Anthurium is a valuable cut flower native to tropical and subtropical regions, highly sensitive to chilling injury (CI) below 10–12 °C, which compromises post-harvest quality. Epibrassinolide (BR) enhances plant tolerance to various stresses, including chilling. This study evaluated post-harvest treatments with 5 and 10 µM BR applied via spray, pulsing, and continuous vase solution on CI mitigation and quality retention of Anthurium cut flowers stored at 4 °C for 0, 10, and 20 days. All BR treatments reduced CI and maintained flower quality, with 10 µM BR in continuous vase solution being the most effective, resulting in a 52% decrease in CI index and a 9-day extension of vase life compared to the control. This treatment improved vase solution uptake, minimized weight loss, and reduced electrolyte leakage and malondialdehyde, indicating enhanced membrane stability. It induced the highest accumulation of proline (8.50 mmol kg⁻¹ FW), glycine betaine (0.22 mmol kg⁻¹ FW), and total protein (0.81 g kg⁻¹ FW), while maintaining the lowest γ-aminobutyric acid (GABA) content (1.60 µmol g⁻¹ FW) at day 20, reflecting effective modulation of the GABA shunt pathway through regulation of GABA transaminase and glutamate decarboxylase activities. BR treatments also significantly suppressed phospholipase-D, lipoxygenase, and polyphenol oxidase activities while enhancing phenylalanine ammonia-lyase, catalase, peroxidase, superoxide dismutase, and total phenols, collectively strengthening the antioxidant system. The coordinated regulation of GABA metabolism, osmolyte accumulation, and antioxidant defenses underlies the reduced CI and extended vase life. Therefore, continuous vase solution treatment with 10 µM BR is recommended as an effective post-harvest strategy to enhance cold tolerance and preserve Anthurium flower quality.
