Molecular cloning, characterization and expression analysis of bolting-associated genes in flowering Chinese cabbage

Bolting and flowering enhance the commercial value of flowering Chinese cabbage. FLOWERING LOCUS C (FLC) and FRIGIDA (FRI) are two key flowering time genes in Arabidopsis thaliana. Here we reported on the cloning and characterization of three 'classical' genes from the autonomous pathway from flowering Chinese cabbage, BrcuFCA, BrcuFLD and BrcuFVE. The results of expression analysis showed BrcuFLC was a gradually up-regulated with the developmental stages. However, temporal mRNA expression of BrcuFRI, BrcuFCA, BrcuFVE, and BrcuFLD were found to follow the opposite transcription patterns. The spatial expression patterns of BrcuFCA, BrcuFLD, and BrcuFVE were similar with the highest levels in flowers, whereas the highest transcription levels of BrcuFLC occurred in leaves and stems and that of BrcuFRI in roots. We presumed that the main pathway of bolting-flowering regulation in flowering Chinese cabbage might be the autonomous pathway and different from the vernalization pathway and FRI-dependent pathway.