AGL9 — Arabidopsis thaliana

Summary

AT1G24260, also known as SEP3, AGL9 or SEPALLATA3, encodes a MADS-box transcription factor with additional annotated activities including histone H3K27me2/H3K27me3 demethylase, nucleosome array spacer, DNA helicase, and transcription corepressor/coactivator functions. In Arabidopsis thaliana, SEP3 is associated with floral organ formation, petal and stamen identity specification, embryo sac morphogenesis, regulation of double fertilization, and negative regulation of seed maturation and floral organ abscission. The gene is linked to seed oil accumulation, abscisic acid breakdown, release of seed from dormancy, and cellular water homeostasis. SEP3 localises to the nucleus, cytosol, plastid, and plasmodesmata, and is associated with traits including pistil size, floral organ length, seed coat hardness and color, inflorescence branching, leaf area index, and osmotic adjustment capacity. Studies of related genes in other species link the family to fruit ripening, sepal growth, and plant height.