Silicon nanoparticles (SiNPs) have emerged as promising tools in sustainable agriculture, offering high efficiency and cost-effectiveness in protecting plants against various biotic and abiotic stresses. This review provides an up-to-date overview of the synthesis, uptake, translocation, and application of SiNPs in agriculture. Key points include: 1. **Synthesis**: SiNPs can be synthesized using physical, chemical, and biological (green synthesis) methods. Green synthesis using agricultural wastes is particularly suitable for large-scale production and recycling agriculture. 2. **Uptake and Translocation**: The uptake and translocation of SiNPs in plants differ significantly from those of silicon (Si). Factors such as plant species, growth stage, and SiNPs properties influence their distribution. 3. **Application**: SiNPs can regulate plant stress acclimation at morphological, physiological, and molecular levels, enhancing plant growth and yield. They also serve as nanocarriers for delivering pesticides and plant growth regulators. 4. **Biotic Stress**: SiNPs directly inhibit the growth and aggressiveness of pathogens and insect pests, and enhance plant resistance to biotic stresses through various mechanisms, including regulation of defense compounds, antioxidant systems, and hormone signals. 5. **Abiotic Stress**: SiNPs alleviate metal, salt, drought, and other abiotic stresses by reducing metal accumulation, maintaining mineral nutrient homeostasis, modulating antioxidant systems, and improving photosynthetic performance. 6. **Synergistic Effects**: Combining SiNPs with other plant growth regulators can enhance their effectiveness in alleviating abiotic stresses. Despite these benefits, several key issues need further investigation, including effective synthesis methods, detailed mechanisms of uptake and translocation, and potential phytotoxicity. The review highlights the potential of SiNPs in sustainable agriculture and calls for more research to optimize their usage.Silicon nanoparticles (SiNPs) have emerged as promising tools in sustainable agriculture, offering high efficiency and cost-effectiveness in protecting plants against various biotic and abiotic stresses. This review provides an up-to-date overview of the synthesis, uptake, translocation, and application of SiNPs in agriculture. Key points include: 1. **Synthesis**: SiNPs can be synthesized using physical, chemical, and biological (green synthesis) methods. Green synthesis using agricultural wastes is particularly suitable for large-scale production and recycling agriculture. 2. **Uptake and Translocation**: The uptake and translocation of SiNPs in plants differ significantly from those of silicon (Si). Factors such as plant species, growth stage, and SiNPs properties influence their distribution. 3. **Application**: SiNPs can regulate plant stress acclimation at morphological, physiological, and molecular levels, enhancing plant growth and yield. They also serve as nanocarriers for delivering pesticides and plant growth regulators. 4. **Biotic Stress**: SiNPs directly inhibit the growth and aggressiveness of pathogens and insect pests, and enhance plant resistance to biotic stresses through various mechanisms, including regulation of defense compounds, antioxidant systems, and hormone signals. 5. **Abiotic Stress**: SiNPs alleviate metal, salt, drought, and other abiotic stresses by reducing metal accumulation, maintaining mineral nutrient homeostasis, modulating antioxidant systems, and improving photosynthetic performance. 6. **Synergistic Effects**: Combining SiNPs with other plant growth regulators can enhance their effectiveness in alleviating abiotic stresses. Despite these benefits, several key issues need further investigation, including effective synthesis methods, detailed mechanisms of uptake and translocation, and potential phytotoxicity. The review highlights the potential of SiNPs in sustainable agriculture and calls for more research to optimize their usage.