SmKFB5 protein regulates phenolic acid biosynthesis by controlling the degradation of phenylalanine ammonia-lyase in <i>Salvia miltiorrhiza</i>

Abstract Phenolic acids are the major secondary metabolites and significant bioactive constituents of medicinal plant Salvia miltiorrhiza. Many enzyme-encoding genes transcription factors involved in biosynthesis phenolic have been identified, but underlying post-translational regulatory mechanisms poorly understood. Here, we demonstrate that S. miltiorrhiza Kelch repeat F-box protein SmKFB5 physically interacts with three phenylalanine ammonia-lyase (PAL) isozymes mediates their proteolytic turnover via ubiquitin-26S proteasome pathway. Disturbing expression reciprocally affected abundance SmPAL accumulation acids, suggesting is a regulator responsible for PAL negatively controlling acids. Furthermore, discovered treatment hairy root methyl jasmonate suppressed while inducing SmPAL1 SmPAL3. These data suggested consolidated both transcriptional regulation to enhance acid biosynthesis. Taken together, our results provide insights into molecular by which jasmonic acid, suggest valuable targets breeders tailoring new cultivars.