Over-expression of AeWRKY2 promotes oleanolic acid and hederagenin accumulation in Aralia elata.

Oleanolic acid (OA) and hederagenin from Aralia elata have important medicinal value due to their anti-cancer and anti-inflammatory activities. Transcription factors (TFs) can affect the production of active substances by regulating the expression of genes in metabolic pathways. In this study, a transcription factor AeWRKY2 was cloned and overexpressed in A. elata. The result of gene expression analysis and high-performance liquid chromatography (HPLC) showed that the key enzyme genes of all transgenic strains analyzed were up-regulated to varying degrees. The contents of oleanolic acid and hederagenin were higher than those of wild type, up to 2.773 mg·g DW and 0.325 mg·g DW, respectively. After one-day MeJA treatment, the contents of oleanolic acid and hederagenin were further increased to 3.31 mg·g and 0.37 mg·g, respectively.