Genome binding/occupancy profiling by high throughput sequencing
Abscisic acid (ABA) is an essential hormone that allows plants to respond to environmental stresses such as high salinity, drought and cold. It also plays a pivotal role in seed maturation and germination. Because of its importance, transcriptome changes in response to ABA have been profiled extensively by the plant community. Very few ChIP-chip/seq of ABA-related TFs have been reported to date. To fill the knowledge gap about how ABA works at the transcriptional level, we carried out ChIP-seq on 21 TFs from 11 different families using both mock- and ABA-treated conditions. Analyses of the resulting 122 ChIP-seq datasets identified 326,698 TF binding events using a stringent statistical cutoff. Based on our data, a comprehensive regulatory network in Arabidopsis thaliana was constructed. We uncovered determinants of dynamic TF binding and defined a hierarchy among TFs to explain differential gene expression and pathway feedback regulation. By extrapolating regulatory characteristics observed for the canonical ABA pathway components, we identified a new family of transcriptional regulators modulating ABA and salt responsiveness, and demonstrate their utility to modulate plant resilience to osmotic stress.
Identification of binding sites for 21 transcription factors using both mock- and ABA-treated conditions with mock IP of wild-type Col-0 ChIPped by anti-GFP antibody as control. Each experiment was carried out with at least two replicates.