Developmentally controlled programmed cell death (dPCD) is a genetically encoded and tightly regulated process necessary for growth, development, and reproduction of multicellular plants and animals. However, in contrast to animal cell death processes, plant dPCD is still a very poorly understood phenomenon. Since little homology was found between animal and plant PCD regulators, we seek for unbiased strategies to discover plant cell death regulators. As a model to unravel the regulation of dPCD in plants we use the root cap of Arabidopsis thaliana. The Arabidopsis root cap is located at the growing root tip and consists of the apical columella and the lateral root cap (LRC) flanking the root meristem. The LRC undergoes PCD as a final differentiation step to ensure a constant root cap size and optimal root growth. Gene expression regulation by transcription factors (TFs) has been shown to be crucial for dPCD control in the root cap: SOMBRERO (SMB), ANAC087 and ANAC046 are NAC TFs that orchestrate different aspects of root cap cell death. Nevertheless, experimental data indicate that the dPCD transcriptional network is complex and requires the action of additional key factors.
We have employed diverse strategies to identify other TFs that are active in dPCD control. Using latest CRISPR-Cas9 approaches as well as inducible gain-of-function strategies, we attempt to identify and characterize new TFs involved in the regulatory network of root cap dPCD.