Jeremy Solly, Nik Cunniffe and Jill Harrison have just published a paper on the growth of liverworts in the journal Current Biology.
Liverworts are the oldest surviving lineage of land plants. They have a flattened, creeping body (the "thallus"), which is not differentiated into stems and leaves. This contrasts with the wide array of beautiful shapes and patterns - branching structures, leaves and flowers - formed by more recently-evolving plant lineages. However, even the growth of the so-called lower plants, including liverworts, was at least until recently not characterised or understood.
The new research uses a combination of live imaging, growth analyses, and statistical and computational modeling to determine what regulates thallus shape in the liverwort Marchantia polymorpha. It shows that small differences in growth rates between different points on the thallus are sufficient to determine its overall shape. This differs from higher plants, for which the orientation of growth, rather than just its rate, is understood to be important. The first author on the work is Jeremy Solly, who until recently was a PhD student in the Department (and is adding to the collection of letters before and after his name by training to be a medical doctor). The research was led by Jill Harrison, who until recently was a Royal Society Research Fellow in this Department, with modelling (mathematical!) by Nik Cunniffe.
The work continues at Jill's new lab at Bristol University, where she has recently moved as a Lecturer.
Read online: Solly JE, Cunniffe NJ, Harrison CJ. Regional Growth Rate Differences Specified by Apical Notch Activities Regulate Liverwort Thallus Shape. (2016) Current Biology.