Molecular Mechanisms and Regulation of Anthocyanin Biosynthesis in Rosaceae Fruits: A Review.

Anthocyanin accumulation in Rosaceae fruits is governed by a multi-layered regulatory network integrating transcriptional control, epigenetic modulation, environmental signaling, and metabolic flux allocation. This review presents a critical synthesis of recent advances in this field, moving beyond descriptive gene lists to examine the mechanistic underpinnings of pigment regulation. We first outline the core biosynthetic pathway and post-synthetic modifications that ensure pigment stability. The central focus is on the MYB-bHLH-WD40 transcriptional complex and its integration with epigenetic mechanisms (DNA methylation, histone modifications, non-coding RNAs) and post-transcriptional regulation. We further examine how environmental cues-light, temperature, and hormones-are transduced through these molecular networks, and analyze metabolic flux control at pathway branch points. A cross-species comparative perspective across major Rosaceae crops (Malus, Pyrus, Fragaria, Prunus) reveals conserved regulatory nodes and genus-specific innovations. Finally, we discuss how this integrated knowledge, combined with multi-omics and gene editing tools, is driving targeted strategies in molecular breeding and postharvest quality management. This framework provides a foundation for rational manipulation of fruit coloration and nutritional quality.