Effects of iron, zinc, and silicon nanoparticles on morpho-physiological growth, yield, and quality of wheat (Triticum aestivum L.) under drought stress

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Drought stress limits wheat ( Triticum aestivum L.) productivity by disrupting plant growth, photosynthesis, and other metabolic activities. During recent times, the use of micronutrient-based nanoparticles (NPs) has emerged as a potential strategy to mitigate drought stress. However, comprehensive studies comparing their individual and combined effects on wheat under varying drought conditions are limited. This knowledge gap includes the lack of physiological and biochemical assessments of the integrated use of different NPs as well as insufficient understanding of their role in regulating oxidative stress and improving grain yield and quality of wheat under drought conditions. This study investigated the ameliorative role of different nanoparticles (NPs), namely iron (Fe), zinc (Zn), and silicon (Si), on wheat under different levels of drought stress. A pot experiment was conducted to assess the impact of these NPs on plant growth, indicators of oxidative stress, activities of antioxidant enzymes, and yield attributes of wheat. Present results revealed a significant reduction in growth, biomass accumulation, and yield attributes under drought stress. On the other hand, the use of NPs led to a marked improvement in morpho-physiological growth, biomass, and yield, suggesting their potential to alleviate the negative impacts of drought on wheat. Among the treatments, the combined use of Fe and Zn-NPs (T 5 ) showed most promising results for wheat growth under drought stress, with the maximum increases in plant height (17.59 %), leaf area (68.2 %), and number of tillers (26.1 %). Moreover, the maximum increase in total chlorophyll (16.6–44.3 %), carotenoids (15.4–46.8 %), soluble proteins (38.5–45.1 %), and relative moisture contents in leaves (31.19–35.2 %) were also recorded in Fe + Zn-NPs under varying drought levels (D 0 , D 1 , D 2 ). Indicators of oxidative stress, such as malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) contents, were decreased by 44.5–46.2 % and 42.1–48.9 %, respectively, in Fe + Zn-NPs treatment under drought stress. Likewise, Fe + Zn-NPs increased the superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activities by 102.7–589 %, 44.5–142.7 %, 74.2–200.2 %, and 16.01–634.2 %, respectively, in the wheat plants under drought stress. Furthermore, Fe + Zn-NPs improved the wheat flour yield (4.7 %) under drought stress. These findings highlight the beneficial role of NPs in enhancing wheat performance under drought stress.