Transcription factor that plays a central role in ovule patterning by regulating cell proliferation of the maternal integuments and differentiation of the maegaspore mother cell (MCC). Involved in AGAMOUS (AG) repression in leaves. Highly expressed in developing ovules. Present in developing primordia and differentiating organs but absent in mature organs. In developing seeds, it is expressed in the embryo, suspensor and endosperm nuclei, but absent in the integuments. In seedlings, it is expressed in the shoot apical meristem and leaf primordia, but not in expanded cotyledons or mature leaves. In reproductive structures, transcripts could be detected in floral apical meristems, floral primordia, stamens and pistils. Also expressed in the tapetum in anthers and in the gynoecium. Weakly expressed in petals, sepals and the walls of carpels. Belongs to the WUS homeobox family.