基于Hiseq测序分析沉香不同层的细菌分布特征

为探究沉香不同层之间细菌群落结构与多样性,该文采用Hiseq高通量测序分别对沉香不同层样品进行细菌群落结构分析。结果表明,沉香5个分层15个样品共获得1 150 096条优化序列及9 690种OTUs,其物种分属于28个细菌门、61个纲、110个目、212个科和384个属中。进一步分析发现,白木层(NL)细菌物种丰富性最低,OTUs种类最少;沉香层(AL)和NL共有OTUs数量为0,差异较大。同时,NL与其他4层在细菌群落结构及物种多样性方面都存在显著性差异,与过渡层(TL)有部分类似的细菌群落分布,如葡萄球菌科Staphylococcaceae的葡萄球菌属Staphylococcus为二者共同优势菌属;非白木的4层组织中的细菌种类结构相似性较大,共有的4个菌属分别为Acidibacter、慢生根瘤菌属Bradyrhizobium、热酸菌属Acidothermus和鞘氨醇单胞菌属Sphingomonas,其中前3种菌属占沉香类物质DA层和AL层细菌群落的主导地位,且Bradyrhizobium在AL层最为丰富。研究结果表明,白木香在结香过程中细菌群落多样性及丰富度在宿主中呈递减分布趋势,不同分层的细菌富集具有显著差异性,为揭示细菌如何参与和调控沉香结香的研究提供基础数据。

Analysis of bacteria distribution characteristics in different layers of agarwood based on Hiseq sequencing

To explore the diversity of bacterial community structure between different layers of agarwood, Hiseq(high-throughput sequencing) was used to analyze the bacterial community structure of samples from different layers of agarwood. Our results showed that 1 150 096 optimized sequences and 9 690 OTUs were obtained from 15 samples of 5 layers of agarwood, which belonged to 28 bacterial phyla, 61 classes, 110 orders, 212 families and 384 genera. Further analysis revealed that the normal layer(NL) had the lowest bacterial species richness and the smallest number of OTUs. And the total number of OTUs of the agarwood layer(AL) and NL was zero, which was quite different.At the same time, there were significant differences in bacterial community structure and species diversity between NL and the other four layers. While there were some common dominant bacterial genera in both transition layer(TL) and NL. The similarity of bacterial distribution in 4 non-NL layers was relatively high, which had four common genera, such as Acidibacter, Bradyrhizobium, Acidothemus and Sphingomonas. While Acidibacter, Bradyrhizobium and Acidothemus were the dominant bacterial genus of DA and AL, and all of these layers contained volatile oil. In addition, the Bradyrhizobium was the most abundant in agarwood layer. Our results showed that bacterial community diversity and abundance were decreasing from DL to AL, and different layers showed significant differences in bacterial enrichment. It provided the clues to investigate how bacteria participate in the formation of agarwood.