Purpose

Agricultural soil multifunctionality is greatly impacted by belowground processesdriven by a complex group of microorganisms that change during plant growth. While most studies in microbial diversity and multifunctionality have focused on soil bacteria or fungi, they have largely overlooked the influence of key microbiome predators- the protists and other microorganisms.

Methods

We manipulated microbial alpha diversity using a dilution-to-extinction approach. Wheat varieties were employed to investigate the effects of manipulated microbial alpha diversity on rhizosphere microbes (including bacteria and eukaryotes-fungi and protists) and soil multifunctionality (nutrient cycling, organic matter decomposition, and plant productivity) during a two-month re-colonization period.

Results

The recovery and re-colonization of the belowground microbial communities were primarily influenced by dilution rather than wheat variety. Random forest (RF) analysis indicated that changes induced by dilution and plant variety in bacterial and protistan assembly in the rhizosphere had stronger effects on soil multifunctionality than those in bulk soil and root endosphere. Reduced microbial diversity led to a decrease in specific functions, such as phosphorus mineralization and nitrification, but did not affect broad functions like microbial respiration and organic decomposition. The rare taxa, such as those belonging to bacterial Burkholderiaceae, Rhizobiaceae, and Sphingobacteriaceae, and protistan Cercozoa, Ochrophyta, and Chlorophyta crucially influenced soil multifunctionality.

Conclusion

The critical role of rhizosphere protistan and bacterial communities in soil multifunctionality underscores the importance of plant-induced shifts in belowground microbial assembly for the resilience of soil multifunctionality to biodiversity loss Moreover, rhizosphere rare bacterial and protistan taxa contributed more to ecosystem functions than expected based on their abundance.

中文翻译：

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微生物多样性丧失和小麦基因型触发的根际细菌和原生生物多样性限制土壤多功能性：来自温室实验的证据

目的

农业土壤的多功能性受到植物生长过程中变化的一组复杂微生物驱动的地下过程的极大影响。虽然大多数关于微生物多样性和多功能性的研究都集中在土壤细菌或真菌上，但他们在很大程度上忽视了关键微生物组捕食者——原生生物和其他微生物的影响。

方法

我们使用稀释到灭绝的方法来操纵微生物的α多样性。利用小麦品种来研究在两个月的重新定植期间，操纵微生物α多样性对根际微生物（包括细菌和真核生物-真菌和原生生物）和土壤多功能性（养分循环、有机质分解和植物生产力）的影响。

结果

地下微生物群落的恢复和重新定殖主要受到稀释的影响，而不是小麦品种的影响。随机森林（RF）分析表明，根际细菌和原生生物组装的稀释和植物多样性引起的变化对土壤多功能性的影响比大块土壤和根内圈的影响更强。微生物多样性的减少导致特定功能的减少，例如磷矿化和硝化作用，但不影响微生物呼吸和有机分解等广泛功能。稀有类群，例如属于细菌伯克霍尔德氏菌科、根瘤菌科和鞘氨醇杆菌科的类群，以及原生动物尾虫门、赭藻门和绿藻门，对土壤多功能性产生了至关重要的影响。

结论

根际原生生物和细菌群落在土壤多功能性中的关键作用强调了植物引起的地下微生物组装变化对于土壤多功能性对生物多样性丧失的恢复力的重要性此外，根际稀有细菌和原生生物类群对生态系统功能的贡献比基于预期的更大他们的丰富性。