A zinc finger protein transcription factor PpZFP6 controls flavonoid biosynthesis in peach by regulating a...

The flavonoid content of peaches has gradually decreased as peach cultivars have been domesticated as part of their evolutionary process, and this reduction is driven by the fact that some flavonoids impart a bitter taste to the fruit. This has resulted in a gradual decrease in flavonoid content as the peach fruit matures during the developmental stages across most current peach cultivars. In this study, we first analyzed changes in flavonoid content among three peach varieties during different fruit developmental stages. We found that 75 days after full blooming was the stage when flavonoid content exhibited the most significant increase. We also performed transcriptome analysis on the fruit samples, screening out 77 differentially expressed genes between the two varieties with different flavonoid accumulation patterns. Combined with the results of previous association analysis, a glycosyltransferase gene, PpUGT73C3, was identified to be a candidate involving flavonoid synthesis. Transient transformation assays demonstrated that both overexpression and silencing of PpUGT73C3 significantly alter flavonoid accumulation, confirming that PpUGT73C3 positively regulates flavonoid biosynthesis in peach fruits. Additionally, PpZFP6, a gene encoding a zinc finger protein and mapping to chromosome 3, can influence the glycosylation modification of flavonoids by regulating the promoter activity of PpUGT73C3, ultimately controlling flavonoid accumulation in peach fruit. This study preliminarily clarified the molecular regulatory network of PpUGT73C3 in peach flavonoid metabolism, laying a research foundation for the breeding of functional fruit cultivars and the development of relevant regulatory strategies.

The online version contains supplementary material available at 10.1007/s11032-026-01692-3.