Salt stress in apple seedlings was mitigated by n-propyl dihydrojasmonate, a synthetic analog of jasmonic acid

tions and superoxide (SOD), peroxidase (POD) and catalase (CAT) activities, but increased the ion leakage, MDA, proline, and Na + concentrations, as well as the hydrogen peroxide (H 2 O 2 ) and endogenous JA and ABA concentrations in the leaves. Foliar application of PDJ before NaCl treatment (PDJ + NaCl + ) decreased Na + concentrations, ion leakage, MDA, proline accumulation and H 2 O 2 generation, but increased K + concentrations, antioxidant capacity, and chlorophyll concentrations in the leaves. In the PDJ + NaCl - group, although the JA and ABA concentrations and MdAOS1 , MdJAR , and MdNCED1 gene expressions were increased, the MdJAZ2 and MdCYP707A1 gene expressions were decreased. In addition, the PDJ + NaCl + group showed higher MdPDH , MdSOS1 , and MdNHX1 gene expressions and lower (cid:16)(cid:134)(cid:19)(cid:891)(cid:6)(cid:22) gene expressions than the PDJ - NaCl + group at 7 and 10 days after treatment. The present data suggested that PDJ application could in-duce rapidly endogenous JA and ABA, enhance SOD, POD, and CAT activities, decrease the Na + uptake, and mitigate NaCl stress.