Deserts cover a significant proportion of the Earth’s surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of the AM fungi occurring in several desert ecosystems worldwide. We sequenced AM fungal DNA from soil samples collected from deserts in six different regions of the globe using the primer pair WANDA-AML2 with Illumina MiSeq. We recorded altogether 50 AM fungal phylotypes. Glomeraceae was the most common family, while Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae were represented with lower frequency and abundance. The most diverse site, with 35 virtual taxa (VT), was in the Israeli Negev desert. Sites representing harsh conditions yielded relatively few reads and low richness estimates, for example, a Saudi Arabian desert site where only three Diversispora VT were recorded. The AM fungal taxa recorded in the desert soils are mostly geographically and ecologically widespread. However, in four sites out of six, communities comprised more desert-affiliated taxa (according to the MaarjAM database) than expected at random. AM fungal VT present in samples were phylogenetically clustered compared with the global taxon pool, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped desert fungal assemblages.

中文翻译：

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沙漠栖息地土壤中的丛枝菌根真菌群落

沙漠覆盖地球表面的很大一部分，并且由于气候变化而继续扩大。互作型丛枝菌根（AM）真菌是功能上重要的植物根部共生菌，在干旱胁迫的系统（例如沙漠）中可能尤其重要。在这里，我们提供了在全球数个沙漠生态系统中发生的AM真菌的第一个分子表征。我们使用引物对WANDA-AML2和Illumina MiSeq对来自全球六个不同地区的沙漠的土壤样品进行了AM真菌DNA测序。我们总共记录了50 AM真菌系统型。茄科是最常见的科，而兜兰科，二歧科和Ac科用较低的频率和丰度表示。拥有35个虚拟分类单元（VT）的最多样化站点位于以色列内盖夫沙漠。代表恶劣条件的站点读取的数据相对较少，而丰富度估算值较低，例如，在沙特阿拉伯的沙漠站点中，仅记录了三个Diversispora VT。沙漠土壤中记录的AM真菌类群大部分在地理和生态上广泛分布。但是，在六个站点中的四个站点中，社区组成的沙漠附属分类单元（根据Maarj AM数据库）比随机估计的要多。与全球分类群相比，样品中存在的AM真菌VT在系统发育上呈簇状，这表明非随机组装过程（尤其是生境过滤）可能会形成沙漠真菌组装体。