Substrate promiscuity of acyltransferases contributes to the diversity of hydroxycinnamic acid derivatives in purple coneflower.

High pliability and promiscuity are observed widely exist in plant specialized metabolism, especially the hydroxycinnamic acid metabolism. Here, we identified an addition BAHD acyltransferase (EpHMT) that catalyzes phaselic acid biosynthesis and found that the substrate promiscuities of identified BAHD and SCPL acyltransferases are responsible for the diversity of hydroxycinnamic acid derivatives in purple coneflower.