CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, 100085, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China.
ISME J. 2023 Aug;17(8):1303-1314. doi: 10.1038/s41396-023-01447-4. Epub 2023 Jun 7.
Ecological and evolutionary processes simultaneously regulate microbial diversity, but the evolutionary processes and their driving forces remain largely unexplored. Here we investigated the ecological and evolutionary characteristics of microbiota in hot springs spanning a broad temperature range (54.8-80 °C) by sequencing the 16S rRNA genes. Our results demonstrated that niche specialists and niche generalists are embedded in a complex interaction of ecological and evolutionary dynamics. On the thermal tolerance niche axis, thermal (T) sensitive (at a specific temperature) versus T-resistant (at least in five temperatures) species were characterized by different niche breadth, community abundance and dispersal potential, consequently differing in potential evolutionary trajectory. The niche-specialized T-sensitive species experienced strong temperature barriers, leading to completely species shift and high fitness but low abundant communities at each temperature ("home niche"), and such trade-offs thus reinforced peak performance, as evidenced by high speciation across temperatures and increasing diversification potential with temperature. In contrast, T-resistant species are advantageous of niche expansion but with poor local performance, as shown by wide niche breadth with high extinction, indicating these niche generalists are "jack-of-all-trades, master-of-none". Despite of such differences, the T-sensitive and T-resistant species are evolutionarily interacted. Specifically, the continuous transition from T-sensitive to T-resistant species insured the exclusion probability of T-resistant species at a relatively constant level across temperatures. The co-evolution and co-adaptation of T-sensitive and T-resistant species were in line with the red queen theory. Collectively, our findings demonstrate that high speciation of niche specialists could alleviate the environmental-filtering-induced negative effect on diversity.
生态和进化过程同时调节微生物多样性，但进化过程及其驱动力在很大程度上仍未得到探索。在这里，我们通过测序 16S rRNA 基因，研究了跨越广泛温度范围（54.8-80°C）的温泉微生物群落的生态和进化特征。我们的研究结果表明，生态位专家和生态位广适者嵌入在复杂的生态和进化动态相互作用中。在热耐受性生态位轴上，对特定温度敏感（在特定温度下）的热敏种和对至少五种温度都耐受的耐温种具有不同的生态位宽度、群落丰度和扩散潜力，因此在潜在的进化轨迹上存在差异。生态位特化的热敏种经历了强烈的温度障碍，导致完全的物种转移和高适合度但在每个温度下丰度低的群落（“本底生态位”），这种权衡因此加强了峰值性能，表现为跨温度的高物种形成和随温度增加的多样化潜力。相比之下，耐温种具有生态位扩张的优势，但在局部表现较差，表现为具有高灭绝的宽生态位宽度，表明这些生态位广适者是“样样通，样样松”。尽管存在这些差异，但热敏种和耐温种在进化上是相互作用的。具体来说，从热敏种到耐温种的连续过渡确保了耐温种在整个温度范围内的排除概率保持在相对稳定的水平。热敏种和耐温种的共同进化和共同适应符合红皇后理论。总的来说，我们的研究结果表明，生态位专家的高物种形成可以减轻环境过滤对多样性的负面影响。
