Diversity Of Rhizosphere And Endophytic Fungi And Their Metabolites In C. Rhizogenes

Plant endophytic was directly or indirectly participated in the growth and development of host plants,metabolism pathways,component accumulation and other processes,so it plays an important role in the health of host plants,especially medicinal plants,it directly affects the geoherbalism and quality of Chinese medicinal materials.Plant endophytic has an important influence on the origin attributes and quality properties of Chinese medicinal materials,mainly reflected in plant immune function,the formation of stress resistance,the formation of medicinal parts,the accumulation of effective components and the improvement of yield,artificial domestication cultivation and so on.In recent years it is one of the research hotspots to reveal the relationship between the structure and function of plant microorganisms and the quality of Chinese medicinal materials.In this paper,using the medicinal plants and rhizosphere soil as the research object,High-throughput sequencing was used to study and analyze the variation of fungal communities,the difference of niche,altitude and site environment in the rhizosphere of Paris polyphylla Sm.In addition,the diversity of rhizosphere fungal and endophytic fungal communities were analyzed by using the pure culture,to detect the species and activity of their metabolites.The main researches are as follows.Firstly,we revealed the structural variability and niche differences of the microbial communities in the rhizosphere and endophytes at different altitudes,while the structural variability of rhizosphere microbial communities in the wild-grown Paris polyphylla Sm.rhizosphere soil was lower than that of endophytic fungal communities.With the increase of altitude,the plant endophytic microorganism is not like the distribution law of the microorganism in the soil,but presents the law of rising first and then falling,which is different from the distribution law of the soil microorganism.In addition,we identified the core flora of the rhizome of Paris polyphylla Sm.Secondly,the difference of rhizosphere soil and endophytic fungi in different sites was revealed by studying wild environment and park environment.There are higher microbial diversity and evenness in the rhizosphere soil in the wild environment than in the park environment,and the amount of microorganisms in the roots,rhizomes and leaves are slightly higher than that in the wild environment.In addition,in the analysis of the physical and chemical properties of the soil under different site environment,we found that there are obvious differences in the physical and chemical properties of the soil under the two environments.Under different site environments we found that both ascomycota and basidiomycota were dominant flora in both soils and within plants,and the relative abundance was greater than 10%.we also found that some of the flora contained in the soil was not detected in plants.Thirdly,the endophytic fungi were cultured purely,and a total of 135 endophytes were isolated,42 of which were isolated in rhizosphere soil.The number of endophytic bacteria isolated from each part of the plant was 23 in the root,37 in the rhizome,28 in the leaf and 5 in the leaf bud.These endophytic bacteria were distributed in 24 genera,among which the species of Altemaria and Fusarium were the most,15 of these strains were less than 99%in sequence comparison and 2 were less than 97%in sequence comparison.In the study of the metabolites of these strains,the obtained fermentation broth had different levels of bacteriostatic activity and may contain saponins or analogues.Nine compounds were obtained in the mass spectrometry analysis of 2 fermentation broths.The results of this study are helpful to understand the relationship between the microbial flora of the rhizosphere soil and the endophytic community of Paris polyphylla Sm.,to perceive the diversity of the microbial community of the rhizome endophytic fungi,to understand the response of the plant rhizosphere and endophytic microorganisms to the changes of the altitude and site environment,and also to provide the theoretical basis for the optimization of the artificial domestication cultivation techniques of Paris polyphylla Sm.With the continuous development of high-throughput sequencing and pure culture technology,the research of plant endophytic microbiology will get a breakthrough,and the research on endophytic microorganisms of medicinal plants,especially those of Chinese medicinal plants with scarce resources,will promote the development and utilization of microbial resources and help to alleviate the shortage of high-quality Chinese herbal resources,the protection of wild medicinal plant resources is of positive significance.