Anthocyanin pathway in eggplant: genetic regulation and future directions for metabolic engineering

Anthocyanins are flavonoids and play a key role in eggplant color, nutritional value, and stress tolerance. Their biosynthesis is tightly regulated through a complex interplay of structural and regulatory genes, primarily by the MYB-bHLH-WD40 (MBW) transcriptional complex. Environmental factors like light, temperature, and abiotic stress regulate anthocyanin accumulation. Different types of anthocyanins accumulate in different eggplant tissues depending on genetic and environmental factors. The intracellular transport and accumulation of anthocyanins rely on specific membrane transporters, which sequester anthocyanins into vacuoles. Recent advances in genetic and metabolic engineering have created novel opportunities for targeted gene editing, overexpression of key transcription factors, and optimization of metabolic pathways to enhance the anthocyanin content of eggplant. This review describes the molecular mechanisms that regulate anthocyanin biosynthesis, transport mechanisms, and accumulation patterns of anthocyanins, as well as the role of regulatory networks and biotechnological strategies that can be adopted to enhance anthocyanin levels for improved nutritional and commercial value.