UV-C irradiation maintains cell membrane integrity at wounds of potato tubers during healing by regulating ROS homeostasis and increasing antioxidant activity

Ultraviolet-C (UV-C), a short-wave ultraviolet light, has been extensively proved to regulate reactive oxygen species (ROS) homeostasis and increase antioxidant activity in fruit and vegetables. However, whether UV-C may regulate ROS homeostasis, antioxidant activity and cell membrane integrity at potato tubers wounds during healing has not been reported. In this study, UV-C irradiation activated calcium-dependent protein kinase (CDPK), NADPH oxidase (NOX) and superoxide dismutase (SOD), and promoted superoxide anion (O2.-) and hydrogen peroxide (H2O2) production at tuber wounds. Meanwhile, UV-C activated catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR), and elevated the levels of ascorbic acid (AsA), reduced glutathione (GSH), total phenolic and flavonoid at tuber wounds. Furthermore, UV-C decreased malondialdehyde (MDA) content and cell membrane permeability at tuber wounds by enhancing the scavenging capacities of DPPH, ABTS+ and FRAP. Taken together, UV-C irradiation could maintain cell membrane integrity at potato tubers wounds during healing by regulating ROS homeostasis and increasing antioxidant activity.