NH5/BLADE-ON-PETIOLE3 (OsBOP3) transcription factor is upregulated in response to submergence during seed germination and coleoptile growth. It is the regulator of proximal-distal patterning of leaves. Interacts with TGAL5, TGAL7, TGAL8 and TGAL9. {ECO:0000269|PubMed:24919709}.