Tripathi Binu M, Moroenyane Itumeleng, Sherman Chen, Lee Yoo Kyung, Adams Jonathan M, Steinberger Yosef
Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon, 21990, Republic of Korea.
Institut National de la Recherche Scientifique, Centre INRS-Institut Armand-Frappier, 531 boulevard de Prairies, Laval, Quebec, H7V 1B7, Canada.
Microb Ecol. 2017 Jul;74(1):168-176. doi: 10.1007/s00248-017-0931-0. Epub 2017 Jan 10.
The soil microbiome is important for the functioning of terrestrial ecosystems. However, the impacts of climate on taxonomic and functional diversity of soil microbiome are not well understood. A precipitation gradient along regional scale transects may offer a model setting for understanding the effect of climate on the composition and function of the soil microbiome. Here, we compared taxonomic and functional attributes of soil microorganisms in arid, semiarid, Mediterranean, and humid Mediterranean climatic conditions of Israel using shotgun metagenomic sequencing. We hypothesized that there would be a distinct taxonomic and functional soil community for each precipitation zone, with arid environments having lower taxonomic and functional diversity, greater relative abundance of stress response and sporulation-related genes, and lower relative abundance of genes related to nutrient cycling and degradation of complex organic compounds. As hypothesized, our results showed a distinct taxonomic and functional community in each precipitation zone, revealing differences in soil taxonomic and functional selection in the different climates. Although the taxonomic diversity remained similar across all sites, the functional diversity was-as hypothesized-lower in the arid environments, suggesting that functionality is more constrained in "extreme" environments. Also, with increasing aridity, we found a significant increase in genes related to dormancy/sporulation and a decrease in those related to nutrient cycling (genes related to nitrogen, potassium, and sulfur metabolism), respectively. However, relative abundance of genes related to stress response were lower in arid soils. Overall, these results indicate that climatic conditions play an important role in shaping taxonomic and functional attributes of soil microbiome. These findings have important implications for understanding the impacts of climate change (e.g., precipitation change) on structure and function of the soil microbiome.
土壤微生物群落对陆地生态系统的功能至关重要。然而，气候对土壤微生物群落的分类和功能多样性的影响尚未得到充分了解。沿区域尺度样带的降水梯度可能为理解气候对土壤微生物群落组成和功能的影响提供一个模型框架。在这里，我们使用鸟枪法宏基因组测序比较了以色列干旱、半干旱、地中海和湿润地中海气候条件下土壤微生物的分类和功能属性。我们假设每个降水区都有一个独特的分类和功能土壤群落，干旱环境的分类和功能多样性较低，应激反应和孢子形成相关基因的相对丰度较高，而与养分循环和复杂有机化合物降解相关的基因相对丰度较低。正如所假设的那样，我们的结果显示每个降水区都有一个独特的分类和功能群落，揭示了不同气候条件下土壤分类和功能选择的差异。尽管所有地点的分类多样性保持相似，但功能多样性正如所假设的那样在干旱环境中较低，这表明功能在“极端”环境中受到的限制更大。此外，随着干旱程度的增加，我们分别发现与休眠/孢子形成相关的基因显著增加，而与养分循环相关的基因（与氮、钾和硫代谢相关的基因）减少。然而，干旱土壤中与应激反应相关的基因相对丰度较低。总体而言，这些结果表明气候条件在塑造土壤微生物群落的分类和功能属性方面起着重要作用。这些发现对于理解气候变化（如降水变化）对土壤微生物群落结构和功能的影响具有重要意义。
