Functional Analysis of Two Flavanone-3-Hydroxylase Genes from Camellia sinensis: A Critical Role in Flavonoid Accumulation

Abstract

Flavonoids are major secondary metabolites in Camellia sinensis. Flavanone-3-hydroxylase (F3H) is a key enzyme in flavonoid biosynthesis in plants. However, its role in the flavonoid metabolism in C. sinensis has not been well studied. In this study, we cloned two F3Hs from C. sinensis, named CsF3Ha and CsF3Hb, where CsF3Ha containing 1107 bases encoded 368 amino acids, and CsF3Hb containing 1071 bases encoded 357 amino acids. Enzymatic activity analysis showed both recombinant CsF3H enzymes in Escherichia coli could convert naringenin and eriodictyol into dihydrokaempferol (DHK) and dihydroquercetin (DHQ), respectively. The expression profiles showed that CsF3Ha and CsF3Hb were highly expressed in the tender leaves of tea plants. Under different abiotic stresses, the two CsF3Hs were induced remarkably by ultraviolet (UV) radiation, sucrose, and abscisic acid (ABA). In the seeds of CsF3Hs transgenic Arabidopsis thaliana, the concentration of most flavonol glycosides and oligomeric proanthocyanidins increased significantly, while the content of monocatechin derivatives decreased. The present study revealed that CsF3Hs played critical roles in flavonoid biosynthesis in tea plants.

Bacillus licheniformis strain POT1 mediated polyphenol biosynthetic pathways genes activation and systemic resistance in potato plants against Alfalfa mosaic virus

“…Interestingly the dual foliar application (T4), before and after the viral infection, showed the highest induction of both genes, CHS and CHI, that are strictly required for flavonoid production in multiple tissues of potato 27,65 . The obtained results showed that F3H, the key enzyme in flavonoid biosynthesis in plants 66 , was the master expressed gene among flavonoid pathway genes with the highest expressions level 116.162-, 367.092-and 588.133-fold change than the control for T2, T3 and T4, respectively. Likewise, F3′H exhibited significant upregulation in both POT1 treatments with relative expression 7.963-and 20.440-fold increased than control.…”

“…The obtained results showed that F3H , the key enzyme in flavonoid biosynthesis in plants 66 , was the master expressed gene among flavonoid pathway genes with the highest expressions level 116.162-, 367.092- and 588.133- fold change than the control for T2, T3 and T4, respectively. Likewise, F3′H exhibited significant up-regulation in both POT1 treatments with relative expression 7.963- and 20.440-fold increased than control.…”

Assessment of Genetic Diversity in Differently Colored Raspberry Cultivars Using SSR Markers Located in Flavonoid Biosynthesis Genes

“…Among these microsatellite loci, six (RcFH01, FaFS01, FaFS02, RiAS01, FaAR01, and RhUF01) were located in the structural genes of the flavonoid biosynthesis (F3H, FLS, ANS, ANR, and UFGT) and two (RiMY01 and RiTT01) in the regulatory genes (MYB10 and TTG1). Flavanone-3-hydroxylase (F3H) is a key enzyme in the flavonoid biosynthesis in plants, as it catalyzes formation of 3-hydroxy flavonol, a common precursor of anthocyanins, flavanols, and proanthocyanidins [35]. Particular attention was paid to the flavonol synthase gene, for which two loci were used.…”

Transcription Factors and microRNA Genes Regulatory Network Construction Under Drought Stress in Sesame (Sesamum indicum L.)

“…Similarly, ABP was reported to have a role in cell wall modification and cell expansion [39]. showed that F3H improved drought tolerance [42,43]. The AOPs are a subfamily of 2-oxoglutaratedependent dioxygenases which involved in glucosinolates (secondary metabolites) biosynthesis.…”