Effect of cadmium on fatty acid composition of lipids in the shoots of Karelian birch cultured in vitro

Abstract

The effects of cadmium (10−6, 10−5, 10−4, and 10−3 M) on the growth and development of stem apical meristem and fatty acid (FA) composition of particular lipid fractions (neutral lipids, glyco-, and phospholipids) were investigated in the shoots of Karelian birch (Betula pendula var. carelica (Mercklin) Hamet-Ahti) produced in vitro. Low cadmium concentration (10−6 M) slightly stimulated shoot morphogenesis. However, at the concentration of 10−4 M, shoot growth and development was terminated, and the concentration of 10−3 M turned out to be critical (the meristem died within the first 5 days). The presence of Cd in the medium considerably affected FA composition in the shoots. The most pronounced changes occurred in the fraction of glycolipids, and the extent of adverse influence significantly depended on metal concentration in the medium. At the Cd concentration of 10−4 M, the content of di-and trienoic FAs decreased by 3–4 times, whereas the level of monoenoic FAs rose by 5 times. The revealed differences in the FA composition of lipids in birch were considered as an indicator of adverse effect of cadmium on the structure and functions of chloroplasts and therefore on photosynthesis.