PLETHORAs: Architects of Plant Development

Summary

Plants require continuous coordination of cell division in order to grow and develop new organs. This process gives rise to the dynamic shapes of the plant, or its architecture. In the model plant Arabidopsis thaliana (thale cress), a small family of PLETHORA genes steer the fundamental development of embryos, roots and shoots; without them, this plant cannot survive. In this thesis, I describe how specific PLETHORA genes control early embryogenesis, the position of leaves, flowers and lateral roots, and how they themselves are regulated. I also show how PLETHORAs regulate shoot architecture in cucumber, which is separated by millions of years of evolution from Arabidopsis thaliana. Through this work, we now better understand the biology of embryos and growth apices in a model plant, as well as in an economically relevant species.