An important event in evolutionary history was the colonisation of the land by plants. In the charophyte green algae, the sister group of land plants, growth occurs from apical initial cells with only one or two cutting faces, producing simple mats, discs and branching forms.
The movement from water to land was accompanied by the acquisition of 3-dimensional (3D) growth, a defining feature of all land plants, which underpins structurally complex biomes that form the foundation of important terrestrial ecosystems. In flowering plants such as Arabidopsis thaliana, the onset of 3D growth occurs during embryogenesis so they cannot easily be exploited to investigate the genetic basis of 3D growth. However, it is possible to genetically dissect 3D growth in the model moss Physcomitrella patens, an extant representative of one of the earliest diverging land plant lineages. In P. patens, a 2-dimensional (2D) growth phase precedes 3D growth initiation and this 2D phase can be maintained indefinitely. Consequently, forward genetics has been used to create 3D-defective mutants. Mapping the causative mutations has revealed genes that are involved in the transition from 2D to 3D growth, including NO GAMETOPHORES 1 and NO GAMETOPHORES 2.
My DPhil research programme will work towards unravelling the genetic network underpinning the 2D to 3D growth transition in P. patens and will focus on how the underlying network is connected to hormone signalling.
My research will also examine whether the mechanism driving 3D growth is conserved throughout the land plants.
Oxford Interdisciplinary Bioscience DTP (BBSRC)