Ascorbic acid treatment inhibits early wound healing in the fresh-cut potato by relegating jasmonic acid biosynthesis and signal transduction

Jasmonic acid (JA) is a wound hormone involved in plant defence responses. Ascorbic acid (AsA) treatment could inhibit early wound healing in fresh-cut potatoes (FCPs), but its regulation of JA pathway during this process remains unclear. We investigated the effects of AsA on JA biosynthesis and signal transduction in FCPs during wound healing. Results showed that AsA treatment decreased JA biosynthesis pathway-related enzyme activities and gene expression (StLOX3.1, StAOS1, StOPR1, StADH1, StKAT2, and StACOT13) at the wound site during healing. The JA content increased from 0.443 to 1.205 μg g^-1 within 10 h but only increased to 0.535 μg g^-1 with AsA. AsA treatment reduced jasmonic acid carboxyl methyltransferase and jasmonic acid-amido synthetase activities, StJMT and StJAR1 expressions, and methyl jasmonate and jasmonoyl-isoleucine contents. Moreover, AsA treatment upregulated StJAZ1 and downregulated StMYC2 expression. These findings suggested that AsA regulates wound healing in FCPs by suppressing JA biosynthesis and signal transduction.