This study aims to investigate the effec- tiveness of an encapsulated powder containing savory essential oil and calcium propionate salt on reactive oxygen species (ROS) and the expression of anti- oxidant genes (SOD, APX, CAT) in pear seedlings (cv. Spadona) inoculated with E. amylovora (ATCC 49946). To this end, the antioxidant activity of 7 types of herbal essential oils with 10 types of differ- ent organic acid salts were evaluated in the laboratory. The most effective candidates (calcium propionate salt + S. hortensis essential oil) were encapsulated in maltodextrin and modified starch by the spray drying technique. To evaluate the efficiency of the encapsu- lated powder, a greenhouse experiment was designed using a Randomized Complete Block Design (RCBD) with six treatments (T 1: 1 g/L encapsulated powder, T 2: 2 g/L encapsulated powder, T3: 3 g/L encapsu- lated powder, streptomycin (positive control, con. 100 ppm), control: no inoculation and no foliar spray treatments, and infected: seedlings inoculated with a concentration of 10^7 cfu/mL of E. amylovora). The findings demonstrated that increasing the concentra- tion of the encapsulated powder treatment led to a relative increase in the expression of the antioxidant genes (SOD, APX, CAT) compared to the reference gene (GAPDH). The highest effect on SOD, APX, and CAT gene expression was seen in the third treat- ment (T3). The T 1, T2, and T 3 treatments decreased the amount of Malondialdehyde (MDA), and led to an increase in total phenolic content (TPC) in pear leaves compared to the control treatment.

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