黎药胆木内生细菌群落结构多样性研究及其基因功能预测分析

Study on Diversity of Endophytic Bacteria Community Structure and Prediction of Gene Function in Medicinal Nauclea officinalis of Li nationality

以海南省5个产区采集的胆木为材料,采用高通量16SrRNA测序技术分析了胆木的根、茎、叶和表皮4个组织的内生细菌群落多样性,并通过PICRUSt分析其内生细菌的潜在功能。结果表明,胆木在16SrRNAV3-V4区高质量序列片段共得到3 759 378条有效序列,划分为3 475个OUTs,内生细菌分为30门、82纲、183目、326科、764属,具有丰富的菌群多样性,组间差异显著。对内生细菌群落结构分析可知,共有优势菌属为Chloroplast_unclassified(25.11%)、芽孢杆菌属Bacillus(15.16%)、伯克霍尔德氏菌属Paraburkholderia(7.06%)、罗尔斯通菌属Ralstonia(5.03%)、马赛菌属Massilia(4.60%)。其中,根优势菌属为芽孢杆菌属(Bacillus)、伯克霍尔德氏菌属(Paraburkholderia)、寡养单胞菌属(Stenotrophomonas)、固氮根瘤菌(Azorhizobium)、根瘤菌属(Rhizobium);茎优势菌属为Chloroplast_unclassified、罗尔斯通菌属(Ralstonia)、马赛菌属(Massilia)、Mitochondria_unclassified;叶优势菌属为短小杆菌属(Curtobacterium);表皮优势菌属为赖氨酸芽胞杆菌属(Lysinibacillus)、类芽孢杆菌属(Paenibacillus)。PICRUSt分析显示,胆木不同组织内生细菌主要涉及6个生物代谢通路及36个子功能。不同组织的内生细菌基因二级功能层预测基因种基本无差异,但基因丰度具有显著差异,代谢为影响胆木植株内生细菌多样性和丰富度的重要因素。通过全面揭示胆木不同组织内生细菌多样性的变化趋势和规律,能为其内生细菌的进一步应用、充分挖掘其蕴含的丰富微生物资源奠定理论基础。

The high-throughput 16S rRNA sequencing technology was used to analyze the community diversity of endophytic bacteria in the root,stem,leaf,and epidermis of Nauclea officinalis collected from five regions in Hainan Province,and the potential function of endophytic bacteria was analyzed by PICRUSt.The results showed that 3759378 effective sequences were obtained from the high-quality sequence fragments in the 16S rRNA V3-V4 region,divided into 3475 OUTs.Endophytic bacteria were divided into 30 phyla,82 classes,183 orders,326 families,and 764 genera,with rich flora diversity and signifi-cant differences among groups.The community structure of endophytic bacteria was analyzed,and the common dominant bacterial genera were chloroplast_unclassified(25.11%),Bacillus(15.16%),Paraburkholderia(7.06%),Ralstonia(5.03%),and Massilia(4.60%).The root-dominant bacteria were Bacillus,Paraburkholderia,Stenotrophomonas,Azorhizobium,and Rhizobium.The dominant stem fungi were Chloroplast_unclassified,Ralstonia,Massilia,and Mitochondria_unclassified.The dominant genus of leaf bacteria was Curtobacterium.The dominant genera of Skin were Lysinibacillus and Paenibacillus.PICRUSt analysis showed that the endophytic bacteria in different tissues of N.officinalis were mainly involved in six bio-logical metabolic pathways and 36 subfunctions.The gene species predicted by the secondary functional layer of endophytic bacteria genes from different tissues are unchanged,but the gene abundance is significantly different,and metabolism is a vital factor affecting the diversity and abundance of endophytic bacteria in N.officinalis.Revealing the changing trends and laws of the various endophytic bacteria in different tissues of N.officinalis can lay a theoretical foundation for the further application of its endophytic bacteria and fully exploit its rich microbial resources.