Multi-tissue resource characteristics and comprehensive utilization of medicinal and edible loquat (Eriobotrya japonica): a review.

Loquat (Eriobotrya japonica (Thunb.) Lindl.), a member of the Rosaceae family, exhibits pronounced tissue-specific metabolic specialization that underpins its nutritional value, pharmacological activities, and industrial potential. Contemporary research on loquat has largely focused on single tissues or individual bioactive compounds, whereas comprehensive cross-tissue comparative profiling and mechanistic analyses remain substantially underexplored. This fragmented research paradigm obscures both the tissue-specific distribution of secondary metabolites and the upstream regulatory networks governing their biosynthesis, resulting in the inefficient exploitation of by-products such as peels and seeds. In this review, we synthesize several decades of empirical and mechanistic studies on the phytochemical profiles, pharmacological functions, and resource-transformation mechanisms of the core bioactive constituents across five major loquat tissues-pulp, peel, seed, leaf, and flower. We clarify the core metabolites conserved across all tissues and the signature compounds specific to individual organs, and summarize their pleiotropic biological activities, including antioxidant, anti-inflammatory, antitumor, hypoglycemic, and multi-organ cytoprotective effects. Beyond phenotypic description, we further examine the evolutionary genomic origins and hierarchical regulatory networks underlying tissue-specific metabolism: lineage-specific whole-genome duplication is proposed to contribute to the heterogeneous accumulation of triterpenoids across tissues, whereas cold-adaptive signaling and developmental hormonal modulation cooperatively reshape organ-specific secondary metabolic reprogramming. Finally, we identify three pivotal industrial constraints on the sustainable valorization of loquat resources-fragmented processing layouts, low-efficiency recycling of agricultural residual biomass, and frost-induced instability of raw material supply-and propose targeted transformation strategies, including marker-assisted germplasm improvement, multi-omics dissection of tissue-specific metabolic regulatory networks, synthetic-biology-based green biosynthesis of high-value phytochemicals, and the development of a comprehensive circular industrial system. These strategies provide a theoretical basis for the integrated utilization of the medicinal and edible resources of loquat.