Nanoparticles enhanced morpho-physiological growth of wheat in contaminated soil by restricting cadmium mobility and accumulation

Abstract

Nanotechnology has obtained importance over conventional technologies to enhance crop growth, yield and environmental sustainability. Cadmium (Cd) is one of the most ecotoxic heavy metals that directly enter the food chain and accumulate in different human body organs such as kidneys, lungs, and liver. Cadmium (Cd) contamination in agricultural soils has now become a big issue, which affects food quality and causes a serious threat to human health and the environment. Nanoparticles (NPs) are effectively used to remediate Cd-contaminated soils, due to having a large surface area and high adsorption capacity. The present study evaluated the effects of three NPs i.e., iron (Fe), silicon (Si) and zinc (Zn) NPs on the growth, and physiology of plants as well as the accumulation of Cd in different parts of plants. The collected soil was spiked with different Cd levels (0, 5, 10, 20 mg kg-1), and NPs were applied at 60 mg kg-1 of soil prior to sowing. At maturity, plants exhibit significant increases in shoot length by 14, 12, 10% and 48, 30, 29% in root length in treatments amended with Fe, Si and Zn-NPs at 5 mg kg-1 Cd contamination levels. The grain yield was enhanced by 78% at 5mg kg-1 Cd level amended with Fe-NPs as compared to the control (no NPs application). The results revealed that NPs have a beneficial effect on stomatal conductance, transpiration rate, and photosynthetic rate compared to control. The Cd concentration in various plant parts viz. roots, shoot and grains decreased by 36%, 35% and 69% after the application of NPs. However, this reduction was more distinct at 5 mg kg-1 Cd with Fe-NPs followed by Zn-NPS and Si-NPs. Overall, it was concluded that NPs play a significant role in the enhancement of plant biomass, increase in nutrient availability, and decrease the Cd accumulation in different plant parts