Effects of Salicylic Acid Treatment on Reactive Oxygen Species Metabolism and Phenylpropanoid Pathway in Rosa sterilis

The Rosa sterilis were used as the material, which were treated with 1.5 mmol/L salicylic acid solutions for 10 min. The change of decay rate, weight loss rate, cell membrane integrity and the key enzymes and metabolites of reactive oxygen species metabolism and phenylpropanoid pathway were analyzed to reveal its effects on the reactive oxygen species metabolism and phenylpropanoid pathway. The result showed that the 1.5 mmol/L salicylic acid solution soaking treatment effectively reduced the rate of weight loss and decay, and maintained the cell membrane integrity during fruit storage time. Salicyli cacid significantly increased O₂⁻· production rate, H₂O₂ content and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in Rosa sterilis. In addition, salicylic acid also increased the activities of phenylalanine ammonia lyase (PAL) and 4-coumarin-CoA ligase (4CL), and induced the accumulation of total phenolic compounds and lignin in the fruits. These results suggested that salicylic acid can enhance the antioxidant capacity and delay senescence in Rosa sterilis by activating the antioxidant enzyme activity, key enzyme activities of phenylpropanoid pathway and accumulation of antibacterial substances.