Diel-scale temporal dynamics recorded for bacterial groups in Namib Desert soil.
Diel-scale temporal dynamics recorded for bacterial groups in Namib Desert soil.
复制标题
DIEL尺度的时间动态记录了纳米布沙漠土壤中细菌群的记录。
DOI：
10.1038/srep40189
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发表时间：
2017-01-10
影响因子：
4.6
通讯作者：
Cowan DA
中科院分区：
文献类型：
--
作者：
Gunnigle E;Frossard A;Ramond JB;Guerrero L;Seely M;Cowan DA
热荒漠土壤中的微生物参与了碳的生物地球化学循环等核心生态系统过程。然而，对于微生物对温度和湿度等高度波动的微环境参数的短期（即超过24小时[日]周期）反应，仍然缺乏根本性的认识。为了解决这个问题，我们利用T-RFLP指纹图谱和16S rrna衍生的cDNA的454焦磷酸测序来表征纳米布沙漠土壤中多个周期的潜在活性细菌。引人注目的是，我们发现活性细菌群的显著变化可能在24小时内发生。例如，从早上到晚上，主要放线菌门的成员表现出显著的相对活性降低，而许多变形菌群则表现出相反的趋势。与我们的主要假设相反，环境参数只能占记录的总变化的10.5%。通过共现网络显示的潜在生物关联表明，非随机的门间和门内关联是“依赖于时间的”，这可能是该系统的一个关键特征。值得注意的是，许多蓝藻群被定位在外部和/或高度相互关联的细菌协会（模块）之间；可能充当模块间的“枢纽”，协调重要功能联盟之间的交互。总的来说，这些结果提供了经验证据，表明热沙漠土壤中的细菌群落表现出复杂的、依赖于饮食的群落间联系。
Microbes in hot desert soil partake in core ecosystem processes e.g., biogeochemical cycling of carbon. Nevertheless, there is still a fundamental lack of insights regarding short-term (i.e., over a 24-hour [diel] cycle) microbial responses to highly fluctuating microenvironmental parameters like temperature and humidity. To address this, we employed T-RFLP fingerprinting and 454 pyrosequencing of 16S rRNA-derived cDNA to characterize potentially active bacteria in Namib Desert soil over multiple diel cycles. Strikingly, we found that significant shifts in active bacterial groups could occur over a single 24-hour period. For instance, members of the predominant Actinobacteria phyla exhibited a significant reduction in relative activity from morning to night, whereas many Proteobacterial groups displayed an opposite trend. Contrary to our leading hypothesis, environmental parameters could only account for 10.5% of the recorded total variation. Potential biotic associations shown through co-occurrence networks indicated that non-random inter- and intra-phyla associations were ‘time-of-day-dependent’ which may constitute a key feature of this system. Notably, many cyanobacterial groups were positioned outside and/or between highly interconnected bacterial associations (modules); possibly acting as inter-module ‘hubs’ orchestrating interactions between important functional consortia. Overall, these results provide empirical evidence that bacterial communities in hot desert soils exhibit complex and diel-dependent inter-community associations.