Changes in the sucrose metabolism in apple fruit following postharvest acibenzolar-S-methyl treatment

BACKGROUND Apple (cv. Ralls) fruit were treated with 0.1 g L-1 acibenzolar-S-methyl (ASM) for 10 min to evaluate the changes in enzyme activity and gene expression in the sucrose metabolism during storage at 20 degrees C with 30%-40% relative humidity. RESULTS The results showed that sucrose phosphate synthase (SPS) and sucrose synthase synthesis (SS-s) activity was enhanced by ASM in apple fruit during the entire storage period. Sucrose synthase-cleavage (SS-c) and neutral invertase (NI) activity was suppressed by ASM treatment but acid invertase (AI) activity was increased in the middle period after ASM treatment. Acibenzolar-S-methyl treatment also significantly inhibited SPS and NI gene expression in apple fruit during storage. However, SS gene expression increased in the ASM-treated apple fruit. High levels of expression of the fructokinase (FK) and hexokinase (HK) genes were observed during the middle storage period in the ASM-treated fruit. CONCLUSION Taken together, these results suggest that ASM delays the senescence of apple fruit by regulating the sugar metabolism. (c) 2018 Society of Chemical Industry