Cell layer-specific functions of the petal identity regulator PhDEF in petunia

We have employed a single-cell RNA-Seq approach using 10X Genomics Chromium to explore how the regulator PhDEF specifies petal identity in petunia. 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 anthesis were colleceted and cut into pieces in an enzymatic mix to obtain protoplasts. Protoplasts were purified by filtration and centrifugation, and viability was assessed before loading into the 10X chip.