Impact of α-Ketoglutarate Treatment on Enhancing Vase Life of Chrysanthemum by Modulating the Isoprenoid Pathway and Increasing Antioxidant Content

Chrysanthemum is a globally valued cut flower with substantial commercial importance; however, its postharvest longevity remains limited. This study investigates the application of α-ketoglutarate (AKG), a cost-effective and environmentally friendly compound, for extending the vase life of cut chrysanthemum flowers. The potential of AKG to enhance vase life was systematically evaluated in this research. The effects of different AKG concentrations (0–5 mM) on vase performance, physiological traits, biochemical composition, and gene expression were examined. AKG improved water balance and water uptake, thereby enhancing flower hydration. It increased the contents of glutathione, ascorbic acid, total phenolics, and flavonoids, and enhanced the activities of catalase (CAT) and superoxide dismutase (SOD). In addition, AKG effectively inhibited the accumulation of reactive oxygen species (ROS) and reduced malondialdehyde (MDA) levels, electrolyte leakage (EL), and lipoxygenase (LOX) activity. AKG also suppressed ethylene (ETH) production by downregulating the activities of 1-aminocyclopropane-1-carboxylic acid synthase (ACS) and oxidase (ACO), as well as reducing the expression of the CmACS and CmACO genes. Collectively, these findings demonstrate that AKG effectively prolongs vase life and represents a sustainable and eco-friendly strategy for enhancing the postharvest quality of cut chrysanthemums.