Root exudates can benefit plant growth and health by reshaping the rhizosphere microbiome. Whether nanoparticles biosynthesized by rhizosphere microbes play a similar role in plant microbiome manipulation remains enigmatic. Herein, we collect elemental selenium nanoparticles (SeNPs) from selenobacteria associated with maize roots. In vitro and soil assays show that the SeNPs enhanced plant performance by recruiting plant growth-promoting bacteria (e.g., Bacillus) in a dose-dependent manner. Multiomic profilings unravel a cross-kingdom-signaling cascade that mediates efficient biosynthesis of SeNPs by selenobacteria. Specifically, maize roots perceive histamine signaling from Bacillus spp., which stimulates the plant to produce p-coumarate via root exudation. The rpoS gene in selenobacteria (e.g., Pseudomonas sp. ZY71) responds to p-coumarate signaling and positively regulates the biosynthesis of SeNPs. This study demonstrates a novel mechanism for recruiting host-beneficial soil microbes by microbially synthesized nanoparticles and unlocks promising possibilities for plant microbiome manipulation.

中文翻译：

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利用生物合成的硒纳米颗粒将有益的土壤微生物募集到植物根系


根系分泌物可以通过重塑根际微生物组来有益于植物的生长和健康。根际微生物生物合成的纳米颗粒是否在植物微生物组操纵中发挥类似作用仍然是个谜。在此，我们从与玉米根相关的硒细菌中收集元素硒纳米颗粒 （SeNPs）。体外 和土壤测定表明，SeNPs 通过以剂量依赖性方式招募植物生长促进细菌（例如芽孢杆菌）来提高植物性能。多组学分析揭示了介导硒细菌对 SeNP 的高效生物合成的跨界信号级联反应。具体来说，玉米根感知来自芽孢杆菌属的组胺信号，这刺激植物通过根渗出产生 p-香豆酸盐。硒菌中的 rpoS 基因 （例如，假单胞菌属 ZY71） 响应对香豆酸信号传导并正向调节 SeNPs 的生物合成。本研究展示了一种通过微生物合成的纳米颗粒募集对宿主有益的土壤微生物的新机制，并为植物微生物组操纵开启了有希望的可能性。