CONTAMINATION WITH CADMIUM AND ZINC, STUDY OF CYTOTOXICITY AND GENOTOXICITY IN Alium cepa.

GALLARDO LV, PÉREZ CHACA MV, CANGIANO MA

San Luis

Congreso; XXXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2020

There are problems associated with the contamination of soils by heavy metals, generating competition between contaminating metals and essential metals. Zinc (Zn) is an essential element, however, in excess it causes alterations in important processes for the development of the organism. Cadmium (Cd) is a heavy metal with no biological functions, which at low concentrations generates damage at the cellular and molecular level. By having the same load as the essential metals, the plant absorbs by the same transporters (IRT1-ZIP) Cd and Zn, getting to interfere with the entry, transport and use of the microelement. The toxicity symptoms of these ions are common for several plant species such as Glycine max, Allium cepa, among others. The phenological aspect observed is: reduction of biomass, decrease in elongation and darkening of the main roots, chlorosis and leaf necrosis, also causing changes in oxidative stress parameters. The objective of this work was to evaluate the cytotoxic and genotoxic effect caused by the interaction of Cd and Zn in apical meristem of Allium cepa. For this test, the cytotoxic and genotoxic effects of both ions were examined through the mitotic index (MI), chromosomal aberrations (CA) and nuclear aberrations (NA). Seedlings after 2 days of development and adaptation under hydroponic conditions, with Hoagland nutrient solution, were subjected for 3 days, to different concentrations of ZnCl (0; 0.6 and 4.8 mM) and to a constant concentration of CdCl (40 µM). The results showed a significant decrease in MI in all treatments with respect to the control (p