Jill Harrison

The radiation of life on Earth depended on the colonisation of land by plants. Plants’ photosynthetic activity enriched oxygen in the atmosphere, plants made the first soils and plants make food and homes for animals. The greening of the land started by the formation of thin soil crusts growing fungi, lichens and algae, and land plants originated from these algae[1-3]. The first land plants had a single tiny stem capped in a reproductive structure, as in modern mosses and other bryophytes. In contrast, most of today’s plants have large and elaborate branching forms nourished by vascular transport[4,5] My lab’s research aims to identify genes and developmental changes that enabled such vascular plant forms to arise during evolution. Whilst this question is simple to articulate, it is hard to address because bryophytes and vascular plants have such disparate overall forms and patterns of development. A handful of tiny fossils suggest that plants gained a capacity to branch before they started to make shoots with indefinitely proliferative shoot tips and leaves[4,5]. Using liverwort[6], moss[7-10] and lycophyte[11,12] model systems we have identified likely roles for PIN[8,9], CLAVATA[10] and KNOX[11] genes in the origin of branching and shoot growth. I wish to build on this work to show the pattern of development in primitive branching forms and identify ancestral mechanisms for branching in the vascular plants. I also wish to identify the molecular basis for the origin of stem cell functions and proliferation in vascular plant shoot tips. If you would like to join my lab please get in touch to discuss your ideas.

[02/02/2026] Evolution and development [06/04/2026] Jill Harrison [18/06/2026] WOX neofunctionalization following an ancient duplication in mosses [01/07/2025] Diversification of CLE expression patterns and nonmeristematic roles for CLAVATA receptor‐like kinases in a moss [04/12/2025] Phylogeny, chromosomal mapping and expression analyses of wheat CLAVATA pathway components suggest differential selection on receptor-like kinases, CLEs and T3 WOXes