[Transcriptional regulation mechanism of differential accumulation of flavonoids in different varieties of Lonicera macranthoides based on metabonomics and transcriptomics].

ABSTRACT

This study aims to explore the molecular regulatory mechanism of the differential accumulation of flavonoids between 'Xianglei' and the wild type of Lonicera macranthoides. The flowers, stems, and leaves of the two varieties of L. macranthoides were collected. Ultra-performance liquid chromatography-mass spectrometry(UPLC-MS) and high-throughput sequencing(RNA-seq) were employed to screen out the differential flavonoids, key differentially expressed genes(DEGs) and transcription factors(TFs). Fourteen DEGs were randomly selected for verification by qRT-PCR. The results showed that a total of 17 differential flavonoids were obtained, including naringin chalcone, apigenin, and quercetin. The transcriptomic analysis predicted 19 DEGs associated with flavonoids, including 2 genes encoding chitin synthase(CHS) and 3 genes encoding chalcone isomerase(CHI). The regulatory network analysis and weighted gene co-expression network analysis(WGCNA) screen out the key enzyme genes CHS1, FLS1, and HCT regulating the accumulation of flavonoids. MYB12 and LBD4 may be involved in the biosynthesis of flavonoids by regulating the expression of key enzyme genes CHS1, FLS1, and HCT. The qRT-PCR and RNA-seq results were similar regarding the expression patterns of the 14 randomly selected DEGs. This study preliminarily analyzed the transcriptional regulatory mechanism for the differential accumulation of flavonoids in the two varieties of L. macranthoides and laid a foundation for further elucidating the regulatory effects of key enzyme genes and TFs on the accumulation of flavonoids.