Project description:H3K27me3 is a histone modification associated with transcriptional repression that plays a pivotal role in differentiation and development in plants and animals. H2A.Z, a histone variant of H2A, is often colocalized with H3K27me3 in Arabidopsis. Previous genome-wide studies have raised the possibility that H2A.Z contributes to H3K27me3 homeostasis in plants. To examine the contribution of H2A.Z to H3K27me3, we utilized hta9 hta11, a plant line which is defective in two of three genes that code for H2A.Z and has been previously characterized as an H2A.Z-depletion mutant. Surprisingly, ChIP-seq analysis of H2A.Z enrichment revealed that hta9 hta11 plants exhibit a nearly indistinguishable genic H2A.Z enrichment pattern relative to wild type with few genes that are enriched or depleted for H2A.Z. Mass spectrometry measurement of histone protein abundance in hta9 hta11 plants in conjunction with our ChIP-seq analysis indicates that the chromatin of hta9 hta11 plants exhibits altered relative abundance of H2A.Z variants rather than a global depletion of H2A.Z. In contrast, ChIP-seq analysis of H3K27me3 reveals that hta9 hta11 plants exhibit a robust global reduction in H3K27me3 enrichment, and numerous genes are identified that exhibit altered levels for H3K27me3. In addition, hta9 hta11 plants exhibit differential expression of thermoresponsive genes that have previously been shown to be dependent on H2A.Z. Our combined analyses indicate that specific H2A.Z isoforms play distinct roles in chromatin composition and gene expression in Arabidopsis, particularly with regards to H3K27me3 homeostasis.
Project description:Callus formation is usually a necessary step in regenerating a new plant from detached plant tissues, and the nature of the callus is similar to that of the root meristem. In this study, we intended to address the molecular basis that directs different plant tissues to form the root-meristem-like callus. We found that leaves, but not roots, of the Polycomb group (PcG) double mutant curly leaf-50 swinger-1 lost the ability to form a callus. Using ChIP-chip analysis, we identified genes that are changed markedly in the histone H3 lysine 27 trimethylation (H3K27me3) levels during callus formation from leaf explants. Among these genes, a number of leaf-regulatory genes were repressed through PcG-mediated H3K27me3. Conversely, certain auxin pathway genes and many root-regulatory genes were derepressed through H3K27 demethylation. Our data indicate that genome-wide H3K27me3 reprogramming, through the PcG-mediated H3K27me3 and the H3K27 demethylation pathways, is critical in directing cell fate transition. This submission represents the gene expression component of the study Leaves from 20-day-old seedlings of wild-type Col-0 and 20-DAC calli were used for RNA preparation.
Project description:H3K27me3 is a histone modification associated with transcriptional repression that plays a pivotal role in differentiation and development in plants and animals. H2A.Z, a histone variant of H2A, is often colocalized with H3K27me3 in Arabidopsis. Previous genome-wide studies have raised the possibility that H2A.Z contributes to H3K27me3 homeostasis in plants. To examine the contribution of H2A.Z to H3K27me3, we utilized hta9 hta11, a plant line which is defective in two of three genes that code for H2A.Z and has been previously characterized as an H2A.Z-depletion mutant. Surprisingly, ChIP-seq analysis of H2A.Z enrichment revealed that hta9 hta11 plants exhibit a nearly indistinguishable genic H2A.Z enrichment pattern relative to wild type with few genes that are enriched or depleted for H2A.Z. Mass spectrometry measurement of histone protein abundance in hta9 hta11 plants in conjunction with our ChIP-seq analysis indicates that the chromatin of hta9 hta11 plants exhibits altered relative abundance of H2A.Z variants rather than a global depletion of H2A.Z. In contrast, ChIP-seq analysis of H3K27me3 reveals that hta9 hta11 plants exhibit a robust global reduction in H3K27me3 enrichment, and numerous genes are identified that exhibit altered levels for H3K27me3. In addition, hta9 hta11 plants exhibit differential expression of thermoresponsive genes that have previously been shown to be dependent on H2A.Z. Our combined analyses indicate that specific H2A.Z isoforms play distinct roles in chromatin composition and gene expression in Arabidopsis, particularly with regards to H3K27me3 homeostasis.
Project description:ChIP-seq analysis with H3K4me3 and H3K27me3 in systemic leaves of Arabidopsis thaliana locally inoculated with Pseudomonas syringae AvrRpm1
Project description:Chromatin and RNA were extracted from young A. thaliana Col-0 rosette leaves. Chromatin immunoprecipitation experiments were performed using commercially available antibodies and analyzed by Illumina sequencing (ChIP-seq). Transcriptome data were generated by RNA-seq. ChIP-seq analysis of H3K4me3 and H3K27me3 enrichment profiles in 2 biological replicates. RNA-seq analysis of mRNA levels in 1 biological replicate.
Project description:H3K27me3 is a histone modification associated with transcriptional repression that plays a pivotal role in differentiation and development in plants and animals. H2A.Z, a histone variant of H2A, is often colocalized with H3K27me3 in Arabidopsis. Previous genome-wide studies have raised the possibility that H2A.Z contributes to H3K27me3 homeostasis in plants. To examine the contribution of H2A.Z to H3K27me3, we made use of hta9 hta11, a plant line which is defective in two of three genes that code for H2A.Z and which has been previously characterized as an H2A.Z-depletion mutant. Surprisingly, ChIP-seq analysis of H2A.Z enrichment revealed that hta9 hta11 plants exhibit a nearly indistinguishable genic H2A.Z enrichment pattern relative to wild type with few genes that are differentially enriched for H2A.Z. Mass spectrometry measurement of histone abundance in hta9 hta11 plants in conjunction with our ChIP-seq analysis indicates that the chromatin of hta9 hta11 plants exhibits altered relative abundance of H2A.Z variants rather than a global depletion of H2A.Z. In contrast, ChIP-seq analysis of H3K27me3 reveals that hta9 hta11 plants exhibit a robustly global reduction in H3K27me3 enrichment, and numerous genes are identified that exhibit altered levels for H3K27me3. In addition, hta9 hta11 plants exhibit differential expression of thermoresponsive genes that have previously been shown to be dependent on H2A.Z. Our combined analyses indicate that specific H2A.Z isoforms play distinct roles in chromatin composition and gene expression in Arabidopsis, particularly with regards to H3K27me3 homeostasis.