Application of Nano Silica Is Associated With Enhanced Wheat Resistance to Fusarium Crown Rot via Regulation of Metabolic Pathways and Soil Microbial Community

Nano silica (NS) has promising agricultural applications, yet its effects and mechanisms in enhancing wheat resistance to Fusarium crown rot (FCR) caused by Fusarium pseudograminearum (FP) remain underexplored. Here, we conducted a pot experiment with 200 mg/L NS, integrating soil metagenomics, plant physiology, and metabolomics to investigate this process. Soil metagenomic analysis revealed that NS was associated with reshaped microbial community structure and distinct functional pathway variations (GO/KEGG annotations). In wheat, NS treatment was linked to activated fructose/mannose metabolism and phenylpropanoid biosynthesis, increasing SOD and POD activities by 14.5% and 169.9% and reducing MDA content by 37.0%. It was also associated with upregulated lignin-related enzymes (PAL, C4H, and 4CL) and their encoding genes, thus promoting lignin accumulation, enhancing stem strength, and restoring cellulose content. Our findings suggest a potential dual mechanism: NS-associated soil microbiome changes coincide with improved plant antioxidant capacity and defence gene expression, reinforcing stem integrity to alleviate FCR, providing new insights for eco-friendly FCR management.