Analysis of ginsenoside content, functional genes involved in ginsenosides biosynthesis, and activities of antioxidant enzymes in Panax quinquefolium L. adventitious roots by fungal elicitors

In this study, Candida tropicalis, Aspergillus niger, and a mixture of their cultures were previously used as fungal elicitors in Panax quinquefolium adventitious root culture to enhance ginsenoside production. The result showed that ginsenoside content (11.47 ± 0.54 mg g−1) was significantly enhanced to 3.25-fold of the control group after treatment with 400 mg L−1 C. tropicalis. The polysaccharide content (213.01 ± 18.63 mg g−1) reached the highest when A. niger was at the concentration of 200 mg L−1. HPLC–ESI-MSn analysis was performed, showing that ginsenosides Rh1 and Ro were identified after treatment with fungal elicitors. Furthermore, we found that C. tropicalis, A. niger, and mix elicitor significantly up-regulated the expression of the squalene synthase, squalene epoxidase, dammarenediol synthase, β-amyrin synthase, protopanaxadiol synthase, protopanaxatriol synthase, and UDP-glycosyltransferase. SDS-polyacrylamide gel electrophoresis was used to analysis the changes of protein. A new band was discovered at the size of 75 kDa. In addition, it found that fungal elicitors significantly increased the activities of catalases and peroxidase.