Diversity Of Endophtic Bacteria From Innermongolia Glycyrrhiza

In this study, To completely know the diversity of endophytic bacteria from Glycyrrhiza uralensis plants—a important Chinese traditional medicine, PCR-DGGE and traditional culture-dependent methods were combined to examine the microbial community of endophytic bacteria from wild and cultivated Glycyrrhiza uralensis plants which collected from Erdos Innermongolia province.The isolation of endophytic bacteria from the roots,stems and leaves of wild and cultivated Glycyrrhiza uralensis plants indicated that Glycyrrhiza uralensis plant has plenty of endophytic bacterium in density and population. The endophytic bacterium density were between 3.10×102～1.37×10~6 (cfu/g fresh weight)and it is higher in wild Glycyrrhiza uralensis than in cultivated Glycyrrhiza uralensis. There were differences in endophytic bacterium density and population between roots,stems and leaves of Glycyrrhiza uralensis. the isolate result show that more endophytic bacterium in roots and leaves than in stems. 121 strains of endophytic bacteria identified by ERIC-PCR . Partial sequence analysis of 16S rDNA gene of 82 strains indicated that these strains were in a high similarity with 19 known genus which belong toα,β,γ-Proteobacteria,Firmicutes and Actinobacteria .γ-Proteobacteria was the first dominant group (45.78% of the total), then the Firmicutes (42.17% of the total), and 12.05% of the total was another three groups. The dominant genus were Bacillus sp.,Pseudomonas sp.,Pantoea sp. and Serratia sp..Using CTAB method to extract the plant genome DNA and amplifying endophytic bacteria 16S rDNA directly from Glycyrrhiza uralensis tissues by using bacterial 16S rDNA primers 799f-1492r, then using PCR-DGGE to examine the microbial community. The DGGE profile show that the species of dominant endophytic bacteria in different tissues were similar, but some tissues still has its own dominant endophytic bacteria. Sequence analysis of DGGE bands indicated that they are in high similarity with Enterobacter sp.,Pantoea sp.,Klebsiella oxytoca,Serratia sp. which belong toγ-Proteobacteria.The integrated DGGE profiles of endophytic bacteria explored with culture-dependent and unculture- dependent approaches indicated that the bands of bacteria DNA from culture-dependent approache were in higher denaturing gradientgel area than the bacteria DNA from unculture-dependent approache, the bands of them couldn't matching well, and only one bacteria species from culture-dependent approache exhibited band in relevant DGGE fingerprints of the endophytic bacteria from unculture-dependent approache.The partial sequence analysis of 16S rDNA gene of isolated strain WS10b show that it was similar with uncultured endophytic bacteria from Genbank. The result of characterazation,APi 20E bacterial identify system,Biolog bacterial identify system and whole 16S rDNA sequence show that it belonged to Pantoea sp.. It still need time to validate weather it was a new srain or not.