A Comparison of Cytotoxic and Genotoxic Damages Induced by 254 Nm and 365 Nm Radiation: Allium Cepa L. Model

Abstract

Living organisms are increasingly exposed to ultraviolet (UV) rays of solar radiation, both due to the thinning of the ozone layer and the widespread uses in sterilization processes. The present study was conducted with the purpose of evaluating the damages of UV-A and UV-C radiations in Allium cepa L. roots. Three groups were formed from Allium bulbs, one of which was the control group. One of the other groups was exposed to 254 nm (UV-C) and the other to 365 nm (UV-A) UV. Growth retardation effect of UV was investigated with respect to germination percentage, total weight gain and root elongation, while genotoxicity arisen from UV exposure analyzed using mitotic index (MI) and chromosomal aberrations (CAs) including micronucleus (MN) frequency. Oxidative stress due to UV application was investigated based on the accumulation of malondialdehyde (MDA) and the total activities of superoxide dismutase (SOD) and catalase (CAT) enzymes. Also, meristematic integrity of the UV treated roots was controlled. UV treatments caused significant changes in all parameters compared to the control, but all effects were much more prominent in 254 nm UV-exposed group. This study clearly revealed that UV exposure triggered growth inhibition, genotoxicity, oxidative stress and meristematic cell damages in A. cepa roots depending on the wavelength.