Plays a regulatory role in meristem function. Functions as component of a regulatory network controlling the establishment and/or development of the shoot system by the regulation of apical meristem function (PubMed:9681014). May play a role in tolerance to boric acid (PubMed:16861809). Expressed in roots and flowers. Expressed in shoot apex, axillary buds, at the basis of flowers and branching points of inflorescences. Induced by abscisic acid (ABA), drought, light and wounding in leaves. Down-regulated by drought and ABA in roots. Plants expressing ectopically MYB13 display peculiar hook structure at pedicel branching points, and a reversed order of first flowers and axillary buds.