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Alleviation of cadmium-induced genotoxicity and cytotoxicity by calcium chloride in faba bean (Vicia faba L. var. minor) roots

Nouairi, Issam, Jalali, Karima, Essid, Sabrine, Zribi, Kais, Mhadhbi, Haythem
Physiology and molecular biology of plants 2019 v.25 no.4 pp. 921-931
Vicia faba, antioxidant activity, cadmium, cadmium chloride, calcium chloride, catalase, cell membranes, chromosome aberrations, cytotoxicity, faba beans, fatty acid composition, genotoxicity, germination, hydrogen peroxide, lipid peroxidation, lipids, malondialdehyde, meristems, mitosis, mutagens, peroxidase, protein content, roots, seedlings, seeds, superoxide dismutase, thiols
Alleviation of cadmium-induced root genotoxicity and cytotoxicity by calcium chloride (CaCl₂) in faba bean (Vicia faba L. var. minor) seedlings were studied. Faba bean seeds were treated with H₂O or 2% CaCl₂ for 6 h before germination. Seeds were then exposed to 0 and 50 µM CdCl₂ concentrations for 7 days. Genotoxic damaging effects of Cd was examined through the determination of the mitotic index (MI), chromosomal aberrations (CA) and micronucleus (MN) in the meristem cells of faba bean roots. Similarly, effects of Cd stress on metal accumulation, total membrane lipid contents, total fatty acid composition (TFA), lipid peroxidation as indicated by malondialdehyde production, soluble protein and non-protein thiols (NP-SH) contents, hydrogen peroxide production and the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPX) were evaluated after 7 days of Cd stress in the seedling roots. Cd stress resulted in the reduction of MI, in addition to MN formation and CA induction in the roots of non-primed seeds (treated with H₂O). Moreover, Cd induced lipid peroxidation, H₂O₂ overproduction and loss of membrane lipid amount and soluble protein content, and changes in the TFA composition in roots of faba bean seedlings. SOD activity declined, but CAT and GPX activities increased. However, seed pre-treatment with CaCl₂ attenuated the genotoxic and cytotoxic effects of Cd on Vicia faba roots. The results showed that CaCl₂ induced reduction of Cd accumulation, improved cell membrane stability and increased the antioxidant defence systems, thus reducing and alleviating Cd genotoxicity and oxidative damage.