Auxin response factors (ARFs) are transcriptional factors that bind specifically to the DNA sequence 5'-TGTCTC-3' found in the auxin-responsive promoter elements (AuxREs). Could act as transcriptional activator or repressor. Formation of heterodimers with Aux/IAA proteins may alter their ability to modulate early auxin response genes expression. Homodimers and heterodimers. Expressed in the whole plant. Interactions between auxin response factors (ARFs) and Aux/IAA proteins occur through their C-terminal dimerization domains III and IV. May be due to a competing acceptor splice site. Belongs to the ARF family.