Oak Ridge National Laboratory, Oak Ridge, TN, USA.
Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama.
Nat Ecol Evol. 2018 Mar;2(3):499-509. doi: 10.1038/s41559-017-0463-5. Epub 2018 Jan 22.
Phosphorus is a scarce nutrient in many tropical ecosystems, yet how soil microbial communities cope with growth-limiting phosphorus deficiency at the gene and protein levels remains unknown. Here, we report a metagenomic and metaproteomic comparison of microbial communities in phosphorus-deficient and phosphorus-rich soils in a 17-year fertilization experiment in a tropical forest. The large-scale proteogenomics analyses provided extensive coverage of many microbial functions and taxa in the complex soil communities. A greater than fourfold increase in the gene abundance of 3-phytase was the strongest response of soil communities to phosphorus deficiency. Phytase catalyses the release of phosphate from phytate, the most recalcitrant phosphorus-containing compound in soil organic matter. Genes and proteins for the degradation of phosphorus-containing nucleic acids and phospholipids, as well as the decomposition of labile carbon and nitrogen, were also enhanced in the phosphorus-deficient soils. In contrast, microbial communities in the phosphorus-rich soils showed increased gene abundances for the degradation of recalcitrant aromatic compounds, transformation of nitrogenous compounds and assimilation of sulfur. Overall, these results demonstrate the adaptive allocation of genes and proteins in soil microbial communities in response to shifting nutrient constraints.
磷是许多热带生态系统中稀缺的养分，但土壤微生物群落如何在基因和蛋白质水平上应对生长受限的磷缺乏仍然未知。在这里，我们报告了在热带森林中进行的一项为期 17 年的施肥实验中，对磷缺乏和磷丰富土壤中的微生物群落进行的宏基因组学和宏蛋白质组学比较。大规模的蛋白质基因组学分析为复杂土壤群落中的许多微生物功能和类群提供了广泛的覆盖。土壤群落对磷缺乏的最强反应是植酸酶基因丰度增加了四倍以上。植酸酶催化植酸中磷酸盐的释放，植酸是土壤有机质中最顽固的含磷化合物。含磷核酸和磷脂的降解以及易降解碳和氮的分解的基因和蛋白质也在磷缺乏的土壤中增强。相比之下，磷丰富土壤中的微生物群落显示出降解顽固芳香族化合物、转化含氮化合物和吸收硫的基因丰度增加。总的来说，这些结果表明，土壤微生物群落中的基因和蛋白质在应对不断变化的养分限制时会进行适应性分配。
