Storage Physiological Characteristics and Transcriptome Expression of Broccoli Under LED Green Light Irradiation Combined with Low Temperature

To explore the regulatory effects and mechanisms of LED green light (peak at 520 nm) combined with different low temperatures on broccoli postharvest storage, the Brassica oleracea var. italica ‘Meiqing’ was harvested and stored under two temperatures and pretreated with supplemental LED green light. Periodic determinations were conducted on physical and chemical indexes, including appearance, texture, nutritional quality, and antioxidant capacity, along with differential gene expression analysis via transcriptome sequencing. Results showed that 0 °C storage outperformed 4 °C overall, and the 1 h green light pretreatment achieved the optimal effect. This treatment significantly delayed curd yellowing, reduced weight loss, maintained high firmness, preserved nutritional components, enhanced the activities of antioxidant enzymes and key enzymes in the AsA-GSH cycle, and alleviated membrane damage by reducing H2O2 and MDA levels. Transcriptome analysis revealed that green light pretreatment regulated gene expression in chlorophyll metabolism and antioxidant-related pathways. Overall, 0 °C combined with 1 h of green light pretreatment effectively prolonged the storage period of broccoli and maintained its commercial and nutritional quality, providing a novel technical strategy for postharvest broccoli preservation.