SPT — Arabidopsis thaliana

Summary

AT4G36930, designated SPT (SPATULA), encodes a basic helix-loop-helix (bHLH) transcription factor that localises to the nucleus and possesses DNA-binding, transcription coactivator, and protein dimerization activities. In Arabidopsis thaliana, SPT is associated with carpel morphogenesis, specification of carpel identity, stigma development, dehiscence, abscission, organ growth, meristem development, shade avoidance, auxin anabolism, sphingolipid anabolism, and regulation of nitrogen utilization. The gene is linked to numerous traits including style length, silique fruit morphology, seed set percent, floral organ number, drought sensitivity, gibberellic acid sensitivity, and seedling cotyledon number. Phenotypic associations include silique dehiscence, seed dispersal, gynoecium development, stomata number, trichome number, and anthocyanin biosynthesis. Studies of related genes in other species connect the SPT family to fruit number, weight, firmness, shape, color, lycopene content, seed weight, and lignin content.