Preharvest GA3 Treatment Enhances Postharvest Storability of ‘Brightwell’ Blueberry by Bolstering Antioxidant Defenses and Modulating Glycerolipid Metabolism

This study evaluated the effects of the preharvest application of 0.2 g/L gibberellin A3 (GA3) or 0.02 g/L forchlorfenuron (CPPU) at full bloom on postharvest storability and defense responses in ‘Brightwell’ blueberry. After ripening, berries were inoculated in vitro with a defined mixture of postharvest fungal pathogens. Fruit quality attributes and physio-logical indices were monitored during storage, and LC-MS metabolomics was performed to characterize treatment-associated metabolic alterations.GA3-treated fruit exhibited higher antioxidant capacity and a lower decay incidence than CPPU-treated and control fruit. Metabolomic profiling showed that GA3 was associated with the accumulation of specific polyphenols, coinciding with enhanced resistance to postharvest pathogens. In parallel, GA3 treatment modulated glycerolipid metabolism and mitigated membrane lipid peroxidation, as indicated by reduced malondialdehyde levels, while enhancing enzymatic (superoxide dismutase and ascorbate peroxidase) and non-enzymatic (poly-phenol) antioxidant defenses. Overall, these results suggest that preharvest GA3 application can improve blueberry storability by coordinating redox homeostasis and lipid-related metabolic remodeling.