Diversity Of Actinomvcetes Associated With 26 Species Of Toxic Plants And Rhizospere Soil In Yunnan

The goals of this study are to research the diversity of endophytic actinomycetes and rhizosphere soil actinomycetes with 26 species of toxic plants in Yunnan,which using macro genome sequencing technology combined with pure culture isolation method.The isolated strains were screened for antibacterial activity and detected the functional genes,in order to develop and protect the endophytic actinomycetes from toxic plants.The 16S rRNA gene V4 region of the Bacteria in the Antiaris toxicaria Lesch,Alangium chinense(Lour.)Harms,Lantana camara L.was sequenced with the Illumina HiSeq PE250 paired-end sequencing method.The three samples received 204,352 effective tags,nearly 1795 OTUs.The endophytic bacteria community of the three toxic plants including the well-known 21 phyla of bacterial and the tentative RsaHF231,WD272,which in sum of 257 bacteria genera.There were 34 genera of actinomycetes,17 genera of Antiaris toxicaria Lesch,both Alangium chinense(Lour.)Harms and Lantana camara L.were 30 genera.Through the analysis of a diversity,we found that the microbial diversity of the Alangium chinense(Lour.)Harms and Lantana camara L.were more abundant and homogeneous than the Antiaris toxicaria Lesch.With the ? diversity analysis conducted,we found that microbial community composition of Alangium chinense(Lour.)Harms and Lantana camara L.were similiar,but significantly different with Antiaris toxicaria Lesch.The another work was study the pure culture method of endophytic actinomycetes from toxic plants.It was found that sodium hypochlorite and sodium thiosulfate could effectively improve the detection rate of endophytic actinomycetes.The plant tissues were pulverized by the homogenizer,and then added with sodium pyrophosphate for enrichment culture could facilitate the contact of the endophytic bacteria with the medium.With the nutrition of plant components such cellulose and xylan as carbon source,amino acid as nitrogen source of the medium separation effect was better than others medium.249 strains of endophytic actinomycetes were isolated from 26 kinds of toxic plants,especially the diversity of rare actinomycetes was abundant.A total of 142 actinomycetes were isolated from rhizosphere of 6 plants,which Streptomyces were mainly.The toxicity of toxic plants had a greater impact on the colonization of endophytic actinomycetes,the highly toxic plants contain less endogenous actinomycetes.Due to the impact of climate,environmental factors and human interference,the composition of endophytic actinomycetes in different habitats were significantly different.Native endemic plants could be considered as another resource of endogenous actinomycetes.Through the antibacterial activity screening shown that antibacterial effects of Streptomyces from plants were better than the rhizosphere soil actinomycetes.Moreover,the plants are rich in rare actinomycetes also have a strong inhibitory effect on certain pathogens.It was found that the tested positive strains mostly have a better antibacterial activity,but the specific mechanisms of actinomycetes need to further genomic sequencing analysis.This study shows that metagenomic sequenced and pure culture combined with would more objective and comprehensive understanding the diversity of endophytic actinomycetes,which Anuobacterial activity by gene screening and detection can effectively elect the potential valuable resource of actinomycetes bacteria.To lay the foundation for studying the biological activity of endophytic actinomycetes,even the mechanism of metabolism between endophytic actinomycetes and host plants.