新疆北部主要盐生植物根部内生细菌群落结构的高通量分析

Estimation of endophytic bacterial diversity in root of halophytes in Northern Xinjiang by high throughput sequencing

摘要:

[目的]揭示同一盐渍环境中不同种盐生植物根部内生细菌群落多样性特征和分布规律，结合根际土壤理化因子探讨其对内生细菌群落结构的影响。[方法]通过罗氏454高通量测序获得内生细菌16S rRNA片段，然后进行生物信息分析。[结果]研究的16种盐生植物其内生细菌群落主要由Proteobacteria、Tenericutes、Actinobacteria和Firmicutes 4个门的细菌组成。从植物“种”的水平来看，不同种盐生植物内生细菌群落存在差异；从植物“属”的水平来看，同一属的盐生植物内生细菌相似；从植物“科”的水平来看，藜科盐生植物内生细菌以Actinobacteria和Proteobacteria门为主；蒺藜科盐生植物内生细菌以Proteobacteria门为主；柽柳科盐生植物内生细菌以Tenericutes门为主；白花丹科盐生植物内生细菌以Proteobacteria、Fimicutes和Actinobacteria门为主。根际土壤中Cl^-含量对盐生植物内生细菌群落变化具有显著影响；而Cl^-、Mg²⁺和总氮组成的集合与内生细菌群落结构相关性最高。[结论]盐生植物内生细菌多样性丰富。在同一盐渍生境中，盐生植物内生细菌群落分布呈现宿主的种属特异性，根际土壤中Cl^-是影响其内生细菌群落变化的主要驱动因素之一。

Abstract:

[Objective] We studied the diversity of endophytic bacterial communities in different species of halophytes growing in the same saline habitat, and analyzed the effect of rhizosphere soil physicochemical properties on endophytic bacterial communities. [Methods] PCR-based Roche FLX 454 pyrosequencing was applied to reveal the diversity of endophytic bacteria. [Results] Endophytic bacterial communities of the 16 species of halophytes mainly included 4 phyla, which were Proteobacteria, Tenericutes, Actinobacteria and Firmicutes. In terms of plant species classification, colonial differences existed among plant species at perspectives of composition of bacterial taxa; in the case of plant genus level, endophytic bacteria of different halophyte plant species but belonging to same plant genus exhibited similarity; as to plant family level, Actinobacteria and Proteobacteria comprised the main abundant phyla of the halophytes belonging to Chenopodiaceae; Proteobacteria comprised the main abundant phyla of the halophytes belonging to Zygophyllaceae; Tenericutes comprised the main abundant phyla of the halophytes belonging to Tamaricaceae; Proteobacteria, Fimicutes and Actinobacteria comprised the main abundant phyla of the halophytes belonging to Plumbaginaceae. The Cl^- in rhizosphere soil has significant effect on endophytic bacterial community structure. Moreover, there is a strong correlation between bacterial community and the combination of Cl^-, Mg²⁺ and total nitrogen. [Conclusion] Halophytes harbors diverse endophytic bacteria. In the same saline habitat, the distribution of endophytic bacteria showed host plant species-specific, and the Cl^- in rhizosphere soil was one of the factors determined the endophytic bacterial community.