College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang 830046, PR China; Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, Xinjiang 830046, PR China.
College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang 830046, PR China; Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, Xinjiang 830046, PR China.
Sci Total Environ. 2024 Dec 1;954:176148. doi: 10.1016/j.scitotenv.2024.176148. Epub 2024 Sep 10.
Microbial communities in desert riparian forest ecosystems have developed unique adaptive strategies to thrive in harsh habitats shaped by prolonged exposure to abiotic stressors. However, the influence of drought stress on the functional and metabolic characteristics of soil rhizosphere microorganisms remains unknown. Therefore, this study aimed to investigate the effects of drought stress on soil biogeochemistry and metabolism and analyze the relationship between the biogeochemical cycle processes and network of differentially-expressed metabolites. Using metagenomics and metabolomics, this study explored the microbial functional cycle and differential metabolic pathways within desert riparian forests. The predominant biogeochemical cycles in the study area were the Carbon and Nitrogen cycles, comprising 78.90 % of C, N, Phosphorus, Sulfur and Iron cycles. Drought led to increased soil C fixation, reduced C degradation and methane metabolism, weakened denitrification, and decreased N fixation. Furthermore, drought can disrupt iron homeostasis and reduce its absorption. The differential metabolic pathways of drought stress include flavonoid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and starch and sucrose degradation. Network analysis of functional genes and metabolism revealed a pronounced competitive relationship between the C cycle and metabolic network, whereas the Fe cycle and metabolic network promoted each other, optimizing resource utilization. Partial least squares analysis revealed that drought hindered the expression and metabolic processes and functional genes, whereas the rhizosphere environment facilitated metabolic expression and the functional genes. The rhizosphere effect primarily promoted metabolic processes indirectly through soil enzyme activities. The integrated multi-omics analysis further revealed that the effects of drought and the rhizosphere play a predominant role in shaping soil functional potential and the accumulation of metabolites. These insights deepen our comprehension of desert riparian forest ecosystems and offer strong support for the functionality of nutrient cycling and metabolite dynamics.
荒漠河岸林生态系统中的微生物群落已经发展出独特的适应策略，以在长期暴露于非生物胁迫因子的恶劣生境中茁壮成长。然而，干旱胁迫对土壤根际微生物功能和代谢特征的影响尚不清楚。因此，本研究旨在调查干旱胁迫对土壤生物地球化学和代谢的影响，并分析生物地球化学循环过程与差异表达代谢物网络之间的关系。本研究使用宏基因组学和代谢组学方法，研究了荒漠河岸林的微生物功能循环和差异代谢途径。研究区域主要的生物地球化学循环是碳氮循环，占 C、N、磷、硫和铁循环的 78.90%。干旱导致土壤碳固定增加、碳降解和甲烷代谢减少、反硝化作用减弱、固氮作用降低。此外，干旱会破坏铁的动态平衡，减少其吸收。干旱胁迫的差异代谢途径包括类黄酮生物合成、花生四烯酸代谢、类固醇激素生物合成以及淀粉和蔗糖降解。功能基因和代谢网络的网络分析表明，C 循环与代谢网络之间存在显著的竞争关系，而铁循环与代谢网络则相互促进，从而优化资源利用。偏最小二乘分析表明，干旱抑制了基因表达和代谢过程以及功能基因，而根际环境促进了代谢表达和功能基因。根际效应主要通过土壤酶活性间接促进代谢过程。综合多组学分析进一步表明，干旱和根际的影响在塑造土壤功能潜力和代谢物积累方面起着主导作用。这些发现加深了我们对荒漠河岸林生态系统的理解，并为养分循环和代谢物动态的功能提供了有力支持。
