Vik Unni, Logares Ramiro, Blaalid Rakel, Halvorsen Rune, Carlsen Tor, Bakke Ingrid, Kolstø Anne-Brit, Økstad Ole Andreas, Kauserud Håvard
Microbial Evolution Research Group, Department of Biosciences, University of Oslo, P.O. 1066 Blindern, 0316 Oslo, Norway.
Sci Rep. 2013 Dec 11;3:3471. doi: 10.1038/srep03471.
Several eukaryotic symbioses have shown to host a rich diversity of prokaryotes that interact with their hosts. Here, we study bacterial communities associated with ectomycorrhizal root systems of Bistorta vivipara compared to bacterial communities in bulk soil using pyrosequencing of 16S rRNA amplicons. A high richness of Operational Taxonomic Units (OTUs) was found in plant roots (3,571 OTUs) and surrounding soil (3,476 OTUs). The community composition differed markedly between these two environments. Actinobacteria, Armatimonadetes, Chloroflexi and OTUs unclassified at phylum level were significantly more abundant in plant roots than in soil. A large proportion of the OTUs, especially those in plant roots, presented low similarity to Sanger 16S rRNA reference sequences, suggesting novel bacterial diversity in ectomycorrhizae. Furthermore, the bacterial communities of the plant roots were spatially structured up to a distance of 60 cm, which may be explained by bacteria using fungal hyphae as a transport vector. The analyzed ectomycorrhizae presents a distinct microbiome, which likely influence the functioning of the plant-fungus symbiosis.
几种真核生物共生关系已被证明容纳了与宿主相互作用的丰富多样的原核生物。在这里，我们通过对16S rRNA扩增子进行焦磷酸测序，研究了与珠芽蓼外生菌根根系相关的细菌群落，并将其与大量土壤中的细菌群落进行比较。在植物根系（3571个操作分类单元）和周围土壤（3476个操作分类单元）中发现了高度丰富的操作分类单元（OTU）。这两种环境中的群落组成明显不同。放线菌门、装甲菌门、绿弯菌门以及在门水平上未分类的OTU在植物根系中的丰度显著高于土壤。很大一部分OTU，尤其是植物根系中的OTU，与桑格16S rRNA参考序列的相似度较低，这表明外生菌根中存在新的细菌多样性。此外，植物根系的细菌群落在距离达60厘米的范围内呈空间结构分布，这可能是因为细菌利用真菌菌丝作为运输载体。所分析的外生菌根呈现出独特的微生物群，这可能会影响植物 - 真菌共生关系的功能。
