Molecular characterization and expression analysis of dihydroflavonol 4-reductase (DFR) gene in Saussurea medusa

Abstract

Dihydroflavonol 4-reductase (DFR), which catalyzes the reduction of dihydroflavonols to leucoanthocyanins, is a key enzyme in the biosynthesis of anthocyanidins, proanthocyanidins, and other flavonoids of importance in plant development and human nutrition. This study isolated a full length cDNA encoding DFR, designated as SmDFR (GenBank Accession No. EF600682), by screening a cDNA library from a red callus line of Saussurea medusa, which is an endangered, traditional Chinese medicinal plant with high pharmacological value. SmDFR was functionally expressed in yeast (Saccharomyces cerevisiae) to confirm that SmDFR can readily reduce dihydroquercetin (DHQ) and dihydrokampferol (DHK), but it could not reduce dihydromyricetin (DHM). The deduced SmDFR structure shared extensive sequence similarity with previously characterized plant DFRs and phylogenetic analysis showed that it belonged to the plant DFR super-family. SmDFR also possessed flavanone 4-reductase (FNR) activity and can catalyze the conversion of eridictyol to luteoforol. Real-time PCR analysis showed that the expression level of SmDFR was higher in flowers compared with both leaves and roots. This work greatly enhances our knowledge of flavonoid biosynthesis in S. medusa and marks a major advance that could facilitate future genetic modification of S. medusa.

Dihydroflavonol 4-Reductase Genes from Freesia hybrida Play Important and Partially Overlapping Roles in the Biosynthesis of Flavonoids

“…However, the expression level of FhDFR3 was significantly higher than FhDFR1/FhDFR2 genes in all tested tissues, which might imply their partial or complete redundant roles. The spatial and temporal expression characteristics of FhDFR genes were found similar in several other species (Nakatsuka et al, 2003; Li et al, 2012; Mori et al, 2014). …”

Functional Characterization of Dihydroflavonol-4-Reductase in Anthocyanin Biosynthesis of Purple Sweet Potato Underlies the Direct Evidence of Anthocyanins Function against Abiotic Stresses

“…flavonols and proanthocyanidin [12], [13], [14]. The substrate dihydroflavonol of DFR can be catalyzed by FLS to produce flavonols, and the leucoanthocyanidins that result from DFR can subsequently be converted to proanthocyanidin by leucoanthocyanidin reductase (LAR) [15], [16], [17].…”

Transgenic Tobacco Overexpressing Tea cDNA Encoding Dihydroflavonol 4-Reductase and Anthocyanidin Reductase Induces Early Flowering and Provides Biotic Stress Tolerance

“…Genes encoding these two enzymes are characterized by a similar exon/intron pattern and enzymatic proteins contained an amino acid sequence motif for NADPH binding. The DFR has been identified and characterized from several plant species [8]–[11]. The transgenic tobacco overexpressing DFR encoding cDNA from Medicago truncatula ( MtDFR ) has been produced and studied with respect to flavonoids content [12].…”