COMPLEX RESISTANCE OF TOBACCO PLANTS TO HEAVY METAL IONS IN VITRO: A FACTOR OF RESISTANCE TO ABIOTIC STRESSES

Functioning and ontogenesis of plants are carried out under genetic control. The full realisation of the genetic potential is a consequence of genotype/environment interaction and depends significantly on environmental conditions. Reactions to various stresses establish distinctions between stable and unstable genotypes. In this case, reactions of the whole plant and reactions realised at the cellular level are distinguished. To determine the contribution of each component to the overall organismal resistance, their parallel study is necessary. In this regard, the best approach is a comparative analysis of the plant and the cell culture initiated from it. To obtain objective information, it is necessary, firstly, to establish stressors that have a versatile effect on the organism. Secondly, identification of general adaptation reactions to them. These conditions correspond to heavy metal ions (HMI), in particular barium cations, Ba2+, and cadmium cations, Cd²⁺. The toxic effect of these cations is similar to the negative effect of osmotic stresses - salinisation and water deficit. Their comparative analysis revealed the key role of cellular level mechanisms. This provides an opportunity to use these cations in cell selection, a biotechnology involving manipulation of cell cultures. The result can be the selection of forms with an increased level of resistance to abiotic stresses.