Silica nanoparticles enhance wheat resistance to fusarium head blight through modulating antioxidant enzyme activities and salicylic acid accumulation

Fusarium head blight (FHB) disease severely impacts wheat production and quality. Silica nanoparticles (SiNPs) are demonstrated as an eco-friendly option for diseases management, but the specific mechanisms behind their ability to confer disease resistance in wheat have not been adequately characterized. This study evaluates the impact of SiNP200 on the resistance of wheat to FHB. Scanning electron microscope observation showed that SiNPs form a physical barrier on the surface of wheat leaves. Pathogenicity tests indicated foliar application of SiNP200 can protect wheat against F. graminearum, resulting in a significant reduction of lesion length by 27.7%, but in-vitro cultivation showed that SiNP200 had no impact on pathogen growth. Antioxidant enzyme activity analysis showed that SiNP200 had little effect on H2O2 contents, POD, and CAT activities under non-stress conditions, but under F. graminearum infection conditions, SiNP200 increased POD and SOD activities while decreased CAT and DHAR activities, and GSH content. Histochemical staining indicated that SiNP200 decreased ROS accumulation, thus reducing oxidative damage. Meanwhile, SiNP200 decreased MDA and Pro contents. Furthermore, SiNP200 increased SA response marker genes (TaPR1a, TaPR2 and TaPR5) expression levels and SA content, contributing to the enhanced wheat resistance to FHB. Summarily, SiNP200 improve wheat resistance to FHB, thereby providing a theoretical basis for SiNP200 application to control this disease.