Plants modulate the soil microbiota by root exudation assembling a complex rhizosphere microbiome with organisms spanning different trophic levels. Here, we assessed the diversity of bacterial, fungal and cercozoan communities in landraces and modern varieties of wheat. The dominant taxa within each group were the bacterial phyla Proteobacteria, Actinobacteria and Acidobacteria; the fungi phyla Ascomycota, Chytridiomycota and Basidiomycota; and the Cercozoa classes Sarcomonadea, Thecofilosea and Imbricatea. We showed that microbial networks of the wheat landraces formed a more intricate network topology than that of modern wheat cultivars, suggesting that breeding selection resulted in a reduced ability to recruit specific microbes in the rhizosphere. The high connectedness of certain cercozoan taxa to bacteria and fungi indicated trophic network hierarchies where certain predators gain predominance over others. Positive correlations between protists and bacteria in landraces were preserved as a subset in cultivars as was the case for the Sarcomonadea class with Actinobacteria. The correlations between the microbiome structure and plant genotype observed in our results suggest the importance of top-down control by organisms of higher trophic levels as a key factor for understanding the drivers of microbiome community assembly in the rhizosphere.

中文翻译：

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小麦根际微生物组中的多营养相互作用：从细菌，真菌到原生生物。

植物通过根系渗出来调节土壤微生物群，将根际微生物组与复杂的根际微生物组跨越不同的营养水平。在这里，我们评估了地方品种和现代小麦品种中细菌，真菌和尾生动物群落的多样性。每组中的优势类群是细菌门的Proteobacteria，Actinobacteria和Acidobacteria。真菌门孢子囊菌，梭菌属和担子菌；和Cercozoa类肉瘤，Thecofilosea和Imbricatea。我们发现，与现代小麦品种相比，小麦地方品种的微生物网络形成了更复杂的网络拓扑，这表明选育导致降低了在根际中吸收特定微​​生物的能力。某些cerzozoan类群与细菌和真菌的高度联系表明，在营养网络层次中，某些捕食者比其他人更占优势。原生动物和地方种细菌之间的正相关被保留为品种中的一个子集，如带有放线菌的肉瘤类。在我们的结果中观察到的微生物组结构与植物基因型之间的相关性表明，营养水平较高的生物自上而下进行控制的重要性是理解根际微生物组群落组装驱动力的关键因素。