Phylogenetic analysis of proteins with R2R3-MYB domains in glaucophytes, red algae, and green plants. A, ML phylogram of proteins with R2R3-MYB domains in algae and M. polymorpha. The MYB protein CDC5 sequences were used as the outgroup. Ultrafast bootstrap values are associated with the internal branches; values <50 were omitted. Orthologs of land plant R2R3-MYB proteins from subfamilies FLP, II, V, ARP, VI, VII, and VIII are labeled in gray blocks. The key applies to the sequences in A to C. B, Sequences of auxiliary motifs of R2R3-MYB TFs from subfamilies FLP, II, V, ARP, VI, VII, and VIII in land plants and their charophycean orthologs. C, Intron-exon structure of MYB genes from subfamilies FLP, V, ARP, VI, and VIII, as well as their algal orthologs in the R2R3-MYB domain-encoding region. D, The presence or absence of orthologs of land plant R2R3-MYB subfamilies in the plant lineage is indicated by solid or open squares, respectively.