Insights into land plant evolution garnered from the Marchantia polymorpha genome

The liverwort Marchantia polymorpha is a fascinating plant for many reasons, including the fact that it is one of the earliest terrestrial species that split off from the rest of the land plants. Therefore, comparisons between Marchantia and green algae or Marchantia and the rest of the land plants tell us a lot about the characteristics of the earliest land plants. Bowman et al. present the first liverwort genome and share what it reveals about the evolution of land plants. This study provides a snapshot of the timing of the evolution of diverse plant processes, and spans phytohormone signaling, control of hydration, and defense responses. The authors also touch on the contribution of horizontal-gene transfer from fungi in supporting the colonization of land by early plants, and ask the question of why whole-genome duplications are lacking in Marchantia. Cell 10.1016/j.cell.2017.09.030