Increasing application of nanoparticles in consumer products enhances its release into the
environment. Plants are the primary target species to work out a comprehensive toxicity profile for
nanoparticles. Toxicity profiles of nanoparticles to the plant system, uptake and its subsequent fate
within the food chain are not available. The phytoxicological behaviour of silver and zinc oxide
nanoparticles on Allium cepa and seeds of Lycopersicum esculentum (tomato), Cucumis sativus
(cucumber) and Zea mays (maize) were experimented. The in vitro studies of Allium cepa root tips
exposed to a concentration-tested range of 25, 50, 75, and 100 μg ml-1 nanoparticles for 4 h revealed
different cytotoxicological effects including mitotic index, chromosomal aberrations, vagrant
chromosomes, sticky chromosomes, disturbed metaphase, breaks, and formation of micronucleus.
Nanoparticles treated seeds showed reduced germination rate and decrease in shoot and root lengths.
Nanoparticles treated seedlings showed reduced shoot and root lengths. The percentage germination of
seeds was delayed with increasing concentration of nanoparticles. Though engineered nanoparticles
have significant advantage in biomedical applications, it also requires a great deal of toxicity profile on
the other side to ascertain the biosafety and risk of using nanoparticles in consumer products.
Keywords: Nanoparticles, Silver, Zinc oxide, Allium cepa, Seeds, Phyto-toxicity, Cyto-toxicity, Surface
characteristics, Accumulation, Adsorption, FT-IR, Mitotic index, Relative germination rate, Chromosomal
aberrations.
