PDF(Pubmed)
Abstract：
Microbes are key drivers of global biogeochemical cycles, and their functional roles arey dependent on temperature. Large population sizes and rapid turnover rates mean that the predominant response of microbes to environmental warming is likely to be evolutionary, yet our understanding of evolutionary responses to temperature change in microbial systems is rudimentary. Natural microbial communities are diverse assemblages of interacting taxa. However, most studies investigating the evolutionary response of bacteria to temperature change are focused on monocultures. Here, we utilize high-throughput experimental evolution of bacteria in both monoculture and community contexts along a thermal gradient to determine how interspecific interactions influence the thermal adaptation of community members. We found that community-evolved isolates tended toward higher maximum growth rates across the temperature gradient compared to their monoculture-evolved counterparts. We also saw little evidence of systematic evolutionary change in the shapes of bacterial thermal tolerance curves along the thermal gradient. However, the effect of community background and selection temperature on the evolution of thermal tolerance curves was variable and highly taxon-specific,with some taxa exhibiting pronounced changes in thermal tolerance while others were less impacted. We also found that temperature acted as a strong environmental filter, resulting in the local extinction of taxa along the thermal gradient, implying that temperature-driven ecological change was a key factor shaping the community background upon which evolutionary selection can operate. These findings offer novel insight into how community background impacts thermal adaptation.
摘要：
微生物是全球生物地球化学循环的关键驱动因素，它们的功能作用取决于温度。庞大的种群规模和快速的更替率意味着微生物对环境变暖的主要反应可能是进化的，然而，我们对微生物系统中温度变化的进化反应的理解是基本的。天然微生物群落是相互作用分类群的不同组合。然而,大多数研究细菌对温度变化的进化反应的研究都集中在单一培养。这里,我们利用细菌在单一培养和群落环境中沿着热梯度的高通量实验进化来确定种间相互作用如何影响群落成员的热适应。我们发现，与单文化进化的分离株相比，群落进化的分离株在温度梯度上的最大增长率更高。我们也几乎没有证据表明细菌热耐受性曲线沿热梯度的形状发生了系统的进化变化。然而,群落背景和选择温度对热耐受曲线演变的影响是可变的，并且具有高度的分类单元特异性，一些分类单元表现出明显的耐热性变化，而另一些则受到的影响较小。我们还发现温度是一个强大的环境过滤器，导致分类单元沿热梯度局部灭绝，这意味着温度驱动的生态变化是塑造进化选择可以运作的社区背景的关键因素。这些发现为社区背景如何影响热适应提供了新的见解。
