Metabolic Profiling and Transcriptome Analysis Provide Insights into the Anthocyanin Types and Biosynthesis in Zingiber striolatum Diels Flower Buds in Three Planting Modes

Abstract

The flower buds of Zingiber striolatum Diels are considered a special vegetable in China, and they are rich in anthocyanins. However, the detailed composition types and the molecular mechanism of anthocyanin biosynthesis in Z. striolatum flower buds are still unclear. In this study, targeted metabolites were used to analyze and identify the anthocyanin types of Z. striolatum in three planting modes: monoculture (CK), intercropping with maize (ZP), and intercropping with soybean (SP). A total of 48 anthocyanins were identified with significant differential accumulation in Z. striolatum flower buds. Among them, cyanidin-3-O-glucoside was the main composition type of anthocyanins. Furthermore, the composition types of blue anthocyanin were identified in flower buds. A total of 15 structure genes were obtained from the transcriptome database of Z. striolatum flower buds. The qRT-PCR results revealed that the expression levels of ZsC4H-1, ZsC4H-2, ZsCHS-2, ZsCHI, ZsF3H, ZsF3’H, ZsDFR, ZsF3’5’H-3, and ZsANS genes were the highest in the ZP model. This study showed that the ZP model contributes to anthocyanin synthesis and accumulation of Z. striolatum flower buds among the three planting modes of Z. striolatum. These findings provide valuable information for research on the planting model and anthocyanin biosynthesis in Z. striolatum flower buds.