Biosynthesized Silica Nanoparticles (Si NPs) Helps in Mitigating Drought Stress in Wheat Through Physiological Changes and Upregulation of Stress Genes

Purpose Among the myriad of abiotic stresses, drought is a prominent stress that harms plant growth, development, crop yield, and quality. Nowadays, the ideas of sustainable agriculture have focused on the introduction of biologically synthesized nanomaterials to maximize crop yield with the least amount of potential toxic effects. The application of nanoparticles is thought to be one of the most effective and promising methods for reducing the consequences of drought stress on crops. Methods The Si nanoparticles were characterized in detail and four different concentrations of Si NPs (30 ppm, 60 ppm, 90 ppm, and 120 ppm) were used for the study at two irrigation regimes with 100% soil moisture content (SMC) under well-watered and 50% SMC under drought stress conditions. Results Substantial improvement in almost all physiological parameters was observed after foliar application of Si NPs at all concentrations, but 60 ppm concentration was found to be the most effective in improving overall plant resistance to drought stress. This was evident by lowered hydrogen peroxidase (H 2 O 2 ) and lipid peroxidation (MDA) content and increased relative water content (RWC), antioxidant enzyme activities (APOX, CAT, and SOD), chlorophyll content, and proline content. A total of 5 stress-related genes ( DREB2, MYB33 MYB3R, WRKY 19, and SnRK 2.4) were studied, which were found to be upregulated after application of Si NPs, indicating its stimulatory role even at molecular levels. Conclusion Our detailed investigational study and findings will open a pragmatic option in research studies related to usage of nanoparticles in mitigating of drought tolerance of wheat. The study can definitely be used a reference for future work in diverse crops, where production is being drastically compromised due to climate change, particularly water deficiency. Graphical abstract Illustrating role of Si NPs in drought stress mitigation (created in BioRender.com)