Putative transcription regulator that controls rice tillering by initiating axillary buds and promoting their outgrowth. Rice tiller is a specialized grain-bearing branch that is formed on the unelongated basal internode and grows independently of the mother stem (culm) by means of its own adventitious roots. Expressed in a small number of epidermal or subepidermal cells at the leaf axils, in axillary meristems and the entire tiller buds. Undetected in the shoot apical meristem. The C-terminal part of the protein is important for tillering. Mutant moc1, in which the last 124 amino acids are missing, is mono culm. Belongs to the GRAS family.