高通量测序研究松茸菌柄土壤细菌群落结构

Bacterial community structure of Tricholoma matsutake stipe soil by high-throughput sequencing

为了解松茸-菌柄根际微生物互作关系,采用Illumina Hiseq 2500平台高通量测序方法,研究松茸菌柄附着土壤的细菌群落结构,分析微生物因素对松茸的形成和生长的影响.通过高通量测序共获得了6 730条质控序列,这些序列按照97%的相似度被分为928个操作分类单元（Operational taxonomic units,OTUs）,这些OTUs又被分为22个细菌门、2个古细菌门、62个细菌纲、4个古细菌纲、90个细菌目、6个古细菌目、162个细菌科、7个古细菌科、275个细菌属、8个古细菌属.在门的水平,变形菌门（Proteobacteria）在所有样品中均占主导,且在松茸菌柄土壤样品中高于对照样品;从纲的水平来看,β-变形菌门（Beta-proteobacteria）占主导,且在松茸菌柄土壤样品中高于对照样品;从属的水平看,伯克氏菌属（Burkholderia）隶属于变形菌门,在松茸土壤样品中的丰度显著高于对照,表明变形菌门对松茸的生长可能具有积极贡献,尤其是伯克氏菌属.此外,一些菌可能对松茸的生长具有消极贡献,如Unknown-Ellin 60等.本研究表明,细菌可能参与了松茸的生长和子实体的形成,但与细菌的丰富度不成正相关,这对松茸的人工种植将具有重要理论指导意义.

In order to understand the interaction between microorganisms in soil attached to the stipes of Tricholoma matsutake,we utilized high-throughput sequencing technology using an Illumina Hi Seq 2500 System（San Diego, CA, USA） to explore the bacterial community structure in such soils and analyzed the effects of microorganisms on the formation and growth of T. matsutake. A total of 6 730 sequences were obtained from the samples, and these sequences were clustered into 928 operational taxonomic units（OTUs） at a 97% similarity level. In addition, these OTUs were grouped into 22 bacterial phyla（including 62 classes, 90 orders, 162 families, and 275 genera） and 2 archaeal phyla（including 4 classes, 6 orders, 7 families, and 8 genera）. Proteobacteria was the dominant phylum present in all the samples, and these bacteria were significantly more abundant in soils attached to stipe of T. matsutake than they were in the control samples. Similarly, Beta-proteobacteria were the dominant class, and bacteria in this class were less abundant than they were in the control samples. Moreover, the genus Burkholderia within the Proteobacteria was more abundant in the control samples than in the T. matsutake soil samples. Generally, Proteobacteria, especially the genus Burkholderia, played an important role in the growth of T. matsutake, whereas other bacteria, such as Unknown-Ellin 60, would probably inhibit the growth of T. matsutake. This study showed that bacteria might be involved in the growth of T. matsutake and the formation of its fruiting bodies, but they had no positive relationship with bacterial abundance, which may provide theoretical guidance for the cultivation of T. matsutake.