[Objective] To isolate a chlorogenic acid(CGA)-producing endophyte, and to study the function of a key gene of the CGA synthetic pathway from the endophyte. [Methods] Endophytes were isolated from Flos Lonicerae japonicae by surface sterilization. The endophytic bacterium producing CGA was screened and confirmed by HPLC and LC-MS. Histidine ammonia lyase(HAL) gene of the endophytic bacterium was cloned and expressed in Escherichia coli and enzyme activity of the recombinant HAL was determined. [Results] An ...