Flavonoid-mediated metabolic underpinning quality variation in red bud-sport pear mutants

Bud-sport mutations are pivotal for enhancing fruit quality traits in horticultural crops. Clarifying the metabolic differences between pears and their red bud-sport variants can help the selection of high-quality red pear resources, but there are fewer related studies. In this study, we investigated how bud-sport modulates flavonoid metabolic networks and affects fruit phenotypic differentiation. The study results showed that the red phenotype of pear mutants was primarily attributed to the accumulation of cyanin-3-O-galactoside. This accumulation was driven by the coordinated upregulation of structural genes (PyANS, PyUFGT, PyCHI) and MYB transcription factors (PyMYB10, PyMYB114). Further analyses showed that the flavonoid metabolic network exhibited a multibranch synergistic remodeling profile: flavone metabolites (e.g., apigenin-7-glucoside) were suppressed, whereas flavonol derivatives showed species-specific accumulation, redirecting metabolic flux toward anthocyanin synthesis. This work enhances the understanding of the flavonoid metabolic network in red pear and provides support for breeding of pear resources with high flavonoid content.