Fig. 1.

Genome-wide mapping of DHSs and H3K27ac sites across flower development. a Schematic representation of the floral induction system (pAP1::AP1-GR ap1 cal) for collecting synchronized flower tissues at four key developmental stages (stage 0, stage 2, stage 4, and stage 7/8). b Genome browser tracks (colored according to stages) showing H3K27ac binding signal (measured by ChIP-seq) and chromatin accessibility (by DNase-seq) around the AP1 (left) and AP3 (right) loci. The expression levels of these two genes measured by RNA-seq are shown in the barcharts below. FPKM, fragments per kilobase of transcript per million mapped reads. S0, stage 0. c The relationship between H3K27ac binding signals (left) or chromatin accessibility (right) and the levels of gene expression at stage 8. In the analysis, the expressed genes were equally divided into 10 groups (n = 2083 genes in each group) from low expression (10%) to high expression (100%) based on the expression levels. Mean-normalized ChIP-seq or DNase-seq densities were plotted within a 6-kb region flanking the transcription start site (TSS) or the transcription end site (TES) for each groups of genes. d Stacked bar plot showing the distribution of H3K27ac peaks and DNase I hypersensitive sites (DHSs) in different genomic regions at  0, 2, 4, and 8 DAI. Promoters are defined as genomic regions encompassing 1 kb upstream of the TSS. Distal intergenic regions are genomic regions except intragenic and promoter regions. Peaks were assigned to each category based on their summits. e Comparison of H3K27ac enrichment at stages 2 and 8 of flower development. Each point represents an H3K27ac enriched region. Regions showing more than 1.5-fold difference of enrichment are indicated in blue (more enrichment at S2) and red (more enrichment at S8). Numbers indicate the number of target genes. Examples of target genes (with black circles) are labeled. The underlying source data for d and e are provided in the Source Data file