Cell layer-specific functions of the petal identity regulator PhDEF in petunia [ChIP-seq]

We have employed a ChIP-Seq approached to identify the direct target genes of the petal identity regulator PhDEF in petunia flowers. In particular, we have applied this approach to wt and mutant flowers (named star and wico) where PhDEF is only expressed in a single cell layer (epidermis or mesophyll), which yields drastically different phenotypes. This study gives insight into the layer-specific function of an homeotic regulator in plants. Overall design: Petals from wild-type, star and wico flowers at stage 8 (tube at about half its final size) were collected, flash-frozen and ground. Nuclei were extracted, fixated and sonicated to release the chromatin, that was incubated with an anti-PhDEF antibody. The immunoprecipitated chromatin (IP) and the control chromatin (INPUT) were sequenced by Illumina.