Abstract

For a small and seemingly peripheral organ, the root cap performs a remarkably large and diverse set of functions in root growth and development. Given its role in many of the defining features of root growth, the evolution of the root cap was probably a central event in the evolution of the root itself. The morphology and function of the root cap are tightly connected, and root cap development is therefore regulated with great precision. Recent work in Arabidopsis has begun to reveal the complex genetic network that controls this developmental process. In particular, two NAC -domain transcription factors, FEZ and SOMBRERO , are central to root cap development, and form a feedback loop which connects pattern formation, stem cell activity and cell differentiation. In this talk I will describe our recent results regarding root cap development, and discuss what implications they have for understanding the evolution of roots.