AP3 — Brassica juncea

Summary

BJUA09G19090S (BjAP3, also known as PMADS1) on chromosome A09 of Indian mustard encodes a MADS-box transcription factor containing MADS-box and K-box domains. The protein has DNA-binding transcription factor activity with RNA polymerase II-specific regulatory activity and protein dimerization activity. BjAP3 is associated with the specification of floral organ identity, particularly petal and stamen identity, as well as maintenance of floral meristem identity and floral organ development. The gene has been linked to numerous traits including flower morphology, petal number, stamen length, seed longevity, cytoplasmic male sterility, photoperiod-sensitive flowering time, and auxin sensitivity. It is also linked to responses to biotic stimuli, silver ion, heat stress, and osmotic conditions. The protein localizes to the nucleus, cytosol, and plasmodesmata. Studies of related genes in other species link the family to petal and stamen formation, floral organ identity, and reproductive development.