The Physcomitrella patens genome – a first stepping stone towards understanding bryophyte and land plant evolution

Physcomitrella patens Hedw. (Bruch & Schimp.), a species belonging to the Funariaceae, is the first bryophyte the genome of which has been completely sequenced. In addition, the species became a model organism for evolutionary-developmental studies. These qualities of P. patens enable the comparison of genomic features across a very broad range of land plants and allow to infer changes that occurred during early land plant evolution. As hybridization and polyploidization occurs frequently among the Funariaceae, P. patens is also an ideal model to compare these mechanisms of genome evolution among land plants. In order to close the remaining gaps between algae and flowering plants in terms of complete genome sequences, it will be necessary to sequence further representatives from other early diverging land plant lineages. The first such additional projects are now proceeding with the cosmopolitan moss Ceratodon purpureus and the liverwort Marchantia polymorpha . In this article we shall review what the P. patens genome may teach us about land plant evolution and which additional species might be useful to explore in future.