Cloning, expression and functional analysis of the SOC1 homologous gene in pak choi (Brassica rapa ssp. Chinensis makino)

Flowering transition is important in plant growth and development, and the SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) gene belongs to the MADS-box gene family, which is an integrator involved in the regulation of flower formation in plants. Current studies have shown that the structural domain of SOC1 is relatively conserved in a variety of plants. To further investigate the function of the SOC1 homologous gene in pak choi, the full-length coding sequence of pak choi BrcSOC1 was cloned, and the structure, subcellular localization and spatiotemporal expression pattern of BrcSOC1 were analyzed in this study. The tissue-specific expression results showed that BrcSOC1 was expressed in roots, leaves, bolts, flowers and pods. The expression results at different developmental stages showed that BrcSOC1 was expressed at the highest level at floral bud differentiation stage 5. When BrcSOC1 was overexpressed in Arabidopsis thaliana, the flowering time in all transgenic plants was significantly earlier than in the wild type, and the expression analysis indicated that BrcSOC1 positively regulated the expression of the downstream genes AGAMOUS-LIKE 24 (AGL24) and LEAFY (LFY). These results provide an important reference for further research on the mechanism of BrcSOC1 in the flowering pathway of pak choi.