Genome-wide identification of chalcone synthase (CHS) family members and their expression patterns at the sprouting stage of common bean (Phaseolus vulgaris) under abiotic stress

Abstract

Secondary metabolites such as flavonoids, produced by plants, could help plants cope with external stress. Flavonoid synthesis is catalyzed by chalcone synthase (CHS). CHS plays a broad role in the growth, development, and physiological activities of plants. However, studies of the CHS gene family in Phaseolus vulgaris are limited. In this study, the HMMER search tool was used to identify 29 CHS members in the reference genome of P. vulgaris. These PvCHS members were divided into 5 subgroups. Notably, subfamilies with close genetic relationships exhibited similarities in motifs and gene structures of PvCHSs. Additionally, analysis of the cis-element indicated the involvement of PvCHSs in response to abiotic stress. Furthermore, quantitative real-time PCR (qRT-PCR) analysis under various abiotic stress conditions revealed that the majority of PvCHSs were associated with the response to salt stress (NaCl), alkaline salt stress (NaHCO3), and heavy metal stress (CdCl2). Particularly, PvCHS01, PvCHS05, PvCHS14, and PvCHS25 were significantly up-regulated under alkaline salt stress. PvCHSs were also correlated with CHS activity and flavonoid content. In addition, exogenous flavonoids were observed to significantly decrease accumulation of ROS in P. vulgaris under alkaline salt stress. This study provides a basis for further analysis of the mechanisms underlying the response of PvCHSs to abiotic stress.