Medicinal plants and microorganisms show a close relationship,both of which are from the plantmicroorganism symbiont system and interact mutually.Microorganisms are closely related to the growth,reproduction and secondary metabolic activities of medicinal plants.The symbiotic relationship between medicinal plants and microbes is the hotspot of medicinal plants in recent years.This paper summarized the relationship between medicinal plants and microorganisms.It reviewed the effects of medicinal plant species and root exudates on the microbial community composition and diversity,the effects of medicinal plant rhizosphere microbes on plant growth,the specificity of microorganism and the molecular recognition mechanism of medicinal plants and microorganisms.This article also provided the basis for excavation and utilization of the mechanism of interaction between medicinal plants and microorganisms,which were significance for the effective use of microbial growth mechanism to improve the stress resistance of medicinal plants,to increase the yield and to improve the quality of medicinal plants.

Triterpenoid saponins is an important secondary metabolites in medicinal plants, and the tetracyclic triterpenoid saponins, as one of the main categories, have very high medicinal value and market demand. However, there is no systematic review on the research. Thus, the elucidation of the biosynthetic pathway and metabolism of the medicinal plant tetracyclic triterpenoid saponins has important theoretical significance and broad application prospects.In this review, the biosynthetic pathway and metabolic regulation of medicinal plant of tetracyclic triterpenoid saponins were discussed. My focus in this paper was to introduce the research development of several metabolic biosynthetic pathways of tetracyclic triterpenoid saponins centered on dammarane type, and the gene improvement by methods such as metabolic pathway and other technological methods. This study provides references on secondary metabolic framework of medicinal plants of tetracyclic triterpenoid saponins, accurately locating secondary metabolism and its key enzymes, and promoting the sustainable uses of medicinal plant resources.