InterPro domain: IPR044830

This is the Class III homeodomain-leucine zipper (HD-Zip III) family of proteins, which includes the five members from Arabidopsis thaliana (REVOLUTA, ATHB-9/PHAVOLUTA, ATHB-14/PHABULOSA, ATHB-15/CORONA and ATHB8) and its homologues from Oryza sativa (OsHOX9-10, OSHOX29, OsHOX32-33) [ 1 , 2 , 3 , 4 ]. These proteins contain an HD-Zip domain involved in DNA binding and protein dimerisation, a START domain and a conserved C-terminal domain of unknown function. This family regulates apical embryo patterning, embryonic shoot meristem formation, organ polarity, vascular development, and meristem function. They show overlapping, antagonistic and divergent functions: PHABULOSA and PHAVOLUTA perform overlapping functions with REVOLUTA, PHABULOSA, PHAVOLUTA, and CORONA/ATHB15 genes perform overlapping functions distinct from REVOLUTA, while ATHB8 and CORONA encode functions that are both antagonistic to those of REVOLUTA within certain tissues and overlapping with REVOLUTA in other tissues [ 5 ].

1. Class III homeodomain-leucine zipper gene family members have overlapping, antagonistic, and distinct roles in Arabidopsis development. Plant Cell 17, 61-76
2. A genome-wide survey of HD-Zip genes in rice and analysis of drought-responsive family members. Plant Mol Biol 66, 87-103
3. REVOLUTA regulates meristem initiation at lateral positions. Plant J 25, 223-36
4. Control of stem cell homeostasis via interlocking microRNA and microProtein feedback loops. Mech Dev 130, 25-33