Transcription activator that recognizes the motif 5'-TAACGG-3' in the promoter of endosperm-induced genes (PubMed:27681170, PubMed:25194028, PubMed:19066902). Promotes vegetative-to-embryonic transition and the formation of somatic embryos from root explants in a WUS-independent manner but via the expression of embryonic genes (e.g. LEC1, LEC2, FUS3 and WUS) (PubMed:18695688). May play an important role during embryogenesis and seed maturation (PubMed:19066902, PubMed:25194028). Together with MYB115, activates the transcription of S-ACP-DES2/AAD2 and S-ACP-DES3/AAD3 thus promoting the biosynthesis of omega-7 monounsaturated fatty acid in seed endosperm (PubMed:27681170). Regulates negatively maturation genes in the endosperm (PubMed:25194028). Mainly expressed in siliques (PubMed:18695688, PubMed:19066902). Also detected at low levels in leaves and flowers (PubMed:19066902). Expressed in embryos from the early heart stage and throughout embryogenesis (PubMed:18695688, PubMed:19066902). Induced at the onset of the maturation phase in the endosperm, in a high and homogeneous repartition (PubMed:18695688, PubMed:19066902, PubMed:25194028, PubMed:27681170). Induced by LEC2. Single and myb118 myb115 double mutants do not show apparent developmental abnormalities (PubMed:18695688, PubMed:25194028). Reduced omega-7 fatty acids accumulation in the endosperm. The endosperm oil of double mutant myb115 myb118 lacks omega-7 fatty acids (PubMed:27681170). Endosperm-specific derepression of maturation-related genes associated with a partial relocation of storage compounds from the embryo to the endosperm (PubMed:25194028). Extended C-terminus.