Histone methyltransferase involved in regulation of flowering time. Required for the expression of the flowering repressors FLC and MADS-box genes of the MAF family (PubMed:19726574, PubMed:19855050). Required for histone H3 dimethylation on 'Lys-36' H3K36me2 at the FLC locus (PubMed:19726574). Required for histone H3 trimethylation on 'Lys-4' (H3K4me3) at the FLC locus. Prevents trimethylation on 'Lys-27' (H3K27me3) at the same locus (PubMed:19855050). Involved in the control of seed dormancy and germination (PubMed:21799800). L-lysyl(4)-[histone H3] + 3 S-adenosyl-L-methionine = 3 H(+) + N(6),N(6),N(6)-trimethyl-L-lysyl(4)-[histone H3] + 3 S-adenosyl-L-homocysteine L-lysyl(36)-[histone H3] + 2 S-adenosyl-L-methionine = 2 H(+) + N(6),N(6)-dimethyl-L-lysyl(36)-[histone H3] + 2 S-adenosyl-L-homocysteine Expressed in the shoot and root apices, vascular tissues and mesophyll cells of rosette leaves. Early flowering (PubMed:19726574, PubMed:19855050). Reduced seed dormancy and increased germination rate of freshly harvested seeds (PubMed:21799800). Belongs to the class V-like SAM-binding methyltransferase superfamily. Histone-lysine methyltransferase family. TRX/MLL subfamily. Sequencing errors.