Description:BnaA09.MYB52 directly targets the BnaBAN promoters and promotes BnaBAN expression in B. napus. BAN, encoding anthocyanidin reductase that converts anthocyanidins to 2,3- cis-flavan-3-ols compounds (proanthocyanidins starter units), is involved in the flavonoid biosynthesis pathway. Thus, Metabolite analysis was conducted to detect the content of flavonoid in WT (Wild-type), OE (BnaA09.MYB52 overexpression lines in the genetic background Westar) and mutants (four homologous genes of BnaMYB52 knocked out) plants. The result showed that the content of several metabolites in flavonoid pathway was reduced in mutants, whereas overexpression lines resulted in the opposite trend compared with WT.