Fig. 2

Knockout of DFR1 gene affects flavonoids accumulation in grape cells. A Schematic of the major branch pathways of flavonoid biosynthesis, starting with phenylpropanoid metabolism. The enzymes involved in the pathways are abbreviated as follows: Phe ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumaroyl:CoA-ligase (4CL), chalconesynthase (CHS), chalcone isomerase (CHI), flavone synthase (FS1 and FS2), flavonoid 3’ hydroxylase (F3’H), flavonoid 3′5’ hydroxylase (F3′5’H), flavanone 3-hydroxylase (F3H), isoflavone synthase (IFS), flavonol synthase (FLS), dihydroflavonol-4-reductas (DFR), stilbene synthase (STS), anthocyanidin synthase (ANS), UDP-glucose flavonoid glucosyltransferase (UFGT), O-methyltransferase (OMT), leucoanthocyanidin reductase (LAR), acyltransferases (ACT). B Target design for DFR1 editing. C Photos of grape cells and ethanol extracts of EV and dfr1 mutant cells. D Mutation frequencies detected at the two targets in DFR1 gene. E Representative mutated sequences detected at the two targets in DFR1 gene. The target sequences and PAMs are indicated in red and blue, respectively. The mutation types are shown on the right. F Flavonoid compounds with significant changes in contents in dfr1 cells. Data are shown as means ± SD (n = 3)