植物的根际富含促进微生物生长的营养物质,其中一些被招募为内生菌。内生真菌,尤其是放线菌,已知会产生过多的生物活性化合物。我们假设Nivale亚种。alpinum(雪绒花),一种罕见的高山药用植物,可能是与该植物相关的罕见放线菌的尚未开发的来源。使用本地高山植物的根际土壤,经过物理和化学预处理,用于分离放线菌。基于形态学选择分离株,并通过基于16SrRNA基因的条形码进行鉴定。结果77个放线菌分离株代表放线菌属,小孢子虫,Asanoa,微细菌,小单孢菌,微球菌,分枝杆菌,诺卡氏菌,和链霉菌.并行,来自同一地点的雪绒花植物进行了表面消毒,分成叶子,根,根茎,和花序,并在基因组DNA提取之前汇集在组织中。宏基因组16SrRNA基因扩增子证实了大量的放线菌操作分类单位(OTU),从根到根茎的多样性下降,叶子和花序。这些宏基因组数据,当使用隔离序列查询时,揭示了两个数据集之间的重叠,表明植物招募了土壤细菌。此外,这项研究发现了一种深刻的多样性的未培养的放线菌,嗜热动物,酸性微生物和未分类的放线菌,特别是在地下组织中,未来可能会被有针对性的隔离方法利用。
The rhizosphere of plants is enriched in nutrients facilitating growth of microorganisms, some of which are recruited as endophytes. Endophytes, especially Actinobacteria, are known to produce a plethora of bioactive compounds. We hypothesized that Leontopodium nivale subsp. alpinum (
Edelweiss), a rare alpine medicinal plant, may serve as yet untapped source for uncommon Actinobacteria associated with this plant. Rhizosphere soil of native Alpine plants was used, after physical and chemical pre-treatments, for isolating Actinobacteria. Isolates were selected based on morphology and identified by 16S rRNA gene-based barcoding. Resulting 77 Actinobacteria isolates represented the genera Actinokineospora, Kitasatospora, Asanoa, Microbacterium, Micromonospora, Micrococcus, Mycobacterium, Nocardia, and Streptomyces. In parallel,
Edelweiss plants from the same location were surface-sterilized, separated into leaves, roots, rhizomes, and inflorescence and pooled within tissues before genomic DNA extraction. Metagenomic 16S rRNA gene amplicons confirmed large numbers of actinobacterial operational taxonomic units (OTUs) descending in diversity from roots to rhizomes, leaves and inflorescences. These metagenomic data, when queried with isolate sequences, revealed an overlap between the two datasets, suggesting recruitment of soil bacteria by the plant. Moreover, this study uncovered a profound diversity of uncultured Actinobacteria from Rubrobacteridae, Thermoleophilales, Acidimicrobiales and unclassified Actinobacteria specifically in belowground tissues, which may be exploited by a targeted isolation approach in the future.