Histone methyltransferase that methylates 'Lys-36' (H3K36me) of histone H3 to produce H3K36me3 (PubMed:29184030). Promotes early stages of cellular dedifferentiation through H3K36me3-dependent, and to a lesser degree H3K4me3-dependent, activation of Lateral organ Boundaries-Domain (LBD) (e.g. LBD16 and LBD29) genes (PubMed:29184030). Positive regulator of root organogenesis including lateral root formation as well as adventitious root formation from wounded leaf tissues (PubMed:29517958). Recruited by JMJ30/ARF (e.g. ARF7 and ARF19) complexes to promote the deposition of H3K36me3 and, to a lower extent, H3K4me3 at LBD genes promoters, thus ensuring their stable activation during callus formation on callus-inducing medium (CIM) (PubMed:29923261, PubMed:29184030). L-lysyl-[histone] + S-adenosyl-L-methionine = H(+) + N(6)-methyl-L-lysyl-[histone] + S-adenosyl-L-homocysteine Interacts with JMJ30 (PubMed:29923261). Binds to ARF7 and ARF19 in the nucleus (PubMed:29184030). Reduced callus formation from somatic cells associated with an impaired reduction of H3K9me3 deposition and lower accumulation of H3K36me3 at LBD16 and LBD29 loci during leaf-to-callus transition (PubMed:29923261, PubMed:29184030). Lower lateral root formation and impaired ability to form adventitious root formation from wounded leaf tissues (PubMed:29517958). The double mutant jmj30-2 atxr2-1 is strongly impaired in callus formation (PubMed:29923261). Belongs to the class V-like SAM-binding methyltransferase superfamily. Histone-lysine methyltransferase family. TRX/MLL subfamily.