1-Methylcyclopropene Reduced the Cold Resistance Induced by Salicylic Acid in Postharvest Plum Fruits During Low-Temperature Storage

Abstract

While salicylic acid (SA) improves the cold resistance of plum fruit, the contribution of ethylene to the efficacy is not well understood. Therefore, the cold resistance of plum fruits treated with SA alone and in combination with 1-methylcyclopropene (1-MCP) (an ethylene receptor competitor that blocks ethylene signaling) was compared. Our findings demonstrate that SA treatment effectively reduced the decay rate and the chilling injury index while preserving membrane integrity and sugar content. Furthermore, it improved the scavenging ability against active oxygen species, suppressed the production of reactive oxygen species, and induced the expression of the PsAOX1a and PsCBF2 genes related to the cold tolerance mechanisms in plum fruit. However, when SA was used in combination with 1-MCP, cold resistance was diminished. The results show that blocking ethylene signaling reduced the SA-induced cold tolerance in plum fruit. The combined application of SA and 1-MCP is not recommended for the prevention of cold damage to plums.