Institute of Plant Sciences, Karl-Franzens-University, Graz, Austria.
FEMS Microbiol Ecol. 2012 Nov;82(2):472-81. doi: 10.1111/j.1574-6941.2012.01425.x. Epub 2012 Jul 3.
The lichen symbiosis allows a self-sustained life under harsh environmental conditions, yet symbiotic integrity can be affected by fungal parasites. Nothing is known about the impact of these biologically diverse and often specific infections on the recently detected bacterial community in lichens. To address this question, we studied the arctic-alpine 'chocolate chip lichen' Solorina crocea, which is frequently infected by Rhagadostoma lichenicola. We sampled healthy and infected lichens at two different sites in the Eastern Alps. High abundances of Acidobacteria, Planctomycetes, and Proteobacteria were identified analyzing 16S rRNA gene regions obtained by barcoded pyrosequencing. At the phylum and genus level, no significant alterations were present among infected and healthy individuals. Yet, evidence for a differentiation of communities emerged, when data were analyzed at the strain level by detrended correspondence analysis. Further, a profile clustering network revealed strain-specific abundance shifts among Acidobacteria and other bacteria. Study of stability and change in host-associated bacterial communities requires a fine-grained analysis at strain level. No correlation with the infection was found by analysis of nifH genes responsible for nitrogen fixation.
地衣共生体允许在恶劣的环境条件下维持自我生存，但共生体的完整性可能会受到真菌寄生虫的影响。对于这些生物多样性且通常具有特异性的感染对最近在地衣中检测到的细菌群落的影响，我们一无所知。为了解决这个问题，我们研究了在东阿尔卑斯山的两个不同地点经常被 Rhagadostoma lichenicola 感染的北极高山“巧克力片地衣”Solorina crocea。我们对健康和感染的地衣进行了采样。通过对 barcoded pyrosequencing 获得的 16S rRNA 基因区域进行分析，鉴定出了大量的酸杆菌门、浮霉菌门和变形菌门。在门和属水平上，感染和健康个体之间没有明显的变化。然而，当通过去趋势对应分析在菌株水平上分析数据时，出现了群落分化的证据。此外，群落聚类网络分析揭示了酸杆菌门和其他细菌中菌株特异性丰度的变化。研究宿主相关细菌群落的稳定性和变化需要在菌株水平上进行精细的分析。分析负责固氮的 nifH 基因并未发现与感染有关的相关性。
