Splivallo Richard, Vahdatzadeh Maryam, Maciá-Vicente Jose G, Molinier Virginie, Peter Martina, Egli Simon, Uroz Stéphane, Paolocci Francesco, Deveau Aurélie
Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt, Germany.
Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt, Frankfurt, Germany.
Front Microbiol. 2019 Jun 28;10:1437. doi: 10.3389/fmicb.2019.01437. eCollection 2019.
Truffle fungi are well known for their enticing aromas partially emitted by microbes colonizing truffle fruiting bodies. The identity and diversity of these microbes remain poorly investigated, because few studies have determined truffle-associated bacterial communities while considering only a small number of fruiting bodies. Hence, the factors driving the assembly of truffle microbiomes are yet to be elucidated. Here we investigated the bacterial community structure of more than 50 fruiting bodies of the black truffle in one French and one Swiss orchard using 16S rRNA gene amplicon high-throughput sequencing. Bacterial communities from truffles collected in both orchards shared their main dominant taxa: while 60% of fruiting bodies were dominated by α-Proteobacteria, in some cases the β-Proteobacteria or the Sphingobacteriia classes were the most abundant, suggesting that specific factors (i.e., truffle maturation and soil properties) shape differently truffle-associated microbiomes. We further attempted to assess the influence in truffle microbiome variation of factors related to collection season, truffle mating type, degree of maturation, and location within the truffle orchards. These factors had differential effects between the two truffle orchards, with season being the strongest predictor of community variation in the French orchard, and spatial location in the Swiss one. Surprisingly, genotype and fruiting body maturation did not have a significant effect on microbial community composition. In summary, our results show, regardless of the geographical location considered, the existence of heterogeneous bacterial communities within fruiting bodies that are dominated by three bacterial classes. They also indicate that factors shaping microbial communities within truffle fruiting bodies differ across local conditions.
松露真菌因其诱人的香气而闻名，这些香气部分由定殖于松露子实体的微生物散发。这些微生物的身份和多样性仍未得到充分研究，因为很少有研究在仅考虑少数子实体的情况下确定与松露相关的细菌群落。因此，驱动松露微生物群落组装的因素尚待阐明。在这里，我们使用16S rRNA基因扩增子高通量测序技术，对法国和瑞士的一个果园中50多个黑松露子实体的细菌群落结构进行了研究。两个果园采集的松露的细菌群落共享其主要优势类群：虽然60%的子实体由α-变形菌纲主导，但在某些情况下，β-变形菌纲或鞘脂杆菌纲是最丰富的，这表明特定因素（即松露成熟度和土壤性质）以不同方式塑造了与松露相关的微生物群落。我们进一步试图评估与采集季节、松露交配型、成熟度以及松露果园内位置相关的因素对松露微生物群落变异的影响。这些因素在两个松露果园之间有不同的影响，在法国果园中，季节是群落变异的最强预测因子，而在瑞士果园中是空间位置。令人惊讶的是，基因型和子实体成熟度对微生物群落组成没有显著影响。总之，我们的结果表明，无论考虑的地理位置如何，子实体内存在由三个细菌类群主导的异质细菌群落。它们还表明，塑造松露子实体内微生物群落的因素因当地条件而异。
