Programmed Cell Death (PCD) is definded as genetically encoded cellular suicide. PCD was adopted by multicellular organisms to remove unwanted cells in a tightly controlled way. In both plants and animals, PCD plays critical roles in development, abiotic stress response and immunity. Yet, in comparison to animals, the knowledge of the molecular mechanisms that control PCD in plants is still very limited. The lateral root cap of Arabidopsis thaliana has been developed as a novel model system to investigate developmental PCD. Prof. Nowack’s lab has identified the transcription factor SOMBRERO that acts as a key regulator of PCD in the root cap. SMB is not only necessary for PCD execution in the root cap, but also sufficient to cause ectopic PCD upon inducible expression outside the root cap context. With this project I will combine the forward- and reverse-genetic methodologies to identify regulators of SMB, including the suppressors, activators and downstream targets. The knowledge generated in this project will be crucial to understand the regulatory network of plant PCD as a fundamental biological process. This information might in turn contribute to the development of new approaches for an environmental-friendly and sustainable agriculture, such as crop yield increase and biological weed control.