Wounding is one of the most effective stress signals to induce
ethylene synthesis in persimmon (Diospyros kaki Thunb.). We found that
wound-induced
ethylene biosynthesis is subjected to negative feedback regulation in mature 'Saijo' persimmon fruit since
ethylene production was enhanced by
1-methylcyclopropene (1-MCP) (an inhibitor of
ethylene perception) pretreatment, which was approximately 1.8 fold of that in control tissues (without 1-MCP pretreatment).
Wound-induced 1-aminocyclopropane-1-carboxylate (
ACC) synthase activity and DK-ACS2 gene expression were substantially increased by
1-MCP pretreatment after 12 h, which resulted in much higher ACC content in
1-MCP pretreated tissues than that in a control after 24 h. These results indicated that
wound-induced DK-ACS2 gene expression was negatively regulated by
ethylene in mature persimmon fruit. However,
1-MCP pretreatment had no effect on DK-ACO1 gene expression, suggesting the independence of
wound-induced DK-ACO1 on
ethylene. Out of accord with DK-ACO1 gene expression,
ACC oxidase activity was enhanced 48 h after wounding in
1-MCP pretreated tissues, reaching a peak 1.5-fold higher than that in control tissues at 60 h.