Aims

Plant health is closely associated with the rhizosphere microbial community. Predatory protists can regulate the rhizosphere microbes and thereby affect plant health. However, there is limited research on how the exogenous addition of predatory protists influences plant rhizosphere microbiome across plant growth.

Methods

Here, we isolated a predatory protist species, named Naegleria sp. QL92, from healthy tomato rhizosphere soil, which can effectively suppress bacterial wilt. We investigated the impact of predatory protist addition on the rhizosphere bacterial community across tomato growth stages in pots.

Results

We found that the predatory protist of Naegleria significantly altered the community structure and composition of the rhizosphere bacteria during the seedling, flowering and fruiting stages of tomato growth. Moreover, the relative abundances of bacterial phylum of Proteobacteria, Gemmatimonadetes, and Nitrospirae as well as majority bacterial genera, especially Pseudomonas were increased during the seedling stage after Naegleria addition. Naegleria inoculation reduced the density of the Ralstonia solanacearum pathogen, which was negatively correlated with Pseudomonas relative abundance. The addition of Naegleria also increased the connections within rhizosphere bacterial communities, resulting in a complex microbial network.

Conclusions

Overall, our study highlighted the application of predatory protists as puppet masters of rhizosphere bacterial communities with enriching plant beneficial microbes, which offer new venues to manage rhizosphere microbial communities to support healthy plant growth in sustainable agriculture.

中文翻译：

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捕食性原生生物通过在植物生长的早期阶段丰富植物有益微生物来促进对细菌性枯萎病的疾病抑制

 目标

植物健康与根际微生物群落密切相关。捕食性原生生物可以调节根际微生物，从而影响植物健康。然而，关于捕食性原生生物的外源添加如何影响植物生长过程中植物根际微生物组的研究有限。

 方法

在这里，我们从健康的番茄根际土壤中分离出一种名为 Naegleria sp. QL92 的捕食性原生生物物种，它可以有效抑制细菌性枯萎病。我们研究了捕食性原生生物添加对盆中番茄生长阶段根际细菌群落的影响。

 结果

我们发现 Naegleria 的捕食性原生生物在番茄生长的幼苗、开花和结果阶段显着改变了根际细菌的群落结构和组成。此外，变形菌门、芽孢杆菌门和硝化螺旋菌门以及大多数细菌属，尤其是假单胞菌属的相对丰度在添加 Naegleria 后的幼苗期增加。Naegleria 接种降低了 Ralstonia solanacearum 病原体的密度，这与 Pseudomonas 的相对丰度呈负相关。Naegleria 的加入还增加了根际细菌群落内的联系，从而形成了复杂的微生物网络。

 结论

总体而言，我们的研究强调了捕食性原生生物作为根际细菌群落的傀儡主人的应用，这些细菌具有丰富的植物有益微生物，这为管理根际微生物群落提供了新的场所，以支持可持续农业中植物的健康生长。