Effect of zinc oxide nanoparticles on growth and antioxidant system of chickpea seedlings

Abstract

Ten days old seedlings of chickpea (Cicer arietinum L var. HC-1) were foliar sprayed with 1.5 or 10 ppm aqueous solution of zinc oxide (ZnO) nanoparticles and effects were compared with corresponding concentration of zinc sulphate and ZnO of normal size. Maximum promontory response with respect to shoot dry weight was observed in seedlings treated with 1.5 ppm ZnO nanoparticles while at 10 ppm the nanoparticles exerted adverse effects on root growth. However, overall biomass accumulation improved in the ZnO nanoparticle treated seedlings. This response may be attributed to low reactive oxygen species (ROS) levels which resulted in less lipid peroxidation as evident from lower malondialdehyde (MDA) content. This was associated with lower activity of prominent antioxidant enzymes, superoxide dismutase (SOD), and peroxidase ZnO nanoparticle treated seedling compared to control. The study indicates importance in precise application of zinc, more so in deficient system, where plant response varies with concentration and is important in understanding the mechanism of action of specific nanomaterials.