IMPACT OF SILICON NANOPARTICLES ON PHOTOSYNTHESIS AND STRESS TOLERANCE IN MAIZE

Abstract

Silicon nanoparticles (SiNPs) have emerged as a promising nano-enabled strategy to enhance crop productivity and resilience under increasingly harsh environmental conditions. This review-based study explores the multifaceted role of SiNPs in improving photosynthesis and abiotic stress tolerance in Zea mays (maize), a globally important C4 cereal crop. Despite its inherent photosynthetic efficiency, maize productivity is significantly constrained by drought, salinity, heat, chilling stress, heavy metal toxicity, and oxidative damage. Conventional silicon fertilizers are limited by low solubility and poor bioavailability; however, SiNPs overcome these constraints due to their nanoscale size, high surface reactivity, and improved plant uptake efficiency. The findings synthesized in this work highlight that SiNPs enhance maize performance through multiple interconnected mechanisms. At the physiological level, they improve stomatal regulation, gas exchange, water use efficiency, and canopy architecture, leading to optimized light interception and a “smart canopy” effect. At the biochemical and molecular levels, SiNPs stabilize photosystem II, maintain chlorophyll content, enhance antioxidant enzyme activity, and sustain key C4 photosynthetic enzymes such as PEPCase and Rubisco under stress conditions. Furthermore, SiNPs modulate silicon transporter genes (Lsi family), promote osmolyte accumulation, regulate aquaporin expression, and improve ion homeostasis under salinity and drought stress. They also contribute to detoxification and sequestration of heavy metals through chelation and structural barriers. Overall, SiNPs significantly improve biomass production, grain yield, and stress resilience in maize by integrating morphological, physiological, and molecular adaptations. The study concludes that SiNPs represent a sustainable nano-agricultural tool with strong potential to enhance food security under climate change, although further research is needed to optimize dosage, evaluate long-term environmental impacts, and ensure safe field-scale application.