Minimum requirements for changing and maintaining endodermis cell identity in the Arabidopsis root.

Changes in gene regulation during differentiation are governed by networks of transcription factors. The Arabidopsis root endodermis is a tractable model to address how transcription factors contribute to differentiation. We used a bottom-up approach to understand the extent to which transcription factors that are required for endodermis differentiation can confer endodermis identity to a non-native cell type. Our results show that the transcription factors SHORTROOT and MYB36 alone have limited ability to induce ectopic endodermal features in the absence of additional cues. The stele-derived signalling peptide CIF2 stabilizes SHORTROOT-induced endodermis identity acquisition. The outcome is a partially impermeable barrier deposited in the subepidermal cell layer, which has a transcriptional signature similar to the endodermis. These results demonstrate that other root cell types can be forced to differentiate into the endodermis and highlight a previously unappreciated role for receptor kinase signalling in maintaining endodermis identity.