Tropical Plant Research

Nanotechnology no doubt is a boom for science but exposure of nanoparticles (NPs) in the environment is a new concern. Application of NPs in agriculture to increase crop yield is still debated. In the present study 10–40 µg.ml^-1 concentrations of ruthenium oxide (RuO₂) NPs were exposed to Broccoli (Brassica oleracea var. italica) seedlings in hydroponic culture. RuO₂ NPs are synthesized via Laser ablation method and hence are contamination free. UV-visible spectroscopy and field emission scanning electron microscope (FE-SEM) is used for the characterization of NPs. Carotenoids, protein and sugar content decreased with increase in concentrations of RuO₂ NPs. Total chlorophyll content increased to maximum with highest content of Chlorophyll a & b at 10 µg.ml^-1 of RuO₂ NPs, but no stimulatory effect was recorded at highest doses. Lipid peroxidation, was unaffected by exposure to 0–20 µg.ml^-1 NPs, but at 40 µg.ml^-1 malondialdehyde (MDA) formation and SOD activity increased by two fold. It is concluded that RuO₂ NPs significantly inhibited the seedlings growth of broccoli by impairing the metabolism of the test plants.