Study On Tanshinones Regulating The Root-associated Microbiomes Of Salvia Miltiorrhiza

The plant root-associated microbiomes include root microbiome and rhizosphere microbiome,which are closely related to plant life activities.Nearly 30%of photosynthesis products of plants are used to synthesize root compounds,there is evidence that root compounds regulate and significantly affect the root microbiome In an iron-deficient growth environment,the coumarin secreted by Arabidopsis roots can inhibit the growth of Pseudomonas through a redox mechanism.Tanshinone compounds are the main fat-soluble components in Salvia miltiorrhiza,and their original purpose is not to treat diseases for humans.The research on the relationship of S.miltiorrhiza participating in the microbiome is still in its infancy.At present,there are many researches on continuous cropping obstacles and biocontrol bacteria screening of S.miltiorrhiza.In order to study whether such compounds can regulate the root microbiome of S.miltiorrhiza,we first identified a mutant S.miltiorrhiza with extremely low tanshinone content.In the mutant,the fifth intron of SmCPS1,the first key enzyme gene that forms the nucleus of tanshinones was identified.Retention results in a significant decrease in the expression of this gene and a stable white root phenotype(BG).Under the conditions of an artificial climate room,wild type(WT)and mutants planted in different soils(nutrient soil and Shandong S.miltiorrhiza base soil)are the research objects,based on 16S rDNA amplicon sequencing technology,using diversity analysis,constitutive analysis and network Analysis and other methods systematically compare the root microorganisms and rhizosphere microorganisms of WT and BG.The results showed that the tanshinones significantly affected the root-associated microbiomes of Salvia miltiorrhiza,and the impact on root microbiomes was more significant.The effects of tanshinones on the rhizosphere and root microbes of the two types of S.miltiorrhiza are mainly manifested in the composition of dominant species,species diversity,distribution of specific specie and coexistence network.There are significant differences between WT and BG root microbiomes in species richness,dominant strains and co-occurrence network.Tanshinones have a certain repelling effect on Bacilli which belongs to Gram-positive,while specifically attract some Gram-negative bacteria such as Betaproteobacteria and some specific genus of Alphaproteobacteria.The dominant genus of Alphaproteobacteria in WT root microbiomes are Roseateles,Novosphingobium,Sphingobium and Sphingomonas.And in the in vitro antibacterial test,the tanshinones mixture has a significant inhibitory effect on the growth of Bacillus.The rhizosphere microbiome of WT and BG are also affected by the content of tanshinone compounds.The rhizosphere microbiome of mutants has higher species richness,and the dominant bacteria Alphaproteobacteria and Bacilli are relatively abundant,while the relative abundant of Actinobacteria in WT is is higher.This study determined the important role of tanshinones in regulating the structure of the root microbiome from multiple angles,aiming to clarify the influence of tanshinones on the root microbiome,screening for functional strains of S.miltiorrhiza in the next step,and artificially regulating the microenvironment in the body of S.miltiorrhiza Promote the improvement of S.miltiorrhiza production and quality to lay a theoretical foundation.It opens the way for the ecologically sustainable cultivation of high-quality S.miltiorrhiza and plant microbiome engineering.At the same time,it is also based on S.miltiorrhiza,exploring the significance of the synthesis of tanshinones to itself,and feeding back the research on the medicinal value of tanshinones.