The Microbial Diversity Of Salvia Miltiorrhiza And Their Inducing Effects

Salvia miltiorrhiza Bunge is a widely used traditional Chinese medicinal plant,which has a significant role on the remedy of cardiovascular diseases.Therefore,the requirement of S.miltiorrhiza market is increasing.It is well-known that microbes play vital roles on the nutrition,growth,tolerance to stresses and promote secondary metabolism.In this study,microbial diversity of rhizosphere and roots from different planting regions were investigated,and microbes isolated from S.miltiorrhiza were carried out to test their effects on the secondary metabolism of its hairy roots.First,the microbial diversity from different areas of S.miltiorrhiza was analyzed using metagenome.According to the results,Proteobacteria was the dominant phylum in rhizosphere soils and roots,with the dominant genus of Sphingomonas or.GP6 in soils and of Rhizobium in roots.Compared to bacteria,all the samples had the same dominant fungus phylum,including Ascomycota and Basidiomycota,while the Glomeromycota was an additional phylum in the rhizosphere soil of ZheJiang.On genus level,the dominant fungus was different between samples of different planting areas.In the rhizosphere soil,the dominant genus of Shandong and Sichuan was Tetracladium,the dominant genus of Ningxia belongs to Hannaella,and the dominant genus of Shannxi and Shanxi is Fusarium;In the roots,the dominnat genus of Shandong,Sichuan,and Zhejiang was Thielaviopsis,the dominnat genus of Ningxia,Shannxi and Shanxi was Tetracladium,Fusarium and Cladosporium,respectively.At the same time,content of active ingredient was checked for the roots of S.miltiorrhiza planted at different areas.The highest total phenolics content was observed in SHX samples,8.23 mg·g-1;The highest total tanshinone content was observed in SX sample,7.23 mg·g-1.The clustering analysis results showed that the quality of S.miltiorrhiza Bunge of sichuan and zhejiang is relatively close,this is similar to the PCA analysis results of the microbial community of S.miltiorrhiza Bunge,which indicated that the microbial community and its active ingredient have a certain correlation.Next,S.miltiorrhiza-associated microbes were used to test the effect on the hairy roots.Out of 64 isolates,29 isolates,including 16 bacteria and 13 fungi,were found to promote the accumulation of growth or active ingredients of hairy roots of S.miltiorrhiza.On the whole,the bacteria could promote the accumulation of phenolic acid significantly and the fungi could promote the accumulation of the content of tanshinone significantly.The 16 strains bacteria were identified into 7 genera including Pseudomonas,Lysobacter,Enterobacter,Sphingomonas,Rhizobiaceae,and Bacillus.Among of them,5 isolates were found to significant promote the accumulation of growth of hairy roots,8 isolates were found to significant promote the accumulation of phenolic acid and 4 isolates were found to significant promote the accumulation of tanshinone.Among of them,HYR26,LYR2 and HYR1,which wereidentified as Pseudomonas chlororaphis,were found to promote the accumulation of growth and the accumulation of phenolic acid and tanshinone of hairy roots,concurrently.The 13 strains fungi were identified into 8 genera including Hypoxylon,Macrophomina,Lichtheimia,Aspergillus,Penicillium,Fusarium,Alternaria and Talaromyces.All of them were were found to promote the accumulation of tanshinone.Especially,LYRSF8,which was identified as Aspergillus fumigatus,could effect on DT-I was 2.62 times,on CT was 1.58 times,on tanshinone I was 7.03 times.We found that a large percentage of the active substance in fungal elicitors was polysaccharide and DT-I and CT had the common metabolic pathways possibly,speculated the same changing trend of their contents as the increase of the polysaccharide.Further analysis shown the content of DT-I and CT firstly increases and then decreases.To sum up,similarity and difference both existed in the content of active ingredients and the composition of microbial communities of S.miltiorrhiza between the plants of different planting areas.And,fungal communities showed more distinct geographic characteristics than bacterial communities.Some bacteria and fungi were found to promote the accumulation of one or several active ingredients of S.miltiorrhiza,which indicated that potential roles of S.miltiorrhiza-associated microbes on the promotion of secondary metabolism.