Nano-scale silicon intervention for improving abiotic stress resilience in rice: mechanistic insights and practical...

Rice, a global food staple, primary food source for half of the world's population, is highly vulnerable to abiotic stresses such as drought, salinity, heat, and heavy metal toxicity. Silicon nanoparticles (SiNPs) have emerged as promising nano-interventions to enhance stress resilience by improving antioxidant defenses, photosynthesis, and ion homeostasis. Recent studies demonstrate that SiNPs modulate the expression of key transporter genes (OsHMA3, OsLsi1, OsABCC1) and activate transcription factors (DREB, NAC, WRKY) that regulate stress tolerance pathways. They also promote the accumulation of compatible solutes and phenolic compounds, reducing oxidative damage and metal toxicity. Omics-based research reveals that SiNPs influence redox signaling, hormonal balance, and epigenetic regulation, providing a clear understanding of their protective mechanisms at the physiological level. These effects are linked to enhanced structural integrity, reactive oxygen species (ROS) scavenging, and better nutrient uptake. However, rice-specific datasets remain limited, and field-scale validations are still scarce. SiNPs show strong potential as smart nanocarriers for nutrient delivery and gene modulation, integrating effectively with precision and sustainable agriculture practices. However, uncertainties regarding dosage, soil persistence, and food safety require careful evaluation before large-scale use. This review synthesizes physiological, molecular, and omics-based insights into SiNP-mediated abiotic stress tolerance in rice, emphasizing advances in understanding underlying resilience mechanisms. It also highlights environmental and regulatory challenges, identifies critical research gaps, and proposes future directions for safe and scalable applications of SiNPs in rice systems.