丹参内生拮抗细菌DS-R5对丹参根际和根表土壤细菌群落结构的影响

Effects of endophytic antagonistic bacterium DS-R5 of Salvia miltiorrhiza on bacterial community structure in rhizospheric and rhizoplanic soil

目的 探究生防细菌DS-R5施入丹参植株后根际和根表土壤细菌群落组成及多样性变化。方法 向丹参植株根部施入生防细菌DS-R5,以未施用细菌为对照组,分别采集根际和根表土壤样品提取总DNA,扩增样品总DNA的V3-V4区,采用Illumina MiSeq测序平台对PCR扩增产物进行双端测序分析,利用生物信息学分析解析丹参植株根际土壤和根表土壤细菌群落结构组成及多样性。结果 菌株DS-R5处理后增加了根际土壤细菌群落的多样性和丰度,降低了根表土壤细菌群落的多样性和丰度;高通量测序得到的根际和根表土壤的有效序列数量和OTU数量相比对照组均有所下降,根际土壤处理样品中微生物种类最丰富,根表土壤处理样品中微生物种类最少,根际土壤处理样品与根际土壤对照物种种类更接近;在门水平上,根际土壤处理样品相比对照变形菌门丰度下降,酸杆菌门丰度升高,根表土壤处理样品相比对照变形菌门和酸杆菌门丰度均升高,放线菌门丰度降低;在属水平上,根际土壤处理样品中鞘氨醇单胞菌属、芽胞杆菌属、慢生根瘤菌属相比根际土壤对照占比均有升高,根表土壤处理样品相比对照黄杆菌属和伯克菌属丰度下降,而土壤中的优势菌属根瘤菌属和芽胞杆菌属丰度升高。结论 丹参植株施用生防细菌DS-R5后,改变了根际土壤和根表土壤中微生物群落结构和多样性。

Objective To explore the changes of bacterial community composition and diversity in rhizospheric and rhizoplanic soil after applying biocontrol bacterium DS-R5 into Salvia miltiorrhiza plants. Methods After the biological control bacterium DS-R5 was applied to the root of Salvia miltiorrhiza, the total DNA was extracted from rhizospheric and rhizoplanic soil samples, and the V3-V4 region of the total DNA was amplified. The PCR products were sequenced by using Illumina MiSeq sequencing platform, and the community structure and diversity of bacteria in rhizospheric and rhizoplanic soil of Salvia miltiorrhiza were analyzed with bioinformatics analysis. Results The strain DS-R5 increased the diversity and abundance of bacterial community in rhizospheric soil, but decreased the those in rhizoplanic soil;the number of effective sequences and OTUs of rhizospheric and rhizoplanic soil obtained using high-throughput sequencing decreased compared with the control. The microbial species in rhizospheric soil treatment was the most abundant and the microbial species in rhizoplanic soil treatment was the least. The species in rhizospheric soil treatment were closer to those in rhizospheric soil control. Compared with the control, the abundance of Proteobacteria in rhizospheric soil treatment decreased, while that of Actinobacteria increased. The abundance of Proteobacteria and Acidobacteria in rhizoplanic soil treatment increased, but that of Actinomycetes decreased. At the genus level, the abundance of Sphingomonas, Bacillus, Bradyrhizobium in rhizospheric soil treatment was higher than that in control. The abundance of Flavobacterium and Burkholderia in rhizoplanic soil decreased compared with the control, but that of beneficial bacteria Rhizobium and Bacillus in soil increased. Conclusion After applying biocontrol bacteria DS-R5 to Salvia miltiorrhiza plants, the microbial community structure and diversity in rhizospheric soil and rhizoplanic soil were changed.