Enhanced sulforaphane accumulation in fresh-cut broccoli via exogenous glutathione-mediated modulation of the AsA-GSH cycle
Yingshuai Jiao, Junjie Wu, Wenlong Yu, Wenya Jiao, Xianghong Wang
Abstract
The effects of exogenous glutathione (GSH) on sulforaphane production during the storage of fresh-cut broccoli were investigated. Treatment with 1.0 g/L GSH reduced Malondialdehyde（MDA）, H₂O₂ and O₂⁻ levels in broccoli florets compared to the control, thereby improving antioxidant capacity . GSH treatment increased the concentrations of endogenous ascorbic acid and glutathione by enhancing the activities of key enzymes in the Ascorbate-Glutathione (AsA-GSH) cycle, including ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR). This contributed to a significant enhancement of myrosinase activity. Furthermore, GSH treatment upregulated the expression of genes associated with sulforaphane synthesis, such as CYP79F1, UGT74B1, MYB28, ST5b , and FMOGS-OX1 . It also increased both the activity of myrosinase and the expression level of the MYO gene, resulting in a 21.61 % increase in sulforaphane content, the highest observed during the study. These findings demonstrate that GSH treatment effectively enhances sulforaphane formation in postharvest fresh-cut broccoli during storage.