Nano-silicon enhances tomato growth and antioxidant defense under salt stress†

Abstract

With the rapid expansion of applications in agriculture, nanotechnology has emerged as an effective alternative for alleviating abiotic stress in plants. In this study, the effects of silicon nanoparticles (SiNPs) on Na⁺ accumulation and salt stress in tomatoes were investigated. The results showed that a concentration of 200 mg L⁻¹ SiNPs significantly improved tomato growth. Furthermore, photosynthesis and chlorophyll content showed positive responses to SiNPs treatment compared to salt treatment alone. Additionally, the application of 200 mg L⁻¹ SiNPs effectively mitigated salt-induced oxidative stress by increasing the activity of antioxidant enzymes and reducing the levels of H₂O₂ (by 41.59% and 34.40%) and MDA (by 45.47% and 49.99%). Simultaneously, SiNPs treatment led to significant increases in the contents of K⁺ and Si in tomato seedlings, while decreasing the absorption of Na⁺. qPCR results demonstrated that SiNPs significantly up-regulated the expression of genes related to antioxidant stress defense and salt tolerance. In summary, SiNPs hold promise as potential modifiers to enhance the response and tolerance to salt stress in tomatoes.