Impact of Metal Oxide Nanoparticles on Potato (Solanum tuberosum L.) Tuber Yield in Hydroponics

Abstract

The application of phyto-nanotechnology in horticulture is a sustainable tool for agriculture due to its cost-effectiveness and eco-friendly properties. Essential micro-elements have been used as nano-fertilizer to enhance crop production. Fine-tuning of the nanoparticle dose is also recognized as the critical factor determining their impact on plant growth. Therefore, this study aimed to investigate the effects of iron (Fe) and manganese (Mn) oxide nanoparticles (NPs) on potato plants physiological and biochemical changes under the hydroponic conditions. Observations revealed that the plant growing in the adapted hydroponics media (supplemented with 4.0 mg L^− 1 Fe₃O₄ NPs and 1.0 mg L^− 1 MnO₂ NPs instead of original Fe and Mn salt respectively) improved various physiological and biochemical parameters, total biomass, and tuber yield compared to the untreated control. The growth-promoting impact of metal oxide NPs (hereafter refers as MONPs) simultaneously induced the activity of various antioxidant enzymes (SOD, CAT, POD) and contributed to the adequate reduction in malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content relative to the untreated control plants. This indicated that the application of MONPs could improve the potato yield per plant via modulating the plant antioxidant machinery. In addition, the application of MONPs as nano-nutrient appreciably improved the photosynthetic efficiency of plants via modulating the photosynthetic pigment content like Chl a, Chl b, total Chl, ratio Chl a/b, carotenoids as well as soluble sugar. The SEM-EDX elemental mapping also showed a slightly higher content of metals ions (Fe, Mn, and Ca) in the root and shoot tissues, however, the TEM analysis also confirmed absorption as well as transportation of MONPs in the root tissues growing in the presence of MONPs. This study opened the opportunity of utilizing MONPs as nano-nutrient in a hydroponic condition for development of pathogen-free potato tuber.