烟草种子内生细菌群落结构与多样性

Community structure and diversity of endophytic bacteria of tobacco seeds

摘要:

[目的] 为了解烟草种子内生细菌的群落结构和多样性。[方法] 分别对3个品种（K326、云烟85、云烟87）烟草种子内生细菌的16S rRNA基因V3-V4区进行扩增，采用Illumina MiSeq测序技术对扩增片段进行高通量测序，并对3个品种烟草种子内生细菌群落结构和多样性进行分析。[结果] 3个品种种子共获得的V3-V4区高质量序列片段128558条，Shannon指数计算为2.03-3.73，K326和云烟85内生菌多样性指数高于云烟87。3品种烟草种子内生细菌的优势门均为变形菌门Proteobacteria、放线菌门Actinobacteria、厚壁菌门Firmicute和拟杆菌门Bacteroidete。3个品种烟草种子内生细菌共有菌属共有27个，K326和云烟85的最优势菌属为假单胞菌属（Pseudomonas），云烟87的最优势菌属为大肠杆菌志贺菌属（Escherichia-shigella）。16S功能预测显示各种子中产生了丰度较高的蛋白质、核苷酸、糖类、辅酶及代谢产物合成的有益功能信息。[结论] 烟草种子内生细菌多样性丰富，不同品种种子细菌群落组成基本相似，其丰度存在一定差异性。种子中存在的潜在有益细菌包括假单胞菌、类芽孢杆菌、根瘤菌、马赛菌、藤黄单胞菌、萨勒河菌、Lelliottia菌等，具有大量代谢相关的有益功能。研究结果为今后烟草种子内生菌的功能研究和利用以及种子病害生物防控提供参考信息。

Abstract:

[Objective] In order to study the endophytic bacterial community structure and diversity of tobacco seeds.[Methods] The V3-V4 region of endophytic bacteria 16S rRNA gene of three varieties tobacco seeds was amplified, and the amplified fragments were sequenced using Illumina MiSeq high-throughput sequencing technology. The endophytic bacterial community structure and diversity of three varieties tobacco seeds were analyzed.[Results] We obtained a total of 128558 high-quality sequences in V3-V4 region from three varieties seeds, and the Shannon indexes varied in the range from 2.03 to 3.73. The endophytic bacterial community diversity indexes of K326 and Yunyan 85 were both higher than that of Yunyan 87. Proteobacteria, Actinobacteria, Firmicute and Bacteroidete were the dominant bacterial phylum of endophytic bacteria of three varieties tobacco seeds. The total number of endophytic bacteria genus in three varieties tobacco seeds was 27. Pseudomonas was the most dominant genera of endophytic bacteria of K326 and Yunyan 85, Escherichia-shigella was the most dominant genera of endophytic bacteria of Yunyan 87. 16S function prediction revealed that a large amount of beneficial function information about synthesis of proteins, nucleotides, sugars, coenzymes and metabolites showed higher abundance in tobacco seeds.[Conclusion] The diversity of endophytic bacteria of tobacco seeds was rich, the composition was basically similar, but their abundances showed some differences. Potential beneficial bacteria presented in seeds included Pseudomonas, Paenibacillus, Rhizobium, Massilia, Luteimonas, Salana and Lelliottia, which have a large number of beneficial metabolism-related functions. These research results could provide some reference information for the functional research and utilization of tobacco seed endophyte and biological control of seed diseases.