201
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Choi K. Advances towards Controlling Meiotic Recombination for Plant Breeding. Mol Cells 2017; 40:814-822. [PMID: 29179262 PMCID: PMC5712510 DOI: 10.14348/molcells.2017.0171] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/10/2017] [Accepted: 11/17/2017] [Indexed: 12/28/2022] Open
Abstract
Meiotic homologous recombination generates new combinations of preexisting genetic variation and is a crucial process in plant breeding. Within the last decade, our understanding of plant meiotic recombination and genome diversity has advanced considerably. Innovation in DNA sequencing technology has led to the exploration of high-resolution genetic and epigenetic information in plant genomes, which has helped to accelerate plant breeding practices via high-throughput genotyping, and linkage and association mapping. In addition, great advances toward understanding the genetic and epigenetic control mechanisms of meiotic recombination have enabled the expansion of breeding programs and the unlocking of genetic diversity that can be used for crop improvement. This review highlights the recent literature on plant meiotic recombination and discusses the translation of this knowledge to the manipulation of meiotic recombination frequency and location with regards to crop plant breeding.
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Affiliation(s)
- Kyuha Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
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202
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Song X, Huang F, Liu J, Li C, Gao S, Wu W, Zhai M, Yu X, Xiong W, Xie J, Li B. Genome-wide DNA methylomes from discrete developmental stages reveal the predominance of non-CpG methylation in Tribolium castaneum. DNA Res 2017; 24:445-457. [PMID: 28449092 PMCID: PMC5737696 DOI: 10.1093/dnares/dsx016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/29/2017] [Indexed: 12/18/2022] Open
Abstract
Cytosine DNA methylation is a vital epigenetic regulator of eukaryotic development. Whether this epigenetic modification occurs in Tribolium castaneum has been controversial, its distribution pattern and functions have not been established. Here, using bisulphite sequencing (BS-Seq), we confirmed the existence of DNA methylation and described the methylation profiles of the four life stages of T. castaneum. In the T. castaneum genome, both symmetrical CpG and non-CpG methylcytosines were observed. Symmetrical CpG methylation, which was catalysed by DNMT1 and occupied a small part in T. castaneum methylome, was primarily enriched in gene bodies and was positively correlated with gene expression levels. Asymmetrical non-CpG methylation, which was predominant in the methylome, was strongly concentrated in intergenic regions and introns but absent from exons. Gene body methylation was negatively correlated with gene expression levels. The distribution pattern and functions of this type of methylation were similar only to the methylome of Drosophila melanogaster, which further supports the existence of a novel methyltransferase in the two species responsible for this type of methylation. This first life-cycle methylome of T. castaneum reveals a novel and unique methylation pattern, which will contribute to the further understanding of the variety and functions of DNA methylation in eukaryotes.
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Affiliation(s)
- Xiaowen Song
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Fei Huang
- Total Genomics Solution (TGS) Institute, Bioinformatics Department, Shenzhen 518083, China
| | - Juanjuan Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Chengjun Li
- Institute of Life Sciences, School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Shanshan Gao
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Wei Wu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Mengfan Zhai
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Xiaojuan Yu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Wenfeng Xiong
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Jia Xie
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Bin Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
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203
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Cavalieri V, Spinelli G. Environmental epigenetics in zebrafish. Epigenetics Chromatin 2017; 10:46. [PMID: 28982377 PMCID: PMC5629768 DOI: 10.1186/s13072-017-0154-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/27/2017] [Indexed: 02/06/2023] Open
Abstract
It is widely accepted that the epigenome can act as the link between environmental cues, both external and internal, to the organism and phenotype by converting the environmental stimuli to phenotypic responses through changes in gene transcription outcomes. Environmental stress endured by individual organisms can also enforce epigenetic variations in offspring that had never experienced it directly, which is termed transgenerational inheritance. To date, research in the environmental epigenetics discipline has used a wide range of both model and non-model organisms to elucidate the various epigenetic mechanisms underlying the adaptive response to environmental stimuli. In this review, we discuss the advantages of the zebrafish model for studying how environmental toxicant exposures affect the regulation of epigenetic processes, especially DNA methylation, which is the best-studied epigenetic mechanism. We include several very recent studies describing the state-of-the-art knowledge on this topic in zebrafish, together with key concepts in the function of DNA methylation during vertebrate embryogenesis.
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Affiliation(s)
- Vincenzo Cavalieri
- Laboratory of Molecular Biology and Functional Genomics, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Edificio 16, 90128, Palermo, Italy. .,Zebrafish Laboratory, Advanced Technologies Network (ATeN) Center, University of Palermo, Viale delle Scienze Edificio 18, 90128, Palermo, Italy.
| | - Giovanni Spinelli
- Laboratory of Molecular Biology and Functional Genomics, Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Edificio 16, 90128, Palermo, Italy.
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204
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Zogli P, Libault M. Plant response to biotic stress: Is there a common epigenetic response during plant-pathogenic and symbiotic interactions? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 263:89-93. [PMID: 28818387 DOI: 10.1016/j.plantsci.2017.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 05/26/2023]
Abstract
Plants constantly interact with pathogenic and symbiotic microorganisms. Recent studies have revealed several regulatory mechanisms controlling these interactions. Among them, the plant defense system is activated not only in response to pathogenic, but also in response to symbiotic microbes. Interestingly, shortly after symbiotic microbial recognition, the plant defense system is suppressed to promote plant infection by symbionts. Research studies have demonstrated the influence of the plant epigenome in modulating both pathogenic and symbiotic plant-microbe interactions, thereby influencing plant survival, adaptation and evolution of the plant response to microbial infections. It is however unclear if plant pathogenic and symbiotic responses share similar epigenomic profiles or if epigenomic changes differentially regulate plant-microbe symbiosis and pathogenesis. In this mini-review, we provide an update of the current knowledge of epigenomic control on plant immune responses and symbiosis, with a special attention being paid to knowledge gap and potential strategies to fill-in the missing links.
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Affiliation(s)
- Prince Zogli
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Marc Libault
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA.
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205
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An YQC, Goettel W, Han Q, Bartels A, Liu Z, Xiao W. Dynamic Changes of Genome-Wide DNA Methylation during Soybean Seed Development. Sci Rep 2017; 7:12263. [PMID: 28947812 PMCID: PMC5613027 DOI: 10.1038/s41598-017-12510-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023] Open
Abstract
Seed development is programmed by expression of many genes in plants. Seed maturation is an important developmental process to soybean seed quality and yield. DNA methylation is a major epigenetic modification regulating gene expression. However, little is known about the dynamic nature of DNA methylation and its effects on gene expression during plant development. Through whole-genome bisulfite sequencing, we showed that DNA methylation went through dynamic changes during seed maturation. An average of 66% CG, 45% CHG and 9% CHH contexts was methylated in cotyledons. CHH methylation levels in cotyledons changed greatly from 6% at the early stage to 11% at the late stage. Transcribed genes were approximately two-fold more likely to be differentially methylated than non-transcribed genes. We identified 40, 66 and 2136 genes containing differentially methylated regions (DMRs) with negative correlation between their expression and methylation in the CG, CHG and CHH contexts, respectively. The majority of the DMR genes in the CHH context were transcriptionally down-regulated as seeds mature: 99% of them during early maturation were down-regulated, and preferentially associated with DNA replication and cell division. The results provide novel insights into the dynamic nature of DNA methylation and its relationship with gene regulation in seed development.
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Affiliation(s)
- Yong-Qiang Charles An
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA.
| | - Wolfgang Goettel
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Qiang Han
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
| | - Arthur Bartels
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
| | - Zongrang Liu
- US Department of Agriculture, Agricultural Research Service, Appalachian Fruit Research Station, Kearneysville, WV, 25430, USA
| | - Wenyan Xiao
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA.
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206
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Kawakatsu T, Nery JR, Castanon R, Ecker JR. Dynamic DNA methylation reconfiguration during seed development and germination. Genome Biol 2017; 18:171. [PMID: 28911331 PMCID: PMC5599895 DOI: 10.1186/s13059-017-1251-x] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/07/2017] [Indexed: 01/07/2023] Open
Abstract
Background Unlike animals, plants can pause their life cycle as dormant seeds. In both plants and animals, DNA methylation is involved in the regulation of gene expression and genome integrity. In animals, reprogramming erases and re-establishes DNA methylation during development. However, knowledge of reprogramming or reconfiguration in plants has been limited to pollen and the central cell. To better understand epigenetic reconfiguration in the embryo, which forms the plant body, we compared time-series methylomes of dry and germinating seeds to publicly available seed development methylomes. Results Time-series whole genome bisulfite sequencing reveals extensive gain of CHH methylation during seed development and drastic loss of CHH methylation during germination. These dynamic changes in methylation mainly occur within transposable elements. Active DNA methylation during seed development depends on both RNA-directed DNA methylation and heterochromatin formation pathways, whereas global demethylation during germination occurs in a passive manner. However, an active DNA demethylation pathway is initiated during late seed development. Conclusions This study provides new insights into dynamic DNA methylation reprogramming events during seed development and germination and suggests possible mechanisms of regulation. The observed sequential methylation/demethylation cycle suggests an important role of DNA methylation in seed dormancy. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1251-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Taiji Kawakatsu
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.,Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.,Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8602, Japan
| | - Joseph R Nery
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.,Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Rosa Castanon
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.,Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Joseph R Ecker
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA. .,Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA. .,Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
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207
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208
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209
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Du J. Structure and Mechanism of Plant DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 945:173-192. [PMID: 27826839 DOI: 10.1007/978-3-319-43624-1_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
DNA methylation is an important epigenetic mark that functions in eukaryotes from fungi to animals and plants, where it plays a crucial role in the regulation of epigenetic silencing. Once the methylation mark is established by the de novo DNA methyltransferase (MTase), it requires specific regulatory mechanisms to maintain the methylation state during chromatin replication, both during meiosis and mitosis. Plants have distinct DNA methylation patterns that are both established and maintained by unique DNA MTases and are regulated by plant-specific pathways. This chapter focuses on the exceptional structural and functional features of plant DNA MTases that provide insights into these regulatory mechanisms.
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Affiliation(s)
- Jiamu Du
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 201602, China.
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210
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Comparative Analysis of Genome Wide DNA Methylation Profiles for the Genic Male Sterile Cabbage Line 01-20S and Its Maintainer Line. Genes (Basel) 2017. [PMID: 28621722 PMCID: PMC5485523 DOI: 10.3390/genes8060159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Methylation modifications play an important role in multiple biological processes. Several studies have reported altered methylation patterns in male sterile plants such as rice and wheat, but little is known about the global methylation profiles and their possible roles in the cabbage (Brassicaoleracea) male sterile line. In this study, single-base-resolution bisulfite sequencing (BS-Seq) was adopted to identify the pattern and degree of cytosine methylation in the male sterile line 01-20S and its near-isogenic fertile line 01-20F. Similar methylation patterns were profiled, with some changes observed in local positions. In total, 505 differentially methylated genomic regions (DMRs) and 106 DMR-associated genes were detected. Nine genes related to pollen development were discovered and further validated by a quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Among these, four were downregulated in 01-20S. In particular, Bol039180 (an invertase/pectin methylesterase inhibitor family protein) is likely involved in pectin degradation, and might play an important role in the pollen separation defects of 01-20S. This study facilitates a better understanding of DNA methylation alterations and their possible roles in genic male sterility in cabbages.
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211
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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212
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Song Q, Zhang T, Stelly DM, Chen ZJ. Epigenomic and functional analyses reveal roles of epialleles in the loss of photoperiod sensitivity during domestication of allotetraploid cottons. Genome Biol 2017; 18:99. [PMID: 28558752 PMCID: PMC5450403 DOI: 10.1186/s13059-017-1229-8] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/03/2017] [Indexed: 02/08/2023] Open
Abstract
Background Polyploidy is a pervasive evolutionary feature of all flowering plants and some animals, leading to genetic and epigenetic changes that affect gene expression and morphology. DNA methylation changes can produce meiotically stable epialleles, which are transmissible through selection and breeding. However, the relationship between DNA methylation and polyploid plant domestication remains elusive. Results We report comprehensive epigenomic and functional analyses, including ~12 million differentially methylated cytosines in domesticated allotetraploid cottons and their tetraploid and diploid relatives. Methylated genes evolve faster than unmethylated genes; DNA methylation changes between homoeologous loci are associated with homoeolog-expression bias in the allotetraploids. Significantly, methylation changes induced in the interspecific hybrids are largely maintained in the allotetraploids. Among 519 differentially methylated genes identified between wild and cultivated cottons, some contribute to domestication traits, including flowering time and seed dormancy. CONSTANS (CO) and CO-LIKE (COL) genes regulate photoperiodicity in Arabidopsis. COL2 is an epiallele in allotetraploid cottons. COL2A is hypermethylated and silenced, while COL2D is repressed in wild cottons but highly expressed due to methylation loss in all domesticated cottons tested. Inhibiting DNA methylation activates COL2 expression, and repressing COL2 in cultivated cotton delays flowering. Conclusions We uncover epigenomic signatures of domestication traits during cotton evolution. Demethylation of COL2 increases its expression, inducing photoperiodic flowering, which could have contributed to the suitability of cotton for cultivation worldwide. These resources should facilitate epigenetic engineering, breeding, and improvement of polyploid crops. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1229-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qingxin Song
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Tianzhen Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - David M Stelly
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, 78743, USA
| | - Z Jeffrey Chen
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, TX, 78712, USA. .,State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
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213
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CpG and Non-CpG Methylation in Epigenetic Gene Regulation and Brain Function. Genes (Basel) 2017; 8:genes8060148. [PMID: 28545252 PMCID: PMC5485512 DOI: 10.3390/genes8060148] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/18/2017] [Accepted: 05/19/2017] [Indexed: 12/13/2022] Open
Abstract
DNA methylation is a major epigenetic mark with important roles in genetic regulation. Methylated cytosines are found primarily at CpG dinucleotides, but are also found at non-CpG sites (CpA, CpT, and CpC). The general functions of CpG and non-CpG methylation include gene silencing or activation depending on the methylated regions. CpG and non-CpG methylation are found throughout the whole genome, including repetitive sequences, enhancers, promoters, and gene bodies. Interestingly, however, non-CpG methylation is restricted to specific cell types, such as pluripotent stem cells, oocytes, neurons, and glial cells. Thus, accumulation of methylation at non-CpG sites and CpG sites in neurons seems to be involved in development and disease etiology. Here, we provide an overview of CpG and non-CpG methylation and their roles in neurological diseases.
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214
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Liu Y, El-Kassaby YA. Regulatory crosstalk between microRNAs and hormone signalling cascades controls the variation on seed dormancy phenotype at Arabidopsis thaliana seed set. PLANT CELL REPORTS 2017; 36:705-717. [PMID: 28197719 DOI: 10.1007/s00299-017-2111-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/26/2017] [Indexed: 05/05/2023]
Abstract
We employed an Illumina sequencing approach to identify candidate microRNA cohorts that may greatly contribute to seed dormancy modulation and to construct a microRNA-gene regulatory network in hormone signalling cascades. MicroRNAs (miRNAs) are important signalling molecules and regulate many developmental programs of plants. Some miRNAs have been integrated into gene regulatory networks (GRNs) and coordinate developmental plasticity, but few study systematically investigated how phenotypical variations are regulated through differential expression of miRNA tags in GRNs during seed set. Using 'top-down' analyses (i.e., identify miRNAs associated with known phenotypical variations), we chose two Arabidopsis ecotypes (Cvi-0 and Col-0) with contrasting seed dormancy and sequenced miRNA reads in the first ten phases at seed set. We computationally predicted target genes of miRNAs and implemented statistical analyses for normalized relative expression of top abundant miRNA cohorts between the two ecotypes. We especially focused on miRNA cohorts targeting mRNAs encoding transcription factors in hormone signalling cascades. We report, with high confidence hits, that a cohort of 14 miRNAs (miR-156b, -159b, -160, -161*, -319a, -390a, -396, -773a, -779, -842, -852, -859, -1886*, and a novel sequence in miR8172 family) may greatly contribute to seed dormancy modulation, of which seven are involved in hormone signalling cascades. Moreover, their expression patterns indicated that 5 ± 1 days after flowering (at embryogenesis-to-maturation transition) is a critical phase at seed set. This study reinforces the notion that miRNAs that regulate seed dormancy modulation and provides a novel paradigm of studying the correlation between genotypes (miRNAs) and phenotypes.
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Affiliation(s)
- Yang Liu
- Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada.
| | - Yousry A El-Kassaby
- Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada.
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215
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Taşkin KM, Özbilen A, Sezer F, Hürkan K, Güneş Ş. Structure and expression of dna methyltransferase genes from apomictic and sexual Boechera species. Comput Biol Chem 2017; 67:15-21. [PMID: 28038368 DOI: 10.1016/j.compbiolchem.2016.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/30/2016] [Accepted: 12/09/2016] [Indexed: 10/20/2022]
Abstract
In this study, we determined the structure of DNA methyltransferase (DNMT) genes in apomict and sexual Boechera species and investigated the expression levels during seed development. Protein and DNA sequences of diploid sexual Boechera stricta DNMT genes obtained from Phytozome 10.3 were used to identify the homologues in apomicts, Boechera holboellii and Boechera divaricarpa. Geneious R8 software was used to map the short-paired reads library of B. holboellii whole genome or B. divaricarpa transcriptome reads to the reference gene sequences. We determined three DNMT genes; for Boechera spp. METHYLTRANSFERASE1 (MET1), CHROMOMETHYLASE 3 (CMT3) and DOMAINS REARRANGED METHYLTRANSFERASE 1/2 (DRM2). We examined the structure of these genes with bioinformatic tools and compared with other DNMT genes in plants. We also examined the levels of expression in silique tissues after fertilization by semi-quantitative PCR. The structure of DNMT proteins in apomict and sexual Boechera species share common features. However, the expression levels of DNMT genes were different in apomict and sexual Boechera species. We found that DRM2 was upregulated in apomictic Boechera species after fertilization. Phylogenetic trees showed that three genes are conserved among green algae, monocotyledons and dicotyledons. Our results indicated a deregulation of DNA methylation machinery during seed development in apomicts.
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Affiliation(s)
- Kemal Melik Taşkin
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey.
| | - Aslıhan Özbilen
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Fatih Sezer
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Kaan Hürkan
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Şebnem Güneş
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
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216
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Song X, Cao X. Transposon-mediated epigenetic regulation contributes to phenotypic diversity and environmental adaptation in rice. CURRENT OPINION IN PLANT BIOLOGY 2017; 36:111-118. [PMID: 28273484 DOI: 10.1016/j.pbi.2017.02.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/03/2017] [Accepted: 02/06/2017] [Indexed: 05/19/2023]
Abstract
Transposable elements (TEs) have long been regarded as 'selfish DNA', and are generally silenced by epigenetic mechanisms. However, work in the past decade has identified positive roles for TEs in generating genomic novelty and diversity in plants. In particular, recent studies suggested that TE-induced epigenetic alterations and modification of gene expression contribute to phenotypic variation and adaptation to geography or stress. These findings have led many to regard TEs, not as junk DNA, but as sources of control elements and genomic diversity. As a staple food crop and model system for genomic research on monocot plants, rice (Oryza sativa) has a modest-sized genome that harbors massive numbers of DNA transposons (class II transposable elements) scattered across the genome, which may make TE regulation of genes more prevalent. In this review, we summarize recent progress in research on the functions of rice TEs in modulating gene expression and creating new genes. We also examine the contributions of TEs to phenotypic diversity and adaptation to environmental conditions.
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Affiliation(s)
- Xianwei Song
- 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
| | - 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.
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217
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Abstract
Hybrid incompatibility resulting from deleterious gene combinations is thought to be an important step toward reproductive isolation and speciation. Here, we demonstrate involvement of a silent epiallele in hybrid incompatibility. In Arabidopsis thaliana accession Cvi-0, one of the two copies of a duplicated histidine biosynthesis gene, HISN6A, is mutated, making HISN6B essential. In contrast, in accession Col-0, HISN6A is essential because HISN6B is not expressed. Owing to these differences, Cvi-0 × Col-0 hybrid progeny that are homozygous for both Cvi-0 HISN6A and Col-0 HISN6B do not survive. We show that HISN6B of Col-0 is not a defective pseudogene, but a stably silenced epiallele. Mutating HISTONE DEACETYLASE 6 (HDA6), or the cytosine methyltransferase genes MET1 or CMT3, erases HISN6B's silent locus identity, reanimating the gene to circumvent hisn6a lethality and hybrid incompatibility. These results show that HISN6-dependent hybrid lethality is a revertible epigenetic phenomenon and provide additional evidence that epigenetic variation has the potential to limit gene flow between diverging populations of a species.
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Lauria M, Echegoyen-Nava RA, Rodríguez-Ríos D, Zaina S, Lund G. Inter-individual variation in DNA methylation is largely restricted to tissue-specific differentially methylated regions in maize. BMC PLANT BIOLOGY 2017; 17:52. [PMID: 28231765 PMCID: PMC5324254 DOI: 10.1186/s12870-017-0997-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/08/2017] [Indexed: 05/26/2023]
Abstract
BACKGROUND Variation in DNA methylation across distinct genetic populations, or in response to specific biotic or abiotic stimuli, has typically been studied in leaf DNA from pooled individuals using either reduced representation bisulfite sequencing, whole genome bisulfite sequencing (WGBS) or methylation sensitive amplified polymorphism (MSAP). The latter represents a useful alterative when sample size is large, or when analysing methylation changes in genomes that have yet to be sequenced. In this study we compared variation in methylation across ten individual leaf and endosperm samples from maize hybrid and inbred lines using MSAP. We also addressed the methodological implications of analysing methylation variation using pooled versus individual DNA samples, in addition to the validity of MSAP compared to WGBS. Finally, we analysed a subset of variable and non-variable fragments with respect to genomic location, vicinity to repetitive elements and expression patterns across leaf and endosperm tissues. RESULTS On average, 30% of individuals showed inter-individual methylation variation, mostly of leaf and endosperm-specific differentially methylated DNA regions. With the exception of low frequency demethylation events, the bulk of inter-individual methylation variation (84 and 80% in leaf and endosperm, respectively) was effectively captured in DNA from pooled individuals. Furthermore, available genome-wide methylation data largely confirmed MSAP leaf methylation profiles. Most variable methylation that mapped within genes was associated with CG methylation, and many of such genes showed tissue-specific expression profiles. Finally, we found that the hAT DNA transposon was the most common class II transposable element found in close proximity to variable DNA regions. CONCLUSIONS The relevance of our results with respect to future studies of methylation variation is the following: firstly, the finding that inter-individual methylation variation is largely restricted to tissue-specific differentially methylated DNA regions, underlines the importance of tissue-type when analysing the methylation response to a defined stimulus. Secondly, we show that pooled sample-based MSAP studies are methodologically appropriate to study methylation variation. Thirdly, we confirm that MSAP is a powerful tool when WGBS is not required or feasible, for example in plant species that have yet to be sequenced.
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Affiliation(s)
- Massimiliano Lauria
- Consiglio Nazionale delle Ricerche, Istituto di Biologia e Biotecnologia Agraria, I-20133 Milan, Italy
| | - Rodrigo Antonio Echegoyen-Nava
- Gertrud Lund, Department of Genetic Engineering, CINVESTAV - Unidad Irapuato, Km. 9.6 Libramiento Norte Carretera Irapuato-Leon, Apdo. Postal 629, C. P. 36500 Irapuato, GTO Mexico
| | - Dalia Rodríguez-Ríos
- Gertrud Lund, Department of Genetic Engineering, CINVESTAV - Unidad Irapuato, Km. 9.6 Libramiento Norte Carretera Irapuato-Leon, Apdo. Postal 629, C. P. 36500 Irapuato, GTO Mexico
| | - Silvio Zaina
- Department of Medical Sciences, Division of Health Sciences, León Campus, University of Guanajuato, Guanajuato, Mexico
| | - Gertrud Lund
- Gertrud Lund, Department of Genetic Engineering, CINVESTAV - Unidad Irapuato, Km. 9.6 Libramiento Norte Carretera Irapuato-Leon, Apdo. Postal 629, C. P. 36500 Irapuato, GTO Mexico
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219
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Satyaki PRV, Gehring M. DNA methylation and imprinting in plants: machinery and mechanisms. Crit Rev Biochem Mol Biol 2017; 52:163-175. [PMID: 28118754 DOI: 10.1080/10409238.2017.1279119] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Imprinting is an epigenetic phenomenon in which genes are expressed selectively from either the maternal or paternal alleles. In plants, imprinted gene expression is found in a tissue called the endosperm. Imprinting is often set by a unique epigenomic configuration in which the maternal chromosomes are less DNA methylated than their paternal counterparts. In this review, we synthesize studies that paint a detailed molecular portrait of the distinctive endosperm methylome. We will also discuss the molecular machinery that shapes and modifies this methylome, and the role of DNA methylation in imprinting.
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Affiliation(s)
- P R V Satyaki
- a Whitehead Institute for Biomedical Research , Cambridge , MA , USA
| | - Mary Gehring
- a Whitehead Institute for Biomedical Research , Cambridge , MA , USA.,b Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA
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220
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Cirilli M, Delfino I, Caboni E, Muleo R. EpiHRMAssay, in tube and in silico combined approach for the scanning and epityping of heterogeneous DNA methylation. Biol Methods Protoc 2017; 2:bpw008. [PMID: 32161783 PMCID: PMC6994072 DOI: 10.1093/biomethods/bpw008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/12/2016] [Accepted: 12/16/2016] [Indexed: 11/18/2022] Open
Abstract
Reliable and cost-effective assays with adequate sensitivity are required to detect the DNA methylation profile in plants for scientific and industrial purposes. The proposed novel assay, named EpiHRMAssay, allows to quantify the overall methylation status at target loci and to enable high-throughput analyses. It combines in tube High Resolution Melting Analysis on bisulphite-treated templates with the in silico prediction of the melting profile of virtual epialleles using uMELTSM software. The predicted melting temperatures (Tm-s) of a set of epialleles characterized by different numbers of methylated cytosines (#mC) or different mC configurations were obtained and used to build calibration models, enabling the quantification of methylation in unknown samples using only the in tube observed melting temperature (Tm-o). EpiHRMAssay was validated by analysing the promoter region of CMT3, DDM1, and ROS1 genes involved in the regulation of methylation/demethylation processes and chromatin remodelling within a population of peach plants. Results demonstrate that EpiHRMAssay is a sensitive and reliable tool for locus-specific large-scale research and diagnostic contexts of the regulative regions of genes, in a broad range of organisms, including mammals. EpiHRMAssay also provides complementary information for the assessment of heterogeneous methylation and can address an array of biological questions on epigenetic regulation for diversity studies and for large-scale functional genomics.
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Affiliation(s)
- Marco Cirilli
- Department of Agricultural and Forestry Sciences, University of Tuscia, Via S. Camillo de Lellis snc, Viterbo 01100, Italy
| | - Ines Delfino
- Department of Ecological and Biological Sciences, University of Tuscia, L.go dell'Università snc, Viterbo 01100, Italy
| | - Emilia Caboni
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Fruit Tree Research Center, Via di Fioranello, 52, 00134 Rome, Italy
| | - Rosario Muleo
- Department of Agricultural and Forestry Sciences, University of Tuscia, Via S. Camillo de Lellis snc, Viterbo 01100, Italy
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221
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Farinati S, Rasori A, Varotto S, Bonghi C. Rosaceae Fruit Development, Ripening and Post-harvest: An Epigenetic Perspective. FRONTIERS IN PLANT SCIENCE 2017; 8:1247. [PMID: 28769956 PMCID: PMC5511831 DOI: 10.3389/fpls.2017.01247] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/30/2017] [Indexed: 05/06/2023]
Abstract
Rosaceae is a family with an extraordinary spectrum of fruit types, including fleshy peach, apple, and strawberry that provide unique contributions to a healthy diet for consumers, and represent an excellent model for studying fruit patterning and development. In recent years, many efforts have been made to unravel regulatory mechanism underlying the hormonal, transcriptomic, proteomic and metabolomic changes occurring during Rosaceae fruit development. More recently, several studies on fleshy (tomato) and dry (Arabidopsis) fruit model have contributed to a better understanding of epigenetic mechanisms underlying important heritable crop traits, such as ripening and stress response. In this context and summing up the results obtained so far, this review aims to collect the available information on epigenetic mechanisms that may provide an additional level in gene transcription regulation, thus influencing and driving the entire Rosaceae fruit developmental process. The whole body of information suggests that Rosaceae fruit could become also a model for studying the epigenetic basis of economically important phenotypes, allowing for their more efficient exploitation in plant breeding.
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Affiliation(s)
- Silvia Farinati
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy
| | - Angela Rasori
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy
| | - Serena Varotto
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy
- Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy
| | - Claudio Bonghi
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy
- Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy
- *Correspondence: Claudio Bonghi,
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222
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Galla G, Zenoni S, Avesani L, Altschmied L, Rizzo P, Sharbel TF, Barcaccia G. Pistil Transcriptome Analysis to Disclose Genes and Gene Products Related to Aposporous Apomixis in Hypericum perforatum L. FRONTIERS IN PLANT SCIENCE 2017; 8:79. [PMID: 28203244 PMCID: PMC5285387 DOI: 10.3389/fpls.2017.00079] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/13/2017] [Indexed: 05/19/2023]
Abstract
Unlike sexual reproduction, apomixis encompasses a number of reproductive strategies, which permit maternal genome inheritance without genetic recombination and syngamy. The key biological features of apomixis are the circumvention of meiosis (i.e., apomeiosis), the differentiation of unreduced embryo sacs and egg cells, and their autonomous development in functional embryos through parthenogenesis, and the formation of viable endosperm either via fertilization-independent means or following fertilization with a sperm cell. Despite the importance of apomixis for breeding of crop plants and although much research has been conducted to study this process, the genetic control of apomixis is still not well understood. Hypericum perforatum is becoming an attractive model system for the study of aposporous apomixis. Here we report results from a global gene expression analysis of H. perforatum pistils collected from sexual and aposporous plant accessions for the purpose of identifying genes, biological processes and molecular functions associated with the aposporous apomixis pathway. Across two developmental stages corresponding to the expression of aposporous apomeiosis and parthenogenesis in ovules, a total of 224 and 973 unigenes were found to be significantly up- and down-regulated with a fold change ≥ 2 in at least one comparison, respectively. Differentially expressed genes were enriched for multiple gene ontology (GO) terms, including cell cycle, DNA metabolic process, and single-organism cellular process. For molecular functions, the highest scores were recorded for GO terms associated with DNA binding, DNA (cytosine-5-)-methyltransferase activity and heterocyclic compound binding. As deregulation of single components of the sexual developmental pathway is believed to be a trigger of the apomictic reproductive program, all genes involved in sporogenesis, gametogenesis and response to hormonal stimuli were analyzed in great detail. Overall, our data suggest that phenotypic expression of apospory is concomitant with the modulation of key genes involved in the sexual reproductive pathway. Furthermore, based on gene annotation and co-expression, we underline a putative role of hormones and key actors playing in the RNA-directed DNA methylation pathway in regulating the developmental changes occurring during aposporous apomixis in H. perforatum.
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Affiliation(s)
- Giulio Galla
- Laboratory of Genomics, Department of Agronomy, Food, Natural Resources, Animals and Environment, University of PadovaPadova, Italy
- *Correspondence: Giulio Galla
| | - Sara Zenoni
- Department of Biotechnology, University of VeronaVerona, Italy
| | - Linda Avesani
- Department of Biotechnology, University of VeronaVerona, Italy
| | - Lothar Altschmied
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
| | - Paride Rizzo
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
| | - Timothy F. Sharbel
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
| | - Gianni Barcaccia
- Laboratory of Genomics, Department of Agronomy, Food, Natural Resources, Animals and Environment, University of PadovaPadova, Italy
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223
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Viggiano L, de Pinto MC. Dynamic DNA Methylation Patterns in Stress Response. PLANT EPIGENETICS 2017. [DOI: 10.1007/978-3-319-55520-1_15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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224
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Lebedeva MA, Tvorogova VE, Tikhodeyev ON. Epigenetic mechanisms and their role in plant development. RUSS J GENET+ 2016. [DOI: 10.1134/s1022795417090083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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225
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Su SY, Chen SH, Lu IH, Chiang YS, Wang YB, Chen PY, Lin CY. TEA: the epigenome platform for Arabidopsis methylome study. BMC Genomics 2016; 17:1027. [PMID: 28155665 PMCID: PMC5260138 DOI: 10.1186/s12864-016-3326-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background Bisulfite sequencing (BS-seq) has become a standard technology to profile genome-wide DNA methylation at single-base resolution. It allows researchers to conduct genome-wise cytosine methylation analyses on issues about genomic imprinting, transcriptional regulation, cellular development and differentiation. One single data from a BS-Seq experiment is resolved into many features according to the sequence contexts, making methylome data analysis and data visualization a complex task. Results We developed a streamlined platform, TEA, for analyzing and visualizing data from whole-genome BS-Seq (WGBS) experiments conducted in the model plant Arabidopsis thaliana. To capture the essence of the genome methylation level and to meet the efficiency for running online, we introduce a straightforward method for measuring genome methylation in each sequence context by gene. The method is scripted in Java to process BS-Seq mapping results. Through a simple data uploading process, the TEA server deploys a web-based platform for deep analysis by linking data to an updated Arabidopsis annotation database and toolkits. Conclusions TEA is an intuitive and efficient online platform for analyzing the Arabidopsis genomic DNA methylation landscape. It provides several ways to help users exploit WGBS data. TEA is freely accessible for academic users at: http://tea.iis.sinica.edu.tw.
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Affiliation(s)
- Sheng-Yao Su
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan.,Institute of Information Science, Academia Sinica, Taipei, Taiwan.,Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Shu-Hwa Chen
- Institute of Information Science, Academia Sinica, Taipei, Taiwan
| | - I-Hsuan Lu
- Institute of Information Science, Academia Sinica, Taipei, Taiwan
| | - Yih-Shien Chiang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Bin Wang
- Institute of Information Science, Academia Sinica, Taipei, Taiwan
| | - Pao-Yang Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
| | - Chung-Yen Lin
- Institute of Information Science, Academia Sinica, Taipei, Taiwan. .,Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan. .,Institute of Fisheries Science, College of Life Science, National Taiwan University, Taipei, Taiwan.
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226
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Gouil Q, Baulcombe DC. DNA Methylation Signatures of the Plant Chromomethyltransferases. PLoS Genet 2016; 12:e1006526. [PMID: 27997534 PMCID: PMC5221884 DOI: 10.1371/journal.pgen.1006526] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 01/09/2017] [Accepted: 12/07/2016] [Indexed: 12/22/2022] Open
Abstract
DNA methylation in plants is traditionally partitioned into CG, CHG and CHH contexts (with H any nucleotide but G). By investigating DNA methylation patterns in trinucleotide contexts in four angiosperm species, we show that such a representation hides spatial and functional partitioning of different methylation pathways and is incomplete. CG methylation (mCG) is largely context-independent whereas, at CHG motifs, there is under-representation of mCCG in pericentric regions of A. thaliana and tomato and throughout the chromosomes of maize and rice. In A. thaliana the biased representation of mCCG in heterochromatin is related to specificities of H3K9 methyltransferase SUVH family members. At CHH motifs there is an over-representation of different variant forms of mCHH that, similarly to mCCG hypomethylation, is partitioned into the pericentric regions of the two dicots but dispersed in the monocot chromosomes. The over-represented mCHH motifs in A. thaliana associate with specific types of transposon including both class I and II elements. At mCHH the contextual bias is due to the involvement of various chromomethyltransferases whereas the context-independent CHH methylation in A. thaliana and tomato is mediated by the RNA-directed DNA methylation process that is most active in the gene-rich euchromatin. This analysis therefore reveals that the sequence context of the methylome of plant genomes is informative about the mechanisms associated with maintenance of methylation and the overlying chromatin structure. Dense cytosine DNA methylation (mC) in eukaryotes is associated with closed chromatin and gene silencing. In plants it is well known that the sequence context of the mC (either mCG, mCHG or mCHH) provides a clue as to which of several mechanisms is involved but now, based on detailed analyses of the DNA methylome in wild type and mutants of four plant species, we reveal that there is additional information in the mC sequence context. Low mCCG and over-representation of mCAA and mCTA or mCAT in A. thaliana and tomato differentiates regions of the chromosomes near the centromere where methylation is dominated by chromomethyltransferases from the chromosome arms in which mCHH is context-independent and predominantly RNA-directed. Rice and maize have similar sequence context-dependent DNA methylation but the corresponding chromosome domains are not spatially separate as in the dicots. The discovery of the subcomponents of plant methylomes based on sequence context will allow greater resolution in past and future analyses of plant methylomes.
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Affiliation(s)
- Quentin Gouil
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - David C. Baulcombe
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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227
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Abstract
Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over long timescales is largely a byproduct of genomic changes. By contrast, methylome evolution over short timescales appears to be driven mainly by spontaneous epimutational events. We argue that novel methods based on analyses of the methylation site frequency spectrum (mSFS) of natural populations can provide deeper insights into the evolutionary forces that act at each timescale.
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Affiliation(s)
- Amaryllis Vidalis
- Population Epigenetics and Epigenomics, Technical University of Munich, Liesel-Beckman-Str. 2, 85354, Freising, Germany
| | - Daniel Živković
- Population Genetics, Technical University of Munich, Liesel-Beckman-Str. 2, 85354, Freising, Germany
| | - René Wardenaar
- Groningen Bioinformatics Centre, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - David Roquis
- Population Epigenetics and Epigenomics, Technical University of Munich, Liesel-Beckman-Str. 2, 85354, Freising, Germany
| | - Aurélien Tellier
- Population Genetics, Technical University of Munich, Liesel-Beckman-Str. 2, 85354, Freising, Germany.
| | - Frank Johannes
- Population Epigenetics and Epigenomics, Technical University of Munich, Liesel-Beckman-Str. 2, 85354, Freising, Germany. .,Institute for Advanced Study, Technical University of Munich, Lichtenbergstr. 2a, 85748, Garching, Germany.
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228
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Pandey G, Sharma N, Sahu PP, Prasad M. Chromatin-Based Epigenetic Regulation of Plant Abiotic Stress Response. Curr Genomics 2016; 17:490-498. [PMID: 28217005 PMCID: PMC5282600 DOI: 10.2174/1389202917666160520103914] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 12/10/2015] [Accepted: 12/13/2015] [Indexed: 12/15/2022] Open
Abstract
Plants are continuously exposed to various abiotic and biotic factors limiting their growth and reproduction. In response, they need various sophisticated ways to adapt to adverse environmental conditions without compromising their proper development, reproductive success and eventually survival. This requires an intricate network to regulate gene expression at transcriptional and post-transcriptional levels, including epigenetic switches. Changes in chromatin modifications such as DNA and histone methylation have been observed in plants upon exposure to several abiotic stresses. In the present review, we highlight the changes of DNA methylation in diverse plants in response to several abiotic stresses such as salinity, drought, cold and heat. We also discuss the progresses made in understanding how these DNA methylation changes might contribute to the abiotic stress tolerance.
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Affiliation(s)
- Garima Pandey
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Namisha Sharma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Pranav Pankaj Sahu
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Manoj Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India,Address correspondence to this author at the National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India; Tel: 91-11-26735160; Fax: 91-11-26741658; 26741146;, E-mails: ,
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229
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Feng SJ, Liu XS, Tao H, Tan SK, Chu SS, Oono Y, Zhang XD, Chen J, Yang ZM. Variation of DNA methylation patterns associated with gene expression in rice (Oryza sativa) exposed to cadmium. PLANT, CELL & ENVIRONMENT 2016; 39:2629-2649. [PMID: 27412910 DOI: 10.1111/pce.12793] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 06/23/2016] [Accepted: 07/05/2016] [Indexed: 05/17/2023]
Abstract
We report genome-wide single-base resolution maps of methylated cytosines and transcriptome change in Cd-exposed rice. Widespread differences were identified in CG and non-CG methylation marks between Cd-exposed and Cd-free rice genomes. There are 2320 non-redundant differentially methylated regions detected in the genome. RNA sequencing revealed 2092 DNA methylation-modified genes differentially expressed under Cd exposure. More genes were found hypermethylated than those hypomethylated in CG, CHH and CHG (where H is A, C or T) contexts in upstream, gene body and downstream regions. Many of the genes were involved in stress response, metal transport and transcription factors. Most of the DNA methylation-modified genes were transcriptionally altered under Cd stress. A subset of loss of function mutants defective in DNA methylation and histone modification activities was used to identify transcript abundance of selected genes. Compared with wide type, mutation of MET1 and DRM2 resulted in general lower transcript levels of the genes under Cd stress. Transcripts of OsIRO2, OsPR1b and Os09g02214 in drm2 were significantly reduced. A commonly used DNA methylation inhibitor 5-azacytidine was employed to investigate whether DNA demethylation affected physiological consequences. 5-azacytidine provision decreased general DNA methylation levels of selected genes, but promoted growth of rice seedlings and Cd accumulation in rice plant.
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Affiliation(s)
- Sheng Jun Feng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xue Song Liu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hua Tao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shang Kun Tan
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shan Shan Chu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Youko Oono
- Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Xian Duo Zhang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jian Chen
- Institute of Food Safety and Quality, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
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230
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Wang Y, Xue X, Zhu JK, Dong J. Demethylation of ERECTA receptor genes by IBM1 histone demethylase affects stomatal development. Development 2016; 143:4452-4461. [PMID: 27697902 PMCID: PMC5201038 DOI: 10.1242/dev.129932] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/19/2016] [Indexed: 12/21/2022]
Abstract
DNA methylation and histone modifications interact to modulate gene expression in biological organisms. The histone demethylase IBM1 suppresses DNA methylation and gene silencing, primarily by targeting genic regions in the Arabidopsis genome. The chromatin regulator EDM2 is also required for prevention of genic DNA methylation because it maintains IBM1 expression by promoting IBM1 mRNA distal polyadenylation. Loss-of-function ibm1 and edm2 mutant plants display a wide range of developmental defects, but little is known about which developmentally important genes are regulated by IBM1 and EDM2. Here, we show that both ibm1 and edm2 mutants display defects in production of stomatal lineage cells, which is linked to DNA hypermethylation of the ERECTA family genes, including ER, ERL1 and ERL2 Stomatal phenotypes and DNA methylation levels of ER genes in ibm1 and edm2 mutants are restored by mutations in the genes encoding the histone methyltransferase KYP and DNA methyltransferase CMT3. Our data demonstrate that a specific plant developmental context is influenced by IBM1-regulated histone modification and DNA methylation on the gene body region of the ERECTA receptors.
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Affiliation(s)
- Yuhua Wang
- Shanghai Center for Plant Stress Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xueyi Xue
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Juan Dong
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA
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231
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Xu J, Tanino KK, Horner KN, Robinson SJ. Quantitative trait variation is revealed in a novel hypomethylated population of woodland strawberry (Fragaria vesca). BMC PLANT BIOLOGY 2016; 16:240. [PMID: 27809774 PMCID: PMC5095969 DOI: 10.1186/s12870-016-0936-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/27/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Phenotypic variation is determined by a combination of genotype, environment and their interactions. The realization that allelic diversity can be both genetic and epigenetic allows the environmental component to be further separated. Partitioning phenotypic variation observed among inbred lines with an altered epigenome can allow the epigenetic component controlling quantitative traits to be estimated. To assess the contribution of epialleles on phenotypic variation and determine the fidelity with which epialleles are inherited, we have developed a novel hypomethylated population of strawberry (2n = 2x = 14) using 5-azacytidine from which individuals with altered phenotypes can be identified, selected and characterized. RESULTS The hypomethylated population was generated using an inbred strawberry population in the F. vesca ssp. vesca accession Hawaii 4. Analysis of whole genome sequence data from control and hypomethylated lines indicate that 5-azacytidine exposure does not increase SNP above background levels. The populations contained only Hawaii 4 alleles, removing introgression of alternate F. vesca alleles as a potential source of variation. Although genome sequencing and genetic marker data are unable to rule out 5-azacytidine induced chromosomal rearrangements as a potential source of the trait variation observed, none were detected in our survey. Quantitative trait variation focusing on flowering time and rosette diameter was scored in control and treated populations where expanded levels of variation were observed among the hypomethylated lines. Methylation sensitive molecular markers indicated that 5-azacytidine induced alterations in DNA methylation patterns and inheritance of methylation patterns were confirmed by bisulfite sequencing of targeted regions. It is possible that methylation polymorphisms might underlie or have induced genetic changes underlying the observable differences in quantitative phenotypes. CONCLUSIONS This population developed in a uniform genetic background provides a resource for the discovery of new variation controlling quantitative traits. Genome sequence analysis indicates that 5-azacytidine did not induce point mutations and the induced variation is largely restricted to DNA methylation. Using this resource, we have identified new variation and demonstrated the inheritance of both variant trait and methylation patterns. Although direct associations remain to be determined, these data suggest epigenetic variation might be subject to selection.
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Affiliation(s)
- Jihua Xu
- Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan Canada
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, Saskatchewan Canada
| | - Karen K. Tanino
- Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan Canada
| | - Kyla N. Horner
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, Saskatchewan Canada
| | - Stephen J. Robinson
- Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan Canada
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, Saskatchewan Canada
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232
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López Sánchez A, Stassen JH, Furci L, Smith LM, Ton J. The role of DNA (de)methylation in immune responsiveness of Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:361-374. [PMID: 27341062 PMCID: PMC5132069 DOI: 10.1111/tpj.13252] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/20/2016] [Indexed: 05/13/2023]
Abstract
DNA methylation is antagonistically controlled by DNA methyltransferases and DNA demethylases. The level of DNA methylation controls plant gene expression on a global level. We have examined impacts of global changes in DNA methylation on the Arabidopsis immune system. A range of hypo-methylated mutants displayed enhanced resistance to the biotrophic pathogen Hyaloperonospora arabidopsidis (Hpa), whereas two hyper-methylated mutants were more susceptible to this pathogen. Subsequent characterization of the hypo-methylated nrpe1 mutant, which is impaired in RNA-directed DNA methylation, and the hyper-methylated ros1 mutant, which is affected in DNA demethylation, revealed that their opposite resistance phenotypes are associated with changes in cell wall defence and salicylic acid (SA)-dependent gene expression. Against infection by the necrotrophic pathogen Plectosphaerella cucumerina, nrpe1 showed enhanced susceptibility, which was associated with repressed sensitivity of jasmonic acid (JA)-inducible gene expression. Conversely, ros1 displayed enhanced resistance to necrotrophic pathogens, which was not associated with increased responsiveness of JA-inducible gene expression. Although nrpe1 and ros1 were unaffected in systemic acquired resistance to Hpa, they failed to develop transgenerational acquired resistance against this pathogen. Global transcriptome analysis of nrpe1 and ros1 at multiple time-points after Hpa infection revealed that 49% of the pathogenesis-related transcriptome is influenced by NRPE1- and ROS1-controlled DNA methylation. Of the 166 defence-related genes displaying augmented induction in nrpe1 and repressed induction in ros1, only 25 genes were associated with a nearby transposable element and NRPE1- and/or ROS1-controlled DNA methylation. Accordingly, we propose that the majority of NRPE1- and ROS1-dependent defence genes are regulated in trans by DNA methylation.
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Affiliation(s)
- Ana López Sánchez
- P3 Institute for Translational Plant and Soil BiologyDepartment of Animal and Plant SciencesThe University of SheffieldSheffieldUK
| | - Joost H.M. Stassen
- P3 Institute for Translational Plant and Soil BiologyDepartment of Animal and Plant SciencesThe University of SheffieldSheffieldUK
| | - Leonardo Furci
- P3 Institute for Translational Plant and Soil BiologyDepartment of Animal and Plant SciencesThe University of SheffieldSheffieldUK
| | - Lisa M. Smith
- P3 Institute for Translational Plant and Soil BiologyDepartment of Animal and Plant SciencesThe University of SheffieldSheffieldUK
| | - Jurriaan Ton
- P3 Institute for Translational Plant and Soil BiologyDepartment of Animal and Plant SciencesThe University of SheffieldSheffieldUK
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233
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Zhao JH, Fang YY, Duan CG, Fang RX, Ding SW, Guo HS. Genome-wide identification of endogenous RNA-directed DNA methylation loci associated with abundant 21-nucleotide siRNAs in Arabidopsis. Sci Rep 2016; 6:36247. [PMID: 27786269 PMCID: PMC5081565 DOI: 10.1038/srep36247] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/12/2016] [Indexed: 12/29/2022] Open
Abstract
In Arabidopsis, the 24-nucleotide (nt) small interfering RNAs (siRNAs) mediates RNA-directed DNA methylation (RdDM) and transcriptional gene silencing (TGS) of transposable elements (TEs). In the present study, we examined genome-wide changes in DNA methylation and siRNA accumulation in Arabidopsis induced by expression of the Cucumber mosaic virus silencing suppressor protein 2b known to directly bind to both the 21/24-nt siRNAs as well as their associated Argonaute proteins. We demonstrated a genome-wide reduction of CHH and CHG methylation in the 2b-transgenic plants. We found that 2b suppressed RdDM not only at the previously annotated loci directed by 24-nt siRNAs but also a new set of loci associated with 21/22-nt siRNAs. Further analysis showed that the reduced methylation of TEs and coding genes targeted by 21/22-nt siRNAs was associated with sequestration of the duplex siRNAs by the 2b protein but not with changes in either siRNA production or transcription. Notably, we detected both the deletion and/or the transposition of multicopy TEs associated with 2b-induced hypomethylation, suggesting potential TE reactivation. We propose that the silencing of many TEs in Arabidopsis is controlled by the 24- and 21-nt endogenous siRNAs analogous to Drosophila TE silencing by PIWI-interacting RNAs and siRNAs.
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Affiliation(s)
- Jian-Hua Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuan-Yuan Fang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Cheng-Guo Duan
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Rong-Xiang Fang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shou-Wei Ding
- Department of Plant Pathology and Microbiology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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234
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Chen JC, Wei MJ, Fang SC. Expression analysis of fertilization/early embryogenesis-associated genes in Phalaenopsis orchids. PLANT SIGNALING & BEHAVIOR 2016; 11:e1237331. [PMID: 27668884 PMCID: PMC5117094 DOI: 10.1080/15592324.2016.1237331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
One of the distinct reproductive programs in orchid species is pollination-triggered ovule development and megasporogenesis. During sexual reproduction, fertilization occurs days to months after pollination. The molecular mechanisms evolved to carry out this strategic reproductive program remain unclear. In the August issue of Plant Physiology 1 , we report comprehensive studies of comparative genome-wide gene expression in various reproductive tissues and the molecular events associated with developmental transitions unique to sexual reproduction of Phalaenopsis aphrodite. Transcriptional factors and signaling components whose expression is specifically enriched in interior ovary tissues when fertilization occurs and embryos start to develop have been identified. Here, we report verification of additional fertilization-associated genes, DOMAINS REARRANGED METHYLTRANSFERASE 1 (PaDRM1), CHROMOMETHYLTRANSFERASE 1 (PaCMT1), SU(VAR)3-9 RELATED PROTEIN 1 (PaSUVR1), INDOLE-3-ACETIC ACID inducible 30-like 1 (PaIAA30L1), and ETHYLENE INSENSITIVE 3-like 1 (PaEIN3L1), and discuss their potential roles in gametophyte development, epigenetic reprogramming, and hormone regulation during fertilization and establishment of embryo development in Phalaenopsis orchids.
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Affiliation(s)
- Jhun-Chen Chen
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Miao-Ju Wei
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Su-Chiung Fang
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- CONTACT Su-Chiung Fang , Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, 741, Taiwan
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235
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Niederhuth CE, Bewick AJ, Ji L, Alabady MS, Kim KD, Li Q, Rohr NA, Rambani A, Burke JM, Udall JA, Egesi C, Schmutz J, Grimwood J, Jackson SA, Springer NM, Schmitz RJ. Widespread natural variation of DNA methylation within angiosperms. Genome Biol 2016; 17:194. [PMID: 27671052 DOI: 10.1101/045880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/09/2016] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND DNA methylation is an important feature of plant epigenomes, involved in the formation of heterochromatin and affecting gene expression. Extensive variation of DNA methylation patterns within a species has been uncovered from studies of natural variation. However, the extent to which DNA methylation varies between flowering plant species is still unclear. To understand the variation in genomic patterning of DNA methylation across flowering plant species, we compared single base resolution DNA methylomes of 34 diverse angiosperm species. RESULTS By analyzing whole-genome bisulfite sequencing data in a phylogenetic context, it becomes clear that there is extensive variation throughout angiosperms in gene body DNA methylation, euchromatic silencing of transposons and repeats, as well as silencing of heterochromatic transposons. The Brassicaceae have reduced CHG methylation levels and also reduced or loss of CG gene body methylation. The Poaceae are characterized by a lack or reduction of heterochromatic CHH methylation and enrichment of CHH methylation in genic regions. Furthermore, low levels of CHH methylation are observed in a number of species, especially in clonally propagated species. CONCLUSIONS These results reveal the extent of variation in DNA methylation in angiosperms and show that DNA methylation patterns are broadly a reflection of the evolutionary and life histories of plant species.
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Affiliation(s)
- Chad E Niederhuth
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Adam J Bewick
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens, GA, 30602, USA
| | - Magdy S Alabady
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Kyung Do Kim
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, 30602, USA
| | - Qing Li
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Nicholas A Rohr
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Aditi Rambani
- Plant and Wildlife Science Department, Brigham Young University, Provo, UT, 84602, USA
| | - John M Burke
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Joshua A Udall
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Chiedozie Egesi
- National Root Crops Research Institute (NRCRI), Umudike, Km 8 Ikot Ekpene Road, PMB 7006, Umuahia, 440001, Nigeria
| | - Jeremy Schmutz
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Scott A Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, 30602, USA
| | - Nathan M Springer
- Plant and Wildlife Science Department, Brigham Young University, Provo, UT, 84602, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA.
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236
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Niederhuth CE, Bewick AJ, Ji L, Alabady MS, Kim KD, Li Q, Rohr NA, Rambani A, Burke JM, Udall JA, Egesi C, Schmutz J, Grimwood J, Jackson SA, Springer NM, Schmitz RJ. Widespread natural variation of DNA methylation within angiosperms. Genome Biol 2016; 17:194. [PMID: 27671052 PMCID: PMC5037628 DOI: 10.1186/s13059-016-1059-0] [Citation(s) in RCA: 313] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/09/2016] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND DNA methylation is an important feature of plant epigenomes, involved in the formation of heterochromatin and affecting gene expression. Extensive variation of DNA methylation patterns within a species has been uncovered from studies of natural variation. However, the extent to which DNA methylation varies between flowering plant species is still unclear. To understand the variation in genomic patterning of DNA methylation across flowering plant species, we compared single base resolution DNA methylomes of 34 diverse angiosperm species. RESULTS By analyzing whole-genome bisulfite sequencing data in a phylogenetic context, it becomes clear that there is extensive variation throughout angiosperms in gene body DNA methylation, euchromatic silencing of transposons and repeats, as well as silencing of heterochromatic transposons. The Brassicaceae have reduced CHG methylation levels and also reduced or loss of CG gene body methylation. The Poaceae are characterized by a lack or reduction of heterochromatic CHH methylation and enrichment of CHH methylation in genic regions. Furthermore, low levels of CHH methylation are observed in a number of species, especially in clonally propagated species. CONCLUSIONS These results reveal the extent of variation in DNA methylation in angiosperms and show that DNA methylation patterns are broadly a reflection of the evolutionary and life histories of plant species.
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Affiliation(s)
- Chad E Niederhuth
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Adam J Bewick
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens, GA, 30602, USA
| | - Magdy S Alabady
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Kyung Do Kim
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, 30602, USA
| | - Qing Li
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Nicholas A Rohr
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA
| | - Aditi Rambani
- Plant and Wildlife Science Department, Brigham Young University, Provo, UT, 84602, USA
| | - John M Burke
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Joshua A Udall
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Chiedozie Egesi
- National Root Crops Research Institute (NRCRI), Umudike, Km 8 Ikot Ekpene Road, PMB 7006, Umuahia, 440001, Nigeria
| | - Jeremy Schmutz
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Scott A Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, 30602, USA
| | - Nathan M Springer
- Plant and Wildlife Science Department, Brigham Young University, Provo, UT, 84602, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, 120 East Green Street, Athens, GA, 30602, USA.
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237
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Niederhuth CE, Schmitz RJ. Putting DNA methylation in context: from genomes to gene expression in plants. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:149-156. [PMID: 27590871 DOI: 10.1016/j.bbagrm.2016.08.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 08/20/2016] [Accepted: 08/23/2016] [Indexed: 12/26/2022]
Abstract
Plant DNA methylation is its own language, interpreted by the cell to maintain silencing of transposons, facilitate chromatin structure, and to ensure proper expression of some genes. Just as in any language, context is important. Rather than being a simple "on-off switch", DNA methylation has a range of "meanings" dependent upon the underlying sequence and its location in the genome. Differences in the sequence context of individual sites are established, maintained, and interpreted by differing molecular pathways. Varying patterns of methylation within genes and surrounding sequences are associated with a continuous range of expression differences, from silencing to constitutive expression. These often-subtle differences have been pieced together from years of effort, but have taken off with the advent of methods for assessing methylation across entire genomes. Recognizing these patterns and identifying underlying causes is essential for understanding the function of DNA methylation and its systems-wide contribution to a range of processes in plant genomes. This article is part of a Special Issue entitled: Plant Gene Regulatory Mechanisms and Networks, edited by Dr. Erich Grotewold and Dr. Nathan Springer.
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Affiliation(s)
- Chad E Niederhuth
- Department of Genetics, The University of Georgia, Athens, GA, 30602, USA
| | - Robert J Schmitz
- Department of Genetics, The University of Georgia, Athens, GA, 30602, USA.
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238
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DNA methylation signature of intergenic region involves in nucleosome remodeler DDM1-mediated repression of aberrant gene transcriptional read-through. J Genet Genomics 2016; 43:513-23. [DOI: 10.1016/j.jgg.2016.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/28/2016] [Accepted: 03/30/2016] [Indexed: 11/23/2022]
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239
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Khan A, Yadav NS, Morgenstern Y, Zemach A, Grafi G. Activation of Tag1 transposable elements in Arabidopsis dedifferentiating cells and their regulation by CHROMOMETHYLASE 3-mediated CHG methylation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1289-98. [PMID: 27475038 DOI: 10.1016/j.bbagrm.2016.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/13/2016] [Accepted: 07/25/2016] [Indexed: 12/11/2022]
Abstract
Dedifferentiation, that is, the acquisition of stem cell-like state, commonly induced by stress (e.g., protoplasting), is characterized by open chromatin conformation, a chromatin state that could lead to activation of transposable elements (TEs). Here, we studied the activation of the Arabidopsis class II TE Tag1, in which two copies, situated close to each other (near genes) on chromosome 1 are found in Landsberg erecta (Ler) but not in Columbia (Col). We first transformed protoplasts with a construct in which a truncated Tag1 (ΔTag1 non-autonomous) blocks the expression of a reporter gene AtMBD5-GFP and found a relatively high ectopic excision of ΔTag1 accompanied by expression of AtMBD5-GFP in protoplasts derived from Ler compared to Col; further increase was observed in ddm1 (decrease in DNA methylation1) protoplasts (Ler background). Ectopic excision was associated with transcription of the endogenous Tag1 and changes in histone H3 methylation at the promoter region. Focusing on the endogenous Tag1 elements we found low level of excision in Ler protoplasts, which was slightly and strongly enhanced in ddm1 and cmt3 (chromomethylase3) protoplasts, respectively, concomitantly with reduction in Tag1 gene body (GB) CHG methylation and increased Tag1 transcription; strong activation of Tag1 was also observed in cmt3 leaves. Notably, in cmt3, but not in ddm1, Tag1 elements were excised out from their original sites and transposed elsewhere in the genome. Our results suggest that dedifferentiation is associated with Tag1 activation and that CMT3 rather than DDM1 plays a central role in restraining Tag1 activation via inducing GB CHG methylation.
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Affiliation(s)
- Asif Khan
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion 84990, Israel
| | - Narendra Singh Yadav
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion 84990, Israel
| | - Yaakov Morgenstern
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion 84990, Israel
| | - Assaf Zemach
- Department of Molecular Biology and Ecology of Plants, Tel-Aviv University, 69978 Tel Aviv, Israel
| | - Gideon Grafi
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion 84990, Israel.
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240
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Vega-Vaquero A, Bonora G, Morselli M, Vaquero-Sedas MI, Rubbi L, Pellegrini M, Vega-Palas MA. Novel features of telomere biology revealed by the absence of telomeric DNA methylation. Genome Res 2016; 26:1047-56. [PMID: 27405804 PMCID: PMC4971770 DOI: 10.1101/gr.202465.115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 06/20/2016] [Indexed: 12/21/2022]
Abstract
Cytosine methylation regulates the length and stability of telomeres, which can affect a wide variety of biological features, including cell differentiation, development, or illness. Although it is well established that subtelomeric regions are methylated, the presence of methylated cytosines at telomeres has remained controversial. Here, we have analyzed multiple bisulfite sequencing studies to address the methylation status of Arabidopsis thaliana telomeres. We found that the levels of estimated telomeric DNA methylation varied among studies. Interestingly, we estimated higher levels of telomeric DNA methylation in studies that produced C-rich telomeric strands with lower efficiency. However, these high methylation estimates arose due to experimental limitations of the bisulfite technique. We found a similar phenomenon for mitochondrial DNA: The levels of mitochondrial DNA methylation detected were higher in experiments with lower mitochondrial read production efficiencies. Based on experiments with high telomeric C-rich strand production efficiencies, we concluded that Arabidopsis telomeres are not methylated, which was confirmed by methylation-dependent restriction enzyme analyses. Thus, our studies indicate that telomeres are refractory to de novo DNA methylation by the RNA-directed DNA methylation machinery. This result, together with previously reported data, reveals that subtelomeric DNA methylation controls the homeostasis of telomere length.
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Affiliation(s)
- Alejandro Vega-Vaquero
- Technical Superior School of Informatics Engineering, University of Seville, 41080 Seville, Spain
| | - Giancarlo Bonora
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Marco Morselli
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - María I Vaquero-Sedas
- Institute of Vegetal Biochemistry and Photosynthesis, CSIC-University of Seville, IBVF (CSIC-US), 41092 Seville, Spain
| | - Liudmilla Rubbi
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Miguel A Vega-Palas
- Institute of Vegetal Biochemistry and Photosynthesis, CSIC-University of Seville, IBVF (CSIC-US), 41092 Seville, Spain
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241
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Structure and function of histone methylation-binding proteins in plants. Biochem J 2016; 473:1663-80. [DOI: 10.1042/bcj20160123] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/29/2016] [Indexed: 12/28/2022]
Abstract
Post-translational modifications of histones play important roles in modulating many essential biological processes in both animals and plants. These covalent modifications, including methylation, acetylation, phosphorylation, ubiquitination, SUMOylation and so on, are laid out and erased by histone-modifying enzymes and read out by effector proteins. Recent studies have revealed that a number of developmental processes in plants are under the control of histone post-translational modifications, such as floral transition, seed germination, organogenesis and morphogenesis. Therefore, it is critical to identify those protein domains, which could specifically recognize these post-translational modifications to modulate chromatin structure and regulate gene expression. In the present review, we discuss the recent progress in understanding the structure and function of the histone methylation readers in plants, by focusing on Arabidopsis thaliana proteins.
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242
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Zhang CJ, Hou XM, Tan LM, Shao CR, Huang HW, Li YQ, Li L, Cai T, Chen S, He XJ. The Arabidopsis acetylated histone-binding protein BRAT1 forms a complex with BRP1 and prevents transcriptional silencing. Nat Commun 2016; 7:11715. [PMID: 27273316 PMCID: PMC4899616 DOI: 10.1038/ncomms11715] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 04/21/2016] [Indexed: 12/20/2022] Open
Abstract
Transposable elements and other repetitive DNA sequences are usually subject to DNA methylation and transcriptional silencing. However, anti-silencing mechanisms that promote transcription in these regions are not well understood. Here, we describe an anti-silencing factor, Bromodomain and ATPase domain-containing protein 1 (BRAT1), which we identified by a genetic screen in Arabidopsis thaliana. BRAT1 interacts with an ATPase domain-containing protein, BRP1 (BRAT1 Partner 1), and both prevent transcriptional silencing at methylated genomic regions. Although BRAT1 mediates DNA demethylation at a small set of loci targeted by the 5-methylcytosine DNA glycosylase ROS1, the involvement of BRAT1 in anti-silencing is largely independent of DNA demethylation. We also demonstrate that the bromodomain of BRAT1 binds to acetylated histone, which may facilitate the prevention of transcriptional silencing. Thus, BRAT1 represents a potential link between histone acetylation and transcriptional anti-silencing at methylated genomic regions, which may be conserved in eukaryotes. Transposons and repetitive sequences are typically subject to transcription silencing. Here, Zhang et al. find that the bromodomain-containing protein BRAT1 forms a complex with BRP1, recognizes histone acetylation and acts to prevent transcriptional silencing in Arabidopsis.
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Affiliation(s)
- Cui-Jun Zhang
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Xiao-Mei Hou
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Lian-Mei Tan
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Chang-Rong Shao
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Huan-Wei Huang
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Yong-Qiang Li
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Lin Li
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Tao Cai
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - She Chen
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
| | - Xin-Jian He
- National Institute of Biological Sciences, No. 7, Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China
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243
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Lee WK, Cho MH. Telomere-binding protein regulates the chromosome ends through the interaction with histone deacetylases in Arabidopsis thaliana. Nucleic Acids Res 2016; 44:4610-24. [PMID: 26857545 PMCID: PMC4889915 DOI: 10.1093/nar/gkw067] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 01/20/2016] [Accepted: 01/28/2016] [Indexed: 01/13/2023] Open
Abstract
Telomeres are nucleoprotein complexes at the end of eukaryotic chromosomes. Many telomere-binding proteins bind to telomeric repeat sequences and further generate T-loops in animals. However, it is not clear if they regulate telomere organization using epigenetic mechanisms and how the epigenetic molecules are involved in regulating the telomeres. Here, we show direct interactions between the telomere-binding protein, AtTRB2 and histone deacetylases, HDT4 and HDA6, in vitro and in vivo AtTRB2 mediates the associations of HDT4 and HDA6 with telomeric repeats. Telomere elongation is found in AtTRB2, HDT4 and HDA6 mutants over generations, but also in met1 and cmt3 DNA methyltransferases mutants. We also characterized HDT4 as an Arabidopsis H3K27 histone deacetylase. HDT4 binds to acetylated peptides at residue K27 of histone H3 in vitro, and deacetylates this residue in vivo Our results suggest that AtTRB2 also has a role in the regulation of telomeric chromatin as a possible scaffold protein for recruiting the epigenetic regulators in Arabidopsis, in addition to its telomere binding and length regulation activity. Our data provide evidences that epigenetic molecules associate with telomeres by direct physical interaction with telomere-binding proteins and further regulate homeostasis of telomeres in Arabidopsis thaliana.
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Affiliation(s)
- Won Kyung Lee
- Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea
| | - Myeon Haeng Cho
- Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea
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244
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Taudt A, Colomé-Tatché M, Johannes F. Genetic sources of population epigenomic variation. Nat Rev Genet 2016; 17:319-32. [DOI: 10.1038/nrg.2016.45] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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245
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Cabrera J, Barcala M, García A, Rio-Machín A, Medina C, Jaubert-Possamai S, Favery B, Maizel A, Ruiz-Ferrer V, Fenoll C, Escobar C. Differentially expressed small RNAs in Arabidopsis galls formed by Meloidogyne javanica: a functional role for miR390 and its TAS3-derived tasiRNAs. THE NEW PHYTOLOGIST 2016; 209:1625-40. [PMID: 26542733 DOI: 10.1111/nph.13735] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/25/2015] [Indexed: 05/20/2023]
Abstract
Root-knot nematodes (RKNs) induce inside the vascular cylinder the giant cells (GCs) embedded in the galls. The distinctive gene repression in early-developing GCs could be facilitated by small RNAs (sRNA) such as miRNAs, and/or epigenetic mechanisms mediated by 24nt-sRNAs, rasiRNAs and 21-22nt-sRNAs. Therefore, the sRNA-population together with the role of the miR390/TAS3/ARFs module were studied during early gall/GC formation. Three sRNA libraries from 3-d-post-inoculation (dpi) galls induced by Meloidogyne javanica in Arabidopsis and three from uninfected root segments were sequenced following Illumina-Solexa technology. pMIR390a::GUS and pTAS3::GUS lines were assayed for nematode-dependent promoter activation. A sensor line indicative of TAS3-derived tasiRNAs binding to the ARF3 sequence (pARF3:ARF3-GUS) together with a tasiRNA-resistant ARF3 line (pARF3:ARF3m-GUS) were used for functional analysis. The sRNA population showed significant differences between galls and controls, with high validation rate and correspondence with their target expression: 21-nt sRNAs corresponding mainly to miRNAs were downregulated, whilst 24-nt-sRNAs from the rasiRNA family were mostly upregulated in galls. The promoters of MIR390a and TAS3, active in galls, and the pARF3:ARF3-GUS line, indicated a role of TAS3-derived-tasiRNAs in galls. The regulatory module miR390/TAS3 is necessary for proper gall formation possibly through auxin-responsive factors, and the abundance of 24-nt sRNAs (mostly rasiRNAs) constitutes a gall hallmark.
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Affiliation(s)
- Javier Cabrera
- Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain
| | - Marta Barcala
- Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain
| | - Alejandra García
- Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain
| | - Ana Rio-Machín
- Molecular Cytogenetics Group, Human Cancer Genetics Programme, Centro Nacional Investigaciones Oncológicas (CNIO), C/Melchor Fernández Almagro, 3, 28029 , Madrid, Spain
| | - Clémence Medina
- INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France
| | - Stephanie Jaubert-Possamai
- INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France
| | - Bruno Favery
- INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France
| | - Alexis Maizel
- Centre for Organismal Studies University of Heidelberg, Im Neuenheimer Feld, 230-69120, Heidelberg, Germany
| | - Virginia Ruiz-Ferrer
- Centro de Investigaciones Biológicas, CSIC, Av. Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Carmen Fenoll
- Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain
| | - Carolina Escobar
- Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain
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246
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Deng S, Jang IC, Su L, Xu J, Chua NH. JMJ24 targets CHROMOMETHYLASE3 for proteasomal degradation in Arabidopsis. Genes Dev 2016; 30:251-6. [PMID: 26798133 PMCID: PMC4743055 DOI: 10.1101/gad.274647.115] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/18/2015] [Indexed: 01/09/2023]
Abstract
H3K9 methylation is usually associated with DNA methylation, and together they symbolize transcriptionally silenced heterochromatin. A number of proteins involved in epigenetic processes have been characterized. However, how the stability of these proteins is regulated at the post-translational level is largely unknown. Here, we show that an Arabidopsis JmjC domain protein, JMJ24, possesses ubiquitin E3 ligase activity. JMJ24 directly targets a DNA methyltransferase, CHROMOMETHYLASE 3 (CMT3), for proteasomal degradation to initiate destabilization of the heterochromatic state of endogenous silenced loci. Our results uncover an additional connection between two conserved epigenetic modifications: histone modification and DNA methylation.
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Affiliation(s)
- Shulin Deng
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA
| | - In-Cheol Jang
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA; Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore
| | - Linlin Su
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA
| | - Jun Xu
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA
| | - Nam-Hai Chua
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA
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247
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Lu YC, Feng SJ, Zhang JJ, Luo F, Zhang S, Yang H. Genome-wide identification of DNA methylation provides insights into the association of gene expression in rice exposed to pesticide atrazine. Sci Rep 2016; 6:18985. [PMID: 26739616 PMCID: PMC4704053 DOI: 10.1038/srep18985] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 12/01/2015] [Indexed: 01/20/2023] Open
Abstract
Atrazine (ATR) is a pesticide widely used for controlling weeds for crop production. Crop contamination with ATR negatively affects crop growth and development. This study presents the first genome-wide single-base-resolution maps of DNA methylation in ATR-exposed rice. Widespread differences were identified in CG and non-CG methylation marks between the ATR-exposed and ATR-free (control) rice. Most of DNA methyltransferases, histone methyltransferases and DNA demethylase were differentially regulated by ATR. We found more genes hypermethylated than those hypomethylated in the regions of upstream, genebody and downstream under ATR exposure. A stringent group of 674 genes (p < 0.05, two-fold change) with a strong preference of differential expression in ATR-exposed rice was identified. Some of the genes were identified in a subset of loss of function mutants defective in DNA methylation/demethylation. Provision of 5-azacytidine (AZA, inhibitor of DNA methylation) promoted the rice growth and reduced ATR content. By UPLC/Q-TOF-MS/MS, 8 degraded products and 9 conjugates of ATR in AZA-treated rice were characterized. Two of them has been newly identified in this study. Our data show that ATR-induced changes in DNA methylation marks are possibly involved in an epigenetic mechanism associated with activation of specific genes responsible for ATR degradation and detoxification.
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Affiliation(s)
- Yi Chen Lu
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Sheng Jun Feng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Jing Jing Zhang
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Fang Luo
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Shuang Zhang
- State key laboratory of food science and technology, Jiangnan University, Wuxi 214122, China
| | - Hong Yang
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
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248
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Hong S, Cheng X. DNA Base Flipping: A General Mechanism for Writing, Reading, and Erasing DNA Modifications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 945:321-341. [PMID: 27826845 DOI: 10.1007/978-3-319-43624-1_14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The modification of DNA bases is a classic hallmark of epigenetics. Four forms of modified cytosine-5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine-have been discovered in eukaryotic DNA. In addition to cytosine carbon-5 modifications, cytosine and adenine methylated in the exocyclic amine-N4-methylcytosine and N6-methyladenine-are other modified DNA bases discovered even earlier. Each modified base can be considered a distinct epigenetic signal with broader biological implications beyond simple chemical changes. Since 1994, crystal structures of proteins and enzymes involved in writing, reading, and erasing modified bases have become available. Here, we present a structural synopsis of writers, readers, and erasers of the modified bases from prokaryotes and eukaryotes. Despite significant differences in structures and functions, they are remarkably similar regarding their engagement in flipping a target base/nucleotide within DNA for specific recognitions and/or reactions. We thus highlight base flipping as a common structural framework broadly applied by distinct classes of proteins and enzymes across phyla for epigenetic regulations of DNA.
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Affiliation(s)
- Samuel Hong
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA, 30322, USA. .,Molecular and Systems Pharmacology Graduate Program, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA, 30322, USA.
| | - Xiaodong Cheng
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA, 30322, USA
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249
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Gallusci P, Hodgman C, Teyssier E, Seymour GB. DNA Methylation and Chromatin Regulation during Fleshy Fruit Development and Ripening. FRONTIERS IN PLANT SCIENCE 2016; 7:807. [PMID: 27379113 PMCID: PMC4905957 DOI: 10.3389/fpls.2016.00807] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/23/2016] [Indexed: 05/19/2023]
Abstract
Fruit ripening is a developmental process that results in the leaf-like carpel organ of the flower becoming a mature ovary primed for dispersal of the seeds. Ripening in fleshy fruits involves a profound metabolic phase change that is under strict hormonal and genetic control. This work reviews recent developments in our understanding of the epigenetic regulation of fruit ripening. We start by describing the current state of the art about processes involved in histone post-translational modifications and the remodeling of chromatin structure and their impact on fruit development and ripening. However, the focus of the review is the consequences of changes in DNA methylation levels on the expression of ripening-related genes. This includes those changes that result in heritable phenotypic variation in the absence of DNA sequence alterations, and the mechanisms for their initiation and maintenance. The majority of the studies described in the literature involve work on tomato, but evidence is emerging that ripening in other fruit species may also be under epigenetic control. We discuss how epigenetic differences may provide new targets for breeding and crop improvement.
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Affiliation(s)
- Philippe Gallusci
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux Villenave d’Ornon, France
- *Correspondence: Philippe Gallusci,
| | - Charlie Hodgman
- School of Biosciences, University of Nottingham Sutton Bonington, UK
| | - Emeline Teyssier
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux Villenave d’Ornon, France
| | - Graham B. Seymour
- School of Biosciences, University of Nottingham Sutton Bonington, UK
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250
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Dicer-independent RNA-directed DNA methylation in Arabidopsis. Cell Res 2015; 26:66-82. [PMID: 26642813 DOI: 10.1038/cr.2015.145] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 11/17/2015] [Accepted: 11/18/2015] [Indexed: 12/30/2022] Open
Abstract
RNA-directed DNA methylation (RdDM) is an important de novo DNA methylation pathway in plants. Small interfering RNAs (siRNAs) generated by Dicers from RNA polymerase IV (Pol IV) transcripts are thought to guide sequence-specific DNA methylation. To gain insight into the mechanism of RdDM, we performed whole-genome bisulfite sequencing of a collection of Arabidopsis mutants, including plants deficient in Pol IV (nrpd1) or Dicer (dcl1/2/3/4) activity. Unexpectedly, of the RdDM target loci that required Pol IV and/or Pol V, only 16% were fully dependent on Dicer activity. DNA methylation was partly or completely independent of Dicer activity at the remaining Pol IV- and/or Pol V-dependent loci, despite the loss of 24-nt siRNAs. Instead, DNA methylation levels correlated with the accumulation of Pol IV-dependent 25-50 nt RNAs at most loci in Dicer mutant plants. Our results suggest that RdDM in plants is largely guided by a previously unappreciated class of Dicer-independent non-coding RNAs, and that siRNAs are required to maintain DNA methylation at only a subset of loci.
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