechanism by which histone methylation regulates these processes, and discuss the role of histone methylation in temperature responses, based on data from Arabidopsis thaliana.
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Affiliation(s)
- Kaixuan He
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaofeng Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xian Deng
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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Butel N, Yu A, Le Masson I, Borges F, Elmayan T, Taochy C, Gursanscky NR, Cao J, Bi S, Sawyer A, Carroll BJ, Vaucheret H. Contrasting epigenetic control of transgenes and endogenous genes promotes post-transcriptional transgene silencing in Arabidopsis. Nat Commun 2021; 12:2787. [PMID: 33986281 PMCID: PMC8119426 DOI: 10.1038/s41467-021-22995-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 04/06/2021] [Indexed: 11/20/2022] Open
Abstract
Transgenes that are stably expressed in plant genomes over many generations could be assumed to behave epigenetically the same as endogenous genes. Here, we report that whereas the histone H3K9me2 demethylase IBM1, but not the histone H3K4me3 demethylase JMJ14, counteracts DNA methylation of Arabidopsis endogenous genes, JMJ14, but not IBM1, counteracts DNA methylation of expressed transgenes. Additionally, JMJ14-mediated specific attenuation of transgene DNA methylation enhances the production of aberrant RNAs that readily induce systemic post-transcriptional transgene silencing (PTGS). Thus, the JMJ14 chromatin modifying complex maintains expressed transgenes in a probationary state of susceptibility to PTGS, suggesting that the host plant genome does not immediately accept expressed transgenes as being epigenetically the same as endogenous genes. Accumulating evidences point to a discrepancy in the epigenetic behaviour of transgenes and endogenous genes. Here, via characterization of mutants impaired in histone demethylases JMJ14 and IBM1, the authors show that transgenes and endogenous genes are regulated by different epigenetic mechanisms in Arabidopsis.
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Affiliation(s)
- Nicolas Butel
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.,Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Agnès Yu
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Ivan Le Masson
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Filipe Borges
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Christelle Taochy
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Nial R Gursanscky
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Jiangling Cao
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Shengnan Bi
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Anne Sawyer
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.
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Baduel P, Colot V. The epiallelic potential of transposable elements and its evolutionary significance in plants. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200123. [PMID: 33866816 PMCID: PMC8059525 DOI: 10.1098/rstb.2020.0123] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
DNA provides the fundamental framework for heritability, yet heritable trait variation need not be completely ‘hard-wired’ into the DNA sequence. In plants, the epigenetic machinery that controls transposable element (TE) activity, and which includes DNA methylation, underpins most known cases of inherited trait variants that are independent of DNA sequence changes. Here, we review our current knowledge of the extent, mechanisms and potential adaptive contribution of epiallelic variation at TE-containing alleles in this group of species. For the purpose of this review, we focus mainly on DNA methylation, as it provides an easily quantifiable readout of such variation. The picture that emerges is complex. On the one hand, pronounced differences in DNA methylation at TE sequences can either occur spontaneously or be induced experimentally en masse across the genome through genetic means. Many of these epivariants are stably inherited over multiple sexual generations, thus leading to transgenerational epigenetic inheritance. Functional consequences can be significant, yet they are typically of limited magnitude and although the same epivariants can be found in nature, the factors involved in their generation in this setting remain to be determined. On the other hand, moderate DNA methylation variation at TE-containing alleles can be reproducibly induced by the environment, again usually with mild effects, and most of this variation tends to be lost across generations. Based on these considerations, we argue that TE-containing alleles, rather than their inherited epiallelic variants, are the main targets of natural selection. Thus, we propose that the adaptive contribution of TE-associated epivariation, whether stable or not, lies predominantly in its capacity to modulate TE mobilization in response to the environment, hence providing hard-wired opportunities for the flexible exploration of the phenotypic space. This article is part of the theme issue ‘How does epigenetics influence the course of evolution?’
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Affiliation(s)
- Pierre Baduel
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Ecole Normale Supérieure, PSL Research University, 75005 Paris, France
| | - Vincent Colot
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Ecole Normale Supérieure, PSL Research University, 75005 Paris, France
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28
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Galati S, Gullì M, Giannelli G, Furini A, DalCorso G, Fragni R, Buschini A, Visioli G. Heavy metals modulate DNA compaction and methylation at CpG sites in the metal hyperaccumulator Arabidopsis halleri. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:133-142. [PMID: 33389774 DOI: 10.1002/em.22421] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/14/2020] [Accepted: 12/26/2020] [Indexed: 06/12/2023]
Abstract
Excess heavy metals affect plant physiology by inducing stress symptoms, however several species have evolved the ability to hyperaccumulate metals in above-ground tissues without phytotoxic effects. In this study we assume that at subcellular level, different strategies were adopted by hyperaccumulator versus the non-accumulator plant species to face the excess of heavy metals. At this purpose the comet assay was used to investigate the nucleoid structure modifications occurring in response to Zn and Cd treatments in the I16 and PL22 populations of the hyperaccumulator Arabidopsis halleri versus the nonaccumulator species Arabidopsis thaliana. Methy-sens comet assay and RT-qPCR were also performed to associate metal induced variations in nucleoids with possible epigenetic modifications. The comet assay showed that Zn induced a mild but non significant reduction in the tail moment in A. thaliana and in both I16 and PL22. Cd treatment induced an increase in DNA migration in nuclei of A. thaliana, whereas no differences in DNA migration was observed for I16, and a significant increase in nucleoid condensation was found in PL22 Cd treated samples. This last population showed higher CpG DNA methylation upon Cd treatment than in control conditions, and an up-regulation of genes involved in symmetric methylation and histone deacetylation. Our data support the hypothesis of a possible role of epigenetic modifications in the hyperaccumulation trait to cope with the high Cd shoot concentrations. In addition, the differences observed between PL22 and I16 could reinforce previous suggestions of divergent strategies for metals detoxification developing in the two metallicolous populations.
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Affiliation(s)
- Serena Galati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Mariolina Gullì
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Gianluigi Giannelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Antonella Furini
- Department of Biotechnology, University of Verona, Verona, Italy
| | | | - Rosaria Fragni
- SSICA, Experimental Station for the Food Preserving Industry, Parma, Italy
| | - Annamaria Buschini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Giovanna Visioli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
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Cambiagno DA, Torres JR, Alvarez ME. Convergent Epigenetic Mechanisms Avoid Constitutive Expression of Immune Receptor Gene Subsets. FRONTIERS IN PLANT SCIENCE 2021; 12:703667. [PMID: 34557212 PMCID: PMC8452986 DOI: 10.3389/fpls.2021.703667] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/09/2021] [Indexed: 05/14/2023]
Abstract
The gene pool encoding PRR and NLR immune receptors determines the ability of a plant to resist microbial infections. Basal expression of these genes is prevented by diverse mechanisms since their hyperactivity can be harmful. To approach the study of epigenetic control of PRR/NLR genes we here analyzed their expression in mutants carrying abnormal repressive 5-methyl cytosine (5-mC) and histone 3 lysine 9 dimethylation (H3K9me2) marks, due to lack of MET1, CMT3, MOM1, SUVH4/5/6, or DDM1. At optimal growth conditions, none of the mutants showed basal expression of the defense gene marker PR1, but all of them had greater resistance to Pseudomonas syringae pv. tomato than wild type plants, suggesting they are primed to stimulate immune cascades. Consistently, analysis of available transcriptomes indicated that all mutants showed activation of particular PRR/NLR genes under some growth conditions. Under low defense activation, 37 PRR/NLR genes were expressed in these plants, but 29 of them were exclusively activated in specific mutants, indicating that MET1, CMT3, MOM1, SUVH4/5/6, and DDM1 mediate basal repression of different subsets of genes. Some epigenetic marks present at promoters, but not gene bodies, could explain the activation of these genes in the mutants. As expected, suvh4/5/6 and ddm1 activated genes carrying 5-mC and H3K9me2 marks in wild type plants. Surprisingly, all mutants expressed genes harboring promoter H2A.Z/H3K27me3 marks likely affected by the chromatin remodeler PIE1 and the histone demethylase REF6, respectively. Therefore, MET1, CMT3, MOM1, SUVH4/5/6, and DDM1, together with REF6, seemingly contribute to the establishment of chromatin states that prevent constitutive PRR/NLR gene activation, but facilitate their priming by modulating epigenetic marks at their promoters.
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Affiliation(s)
- Damián Alejandro Cambiagno
- Unidad de Estudios Agropecuarios (UDEA), INTA-CONICET, Córdoba, Argentina
- *Correspondence: Damián Alejandro Cambiagno,
| | - José Roberto Torres
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María Elena Alvarez
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
- María Elena Alvarez,
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30
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Borges F, Donoghue MTA, LeBlanc C, Wear EE, Tanurdžić M, Berube B, Brooks A, Thompson WF, Hanley-Bowdoin L, Martienssen RA. Loss of Small-RNA-Directed DNA Methylation in the Plant Cell Cycle Promotes Germline Reprogramming and Somaclonal Variation. Curr Biol 2020; 31:591-600.e4. [PMID: 33275892 DOI: 10.1016/j.cub.2020.10.098] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/24/2020] [Accepted: 10/30/2020] [Indexed: 02/07/2023]
Abstract
5-methyl cytosine is widespread in plant genomes in both CG and non-CG contexts. During replication, hemi-methylation on parental DNA strands guides symmetric CG methylation on nascent strands, but non-CG methylation requires modified histones and small RNA guides. Here, we used immortalized Arabidopsis cell suspensions to sort replicating nuclei and determine genome-wide cytosine methylation dynamics during the plant cell cycle. We find that symmetric mCG and mCHG are selectively retained in actively dividing cells in culture, whereas mCHH is depleted. mCG becomes transiently asymmetric during S phase but is rapidly restored in G2, whereas mCHG remains asymmetric throughout the cell cycle. Hundreds of loci gain ectopic CHG methylation, as well as 24-nt small interfering RNAs (siRNAs) and histone H3 lysine dimethylation (H3K9me2), without gaining CHH methylation. This suggests that spontaneous epialleles that arise in plant cell cultures are stably maintained by siRNA and H3K9me2 independent of the canonical RNA-directed DNA methylation (RdDM) pathway. In contrast, loci that fail to produce siRNA may be targeted for demethylation when the cell cycle arrests. Comparative analysis with methylomes of various tissues and cell types suggests that loss of small-RNA-directed non-CG methylation during DNA replication promotes germline reprogramming and epigenetic variation in plants propagated as clones.
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Affiliation(s)
- Filipe Borges
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA; Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Mark T A Donoghue
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Chantal LeBlanc
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Emily E Wear
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Milos Tanurdžić
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Benjamin Berube
- Cold Spring Harbor Laboratory School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Ashley Brooks
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - William F Thompson
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Robert A Martienssen
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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31
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To TK, Nishizawa Y, Inagaki S, Tarutani Y, Tominaga S, Toyoda A, Fujiyama A, Berger F, Kakutani T. RNA interference-independent reprogramming of DNA methylation in Arabidopsis. NATURE PLANTS 2020; 6:1455-1467. [PMID: 33257860 DOI: 10.1038/s41477-020-00810-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/16/2020] [Indexed: 06/12/2023]
Abstract
DNA methylation is important for silencing transposable elements (TEs) in diverse eukaryotes, including plants. In plant genomes, TEs are silenced by methylation of histone H3 lysine 9 (H3K9) and cytosines in both CG and non-CG contexts. The role of RNA interference (RNAi) in establishing TE-specific silent marks has been extensively studied, but the importance of RNAi-independent pathways remains largely unexplored. Here, we directly investigated transgenerational de novo DNA methylation of TEs after the loss of silent marks. Our analyses uncovered potent and precise RNAi-independent pathways for recovering non-CG methylation and H3K9 methylation in most TE genes (that is, coding regions within TEs). Characterization of a subset of TE genes without the recovery revealed the effects of H3K9 demethylation, replacement of histone H2A variants and their interaction with CG methylation, together with feedback from transcription. These chromatin components are conserved among eukaryotes and may contribute to chromatin reprogramming in a conserved manner.
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Affiliation(s)
- Taiko Kim To
- Department of Biological Sciences, The University of Tokyo, Tokyo, Japan.
| | - Yuichiro Nishizawa
- Department of Biological Sciences, The University of Tokyo, Tokyo, Japan
| | - Soichi Inagaki
- Department of Biological Sciences, The University of Tokyo, Tokyo, Japan
- Department of Integrated Genetics, National Institute of Genetics (NIG), Mishima, Shizuoka, Japan
- PREST, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Yoshiaki Tarutani
- Department of Integrated Genetics, National Institute of Genetics (NIG), Mishima, Shizuoka, Japan
| | - Sayaka Tominaga
- Department of Biological Sciences, The University of Tokyo, Tokyo, Japan
| | - Atsushi Toyoda
- Center for Genetic Resource Information, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Asao Fujiyama
- Center for Genetic Resource Information, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna, Austria
| | - Tetsuji Kakutani
- Department of Biological Sciences, The University of Tokyo, Tokyo, Japan.
- Department of Integrated Genetics, National Institute of Genetics (NIG), Mishima, Shizuoka, Japan.
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32
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Epigenetics and epigenomics: underlying mechanisms, relevance, and implications in crop improvement. Funct Integr Genomics 2020; 20:739-761. [PMID: 33089419 DOI: 10.1007/s10142-020-00756-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 01/21/2023]
Abstract
Epigenetics is defined as changes in gene expression that are not associated with changes in DNA sequence but due to the result of methylation of DNA and post-translational modifications to the histones. These epigenetic modifications are known to regulate gene expression by bringing changes in the chromatin state, which underlies plant development and shapes phenotypic plasticity in responses to the environment and internal cues. This review articulates the role of histone modifications and DNA methylation in modulating biotic and abiotic stresses, as well as crop improvement. It also highlights the possibility of engineering epigenomes and epigenome-based predictive models for improving agronomic traits.
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Lai Y, Lu XM, Daron J, Pan S, Wang J, Wang W, Tsuchiya T, Holub E, McDowell JM, Slotkin RK, Le Roch KG, Eulgem T. The Arabidopsis PHD-finger protein EDM2 has multiple roles in balancing NLR immune receptor gene expression. PLoS Genet 2020; 16:e1008993. [PMID: 32925902 PMCID: PMC7529245 DOI: 10.1371/journal.pgen.1008993] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/01/2020] [Accepted: 07/14/2020] [Indexed: 12/19/2022] Open
Abstract
Plant NLR-type receptors serve as sensitive triggers of host immunity. Their expression has to be well-balanced, due to their interference with various cellular processes and dose-dependency of their defense-inducing activity. A genetic “arms race” with fast-evolving pathogenic microbes requires plants to constantly innovate their NLR repertoires. We previously showed that insertion of the COPIA-R7 retrotransposon into RPP7 co-opted the epigenetic transposon silencing signal H3K9me2 to a new function promoting expression of this Arabidopsis thaliana NLR gene. Recruitment of the histone binding protein EDM2 to COPIA-R7-associated H3K9me2 is required for optimal expression of RPP7. By profiling of genome-wide effects of EDM2, we now uncovered additional examples illustrating effects of transposons on NLR gene expression, strongly suggesting that these mobile elements can play critical roles in the rapid evolution of plant NLR genes by providing the “raw material” for gene expression mechanisms. We further found EDM2 to have a global role in NLR expression control. Besides serving as a positive regulator of RPP7 and a small number of other NLR genes, EDM2 acts as a suppressor of a multitude of additional NLR genes. We speculate that the dual functionality of EDM2 in NLR expression control arose from the need to compensate for fitness penalties caused by high expression of some NLR genes by suppression of others. Moreover, we are providing new insights into functional relationships of EDM2 with its interaction partner, the RNA binding protein EDM3/AIPP1, and its target gene IBM1, encoding an H3K9-demethylase. We previously found the Arabidopsis thaliana PHD-finger protein EDM2 to serve as a chromatin-associated factor controlling expression of the NLR-type immune receptor gene RPP7. EDM2 binds to the transposon-silencing signal H3K9me2 and affects levels of this epigenetic mark at various loci. By genome-wide profiling of transcript- and H3K9me2-levels we now found EDM2 to have a broader role in controlling NLR gene expression. In order to mitigate fitness costs caused by its promoting effects on RPP7 expression and that of several other NLR genes, EDM2 seems to suppress expression of many additional members of this gene family. This observation is in line with multiple reports demonstrating the need for balanced expression of NLRs, which can substantially reduce overall plant fitness, but need to be present at certain minimal levels to confer sufficient immune protection. Our previous results demonstrated that the influence of EDM2 on RPP7 expression was co-opted to this immune receptor gene by the insertion of an EDM2-controlled transposon. Here, we are providing additional examples for transposon-associated effects on NLR gene expression, suggesting that these mobile elements play an important role for NLR genes by equipping members of this rapidly evolving gene family with regulatory mechanisms needed for balanced expression.
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Affiliation(s)
- Yan Lai
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plan Sciences, University of California at Riverside, Riverside, CA, United States of America
- College of Life Sciences, Fujian Agricultural and Forestry University, Fuzhou, Fujian, China
| | - Xueqing Maggie Lu
- Center for Infectious Disease and Vector Research, Institute of Integrative Genome Biology, Department of Molecular, Cell and Systems Biology, University of California at Riverside, Riverside, CA, United States of America
| | - Josquin Daron
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Songqin Pan
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plan Sciences, University of California at Riverside, Riverside, CA, United States of America
| | - Jianqiang Wang
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plan Sciences, University of California at Riverside, Riverside, CA, United States of America
| | - Wei Wang
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, United States of America
| | - Tokuji Tsuchiya
- College of Bioresource Sciences, Nihon University, Kanagawa, Japan
| | - Eric Holub
- School of Life Sciences, University of Warwick, Wellesbourne campus, United Kingdom
| | - John M. McDowell
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, United States of America
| | - R. Keith Slotkin
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Donald Danforth Plant Science Center, St. Louis, Missouri, United States of America
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Karine G. Le Roch
- Center for Infectious Disease and Vector Research, Institute of Integrative Genome Biology, Department of Molecular, Cell and Systems Biology, University of California at Riverside, Riverside, CA, United States of America
- * E-mail: (KGLR); (TE)
| | - Thomas Eulgem
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plan Sciences, University of California at Riverside, Riverside, CA, United States of America
- * E-mail: (KGLR); (TE)
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34
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Rambani A, Pantalone V, Yang S, Rice JH, Song Q, Mazarei M, Arelli PR, Meksem K, Stewart CN, Hewezi T. Identification of introduced and stably inherited DNA methylation variants in soybean associated with soybean cyst nematode parasitism. THE NEW PHYTOLOGIST 2020; 227:168-184. [PMID: 32112408 DOI: 10.1111/nph.16511] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
DNA methylation is a widespread epigenetic mark that contributes to transcriptome reprogramming during plant-pathogen interactions. However, the distinct role of DNA methylation in establishing resistant and susceptible responses remains largely unexplored. Here, we developed and used a pair of near-isogenic lines (NILs) to characterize DNA methylome landscapes of soybean roots during the susceptible and resistant interactions with soybean cyst nematode (SCN; Heterodera glycines). We also compared the methylomes of the NILs and their parents to identify introduced and stably inherited methylation variants. The genomes of the NILs were substantially differentially methylated under uninfected conditions. This difference was associated with differential gene expression that may prime the NIL responses to SCN infection. In response to SCN infection, the susceptible line exhibited reduced global methylation levels in both protein-coding genes and transposable elements, whereas the resistant line showed the opposite response, increased global methylation levels. Heritable and novel nonparental differentially methylated regions overlapping with genes associated with soybean response to SCN infection were identified and validated using transgenic hairy root system. Our analyses indicate that DNA methylation patterns associated with the susceptible and resistant interactions are highly specific and that novel and stably inherited methylation variants are of biological significance.
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Affiliation(s)
- Aditi Rambani
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Vince Pantalone
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Songnan Yang
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - J Hollis Rice
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Qijian Song
- Soybean Genomics and Improvement Laboratory, USDA-ARS, Beltsville Agricultural Research Center, Beltsville, MD, 20705, USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | | | - Khalid Meksem
- Department of Plant, Soil, and Agricultural Systems, Southern Illinois University, Carbondale, IL, 62901, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tarek Hewezi
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
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Espinas NA, Tu LN, Furci L, Shimajiri Y, Harukawa Y, Miura S, Takuno S, Saze H. Transcriptional regulation of genes bearing intronic heterochromatin in the rice genome. PLoS Genet 2020; 16:e1008637. [PMID: 32187179 PMCID: PMC7145194 DOI: 10.1371/journal.pgen.1008637] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 04/09/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Intronic regions of eukaryotic genomes accumulate many Transposable Elements (TEs). Intronic TEs often trigger the formation of transcriptionally repressive heterochromatin, even within transcription-permissive chromatin environments. Although TE-bearing introns are widely observed in eukaryotic genomes, their epigenetic states, impacts on gene regulation and function, and their contributions to genetic diversity and evolution, remain poorly understood. In this study, we investigated the genome-wide distribution of intronic TEs and their epigenetic states in the Oryza sativa genome, where TEs comprise 35% of the genome. We found that over 10% of rice genes contain intronic heterochromatin, most of which are associated with TEs and repetitive sequences. These heterochromatic introns are longer and highly enriched in promoter-proximal positions. On the other hand, introns also accumulate hypomethylated short TEs. Genes with heterochromatic introns are implicated in various biological functions. Transcription of genes bearing intronic heterochromatin is regulated by an epigenetic mechanism involving the conserved factor OsIBM2, mutation of which results in severe developmental and reproductive defects. Furthermore, we found that heterochromatic introns evolve rapidly compared to non-heterochromatic introns. Our study demonstrates that heterochromatin is a common epigenetic feature associated with actively transcribed genes in the rice genome.
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Affiliation(s)
- Nino A. Espinas
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science (CSRS), Yokohama city, Kanagawa, Japan
| | - Le Ngoc Tu
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Leonardo Furci
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Yasuka Shimajiri
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- EditForce, Fukuoka, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Shohei Takuno
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
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Natural variation in DNA methylation homeostasis and the emergence of epialleles. Proc Natl Acad Sci U S A 2020; 117:4874-4884. [PMID: 32071208 DOI: 10.1073/pnas.1918172117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In plants and mammals, DNA methylation plays a critical role in transcriptional silencing by delineating heterochromatin from transcriptionally active euchromatin. A homeostatic balance between heterochromatin and euchromatin is essential to genomic stability. This is evident in many diseases and mutants for heterochromatin maintenance, which are characterized by global losses of DNA methylation coupled with localized ectopic gains of DNA methylation that alter transcription. Furthermore, we have shown that genome-wide methylation patterns in Arabidopsis thaliana are highly stable over generations, with the exception of rare epialleles. However, the extent to which natural variation in the robustness of targeting DNA methylation to heterochromatin exists, and the phenotypic consequences of such variation, remain to be fully explored. Here we describe the finding that heterochromatin and genic DNA methylation are highly variable among 725 A. thaliana accessions. We found that genic DNA methylation is inversely correlated with that in heterochromatin, suggesting that certain methylation pathway(s) may be redirected to genes upon the loss of heterochromatin. This redistribution likely involves a feedback loop involving the DNA methyltransferase, CHROMOMETHYLASE 3 (CMT3), H3K9me2, and histone turnover, as highly expressed, long genes with a high density of CMT3-preferred CWG sites are more likely to be methylated. Importantly, although the presence of CG methylation in genes alone may not affect transcription, genes containing CG methylation are more likely to become methylated at non-CG sites and silenced. These findings are consistent with the hypothesis that natural variation in DNA methylation homeostasis may underlie the evolution of epialleles that alter phenotypes.
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Cheng K, Xu Y, Yang C, Ouellette L, Niu L, Zhou X, Chu L, Zhuang F, Liu J, Wu H, Charron JB, Luo M. Histone tales: lysine methylation, a protagonist in Arabidopsis development. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:793-807. [PMID: 31560751 DOI: 10.1093/jxb/erz435] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 09/17/2019] [Indexed: 05/20/2023]
Abstract
Histone methylation plays a fundamental role in the epigenetic regulation of gene expression driven by developmental and environmental cues in plants, including Arabidopsis. Histone methyltransferases and demethylases act as 'writers' and 'erasers' of methylation at lysine and/or arginine residues of core histones, respectively. A third group of proteins, the 'readers', recognize and interpret the methylation marks. Emerging evidence confirms the crucial roles of histone methylation in multiple biological processes throughout the plant life cycle. In this review, we summarize the regulatory mechanisms of lysine methylation, especially at histone H3 tails, and focus on the recent advances regarding the roles of lysine methylation in Arabidopsis development, from seed performance to reproductive development, and in callus formation.
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Affiliation(s)
- Kai Cheng
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Yingchao Xu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chao Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Luc Ouellette
- Department of Plant Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Longjian Niu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Xiaochen Zhou
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liutian Chu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Feng Zhuang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jin Liu
- Institute for Food and Bioresource Engineering, Department of Energy and Resources Engineering and BIC-ESAT, College of Engineering, Peking University, Beijing, China
| | - Hualing Wu
- Tea Research Institute, Guangdong Academy of Agricultural Sciences; Guangdong Key Laboratory of Tea Plant Resources Innovation & Utilization, Guangzhou, Guangdong, China
| | - Jean-Benoit Charron
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Ming Luo
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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Chan C, Zimmerli L. The Histone Demethylase IBM1 Positively Regulates Arabidopsis Immunity by Control of Defense Gene Expression. FRONTIERS IN PLANT SCIENCE 2019; 10:1587. [PMID: 31956325 PMCID: PMC6951416 DOI: 10.3389/fpls.2019.01587] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/12/2019] [Indexed: 05/23/2023]
Abstract
Epigenetic modifications involve complex and sophisticated control over chromatin states and DNA methylation patterns, which are important for stress tolerance in plants. While the identification of epigenetic modulating enzymes keeps growing, such as MET1, for CG methylation; CMT3, DRM2, DRM3 for CHH methylation; and IBM1, SUVH4 for CHG methylation; the molecular roles of these regulators in specific physiological functions remain obscure. In a mutant screen, we identified IBM1 as a new player in plant immunity. The ibm1 mutants were hyper-susceptible to hemi-biotrophic bacteria Pseudomonas syringae. Accordingly, bacteria-induced up-regulation of PR1, PR2, and FRK1 defense markers was abolished in ibm1 mutants. Consistently, at the chromatin level, these defense marker genes showed enrichment of the inactivation mark, H3K9me2; while the activation mark H3K4me3 was reduced in ibm1 mutants. Immunoprecipitation of associated chromatin further demonstrated that IBM1 binds directly to the gene body of PR1, PR2, and FRK1. Taken together, these data suggest that IBM1 plays a critical role in modulating Arabidopsis immunity through direct regulation of defense gene expression. Notably, IBM1 maintains a permissive chromatin environment to ensure proper induction of defense genes under some biotic stress.
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Integrated Analysis of Small RNA, Transcriptome and Degradome Sequencing Provides New Insights into Floral Development and Abscission in Yellow Lupine ( Lupinus luteus L.). Int J Mol Sci 2019; 20:ijms20205122. [PMID: 31623090 PMCID: PMC6854478 DOI: 10.3390/ijms20205122] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/03/2019] [Accepted: 10/14/2019] [Indexed: 01/09/2023] Open
Abstract
The floral development in an important legume crop yellow lupine (Lupinus luteus L., Taper cv.) is often affected by the abscission of flowers leading to significant economic losses. Small non-coding RNAs (sncRNAs), which have a proven effect on almost all developmental processes in other plants, might be of key players in a complex net of molecular interactions regulating flower development and abscission. This study represents the first comprehensive sncRNA identification and analysis of small RNA, transcriptome and degradome sequencing data in lupine flowers to elucidate their role in the regulation of lupine generative development. As shedding in lupine primarily concerns flowers formed at the upper part of the inflorescence, we analyzed samples from extreme parts of raceme separately and conducted an additional analysis of pedicels from abscising and non-abscising flowers where abscission zone forms. A total of 394 known and 28 novel miRNAs and 316 phased siRNAs were identified. In flowers at different stages of development 59 miRNAs displayed differential expression (DE) and 46 DE miRNAs were found while comparing the upper and lower flowers. Identified tasiR-ARFs were DE in developing flowers and were strongly expressed in flower pedicels. The DEmiR-targeted genes were preferentially enriched in the functional categories related to carbohydrate metabolism and plant hormone transduction pathways. This study not only contributes to the current understanding of how lupine flowers develop or undergo abscission but also holds potential for research aimed at crop improvement.
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Hirakawa T, Kuwata K, Gallego ME, White CI, Nomoto M, Tada Y, Matsunaga S. LSD1-LIKE1-Mediated H3K4me2 Demethylation Is Required for Homologous Recombination Repair. PLANT PHYSIOLOGY 2019; 181:499-509. [PMID: 31366719 PMCID: PMC6776857 DOI: 10.1104/pp.19.00530] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/22/2019] [Indexed: 05/18/2023]
Abstract
Homologous recombination is a key process for maintaining genome integrity and diversity. In eukaryotes, the nucleosome structure of chromatin inhibits the progression of homologous recombination. The DNA repair and recombination protein RAD54 alters the chromatin structure via nucleosome sliding to enable homology searches. For homologous recombination to progress, appropriate recruitment and dissociation of RAD54 is required at the site of homologous recombination; however, little is known about the mechanism regulating RAD54 dynamics in chromatin. Here, we reveal that the histone demethylase LYSINE-SPECIFIC DEMETHYLASE1-LIKE 1 (LDL1) regulates the dissociation of RAD54 at damaged sites during homologous recombination repair in the somatic cells of Arabidopsis (Arabidopsis thaliana). Depletion of LDL1 leads to an overaccumulation of RAD54 at damaged sites with DNA double-strand breaks. Moreover, RAD54 accumulates at damaged sites by recognizing histone H3 Lys 4 di-methylation (H3K4me2); the frequency of the interaction between RAD54 and H3K4me2 increased in the ldl1 mutant with DNA double-strand breaks. We propose that LDL1 removes RAD54 at damaged sites by demethylating H3K4me2 during homologous recombination repair and thereby maintains genome stability in Arabidopsis.
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Affiliation(s)
- Takeshi Hirakawa
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Keiko Kuwata
- Institute of Transformative Bio-Molecules, Nagoya University, Nagoya 464-8601, Japan
| | - Maria E Gallego
- Génétique, Reproduction et Développement, Unité de Mixte de Recherche, Centre National de la Recherche Scientifique 6293, Clermont Université, Institut National de la Santé et de la Recherche Médicale U1103, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France
| | - Charles I White
- Génétique, Reproduction et Développement, Unité de Mixte de Recherche, Centre National de la Recherche Scientifique 6293, Clermont Université, Institut National de la Santé et de la Recherche Médicale U1103, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France
| | - Mika Nomoto
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Yasuomi Tada
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Sachihiro Matsunaga
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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Wendte JM, Zhang Y, Ji L, Shi X, Hazarika RR, Shahryary Y, Johannes F, Schmitz RJ. Epimutations are associated with CHROMOMETHYLASE 3-induced de novo DNA methylation. eLife 2019; 8:e47891. [PMID: 31356150 PMCID: PMC6663294 DOI: 10.7554/elife.47891] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/19/2019] [Indexed: 12/20/2022] Open
Abstract
In many plant species, a subset of transcribed genes are characterized by strictly CG-context DNA methylation, referred to as gene body methylation (gbM). The mechanisms that establish gbM are unclear, yet flowering plant species naturally without gbM lack the DNA methyltransferase, CMT3, which maintains CHG (H = A, C, or T) and not CG methylation at constitutive heterochromatin. Here, we identify the mechanistic basis for gbM establishment by expressing CMT3 in a species naturally lacking CMT3. CMT3 expression reconstituted gbM through a progression of de novo CHG methylation on expressed genes, followed by the accumulation of CG methylation that could be inherited even following loss of the CMT3 transgene. Thus, gbM likely originates from the simultaneous targeting of loci by pathways that promote euchromatin and heterochromatin, which primes genes for the formation of stably inherited epimutations in the form of CG DNA methylation.
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Affiliation(s)
- Jered M Wendte
- Department of GeneticsUniversity of GeorgiaAthensUnited States
| | - Yinwen Zhang
- Institute of BioinformaticsUniversity of GeorgiaAthensUnited States
| | - Lexiang Ji
- Institute of BioinformaticsUniversity of GeorgiaAthensUnited States
| | - Xiuling Shi
- Department of GeneticsUniversity of GeorgiaAthensUnited States
| | - Rashmi R Hazarika
- Department of Plant ScienceTechnical University of MunichFreisingGermany
| | - Yadollah Shahryary
- Department of Plant ScienceTechnical University of MunichFreisingGermany
| | - Frank Johannes
- Department of Plant ScienceTechnical University of MunichFreisingGermany
- Institute for Advanced StudyTechnical University of MunichGarchingGermany
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42
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Wendte JM, Zhang Y, Ji L, Shi X, Hazarika RR, Shahryary Y, Johannes F, Schmitz RJ. Epimutations are associated with CHROMOMETHYLASE 3-induced de novo DNA methylation. eLife 2019. [PMID: 31356150 DOI: 10.7554/elife.47891.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
In many plant species, a subset of transcribed genes are characterized by strictly CG-context DNA methylation, referred to as gene body methylation (gbM). The mechanisms that establish gbM are unclear, yet flowering plant species naturally without gbM lack the DNA methyltransferase, CMT3, which maintains CHG (H = A, C, or T) and not CG methylation at constitutive heterochromatin. Here, we identify the mechanistic basis for gbM establishment by expressing CMT3 in a species naturally lacking CMT3. CMT3 expression reconstituted gbM through a progression of de novo CHG methylation on expressed genes, followed by the accumulation of CG methylation that could be inherited even following loss of the CMT3 transgene. Thus, gbM likely originates from the simultaneous targeting of loci by pathways that promote euchromatin and heterochromatin, which primes genes for the formation of stably inherited epimutations in the form of CG DNA methylation.
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Affiliation(s)
- Jered M Wendte
- Department of Genetics, University of Georgia, Athens, United States
| | - Yinwen Zhang
- Institute of Bioinformatics, University of Georgia, Athens, United States
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens, United States
| | - Xiuling Shi
- Department of Genetics, University of Georgia, Athens, United States
| | - Rashmi R Hazarika
- Department of Plant Science, Technical University of Munich, Freising, Germany
| | - Yadollah Shahryary
- Department of Plant Science, Technical University of Munich, Freising, Germany
| | - Frank Johannes
- Department of Plant Science, Technical University of Munich, Freising, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, United States
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Ito T, Nishio H, Tarutani Y, Emura N, Honjo MN, Toyoda A, Fujiyama A, Kakutani T, Kudoh H. Seasonal Stability and Dynamics of DNA Methylation in Plants in a Natural Environment. Genes (Basel) 2019; 10:genes10070544. [PMID: 31319612 PMCID: PMC6679105 DOI: 10.3390/genes10070544] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/14/2019] [Accepted: 07/15/2019] [Indexed: 12/21/2022] Open
Abstract
DNA methylation has been considered a stable epigenetic mark but may respond to fluctuating environments. However, it is unclear how they behave in natural environments. Here, we analyzed seasonal patterns of genome-wide DNA methylation in a single clone from a natural population of the perennial Arabidopsis halleri. The genome-wide pattern of DNA methylation was primarily stable, and most of the repetitive regions were methylated across the year. Although the proportion was small, we detected seasonally methylated cytosines (SeMCs) in the genome. SeMCs in the CHH context were detected predominantly at repetitive sequences in intergenic regions. In contrast, gene-body CG methylation (gbM) itself was generally stable across seasons, but the levels of gbM were positively associated with seasonal stability of RNA expression of the genes. These results suggest the existence of two distinct aspects of DNA methylation in natural environments: sources of epigenetic variation and epigenetic marks for stable gene expression.
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Affiliation(s)
- Tasuku Ito
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan
| | - Haruki Nishio
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan
| | - Yoshiaki Tarutani
- Department of Chromosome Science, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Naoko Emura
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan
- Department of Environmental Sciences and Technology, Faculty of Agriculture, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan
| | - Mie N Honjo
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Asao Fujiyama
- Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Tetsuji Kakutani
- Department of Chromosome Science, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Kudoh
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan.
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Regulation of ectopic heterochromatin-mediated epigenetic diversification by the JmjC family protein Epe1. PLoS Genet 2019; 15:e1008129. [PMID: 31206516 PMCID: PMC6576747 DOI: 10.1371/journal.pgen.1008129] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 04/09/2019] [Indexed: 01/28/2023] Open
Abstract
H3K9 methylation (H3K9me) is a conserved marker of heterochromatin, a transcriptionally silent chromatin structure. Knowledge of the mechanisms for regulating heterochromatin distribution is limited. The fission yeast JmjC domain-containing protein Epe1 localizes to heterochromatin mainly through its interaction with Swi6, a homologue of heterochromatin protein 1 (HP1), and directs JmjC-mediated H3K9me demethylation in vivo. Here, we found that loss of epe1 (epe1Δ) induced a red-white variegated phenotype in a red-pigment accumulation background that generated uniform red colonies. Analysis of isolated red and white colonies revealed that silencing of genes involved in pigment accumulation by stochastic ectopic heterochromatin formation led to white colony formation. In addition, genome-wide analysis of red- and white-isolated clones revealed that epe1Δ resulted in a heterogeneous heterochromatin distribution among clones. We found that Epe1 had an N-terminal domain distinct from its JmjC domain, which activated transcription in both fission and budding yeasts. The N-terminal transcriptional activation (NTA) domain was involved in suppression of ectopic heterochromatin-mediated red-white variegation. We introduced a single copy of Epe1 into epe1Δ clones harboring ectopic heterochromatin, and found that Epe1 could reduce H3K9me from ectopic heterochromatin but some of the heterochromatin persisted. This persistence was due to a latent H3K9me source embedded in ectopic heterochromatin. Epe1H297A, a canonical JmjC mutant, suppressed red-white variegation, but entirely failed to remove already-established ectopic heterochromatin, suggesting that Epe1 prevented stochastic de novo deposition of ectopic H3K9me in an NTA-dependent but JmjC-independent manner, while its JmjC domain mediated removal of H3K9me from established ectopic heterochromatin. Our results suggest that Epe1 not only limits the distribution of heterochromatin but also controls the balance between suppression and retention of heterochromatin-mediated epigenetic diversification. Suppression of unscheduled epigenetic alterations is important for maintenance of homogeneity among clones, while emergence of epigenetic differences is also important for adaptation or differentiation. The mechanisms that balance both processes warrant further investigation. Epe1, a fission yeast JmjC domain-containing protein, is thought to be an H3K9me demethylase that targets ectopic heterochromatin via its JmjC-dependent demethylation function. Here we found that loss of epe1 induced stochastic ectopic heterochromatin formation genome-wide, suggesting that the fission yeast genome had multiple potential heterochromatin formation sites, which were protected by Epe1. We found that Epe1 prevented deposition of ectopic H3K9me independently of its JmjC-mediated demethylation before heterochromatin establishment. By contrast, Epe1 could attack already-established ectopic heterochromatin via its JmjC domain, but demethylation was not 100% effective, which provided a basis for epigenetic variation. Together, our findings indicate that Epe1 is involved in both maintenance and alteration of heterochromatin distribution, and shed light on the mechanisms controlling individual-specific epigenome profiles.
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Deremetz A, Le Roux C, Idir Y, Brousse C, Agorio A, Gy I, Parker JE, Bouché N. Antagonistic Actions of FPA and IBM2 Regulate Transcript Processing from Genes Containing Heterochromatin. PLANT PHYSIOLOGY 2019; 180:392-403. [PMID: 30814131 PMCID: PMC6501070 DOI: 10.1104/pp.18.01106] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 02/21/2019] [Indexed: 05/06/2023]
Abstract
Repressive epigenetic marks, such as DNA and histone methylation, are sometimes located within introns. In Arabidopsis (Arabidopsis thaliana), INCREASE IN BONSAI METHYLATION2 (IBM2), an RNA-binding protein containing a bromo-adjacent homology domain, is required to process functional transcript isoforms of genes carrying intronic heterochromatin. In a genetic screen for suppressors of the ibm2 mutation, we identified FPA, an RNA-binding protein that promotes use of proximal polyadenylation sites in genes targeted by IBM2, including IBM1 encoding an essential H3K9 histone demethylase and the disease resistance gene RECOGNITION OF PERONOSPORA PARASITICA7 Both IBM2 and FPA are involved in the processing of their common mRNA targets: Transcription of IBM2 target genes is restored when FPA is mutated in ibm2 and impaired in transgenic plants overexpressing FPA By contrast, transposons targeted by IBM2 and localized outside introns are not under this antagonistic control. The DNA methylation patterns of some genes and transposons are modified in fpa plants, including the large intron of IBM1, but these changes are rather limited and reversed when the mutant is complemented, indicating that FPA has a restricted role in mediating silencing. These data reveal a complex regulation by IBM2 and FPA pathways in processing mRNAs of genes bearing heterochromatic marks.
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Affiliation(s)
- Aurélie Deremetz
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
- Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Clémentine Le Roux
- Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, D-50829 Cologne, Germany
| | - Yassir Idir
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
- Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Cécile Brousse
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
| | - Astrid Agorio
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
| | - Isabelle Gy
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
| | - Jane E Parker
- Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, D-50829 Cologne, Germany
| | - Nicolas Bouché
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique, 78000 Versailles, France
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Smith LM. Epigenetic Regulation of mRNA Polyadenylation Site Selection. PLANT PHYSIOLOGY 2019; 180:7-9. [PMID: 31053672 PMCID: PMC6501073 DOI: 10.1104/pp.19.00374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Lisa M Smith
- Department of Animal and Plant Sciences and The Plant Production and Protection (P3) Centre, University of Sheffield, Sheffield, United Kingdom
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Primed histone demethylation regulates shoot regenerative competency. Nat Commun 2019; 10:1786. [PMID: 30992430 PMCID: PMC6467990 DOI: 10.1038/s41467-019-09386-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 03/07/2019] [Indexed: 01/09/2023] Open
Abstract
Acquisition of pluripotency by somatic cells is a striking process that enables multicellular organisms to regenerate organs. This process includes silencing of genes to erase original tissue memory and priming of additional cell type specification genes, which are then poised for activation by external signal inputs. Here, through analysis of genome-wide histone modifications and gene expression profiles, we show that a gene priming mechanism involving LYSINE-SPECIFIC DEMETHYLASE 1-LIKE 3 (LDL3) specifically eliminates H3K4me2 during formation of the intermediate pluripotent cell mass known as callus derived from Arabidopsis root cells. While LDL3-mediated H3K4me2 removal does not immediately affect gene expression, it does facilitate the later activation of genes that act to form shoot progenitors when external cues lead to shoot induction. These results give insights into the role of H3K4 methylation in plants, and into the primed state that provides plant cells with high regenerative competency. Plant regeneration can occur via formation of a mass of pluripotent cells known as callus. Here, Ishihara et al. show that acquisition of regenerative capacity of callus-forming cells requires a lysine-specific demethylase that removes H3K4me2 to prime gene expression in response to regenerative cues.
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Qian Y, Chen C, Jiang L, Zhang J, Ren Q. Genome-wide identification, classification and expression analysis of the JmjC domain-containing histone demethylase gene family in maize. BMC Genomics 2019; 20:256. [PMID: 30935385 PMCID: PMC6444447 DOI: 10.1186/s12864-019-5633-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 03/21/2019] [Indexed: 12/31/2022] Open
Abstract
Background Histone methylation mainly occurs on the lysine residues and plays a crucial role during flowering and stress responses of plants, through changing the methylation status or ratio of lysine residues. Histone lysine residues of plants can arise in three forms of methylation (single, double and triple) and the corresponding demethylation can also ensue on certain occasions, by which the plants can accommodate the homeostasis of histone methylation by means of lysine methyltransferase and demethylase. The JmjC domain-containing proteins, an important family of histone lysine demethylases, play a vital role in maintaining homeostasis of histone methylation in vivo. Results In this study, we have identified 19 JmjC domain-containing histone demethylase (JHDM) proteins in maize. Based on structural characteristics and a comparison of phylogenetic relationships of JHDM gene families from Arabidopsis, rice and maize, all 19 JHDM proteins in maize were categorized into three different subfamilies. Furthermore, chromosome location and schematic structure revealed an unevenly distribution on chromosomes and structure features of ZmJMJ genes in maize, respectively. Eventually, the 19 ZmJMJ genes displayed different expression patterns at diverse developmental stages of maize based on transcriptome analysis. Further, quantitative real-time PCR analysis showed that all 19 ZmJMJ genes were responsive to heat stress treatment, suggesting their potential roles in heat stress response. Conclusions Overall, our study will serve to present an important theoretical basis for future functional verification of JHDM genes to further unravel the mechanisms of epigenetic regulation in plants. Electronic supplementary material The online version of this article (10.1186/s12864-019-5633-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yexiong Qian
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China.
| | - Changle Chen
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China
| | - Lingyu Jiang
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China
| | - Jing Zhang
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China
| | - Qiaoyu Ren
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China
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Genome defense against integrated organellar DNA fragments from plastids into plant nuclear genomes through DNA methylation. Sci Rep 2019; 9:2060. [PMID: 30765781 PMCID: PMC6376042 DOI: 10.1038/s41598-019-38607-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 12/31/2018] [Indexed: 01/09/2023] Open
Abstract
Nuclear genomes are always faced with the modification of themselves by insertions and integrations of foreign DNAs and intrinsic parasites such as transposable elements. There is also substantial number of integrations from symbiotic organellar genomes to their host nuclear genomes. Such integration might have acted as a beneficial mutation during the evolution of symbiosis, while most of them have more or less deleterious effects on the stability of current genomes. Here we report the pattern of DNA substitution and methylation on organellar DNA fragments integrated from plastid into plant nuclear genomes. The genome analyses of 17 plants show homology–dependent DNA substitution bias. A certain number of these sequences are DNA methylated in the nuclear genome. The intensity of DNA methylation also decays according to the increase of relative evolutionary times after being integrated into nuclear genomes. The methylome data of epigenetic mutants shows that the DNA methylation of organellar DNA fragments in nuclear genomes are mainly dependent on the methylation maintenance machinery, while other mechanisms may also affect on the DNA methylation level. The DNA methylation on organellar DNA fragments may contribute to maintaining the genome stability and evolutionary dynamics of symbiotic organellar and their host’s genomes.
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Fan D, Wang X, Tang X, Ye X, Ren S, Wang D, Luo K. Histone H3K9 demethylase JMJ25 epigenetically modulates anthocyanin biosynthesis in poplar. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:1121-1136. [PMID: 30218582 DOI: 10.1111/tpj.14092] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/26/2018] [Accepted: 09/06/2018] [Indexed: 05/20/2023]
Abstract
Anthocyanins are involved in several aspects of development and defence in poplar (Populus spp.). Although, over the past decades, significant progress has been made in uncovering these anthocyanin biosynthetic and regulatory mechanisms, the fundamental understanding of the epigenetic regulation in this pathway is still largely unclear. Here, we isolated a histone H3K9 demethylase gene JMJ25 from Populus and characterized its role in anthocyanin biosynthesis by genetic and biochemical approaches. JMJ25 was induced by continuous dark treatment. Overexpression of JMJ25 led to downregulated expression of anthocyanin biosynthetic genes in transgenic poplar, resulting in a significant reduction in anthocyanin content. ChIP-qPCR assays showed that JMJ25 could directly associate with MYB182 chromatin and dynamically demethylate at H3K9me2. Furthermore, JMJ25 also affected the DNA methylation levels of MYB182. By contrast, knockout of JMJ25 by CRISPR/Cas9 resulted in ectopic anthocyanin accumulation under dark condition and increased expression of anthocyanin biosynthetic genes. Our results support a model in which JMJ25 directly affects MYB182 expression by altering the histone methylation status of its chromatin and DNA methylation, resulting in repression of anthocyanin accumulation. This study uncovered an epigenetic mechanism that modulates anthocyanin biosynthesis in poplar.
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Affiliation(s)
- Di Fan
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xianqiang Wang
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiaofeng Tang
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiao Ye
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Sha Ren
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Denghui Wang
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Keming Luo
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China
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