HB-3 — Medicago truncatula

Summary

MTR_7G025010 (MtHB-3, also known as MtWOX9A, MtSTIP, and MtWOX9B) on barrel medic chromosome 7 encodes a homeodomain-containing transcription factor of the WOX8/9-like family. The gene product is associated with DNA-binding transcription factor activity, transcription coactivator activity, and transcription cis-regulatory region binding, as well as 4Fe-4S cluster binding, chlorophyll binding, and electron transfer activity. MtHB-3 is linked to numerous developmental and physiological processes, including cotyledon boundary formation, seed growth, regulation of meristem size, gibberellic acid homeostasis, leaf abscission, and hyperosmotic salinity response. It has been connected to traits such as seed set, shoot system elongation, whole plant size, male sterility, pollen fertility, drought tolerance, anthocyanin content, and flowering time. The protein localizes to the nucleus, cytoplasm, photosystem I, and chloroplast thylakoid membrane. Studies of related genes in other species link the WOX8/9 family to embryonic patterning, zygote asymmetry, meristem maintenance, and shoot regeneration.