An ancient transcription factor controlling cuticle development and water transport in the liverwort Marchantia polymorpha

We identified a basic helix loop helix transcription factor (called ZOU) which is specifically expressed in the endosperm of seed in flowering plants. ZOU controls the breakdown and death of the endosperm, allowing the embryo to grow and fill the seed. ZOU also regulates a signalling pathway that monitors the integrity of the embryonic cuticle. To our surprise, we found that the ZOU gene is conserved in all land plants, even ones that lack seed or endosperm. To find out the role of ZOU in early diverging land plants, we have used the liverwort Marchantia polymorpha, an emerging model for comparative evolutionary and developmental studies. By inactivating ZOU using genome editing we found that it controls cuticle integrity in liverworts as well, but also the development of a novel cell type called pegged rhizoids. Pegged rhizoids function in water transport and like xylem have secondary thickening and undergo programmed cell death. Using transcriptional profiling we have identified the genes that are regulated by ZOU during pegged rhizoid formation, these include genes likely involved in programmed cell death and cell wall modification. The aim of this project is to determine the role of the targets, for example by characterizing their expression pattern, inactivating them, and mis-expressing them to test the effects on rhizoid development. The student would get training in current techniques in plant genetic modification and analysis as well as cell biology. In addition, the student would interact with leading laboratories in UK and Europe by virtue of collaborations existing in my group.

Web: http://goodrich.bio.ed.ac.uk/