Abstract

Branching growth in the shoot is a key component of plant body architecture, and sculpts our natural environment. As well as being crucial for optimising traits such as light-harvesting potential, the development of branching shoots was likely a key event in the evolutionary history of land plants, perhaps being a prerequisite for leaf evolution. Palaeontological evidence suggests that thalloid organisms dominated the first land flora, and the current generally accepted phylogenies place the liverworts as the sister group to the rest of the land plants. In this context, my project aims to use the thalloid liverwort Marchantia as a model to understand branching in this anciently diverging group of plants. We plan to use whole-organism live-imaging, clonal analysis, and T-DNA mutagenesis to understand how branching operates at a molecular and cellular level, and how this is ultimately translated into a branched thallus structure. We hope that this will contribute to debates about how branching mechanisms have changed during land plant evolution, and how the first land plants might have elaborated their thalloid body structures.