Genome-wide characterization and analysis of the anthocyanin biosynthetic genes in Brassica oleracea

From Brassica oleracea genome, 88 anthocyanin biosynthetic genes were identified. They expanded via whole-genome or tandem duplication and showed significant expression differentiation. Functional characterization revealed BoMYB113.1 as positive and BoMYBL2.1 as negative regulators responsible for anthocyanin accumulation. Brassica oleracea produces various health-promoting phytochemicals, including glucosinolates, carotenoids, and vitamins. Despite the anthocyanin biosynthetic pathways in the model plant Arabidopsis thaliana being well characterized, little is known about the genetic basis of anthocyanin biosynthesis in B. oleracea. In this study, we identified 88 B. oleracea anthocyanin biosynthetic genes (BoABGs) representing homologs of 46 Arabidopsis anthocyanin biosynthetic genes (AtABGs). Most anthocyanin biosynthetic genes, having expanded via whole-genome duplication and tandem duplication, retained more than one copy in B. oleracea. Expression analysis revealed diverse expression patterns of BoABGs in different tissues, and BoABG duplications showed significant expression differentiation. Additional expression analysis and functional characterization revealed that the positive regulator BoMYB113.1 and negative regulator BoMYBL2.1 may be key genes responsible for anthocyanin accumulation in red cabbage and ornamental kale by upregulating the expression of structural genes. This study paves the way for a better understanding of anthocyanin biosynthetic genes in B. oleracea and should promote breeding for anthocyanin content.