AlgaTerrest: How the evolution of cell division and filament branching enabled the transition from algae to land plants.

• Applicant: Professor Dr. Henrik Buschmann
• Subject Area: Plant Cell and Developmental Biology ; Evolution and Systematics of Plants and Fungi
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440540015

The evolution from green algae to land plants involved a dramatic change of body plan. This transition required that simple 1-D algal filaments advanced to 2-D and eventually 3-D growth. The formation of the new body plans became possible through the evolution of branching mechanisms, including profound changes in the mode of cell division. The suggested research is a comparative study aiming at the discovery and analysis of branching and cell division genes. In the zygnematophycean alga Mougeotia filament branching is inducible through a simple terrestrialization system, for which the algal filaments are transferred to solid (e.g. agar) surfaces. Based on this system the cell biology of Mougeotia terrestrialization will be studied using live-cell microscopy and TEM. Next, branching and cell division will be analyzed by a transcriptomic study. Orthologues of genes revealed in this way will be knocked out in the liverwort Marchantia. Phenotypic analyses of the obtained Marchantia plants can reveal how algal genes and proteins evolved to allow for the formation of a bryophyte body plan. This evolutionary comparative approach will reveal how the evolution of cell division and branching enabled the formation of the land plants.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2237: MAdLand — Molecular Adaptation to Land: plant evolution to change