DcMADS3, a MADS-Box Transcription Factor, Highly Expressed at the Middle Flower Bud Stage and Involved in...

Carrot (Daucus carota), an Apiaceae family crop, possesses the typical compound umbellate inflorescence with small flowers. The mechanism of carrot floral development is still unknown. APETALA3 (AP3) is a MADS-box transcription factor that primarily participates in stamen and petal development. In this study, DcMADS3 belonging to the APETALA3 group was cloned, which can form a heterodimer with DcMADS2 belonging PI (PISTILLATA) group. Expression analysis revealed DcMADS3 was higher in 'Kurodagosun' (normal flower, KRD) than 'Deep Purple' ('petaloid' CMS phenotype, DPP) at the middle flower bud stage. Its expression was greater in DPP petals (normal petal and petaloid petal) than in KRD petals, suggesting its potential role in regulating petalization development in carrot. Transgenic Arabidopsis overexpressing DcMADS3 resulted in altered petal size, increased petal number, and altered flower symmetry. Furthermore, yeast one-hybrid (Y1H) library screening identified DcXTH-like (DCAR_009699) as a potential factor binding to the DcMADS3 promoter. These results provided a theoretical foundation for further investigation of carrot floral organ development mechanism.