Abstract

Plant cells are stuck together by their walls and cannot undergo rearrangements during development. Therefore, the regulation of organ size and shape in plants must involve differential patterns of growth and cell division across each structure as it develops. The development of multi-cellular structures predated the transition to land in the plant lineage and plants share a basic molecular ‘toolkit’ to regulate growth. Recently, growth patterns in flowering plant organs have been measured in detail and modelled, allowing us to gain mechanistic insight into the growth regulatory processes underpinning organ formation. However, very little is known about growth regulation in the living representatives of the earliest plants.

A plant growth form that is very different to any structures found in flowering plants is the haploid liverwort thallus – a flattened, forking mat which grows across the ground. The liverworts are the most basal living plant group and the fossil record suggests that thalloid forms may have dominated the early terrestrial flora. My project aims to understand how the thallus grows and what molecular components regulate this.