Elicitation of (E)-2-Hexenal and 2,3-Butanediol on the Bioactive Compounds in Adventitious Roots of Astragalus membranaceus var. mongholicus

This study aimed to investigate the elicitation of volatile organic compounds (E)-2-hexenal and 2,3-butanediol on bioactive metabolites in Astragalus membranaceus var. mongholicus adventitious root cultures by adding them into the medium. The experiment was performed for 72 h and the roots were dynamically sampled for quantification of representative astragaloside IV, calycosin-7-O-beta-D-glucoside (CG), ononin, and the gene expression. Compared with the controls, the combination of 2,3-butanediol and (E)-2-hexenal advanced the peak accumulation of astragaloside IV and was the most effective, but their individual application delayed it. Meanwhile, 2,3-butanediol and (E)-2-hexenal had no obviously promoting effect on the production of CG and ononin but chronologically changed their accumulation patterns. The underlying mechanism was uncovered by the correlation analysis between the metabolites and the gene expression, as did the identification of the target genes. Collectively, 2,3-butanediol and (E)-2-hexenal were important cues shaping the production of bioactive products in the herbal plant.

Automated summary

This study investigated the effects of adding (E)-2-hexenal and 2,3-butanediol into the medium on bioactive metabolites in Astragalus membranaceus var. mongholicus adventitious root cultures. The results showed that the combination of 2,3-butanediol and (E)-2-hexenal promoted the accumulation of astragaloside IV, while their individual application delayed it. The production of CG and ononin was not significantly affected, but their accumulation patterns were changed. This finding provides important insights into the production of bioactive products in herbal plants.