Required to prevent the formation of axillary meristems within the spikelet meristem and permit the subsequent establishment of floral meristem identity (PubMed:12835399, PubMed:14503923). Mediates the transition from spikelet to floret meristem (PubMed:14503923). Determines the transition from panicle branching to spikelet formation. May specify floral organ identity by regulating the class B genes (Agamous-like genes) MADS6 and MADS17, as well as class E genes MADS1, MADS7 and MADS8 in floral meristem (PubMed:26744119). Possesses transactivation activity (PubMed:12835399). Expressed at the time of rudimentary glumes differentiation in a half-ring domain at the base of the rudimentary glume primordium. Altered specification of terminal and lateral spikelet meristems, resulting in the generation of a panicle composed of excessive ramification of rachis-branches. Belongs to the AP2/ERF transcription factor family. ERF subfamily. Truncated N-terminus.