Physiological and structural responses of hybrid firs embryogenic tissue under cadmium stress

The study was focused on the investigation of cadmium (Cd) effect on the embryogenic tissue of hybrid firs growing under in vitro conditions. Two cell lines AC78 (Abies alba x A. cephalonica) and AN72 (Abies alba x A. numidica) were cultured on DCR medium supplemented with 100 and 250 µM of Cd(NO3)2·4H2O. The tissue accumulated heavy metal ions during the culture period and at the end of growth cycle 91.4% of Cd2+ present in the medium was accumulated in AN72 and 94.6% in cell line AC78. Higher concentration of Cd2+ affected negatively the growth of tissue exerted as decline in fresh as well as dry mass accumulation, although in comparison to control tissue statistically significant reduction has been recorded only for cell line AN72. The toxic effect of cadmium was also apparent on the micromorphology of early somatic embryos and resulted in loss of bipolarity as well as complete structural disintegration. The increased malondialdehyde content in response to Cd2+ in culture medium indicated lipid peroxidation as a consequence of membrane damage. The embryogenic tissue is suitable experimental system for the study of cadmium effect on the cells cultured in extremly controlled environment in vitro. © 2020 SAAB