Copper ions suppress abscisic acid biosynthesis to enhance defence against Phytophthora infestans in potato

摘要

Copper‐based antimicrobial compounds are widely and historically used to control plant diseases, such as late blight caused by , which seriously affects the yield and quality of potato. We previously identified that copper ion (Cu ) acts as an extremely sensitive elicitor to induce ethylene (ET)‐dependent immunity in . Here, we found that Cu induces the defence response to in potato. Cu suppresses the transcription of the abscisic acid (ABA) biosynthetic genes and , resulting in decreased ABA content. Treatment with ABA or inhibitor fluridone made potato more susceptible or resistance to late blight, respectively. In addition, potato with knockdown of or showed greater resistance to late blight, suggesting that ABA negatively regulates potato resistance to . Cu also promotes the rapid biosynthesis of ET. Potato plants treated with 1‐aminocyclopropane‐1‐carboxylate showed enhanced resistance to late blight. Repressed expression of or resulted in enhanced transcription of and , accumulation of ABA and susceptibility to . Consistently, StEIN3 directly binds to the promoter regions of and . Overall, we concluded that Cu triggers the defence response to potato late blight by activating ET biosynthesis to inhibit the biosynthesis of ABA.