Cerium oxide nanomaterial regulates endophytic and rhizospheric bacteria of wheat to enhance resistance under simulated microgravity stress

Abstract

Abstract Certain nanomaterials, including cerium dioxide nanoparticle (CeO2 NP), have shown promise in modulating microbial composition in plants, thereby alleviating stressors such as the notable microgravity in space conditions. Using 16S rRNA gene amplicon sequencing, we explored microbial community variations within the wheat rhizosphere and endosphere under simulated microgravity. With a 500 mg/L concentration, CeO2 NP enhanced wheat growth, particularly augmenting root growth, elevating stem diameter and root-to-shoot ratio, and improving endophytic microbial diversity with less impact on the rhizospheric community. Importantly, CeO2 NP mitigated simulated microgravity impact, including a notable increase in Bacteroidetes and a lesser decline of Firmicutes, thus bolstering microbial network stability. Additionally, CeO2 NP upregulated metabolic pathways related to carbohydrate metabolism, secondary metabolite biosynthesis, and nucleotide metabolism in rhizospheric microbiota, alongside nucleotide metabolism in endophytic microbiota. This insight deepens our understanding of cerium dioxide nanoparticles' potential in alleviating the adverse effects of simulated microgravity on plants through microbial modulation and provides new implications for future exploration of nanomaterials in enhancing plant health in space agriculture.