Inhibition of wound healing in fresh-cut potatoes by ascorbic acid is associated with control of the levels of reactive oxygen species and the AsA-GSH cycle

This study aimed to investigate the regulatory mechanisms of ascorbic acid (AsA) treatment on reactive oxygen species (ROS) and the ascorbate-glutathione (AsA-GSH) cycle during wound healing of fresh-cut potatoes (FCPes). AsA treatment at two concentrations (5 and 10 g L-1) was used to measure changes in H2O2 and O-2(.-) contents, antioxidant enzymes of SOD, POD, and CAT activities, StPOD-related genes expression levels, and the AsA-GSH cycle metabolism activity. The results showed that AsA treatment could reduce the contents of H2O2 and O-2(.-), downregulate the expressions of suberization-associated StPOD genes, decrease the activities of SOD, POD, MDHAR, and DHAR, induce the activities of CAT, APX, GR, and GPX, as well as maintain high levels of AsA and GSH and AsA/(AsA + DHA) and GSH/(GSH + GSSG) ratios. In summary, exogenous AsA treatment delayed the wound-healing process and maintained the quality of FCPes by reducing ROS production, inducing antioxidant enzyme activities, and enhancing the AsA-GSH cycle metabolism activity, thus improving the overall antioxidant capacity and balancing the generation of ROS and the antioxidant defense system.