Ethylene-Inducible AP2/ERF Transcription Factor Involved in the Capsaicinoid Biosynthesis in Capsicum

<jats:p>Ethylene is very important in the process of plant development and regulates the biosynthesis of many secondary metabolites. In these regulatory mechanisms, transcription factors (TFs) that mediate ethylene signals play a very important role. Capsaicinoids (CAPs) are only synthesized and accumulated in <jats:italic>Capsicum</jats:italic> species, causing their fruit to have a special pungent taste, which can protect against attack from herbivores and pathogens. In this study, we identified the TF <jats:italic>CcERF2</jats:italic>, which is induced by ethylene, and demonstrated its regulatory effect on CAPs biosynthesis. Transcriptome sequencing analysis revealed that the expression patterns of <jats:italic>CcERF2</jats:italic> and multiple genes associated with CAPs biosynthesis were basically the same. The spatiotemporal expression results showed <jats:italic>CcERF2</jats:italic> was preferentially expressed in the placenta of the spicy fruit. Ethylene can induce the expression of <jats:italic>CcERF2</jats:italic> and CAPs biosynthesis genes (CBGs). <jats:italic>CcERF2</jats:italic> gene silencing and 1-methylcyclopropene (1-MCP) and pyrazinamide (PZA) treatments caused a decrease in expression of CBGs and a sharp decrease in content of CAPs. The results indicated that <jats:italic>CcERF2</jats:italic> was indeed involved in the regulation of structural genes of the CAPs biosynthetic pathway.</jats:p>