PDF(Pubmed)
Abstract：
The complex interactions between epiphytic bacteria and marine macroalgae are still poorly understood, with limited knowledge about their community structure, interactions, and functions. This study focuses on comparing epiphytic prokaryotes community structure between three seaweed phyla; Chlorophyta, Rhodophyta, and Heterokontophyta in an easternmost rocky intertidal site of the Mediterranean Sea. By taking a snapshot approach and simultaneously collecting seaweed samples from the same habitat, we minimize environmental variations that could affect epiphytic bacterial assembly, thereby emphasizing host specificity. Through 16S rRNA gene amplicon sequencing, we identified that the microbial community composition was more similar within the same seaweed phylum host compared to seaweed host from other phyla. Furthermore, exclusive Amplicon Sequence Variants (ASVs) were identified for each algal phyla despite sharing higher taxonomic classifications across the other phyla. Analysis of niche breadth indices uncovers distinctive affinities and potential specialization among seaweed host phyla, with 39% of all ASVs identified as phylum specialists and 13% as generalists. Using taxonomy function prediction, we observed that the taxonomic variability does not significantly impact functional redundancy, suggesting resilience to disturbance. The study concludes that epiphytic bacteria composition is connected to host taxonomy, possibly influenced by shared morphological and chemical traits among genetically related hosts, implying a potential coevolutionary relationship between specific bacteria and their host seaweeds.
摘要：
附生细菌和海洋大型藻类之间的复杂相互作用仍然知之甚少，对他们的社区结构了解有限，互动,和功能。本研究的重点是比较三种海藻门之间的附生原核生物群落结构；绿藻，红藻,和位于地中海最东部的潮间带岩石的Heterokontophyta。通过采取快照方法并同时从同一栖息地收集海藻样本，我们尽量减少可能影响附生细菌组装的环境变化，从而强调宿主特异性。通过16SrRNA基因扩增子测序，我们发现，与其他门的海藻宿主相比，同一海藻门宿主内的微生物群落组成更相似。此外，尽管每个藻类门具有更高的分类学分类，但每个藻类门都鉴定了专有的扩增子序列变体（ASV）。生态位宽度指数的分析揭示了海藻寄主门之间独特的亲和力和潜在的专业化，39%的ASV被认定为门类专家，13%为通才。使用分类函数预测，我们观察到分类学变异性不会显着影响功能冗余，表明对干扰的韧性。该研究得出结论，附生细菌的组成与宿主分类学有关，可能受到遗传相关宿主之间共同的形态和化学性状的影响，暗示特定细菌及其宿主海藻之间潜在的共同进化关系。
