Chilling-induced oxidative stress and antioxidant responses in mume (Prunus mume) fruit during low temperature storage

摘要

Mume (Prunus mume Sieb. et Zucc.) fruit are harvested and consumed at the mature green stage and have a short storage life at ambient temperature. While cold temperature extends their storage life, improper refrigeration causes severe chilling injury (CI), with fruit suffering more severe CI at of 5-6pC than at 1pC. The objective of this research was to determine the involvement of reactive oxygen species (ROS) and antioxidant systems in fruit under chilling stress. 'Nankou' fruit were stored at 1pC or 6pC for 15 days. Hydrogen peroxide, a preventive ROS, decreased at a slower rate at 6pC than 1pC during storage. Malondialdehyde (MDA), an indicator of lipid peroxidation caused by ROS, increased during storage and the contents were higher in fruit stored at 6pC than at 1pC. On the other hand, fruit stored at 6pC had a lower total antioxidant capacity (TAC) and lower activities of antioxidant-related enzymes including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) than at 1pC. These results indicate that the fruit at 6pC had more oxidative stress; thus the fruit had more severe CI symptoms than at 1pC.