The role of the miR156-SPL genetic network during land plant evolution: a comparative analysis of sporophyte development in divergent plant lineages

An ancient divergence in land plant evolution gave rise to the vascular plant (e.g. Arabidopsis) and bryophyte (e.g. moss) groups.

Prolonged apical growth is a defining feature of vascular plants and the establishment of elaborate shoot systems with delayed reproductive development enabled their extraordinary evolutionary success. In contrast, mosses undergo transient apical growth prior to rapid reproductive development.

In Arabidopsis, the microRNA miR156 represses members of the SPL family of transcription factors that inhibit apical growth and promote developmental transitions. However, the role of the miR156-SPL module in plant evolution remains to determined. SPL genes evolved before plants colonised land, whereas miR156 arose during early plant evolution.

It is possible, therefore, that miR156 was a critical innovation in land plant evolution that facilitated the elaboration of vascular plant forms. My Proposal will test this hypothesis by taking a comparative developmental approach.

Using gain and loss-of function genetic techniques I will characterise the role of miR156 and SPL genes in moss sporophyte development, specifically, their effects on apical growth and reproductive development.

In Arabidopsis, I will test how SPL genes regulate apical growth using reporter genes assays, advanced imaging and genome-wide surveys of SPL-targets.

Finally, I will test the importance of intercellular signaling to apical growth in moss and Arabidopsis by blocking connections between cells.

This Fellowship will provide training from a world-leading expert in cutting-edge techniques that are critical to my long-term research objectives.

It will allow me to extend my research portfolio by asking fundamental biological questions in a new experimental system (moss) within a highly stimulating scientific environment.

The training and outstanding professional development opportunities provided by the University of Bristol will be vital to achieve my career ambitions.