Nanoparticles Enhancing Drought Stress Tolerance in Crops: Pathways, Transport, and Mechanistic Insights

Abstract

: Drought stress is a major constraint to crop productivity and global food security under changing climatic conditions. This review critically synthesizes current evidence on the potential of nanoparticles to enhance drought tolerance in crops, with emphasis on their uptake, transport, transformation, and interactions with plant physiological and molecular processes. The available evidence indicates that nanoparticles can improve drought resilience by modulating reactive oxygen species (ROS) homeostasis, antioxidant defense, osmolyte accumulation, photosynthesis, abscisic acid (ABA) signaling, aquaporin activity, and drought-responsive genes, including DREB , WRKY , and NAC . However, responses vary substantially with nanoparticle properties, dose, application route, plant species, developmental stage, and exposure conditions. Recent advances further indicate important roles of nanoparticle-mediated molecular regulation, rhizosphere interactions, and epigenetic responses, while evidence on long-term accumulation, phytotoxicity, soil microbial effects, and field-scale performance remains limited. Overall, this review integrates physiological, molecular, and environmental perspectives to identify the determinants of nanoparticle-mediated drought tolerance and highlights the need for field validation, long-term biosafety assessment, and omics-based approaches for their sustainable agricultural application