Promotes periclinal root capforming cell divisions. Activates expression of its negative regulator SMB in a feedback loop for controlled switches in cell division plane. Expressed in root cap stem cells and their immediate daughters. First expressed at globular stage onward in the COL progenitors after the first division of the hypophyseal cell. Later observed in these cells and their descendants, mostly in direct daughter cells. Also detected in the Epi/LRC stem cells and daughters, and is retained in maturing LRC layers. Present in elongated stem cells that are about to divide. Repressed by SMB in oriented-divised root cap stem cells. The NAC domain includes a DNA-binding domain and a dimerization domain. Fewer root cap layers; reduced number of columella (COL) and lateral root cap (LRC) cell layers from late embryogenesis due to impaired periclinal divisions in epidermal (Epi)/LRC and COL stem cells.