Methyltransferase that may methylate 1,7-paraxanthine (PubMed:26768601). Prevents seed germination and modulates root architecture during early seedlings development (PubMed:26768601). Plays a minor role in defense responses toward pathogenic bacteria (e.g. P.syringae) (PubMed:28401908). Binds 1 Mg(2+) ion per subunit. Homodimer. During seed germination, predominantly expressed in the radicle and, to a lower extent, in hypocotyls. Induced in the presence of the herbivory P.xylostella larvae (PubMed:14617060). Silenced by miR163 (PubMed:21602291, PubMed:26768601, PubMed:28401908). Down-regulated during seedling deetiolation and seed germination via light-induced silencing mediated by miR163 (PubMed:21602291, PubMed:26768601). Accumulates in etiolated seedlings (PubMed:26768601). Induced by the fungal elicitor alamethicin (PubMed:21602291). Slightly up-regulated by P.syringae. Induced by exogenous salicylic acid (SA) (PubMed:28401908). Belongs to the methyltransferase superfamily. SABATH family. Truncated N-terminus. Truncated N-terminus.