CeO2 nanomaterial regulates wheat endophytic and rhizospheric bacteria to enhance resistance under simulated microgravity stress.

Certain nanomaterials, including cerium dioxide nanoparticle (CeO₂ NP), have shown potential in modulating plant microbial communities to alleviate stressors like simulated microgravity. Using 16S rRNA amplicon sequencing, we investigated microbial variations in wheat rhizosphere and endosphere under simulated microgravity. With a 500 mg/L concentration, CeO₂ NP enhanced wheat growth, particularly enhancing roots, increasing stem diameter, root-to-shoot ratio, and improving endophytic microbial diversity with less impact on the rhizospheric community. CeO₂ NP mitigated microgravity impacts by increasing Bacteroidetes, reducing Firmicutes decline, and stabilizing microbial networks. It also enhanced carbohydrate and nucleotide metabolism pathways in rhizospheric microbiota and nucleotide metabolism in endophytic microbiota. Together with wheat metabolomics, these results underscore how CeO₂ NP help wheat adapt to simulated microgravity by aligning microbial activity for an integrated adaptive response. These findings highlight CeO₂ NP's role in mitigating simulated microgravity effects on plants via microbial modulation, offering insights for future applications in space agriculture.