From uptake to resilience: How metal-based nanoparticles can enhance plant drought tolerance

Abstract Background Drought stress (DS) is a major abiotic constraint threatening agricultural productivity and global food security. Traditional agronomic approaches have achieved limited success in sustainably enhancing plant drought tolerance. Nano-enabled agriculture, particularly using metal-based nanoparticles (MNPs), has emerged as a promising strategy to improve plant resilience under stress. In addition to serving as micronutrient supplements, MNPs interact with plant signalling systems to regulate physiological, biochemical, and molecular responses to DS. Scope This review synthesises current knowledge on uptake, translocation, accumulation, and physiological interactions of MNPs in plants, focusing on their drought-alleviating potential. We analyse how MNPs modulate water retention, activate antioxidant defence systems, enhance photosynthetic efficiency, and improve root nutrient acquisition under DS. A special emphasis is placed on the role of MNPs in regulating drought-responsive gene expression and stress-signalling pathways. We identify major research gaps requiring future attention, including: (1) optimising nanoparticle formulations for targeted delivery; (2) elucidating interactions between MNPs and soil microbial communities; (3) understanding long-term ecological effects and fate of MNPs in soil–plant systems; and (4) developing reliable field application strategies maximising efficacy while ensuring environmental safety. Conclusion Nano-enabled agriculture using MNPs offers a promising route to enhance plant drought resilience by improving water relations, redox balance, photosynthesis and nutrient uptake. To move from concept to practice, future work must link the mechanistic understanding of above processes with long-term fate assessments and socio-economic analyses so that nano-inputs are safe-by-design, well-regulated and genuinely affordable for farmers.