Transcription factor that modulates the balance between cellular proliferation and differentiation in root growth. Does not act through cytokinin and auxin signaling, but by repressing peroxidase expression in the elongation zone. Homodimer. Expressed in the root vascular tissue and in root hairs and lateral root caps. Detected at the protein level in all cell files in the elongation zone. Up-regulated by reactive oxygen species. Enlargment of the meristem and longer root length. Truncated N-terminus.