The petal identity gene PhDEF has a major binding and regulatory action in the epidermis.

PhDEF exhibits a major regulatory action in the petal epidermis, with significantly more prominent binding activity compared to the mesophyll in petunia flowers.

• Why it matters: Understanding how floral homeotic genes like PhDEF function in specific cell layers is crucial for revealing the mechanisms of floral organ development and cell layer identity, which are not well characterized.
• What they did: Using single-cell RNA-Seq and chromatin immunoprecipitation on cell layer-specific mutants, the study identified that PhDEF regulates distinct target genes in the petal epidermis and mesophyll, with a focus on its major role in the epidermis.
• The result: The findings demonstrate that PhDEF has a complex, layer-specific binding profile, emphasizing that cell layer identity influences the regulatory actions of floral homeotic genes, which may impact floral organ development understanding.