Genome-wide identification, characterization and expression analysis of the chalcone synthase gene family in Chinese cabbage.

Abstract

Background: Chalcone synthase (CHS) is a key rate-limiting enzyme in the flavonoid synthesis pathway. Flavonoids are crucial secondary metabolites that play significant roles in plant growth, development, and stress resistance. The CHS gene (BrCHS) family in Chinese cabbage has not yet been studied.

Results: We identified 10 BrCHS genes distributed across 7 chromosomes in the Chinese cabbage genome. Their encoded proteins all contain the Chal_Sti_Synt_C (PF02797) and Chal_Sti_Synt_N (PF00195) domains and can be classified into two groups based on systematic evolution analysis. These BrCHS genes contain 2-4 exons and numerous cis-acting elements responsive to light, hormones, stress, growth and development in the BrCHS gene promoters. We also revealed that the expression of BrCHS2 and BrCHS8 increased under treatment with methyl jasmonate, salt, or drought stress. Virus-induced gene silencing (VIGS) of BrCHS4 inhibited the expression of BrCHS4 and reduced the flavonoid and anthocyanin contents in leaves.

Conclusions: Ten BrCHS family genes are present in the genome of Chinese cabbage. These BrCHS genes seemingly maintained similar characteristics and functionalities during evolution. Our results demonstrated that BrCHS4 is involved in flavonoid and anthocyanin accumulation in Chinese cabbage and identified candidate genes for purple Chinese cabbage breeding.