Identification and Validation of NAC Transcription Factors Enhancing Phenolic Acid Production in Perilla frutescens

Phenolic acids are the major bioactive compounds in Perilla frutescens (L.) Britt; however, the regulatory roles of NAC transcription factors (TFs) in their biosynthesis remain unclear. Here, we performed a genome-wide identification and characterization of the NAC family in P. frutescens and explored their involvement in phenolic acid production. A total of 108 PfNAC genes were identified and classified into 17 subfamilies. Expression and promoter analyses suggested potential roles in secondary metabolism. PfNAC29 is located in the plasma membrane and necleus, while PfNAC40 and PfNAC80 are located in the nucleus.Yeast one-hybrid and dual-luciferase assays demonstrated that these TFs bind to the CATGTG motif in the PfC4H promoter and activate its transcription. Overexpression in transgenic hairy roots significantly increased rosmarinic acid, caffeic acid, and ferulic acid accumulation, accompanied by upregulation of key biosynthetic genes. These results indicate that PfNAC29, PfNAC40, and PfNAC80 act as positive regulators of phenolic acid biosynthesis and provide promising targets for metabolic engineering in medicinal plants.