Integrated transcriptome and metabolome analysis reveals flavor quality regulations in post-harvest fruits of Actinidia melanandra

The utilization of the fruit of Actinidia melanandra is limited by insufficient understanding of its quality attributes and regulatory mechanisms in the fruit during soft ripening stages. In this study, we employed multi-omics approaches to investigate the post-harvest quality dynamics and the regulatory mechanisms in the fruit of A. melanandra. The results showed that the kiwifruit had better palatability at the final stage during the soft ripening stages due to its higher soluble solids content and unique flavor. Volatile profiling identified 36 aroma-active compounds that were dominated by aldehydes and terpenoids, showing progressive terpenoid diversification during maturation. Anthocyanin-specific analysis demonstrated cyanidin-3-O-galactoside as the primary pigment, co-regulating coloration with pelargonidin-3-O-galactoside. The combination of integrated omics and subsequent qRT-PCR validation identified 31 structural genes and 8 transcriptional regulators governing the metabolic pathways of sugar accumulation, monoterpene biosynthesis, and anthocyanin biosynthesis. Our study provides new insights into flavor regulation during fruit soft ripening, lays a foundation for kiwifruit flavor improvement, and guides better exploitation of A. melanandra resources.