Identification and Characterization of Flavonoid Biosynthetic Enzyme Genes in Salvia miltiorrhiza (Lamiaceae)

Abstract

Flavonoids are a class of important secondary metabolites with a broad spectrum of pharmacological functions. Salvia miltiorrhiza Bunge (Danshen) is a well-known traditional Chinese medicinal herb with a broad diversity of flavonoids. However, flavonoid biosynthetic enzyme genes have not been systematically and comprehensively analyzed in S. miltiorrhiza. Through genome-wide prediction and molecular cloning, twenty six flavonoid biosynthesis-related gene candidates were identified, of which twenty are novel. They belong to nine families potentially encoding chalcone synthase (CHS), chalcone isomerase (CHI), flavone synthase (FNS), flavanone 3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H), flavonoid 3′,5′-hydroxylase (F3′5′H), flavonol synthase (FLS), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), respectively. Analysis of intron/exon structures, features of deduced proteins and phylogenetic relationships revealed the conservation and divergence of S. miltiorrhiza flavonoid biosynthesis-related proteins and their homologs from other plant species. These genes showed tissue-specific expression patterns and differentially responded to MeJA treatment. Through comprehensive and systematic analysis, fourteen genes most likely to encode flavonoid biosynthetic enzymes were identified. The results provide valuable information for understanding the biosynthetic pathway of flavonoids in medicinal plants.

Identification of the Genes Involved in Anthocyanin Biosynthesis and Accumulation in Taxus chinensis

“…TcCHS was included in clade1 with GbCHS, GmCHS, MdCHS, AtCHS, CsCHS, MsCHS, PtCHS, VvCHS, TuCHS, OsCHS, and GaCHS. Clade1 included both angiosperms and gymnosperms CHSs, indicating the function of these CHSs is highly conserved and consistent with a previous study [12]. The expression levels of TcCHS in roots, leaves, phloem, and xylem were analyzed using qPCR ( Figure 2b).…”

“…The TcCHIs contained the conserved domain Chalcone_3 (pfam02431) ( Figure S1). Multiple amino acid sequence alignments of TcCHIs and type I (AtCHI), type II (MsCHI), type III (AtFAP1), and type IV (AtCHIL) were performed [12,28,29] ( Figure S5). Due to TcCHI1 possessing two Chalcone_3 domains, we separated it into two fragments for the alignment.…”

“…F3H and ANS contain two conserved domains, including DIOX_N (pfam03171) and 2OG-FeII_Oxy (pfam14226) ( Figure S1), and they belong to the 2-oxoglutarate dependent dioxygenase (2-ODD) superfamily. The DIOX_N domain is highly conserved in the N-terminal region with 2-oxoglutarate/Fe (II)-dependent dioxygenase activity [12,[31][32][33]. F3H catalyzes naringenin, eriodictyol, and dihydrotricetin into dihydrokaempferol, dihydroquercetin, and dihydromyricetin.…”

“…The structure and biosynthesis pathways of anthocyanins have been well studied. The genes related to anthocyanin biosynthesis have been reported in many plant species such as Arabidopsis thaliana, Medicago sativa, Petunia hybrida, and Salvia miltiorrhiza [9][10][11][12], which provide a good basis for understanding anthocyanin biosynthesis in these species. The biosynthesis of anthocyanin is complex.…”

Combined De Novo Transcriptome and Metabolome Analysis of Common Bean Response to Fusarium oxysporum f. sp. phaseoli Infection

“…In our metabolome, the most significantly enriched pathway was flavonoid biosynthesis pathway (Figure 7). These compounds are regulated by chalcone synthase (CHS), chalcone isomerase (CHI), isoflavone synthase (IFS), isoflavone reductase (IFR), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), and leucoanthocyanidin reductase (LAR) genes and manipulated by MYB transcription factors [43]. As detailed in Table S5, these genes (except LAR gene(s)) were upregulated in FO-24 infected common bean roots.…”