Catalyzes methylation of the sphingoid base component of glucosylceramides (GluCers) at the C9-position. Sphingolipid C9-methylation requires 4,8-desaturated ceramides as substrates. Glucosylceramides play important roles in growth, differentiation and pathogenicity. The methyl group at the C9-position distinguishes fungal glucosylceramides from those of plants and animals and may thus play a role in host-pathogen interactions enabling the host to recognize the fungal attack and initiate specific defense responses. However, C-9 methylation of GlcCers is not essential for the sensitivity of F.graminearum to plant defensins MsDef1 and RsAFP2. a (4E,8E)-4-sphinga-4,8-dienine ceramide + S-adenosyl-L-methionine = a 9-methyl-(4E,8E)-sphinga-4,8-dienine ceramide + H(+) + S-adenosyl-L-homocysteine Lipid metabolism; sphingolipid metabolism. Produces 65 to 75% nonmethylated and 25 to 35% methylated GlcCers. Exhibits severe growth defects and produces abnormal conidia. Also exhibits drastically reduced disease symptoms in wheat and much-delayed disease symptoms in Arabidopsis thaliana. A double-knockout with its paralog MT1 is not viable. Belongs to the CFA/CMAS family.