Probable transcription factor involved in the determination of adaxial-abaxial polarity in ovule primordium. Specifies adaxial leaf fates. Binds to the DNA sequence 5'-GTAAT[GC]ATTAC-3'. Binds DNA as homodimer (PubMed:9747806). Interacts with ESR1 and ESR2 (PubMed:17376809). Interacts with ZPR3 (PubMed:18408069). By auxin. Repressed by miR165 and miR166. Belongs to the HD-ZIP homeobox family. Class III subfamily. Truncated N-terminus.