Abiotic Factors Shape Microbial Diversity in Sonoran Desert Soils
Abiotic Factors Shape Microbial Diversity in Sonoran Desert Soils
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DOI：
10.1128/aem.01459-12
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Dontsova, Katerina
中科院分区：
文献类型：
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作者：
Andrew, David R.;Fitak, Robert R.;Dontsova, Katerina
高通量，培养独立的调查土壤中的细菌和古菌群落已经阐明了土壤和生物对微生物多样性的影响的重要性，但很少有研究比较这些因素的相对重要性。在这里，我们采用多重焦磷酸测序的16S rRNA基因检查土壤和仙人掌相关的根际微生物群落的索诺兰沙漠和生物圈2号研究设施的人工沙漠生物群系。我们的重复采样方法的结果表明，微生物群落的形状主要是由与地理位置相关的土壤特性，而根际协会是次要因素。我们发现，生态相似的仙人掌（Saguaro）和Cardon（Pachycerus pringlei）仙人掌的根际群落之间的差异不大。根际和土壤群落均由不成比例丰富的Crenarchaeota类Thermoprotei占主导地位，其占183，320个总焦磷酸测序读数的18.7%，来自36，162个总操作分类单位（OTU）中相对较少的数量（1，337或3.7%）。土壤和根际样品共同的OTU包括大部分原始序列读段，表明土壤和根际微生物的共享群落构成共同和丰富的分类群，特别是在细菌门变形菌门、放线菌门、浮游菌门、厚壁菌门、拟杆菌门、绿杆菌门和酸杆菌门中。然而，绝大多数OTU在土壤或根际群落中是罕见和独特的，并且在相距数十公里的位置之间存在差异。几个土壤性质，特别是土壤pH值和碳含量，显着相关的社区多样性的测量。我们的研究结果强调了非培养方法在调查极端环境中微生物群落的重要性。
High-throughput, culture-independent surveys of bacterial and archaeal communities in soil have illuminated the importance of both edaphic and biotic influences on microbial diversity, yet few studies compare the relative importance of these factors. Here, we employ multiplexed pyrosequencing of the 16S rRNA gene to examine soil-and cactus-associated rhizosphere microbial communities of the Sonoran Desert and the artificial desert biome of the Biosphere2 research facility. The results of our replicate sampling approach show that microbial communities are shaped primarily by soil characteristics associated with geographic locations, while rhizosphere associations are secondary factors. We found little difference between rhizosphere communities of the ecologically similar saguaro (Carnegiea gigantea) and cardon (Pachycereus pringlei) cacti. Both rhizosphere and soil communities were dominated by the disproportionately abundant Crenarchaeota class Thermoprotei, which comprised 18.7% of 183,320 total pyrosequencing reads from a comparatively small number (1,337 or 3.7%) of the 36,162 total operational taxonomic units (OTUs). OTUs common to both soil and rhizosphere samples comprised the bulk of raw sequence reads, suggesting that the shared community of soil and rhizosphere microbes constitute common and abundant taxa, particularly in the bacterial phyla Proteobacteria, Actinobacteria, Planctomycetes, Firmicutes, Bacteroidetes, Chloroflexi, and Acidobacteria. The vast majority of OTUs, however, were rare and unique to either soil or rhizosphere communities and differed among locations dozens of kilometers apart. Several soil properties, particularly soil pH and carbon content, were significantly correlated with community diversity measurements. Our results highlight the importance of culture-independent approaches in surveying microbial communities of extreme environments.