DNA METHYLTRANSFERASE 1 is involved in (m)CG and (m)CCG DNA methylation and is essential for sporophyte development in Physcomitrella patens.

DNA methylation has a crucial role in plant development regulating gene expression and silencing of transposable elements. Maintenance DNA methylation in plants occurs at symmetrical m CG and m CHG contexts ( m = methylated) and is maintained by DNA METHYL- TRANSFERASE 1 (MET1) and CHROMOMETHYL- ASE (CMT) DNA methyltransferase protein families, respectively. While angiosperm genomes encode for sev- eral members of MET1 and CMT families, the moss Phy- scomitrella patens, serving as a model for early divergent land plants, carries a single member of each family. To determine the function of P. patens PpMET we generated