Green synthesis of nano iron oxide using Emblica officinalis L. fruit extract and its impact on growth, chlorophyll content, and metabolic activity of Solanum lycopersicum L.

Abstract

Micronutrient deficiency among crop plants has been a concerning problem that hinders their growth, declines productivity, and causes economic losses. The nutritional deficiency of iron has been established widely among plants, especially in calcareous soils. Biogenic metallic nanoparticles (NPs) are one of the innovative strategies for their effective utilization as nanonutrients or nanofertilizers as compared to conventional fertilizers with reduced environmental risk. The current research work accounts for the evaluation of biologically synthesized iron oxide NPs (Fe3 O4 NPs) from Emblica officinalis L. fruit extract and its impact on growth, chlorophyll content, and metabolic activity of Solanum lycopersicum L. The spectral analysis of synthesized NPs was performed using UV-visible, Fourier transform infrared, X-ray diffraction, dynamic light scattering, scanning electron microscope, and transmission electron microscopy spectroscopic techniques. Seeds of S. lycopersicum L. were treated with Fe3 O4 NPs, prepared from aqueous solution of ferrous sulfate and ferric chloride salt (1:2 molar ratio of Fe2+ and Fe3+ salt solution) and E. officinalis L. fruit extract at a concentration of 10, 50, and 100 mg/L in sand culture medium. The effect of these treatments was studied on different biophysical and biochemical parameters of tomato seedlings. The lower dose of Fe3 O4 NPs on tomato seedlings was observed to have a promontory effect on growth parameters contrary to the control and bulk form of iron salt. At higher concentration inhibitory effect on plant growth, an increase in oxidative stress biomarkers parameters and superoxide dismutase activity was observed. The results indicate that appropriate dose and precise application of NPs depending on the plant species could prove to be efficacious measures to address nutritional deficiency among crops.