The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities
The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities
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DOI：
10.1038/ismej.2011.170
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发表时间：
2012-05-01
期刊：
影响因子：
11
通讯作者：
Cary, Stephen Craig
中科院分区：
文献类型：
--
作者：
Lee, Charles K.;Barbier, Beatrice A.;Cary, Stephen Craig
最近，分子遗传学在麦克默多干河谷和其他地方的土壤微生物群落中的应用推翻了长期以来认为南极土壤微生物多样性极其有限的观点。山谷间土壤比较调查旨在通过将分子遗传学方法与生物地球化学分析相结合，阐明影响这些独特微生物群落及其生物地理学的因素。尽管干旱河谷土壤的微生物群落可能是复杂的，但毫无疑问，生态系统的食物网相对简单，而且有证据表明，物理化学条件可能在塑造微生物群落方面起着主导作用。为了验证这一假设，利用分子遗传学工具，包括16S rRNA基因PCR扩增产物的焦磷酸测序，分析了从四个地理位置不同的干旱山谷采集的具有代表性的土壤样品中的细菌群落。结果表明，这4个群落在结构和系统发育上是截然不同的，具有明显不同的多样性水平。引人注目的是，在所有四个山谷中，只发现了214个系统类型中的2个，挑战了一个普遍存在的假设，即干燥山谷的微生物区系由几个世界性物种组成。土壤地球化学性质的分析表明，盐分含量、海拔和Cu2+与微生物群落的差异显著相关。我们的结果表明，干旱河谷土壤的微生物生态是高度局部化的，物理化学因素可能在塑造南极无冰地区的微生物方面发挥重要作用。这些发现暗示了干谷冰川地貌和微生物生态之间的联系，并提出了与这一独特生态系统的环境管理有关的以前未被认识到的问题。《ISME期刊》(2012年)6,1046-1057；doi：10.1038/ismej.2011.170；2011年12月15日在线发布
Recent applications of molecular genetics to edaphic microbial communities of the McMurdo Dry Valleys and elsewhere have rejected a long-held belief that Antarctic soils contain extremely limited microbial diversity. The Inter-Valley Soil Comparative Survey aims to elucidate the factors shaping these unique microbial communities and their biogeography by integrating molecular genetic approaches with biogeochemical analyses. Although the microbial communities of Dry Valley soils may be complex, there is little doubt that the ecosystem's food web is relatively simple, and evidence suggests that physicochemical conditions may have the dominant role in shaping microbial communities. To examine this hypothesis, bacterial communities from representative soil samples collected in four geographically disparate Dry Valleys were analyzed using molecular genetic tools, including pyrosequencing of 16S rRNA gene PCR amplicons. Results show that the four communities are structurally and phylogenetically distinct, and possess significantly different levels of diversity. Strikingly, only 2 of 214 phylotypes were found in all four valleys, challenging a widespread assumption that the microbiota of the Dry Valleys is composed of a few cosmopolitan species. Analysis of soil geochemical properties indicated that salt content, alongside altitude and Cu2+, was significantly correlated with differences in microbial communities. Our results indicate that the microbial ecology of Dry Valley soils is highly localized and that physicochemical factors potentially have major roles in shaping the microbiology of ice-free areas of Antarctica. These findings hint at links between Dry Valley glacial geomorphology and microbial ecology, and raise previously unrecognized issues related to environmental management of this unique ecosystem. The ISME Journal (2012) 6, 1046-1057; doi:10.1038/ismej.2011.170; published online 15 December 2011