Fig. 4

Flagellin recognition leads to HD2B redistribution to a new set of genes. a Comparison of HD2B tag density in the regions of ± 1 kb around the HD2B-occupied loci upon flg22 treatment. HD2B binding was determined by ChIP-seq experiments with an anti-GFP antibody in pHD2B::GFP-HD2B seedlings upon either mock or flg22 treatment. A comparison with the Input tag density confirmed HD2B enrichment after ChIP-seq in mock and flg22 conditions. b Pie chart representation of the classification of HD2B target genes upon mock or flg22 treatment. Genomic annotation of the detected HD2B peaks was performed using the Genomic Position Annotation Tool (GPAT). c HD2B global profiles. The majority of HD2B peaks were located at approximately 300 bp downstream of the transcription start site. HD2B peaks in both mock-treated and flg22-treated plants are represented to compare their relative position to the TSS. d Genome Browser view of ChIP-seq data across a region of chromosome 3 targeted by HD2B. e Flagellin treatment induces HD2B targeting to a new set of genes involved in plastid organization which is repressed by biotic stresses. The Venn diagram represents the overlap between HD2B targets in mock and flg22 conditions (left). The hierarchical tree graph shows a significant enrichment of the specific flg22-HD2B-targets in “plastid organization” with Agrigo GO Analysis Toolkit (middle). The heatmap generated with publicly available microarray data and the Genevestigator software 56 indicates that specific flg22-HD2B target genes are repressed after biotic or elicitor stresses. Each column represents a gene from the list and each line represents a particular microarray experiment. Red, green, and black colors indicate upregulation or downregulation or no change of gene expression, respectively (right)