A new simplified synthetic endophyte community regulates the synthesis of active ingredients in Glycyrrhiza uralensis Fisch

Abstract

The quality of Glycyrrhiza uralensis Fisch. (licorice) is influenced by a combination of abiotic factors and microbial interactions. Recent studies have demonstrated that root endophytes communicate closely with plants and can help increase the accumulation of secondary metabolites. However, the specific impact of this regulatory mechanism on licorice quality remains to be fully elucidated. In this study, the multi-omics techniques were employed to investigate the relationship between licorice endophytes and their metabolites. The findings revealed significant differences in the composition and function of endophytes in cultivated and wild licorice from the main and Dao-di production areas in China. Some specific root endophytes in wild licorice may be involved in regulating the contents of glycyrrhizic acid and flavonoids, which were important active substances in the host. Furthermore, a synthetic community (SynCom) of 12 bacterial strains and 11 fungal strains in different combinations was constructed to regulate the content of active substances in cultivated licorice. Then the SynCom was simplified to consist of five bacterial species, which was superior to the original SynCom and significantly promoted the accumulation of flavonoid components and triterpenoid components in cultivated licorice. The functions of these bacteria were related to the expression of key enzyme-encoding genes involved in the biosynthesis of host active ingredients. Our findins demonstrated that SynComs derived from wild licorice could suces sfully colonize and enhance the accumulation of flavonoids and glycyrrhizic acid in cultivated licorice. This underscores the potential of SynComs as precise regulators of medicinal plant quality, offering a promising avenue for optimizing the production of bioactive compounds in cultivated licorice.