Scientific publications

The effect of different concentrations of cadmium (10_-6–10_-3 M) on the morpho- and organogenesis in birch was studied in vitro. It is shown that at a concentration of 10_-6 M cadmium is able to stimulate the growth of shoots and the formation of foliage. Simultaneously an increase in the content of unsaturated fatty acids in the lipid composition was observed. With the increase in the medium cadmium concentrations up to 10_-5 M its accumulation occurred in the growing shoots, which was accompanied by a decrease in the rate of organogenesis in tissue culture as well as in the level of unsaturated fatty acids. In the treatment with cadmium concentration of 10_-4 M, the inhibition of morpho- and organogenesis in birch as well as a decline in the absorption and transport of mineral elements was noted. The coefficient of unsaturated lipids was close to one. Cadmium concentration of 10_-3 M was critical. In this case the growth and development of shoots stopped completely and 5–7 days later they died back. Based on the obtained data, a change in the unsaturated fatty acid composition of lipids is one of the most important indicators in the development of protective and adaptive response of birch shoots to in vitro exposure to cadmium: it increases with an activation of metal detoxification mechanisms and decreases with its malfunction.