Feng Jiao, Zeng Xiao-Min, Zhang Qianggong, Zhou Xin-Quan, Liu Yu-Rong, Huang Qiaoyun
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.
College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
ISME Commun. 2021 Dec 3;1(1):71. doi: 10.1038/s43705-021-00076-2.
Trait-based approaches provide a candidate framework for linking soil microbial community to ecosystem processes, yet how the trade-offs in different microbial traits regulate the community-level metabolic efficiency remains unknown. Herein we assessed the roles of the microbial taxa with particular trait strategies in mediating soil microbial metabolic efficiency along an altitude gradient on the Tibetan Plateau. Results showed that soil microbial metabolic efficiency declined with increasing altitude, as indicated by the increasing metabolic quotient (microbial respiration per unit biomass, qCO) and decreasing carbon use efficiency (CUE). Both qCO and CUE were predominantly predicted by microbial physiological and taxonomic attributes after considering key environmental factors including soil pH, substrate quantity and quality. Specifically, the reduced metabolic efficiency was associated with higher investment into nutrient (particularly for phosphorus) acquisitions via enzymes. Furthermore, we identified key microbial assemblies selected by harsh environments (low substrate quality and temperature) as important predictors of metabolic efficiency. These results suggest that particular microbial assemblies adapted to nutrient limited and cold habitats, but at the expense of lower metabolic efficient at higher altitude. Our findings provide a candidate mechanism underlying community-level metabolic efficiency, which has important implications for microbial-mediated processes such as carbon dynamics under global climate changes.
基于性状的方法为将土壤微生物群落与生态系统过程联系起来提供了一个候选框架，但不同微生物性状之间的权衡如何调节群落水平的代谢效率仍不清楚。在此，我们评估了具有特定性状策略的微生物类群在青藏高原海拔梯度上介导土壤微生物代谢效率中的作用。结果表明，土壤微生物代谢效率随着海拔升高而下降，这表现为代谢商（单位生物量的微生物呼吸，qCO）增加和碳利用效率（CUE）降低。在考虑包括土壤pH值、底物数量和质量等关键环境因素后，qCO和CUE主要由微生物生理和分类属性预测。具体而言，代谢效率降低与通过酶获取养分（特别是磷）的更高投入有关。此外，我们确定了由恶劣环境（低底物质量和温度）选择的关键微生物组合是代谢效率的重要预测因子。这些结果表明，特定的微生物组合适应了养分有限和寒冷的栖息地，但在高海拔地区以较低的代谢效率为代价。我们的研究结果为群落水平的代谢效率提供了一种潜在机制，这对微生物介导的过程（如全球气候变化下的碳动态）具有重要意义。
