plays a crucial role in the early biosynthesis of ethylene elicited by Cu ions.

Cu ions are required by all living organisms and play important roles in many bactericides and fungicides. We previously reported that Cu can elicit defense responses, which are dependent on the ethylene signaling pathway in However, the mechanism by which Cu elicits the biosynthesis of ethylene remains unclear. Here, we show that CuSO treatment rapidly increases the production of ethylene. In addition, it upregulates the expression of several defense-related genes and ethylene biosynthesis genes, including genes encoding -adenosylmethionine synthase, 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) and ACC oxidase. Among these genes, () was identified as essential for the defense response and early ethylene biosynthesis induced by Cu Furthermore, Cu-induced expression depended on the copper-response -element (CuRE) in the promoter of Our study indicates that Cu specifically activates the expression of to promote the early biosynthesis of ethylene that elicits plant immunity in plants.