Isolation of Endophytic Fungi and Effects on Secondary Metabolites in Hairy Roots of <i>Salvia miltiorrhiza</i>

The slow growth rate of medicinal plants has made them unable to meet people's needs, and the use of biotechnology to obtain natural products from medicinal plants can alleviate this problem. This study isolated and identified 42 endophytic fungi from the roots, stems, and leaves of <i>Salvia miltiorrhiza</i>, belonging to 13 genera. The endophytic fungi that promote the accumulation of secondary metabolites in the hairy roots of <i>S. miltiorrhiza</i> were screened by co-culture and elicitors preparation. Among them, 15 endophytic fungi presented relatively high crude polysaccharide yields. Co-culture experiments showed that endophytic strains had different effects on the biomass and the accumulation of secondary metabolites in the hairy roots of <i>S. miltiorrhiza</i>, with strain KLBMPSM237 being the most effective. The contents of tanshinone I, salvianolic acid B and rosmarinic acid in the hairy roots of <i>S. miltiorrhiza</i> were significantly increased by KLBMPSM237 polysaccharide inducers at different concentrations. This study provides new microbial resources and technical methods for increasing the natural products in hairy roots of <i>S. miltiorrhiza</i>.