Postharvest application of acibenzolar- S-methyl delays the senescence of pears by mediating the ascorbate-glutathione cycle

This study was conducted to explore the changes of quality indicators and ascorbate-glutathione (AsA-GSH) cycle in 'Docteur Jules Guyot' pears after acibenzolar-S-methyl (ASM) dipping. Results demonstrated that ASM delayed the yellowing and flesh firmness decline, decreased the ethylene release and titratable acidity, and increased soluble solid content in pears. Additionally, ASM enhanced the hydrogen peroxide, ascorbic acid, and reduced glutathione contents, improved the activities of ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase in the exocarp and mesocarp of pears. However, enzymes activities and hydrogen peroxide content in the exocarp were higher than that in the mesocarp after dipping with ASM. These results suggest that postharvest application of ASM could modulate the AsA-GSH cycle to delay senescence of pears, and the exocarp responded more rapidly than the mesocarp.