Exogenous glutathione modulates redox homeostasis in okra (Abelmoschus esculentus) during storage

Glutathione (GSH) improves the scavenging capacity of reactive oxygen species (ROS) in postharvest fruit and vegetable, but the effect of exogenous GSH in okra (Abelmoschus esculentus) has not been clarified. This study investigated the effect of GSH on ROS scavenging in postharvest okra and found that GSH treatment effectively inhibited weight loss and alleviated browning and thereby maintained the appearance and quality of the fruit. Moreover, GSH suppressed levels of hydrogen peroxide (H2O2), superoxide radical (O2-), and malondialdehyde (MDA). Treatment with exogenous GSH increased the contents of ascorbic acid (AsA) and GSH in okra, while decreased the contents of dehydroascorbic acid (DHA) and oxidized glutathione (GSSG). GSH treatment also enhanced the ROS-scavenging ability of okra by upregulating the expression of AeAPXs, AeGRs, AeMDHARs and AeDHARs, all of which are associated with redox homeostasis. Collectively, our findings demonstrate that exogenous GSH treatment can extend the shelf life of okra by mediating redox homeostasis.