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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 ^mCG and ^mCHG contexts (^m = methylated) and is maintained by DNA METHYLTRANSFERASE 1 (MET1) and CHROMOMETHYLASE (CMT) DNA methyltransferase protein families, respectively. While angiosperm genomes encode for several members of MET1 and CMT families, the moss Physcomitrella 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 ΔPpmet deletion mutant which lost ^mCG and unexpectedly ^mCCG methylation at loci tested. In order to evaluate the extent of ^mCCG methylation by MET1, we reexamined the Arabidopsis thaliana Atmet1 mutant methylome and found a similar pattern of …