[Transcriptional regulation mechanism of differential accumulation of flavonoids in leaves and roots of Sarcandra glabra based on metabonomics and transcriptomics].

This study aims to explore the molecular regulation mechanism of the differential accumulation of flavonoids in the leaves and roots of Sarcandra glabra. Liquid chromatography-mass spectrometry(LC-MS) and high-throughput transcriptome sequencing(RNA-seq) were employed to screen out the flavonoid-related differential metabolites and differentially expressed genes(DEGs) encoding key metabolic enzymes. Eight DEGs were randomly selected for qRT-PCR verification. The results showed that a total of 37 flavonoid-related differential metabolites between the leaves and roots of S. glabra were obtained, including pinocembrin, phlorizin, na-ringenin, kaempferol, leucocyanidin, and 5-O-caffeoylshikimic acid. The transcriptome analysis predicted 36 DEGs associated with flavonoids in the leaves and roots of S. glabra, including 2 genes in the PAL pathway, 3 genes in the 4CL pathway, 2 genes in the CHS pathway, 4 genes in the CHI pathway, 2 genes in the FLS pathway, 1 gene in the DFR pathway, 1 gene in the CYP73A pathway, 1 gene in the CYP75B1 pathway, 3 genes in the PGT1 pathway, 6 genes in the HCT pathway, 2 genes in the C3'H pathway, 1 gene in the CCOAOMT pathway, 1 gene in the ANR pathway, 1 gene in the LAR pathway, 2 genes in the 3AT pathway, 1 gene in the BZ1 pathway, 2 genes in the IFTM7 pathway, and 1 gene in the CYP81E9 pathway. Six transcription factors, including C2H2, bHLH, and bZIP, were involved in regulating the differential accumulation of flavonoids in the leaves and roots of S. glabra. The qRT-PCR results showed that the up-or down-regulated expression of the 8 randomly selected enzyme genes involved in flavonoid synthesis in the leaves and roots of S. glabra was consistent with the transcriptome sequencing results. This study preliminarily analyzed the transcriptional regulation mechanism of differential accumulation of flavonoids in the leaves and roots of S. glabra, laying a foundation for further elucidating the regulatory effects of key enzyme genes and corresponding transcription factors on the accumulation of flavonoids in S. glabra.