Small RNA sequencing from Arabidopsis adult leaves and profiling of Arabidopsis transcripts in response to flg22 peptide
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE40044 | GEO | 2013/02/04
SECONDARY ACCESSION(S): PRJNA172443
REPOSITORIES: GEO
Similar Datasets
Project description:DNA methylation is an epigenetic mark that silences transposable elements (TEs) and repeats. Whereas the establishment and maintenance of DNA methylation are relatively well understood, little is known on their dynamics and biological relevance in plant and animal innate immunity. Here, we show that some TEs are demethylated and transcriptionally reactivated during antibacterial defense in Arabidopsis. This effect is concomitant with the down-regulation of key transcriptional gene silencing factors as well as an active demethylation process. DNA demethylation restricts multiplication and vascular propagation of the bacterial pathogen Pseudomonas syringae in leaves and, accordingly, some immune-response genes, containing repeats in their promoters, are negatively regulated by DNA methylation. This study provides evidence that DNA demethylation is part of a plant-induced immune response, potentially acting to prime transcriptional activation of some defense genes linked to Tes/repeats. We have monitored the transcript changes in Arabidopsis plants treated with a flagellin-derived peptide. DNA methylation is closely related to 24nt sRNAs. This is why we sequenced small RNA population in our study. 5-week-old Col-0 leaf samples (treated with either water or flg22 at 1 ?M concentration for 6 h) and deep sequenced by Fasteris (Geneva) on the Illumina HiSeq 2000 platform.
2013-02-04 | E-GEOD-40044 | biostudies-arrayexpress
Project description:DNA methylation is important for silencing transposable elements (TEs) in diverse eukaryotes including plants. In plant genomes, TEs are heavily methylated at cytosines of both CG and non-CG (or CH, where H can be A, T, or C) contexts. The role of RNA interference (RNAi) in establishing TE-specific DNA methylation has been extensively studied, although the significance of RNAi-independent pathways in DNA-methylation reprograming remains unexplored. Here, we directly investigated transgenerational de novo DNA methylation of TEs after the loss of DNA methylation. Our analyses identified very potent and precise RNAi-independent pathways for recovering CH methylation in most TE genes, or coding regions within TEs. Characterization of a small subset of TE genes that did not show CH methylation recovery revealed the impacts of H3K9 demethylation and replacement of histone H2A variants. These chromatin components are conserved between plants and animals and may contribute to chromatin reprograming in a conserved manner.
2020-09-30 | GSE148753 | GEO
Project description:Transposable elements (TEs) are often the primary determinant of genome size differences among eukaryotes. In plants, the proliferation of TEs is countered through epigenetic silencing mechanisms that prevent transposition. Recent studies using the model plant Arabidopsis thaliana have revealed that methylated TE insertions are often associated with reduced expression of nearby genes, and these insertions may be subject to purifying selection due to their effect on nearby genes. Less is known about the genome-wide patterns of epigenetic silencing of TEs in other plant species. Here, we compare the 24-nt siRNA complement from Arabidopsis thaliana and a closely related congener with a two- to three-fold higher TE copy number, A. lyrata. We show that TEs, and particularly siRNA-targeted TEs, are associated with reduced gene expression within both species and also with gene expression differences between orthologs. In addition, A. lyrata TEs are targeted by a lower fraction of uniquely matching siRNAs, which are associated with more effective silencing of TE expression. Overall, our results suggest that the efficacy of RNA-directed DNA methylation silencing is lower in A. lyrata, a finding that may shed light on the causes of differential TE proliferation among species. 4 A. lyrata mRNA-seq samples
2011-02-11 | E-GEOD-24571 | biostudies-arrayexpress
Project description:Transposable elements (TEs) are often the primary determinant of genome size differences among eukaryotes. In plants, the proliferation of TEs is countered through epigenetic silencing mechanisms that prevent transposition. Recent studies using the model plant Arabidopsis thaliana have revealed that methylated TE insertions are often associated with reduced expression of nearby genes, and these insertions may be subject to purifying selection due to their effect on nearby genes. Less is known about the genome-wide patterns of epigenetic silencing of TEs in other plant species. Here, we compare the 24-nt siRNA complement from Arabidopsis thaliana and a closely related congener with a two- to three-fold higher TE copy number, A. lyrata. We show that TEs, and particularly siRNA-targeted TEs, are associated with reduced gene expression within both species and also with gene expression differences between orthologs. In addition, A. lyrata TEs are targeted by a lower fraction of uniquely matching siRNAs, which are associated with more effective silencing of TE expression. Overall, our results suggest that the efficacy of RNA-directed DNA methylation silencing is lower in A. lyrata, a finding that may shed light on the causes of differential TE proliferation among species.
2011-02-11 | GSE24571 | GEO
Project description:Purpose: The goal of this study is to compare the transcriptome profilling (RNA-seq) of inflorescences infected with tobacco ratle virus (TRV) to mock inoculated inflorescences (negative controls), in Arabidopsis plants Methods: Inflorescences of systemically TRV infected or mock-inoculated plants were collected from more than 40 independent Arabidopsis plants, at 14 days post-inoculation (dpi). TRV and mock mRNA profiles were generated by deep sequencing by Illumina HiSeq 2000. The sequence reads that passed quality filters (SOAPnuke) were analysed by Burrows-Wheeler (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. Genes and isoforms were quantified by RSEM sofware package. qRT-PCR validation was performed using TaqMan and SYBR Green assays. Results: Here we report a significant repression of DNA methylation genes in inflorescences of Arabidopsis plants infected with Tobacco rattle virus (TRV) that coincides with dynamic changes in methylation at the whole genome level. Arabidopsis mutants deficient in DNA methylation were more resistant to this virus in early colonized tissues but more susceptible at later time points of infection, indicating that DNA methylation was critical to control both proliferation and antiviral defense. We found that TRV interference with DNA methylation leads to changes in the methylation and trancriptional status of transposable elements (TEs), including TEs located in the promoter of disease resistance genes that were significantly repressed in plants exposed to TRV. Activation of both TEs and their nearby disease resistance genes was altered in a range of hypo- and hyper-methylated Arabidopsis mutants, indicating that perturbations in DNA methylation contributes to modulate their expression in infected plants. Conclussion: Our study showed that TRV interferes with DNA methylation to alter the transcriptional silencing of TEs, which in turn compromises the expression of neighboring disease resistance genes.
2018-12-01 | GSE117417 | GEO
Project description:The eukaryotic genome is divided into regions of heterochromatin and euchromatin. The histone variant H2A.Z specifically localizes at euchromatin and displays a genome-wide anti-correlation with DNA methylation. DNA methylation plays a central role in the epigenetic regulation of many eukaryotic genomes. Active DNA demethylation is critical for controlling the epigenome in plants and mammals. Yet, little is known about how DNA demethylases are recruited to target loci. Here we report that SWR1, a conserved histone H2A.Z deposition complex, regulates DNA demethylation in Arabidopsis thaliana by recruiting the plant DNA demethylase ROS1. A forward genetic screen for anti-silencing mutants identified two SWR1 components, PIE1 and ARP6, as cellular factors required for ROS1-mediated DNA demethylation. We further discovered two bromodomain-containing proteins, the methyl-DNA-binding protein AtMBD9, and NPX1, a plant homolog of ScBDF1 in yeast, as components of the SWR1 complex in Arabidopsis. AtMBD9 and NPX1 function redundantly in preventing DNA hypermethylation and transcriptional gene silencing by recognizing histone acetylation marks established by IDM1, a known regulator of DNA demethylation. We show that IDM1 is required for H2A.Z deposition in many genomic regions targeted for active DNA demethylation. We found that H2A.Z interacts with ROS1 and is required for locus-specific DNA demethylation and antisilencing. Our results reveal a role of H2A.Z in active DNA demethylation, and a mechanism through which DNA demethylases can be recruited to target regions by specific histone acetylation marks.
2019-08-01 | GSE115170 | GEO
Project description:Heterochromatin of flowering plants is occupied by histone variant H2A.W and marked by DNA and H3K9 methylation. The relative impact of these heterochromatic features on activity of Transposable Elements (TEs) remains largely unknown. We obtained mutants deficient for H2A.W and key components controlling each of the key heterochromatic pathway in Arabidopsis and observed that knock out of individual pathway does not affect in a major manner TEs activity. However, when we combine the loss of H2A.W with any of the other heterochromatin controller we observe synergistic effects on heterochromatin compaction as well TEs activity. H2A.W appears to control expression of all TEs while each other heterochromatin controller target distinct subsets of TEs. We also observe an impact of linker histone H1. We propose that H2A.W acts together with several components of heterochromatin to prevents activity of distinct sets of TEs activity and chromatin architecture. Synergistic action with H2A.W is more prominent specifically in pathways controlled by the plant specific DNA chromomethyltransferases, CMT2 and CMT3.
2022-12-31 | GSE116643 | GEO
Project description:Cytosine DNA methylation is considered to be a stable epigenetic mark, but active demethylation has been observed in both plants and animals. In Arabidopsis thaliana, DNA glycosylases of the DEMETER (DME) family remove methylcytosines from DNA. Demethylation by DME is necessary for genomic imprinting and demethylation by a related protein, REPRESSOR OF SILENCING1, which prevents gene silencing in a transgenic background. However, the extent and function of demethylation by DEMETER-LIKE (DML) proteins in WT plants is not known. Using genome-tiling microarrays, we mapped DNA methylation in mutant and WT plants and identified 179 loci actively demethylated by DML enzymes. Mutations in DML genes lead to locus-specific DNA hypermethylation. Reintroducing WT DML genes restores most loci to the normal pattern of methylation, although at some loci, hypermethylated epialleles persist. Of loci demethylated by DML enzymes, >80% are near or overlap genes. Genic demethylation by DML enzymes primarily occurs at the 5' and 3' ends, a pattern opposite to the overall distribution of WT DNA methylation. Our results show that demethylation by DML DNA glycosylases edits the patterns of DNA methylation within the Arabidopsis genome to protect genes from potentially deleterious methylation. Keywords: whole genome profiling, DNA methylation, demethylase
2007-04-02 | GSE7336 | GEO
Project description:Arabidopsis ROS1 is the first genetically characterized DNA demethylase in eukaryotes. Dysfunction of ROS1 leads to increase in DNA methylation level at thousands of genomic loci. However, the features of ROS1 targets are not well understood. In this study, we identified and characterized ROS1 target loci in Arabidopsis Col-0 and C24 ecotypes. Most ROS1 targets are transposable elements (TEs) and intergenic regions. Compared to other TEs, ROS1-targeted TEs are closer to protein coding genes, suggesting a role for ROS1 in preventing the spreading of DNA methylation from highly methylated TEs to nearby genes. Interestingly, we found that unlike general TEs, ROS1 targets are associated with an enrichment of H3K18ac and H3K27me3, and depletion of H3K27me and H3K9me2. We investigated the antagonism between ROS1 and RNA-directed DNA methylation (RdDM) by identifying and characterizing thousands of genomic regions regulated by both ROS1 and RdDM. Unexpectedly, we uncovered thousands of previously unidentified RdDM targets by analyzing the DNA methylome of ros1/nrpd1 double mutant plants. In addition, we show that ROS1 also antagonizes RdDM-independent DNA methylation at more than a thousand genomic loci. Our results provide significant insights into the genome-wide effects of both ROS1-mediated active DNA demethylation and RNA-directed DNA methylation as well as their interaction in plants.
2016-11-01 | GSE83801 | GEO
Project description:Cytosine methylation is a DNA modification with important regulatory functions in eukaryotes. In flowering plants, sexual reproduction is accompanied by extensive DNA demethylation, which is required for proper gene expression in the endosperm, a nutritive extra-embryonic seed tissue. Endosperm arises from a fusion of a sperm cell carried in the pollen and a female central cell. Endosperm DNA demethylation is observed specifically on the chromosomes inherited from the central cell in Arabidopsis thaliana, rice and maize, and requires the DEMETER DNA demethylase in Arabidopsis. DEMETER is expressed in the central cell prior to fertilization, suggesting that endosperm demethylation patterns are inherited from the central cell. Downregulation of the MET1 DNA methyltransferase has also been proposed to contribute to demethylation in the central cell. However, with the exception of three maize genes, central cell DNA methylation has not been directly measured, leaving the origin and mechanism of endosperm demethylation uncertain. Here, we report genome-wide analysis of DNA methylation in the central cells of Arabidopsis and rice, as well as in rice egg cells. We find that DNA demethylation in both species is initiated in central cells, which requires DEMETER in Arabidopsis. However, we do not observe a global reduction of CG methylation that would be indicative of lowered MET1 activity; on the contrary, CG methylation efficiency is elevated in female gametes compared to non-sexual tissues. Our results demonstrate that locus-specific, active DNA demethylation in the central cell is the origin of maternal chromosome hypomethylation in the endosperm.
2016-11-30 | GSE89789 | GEO