The effect of benzylaminopurine on fatty-acid composition of membrane lipids in shoots of Karelian birch in vitro

Resumo

The effect of the synthetic analogue of natural cytokinin 6-benzylaminopurine (BAP) on the fatty-acid composition of membrane lipids in shoots of Karelian (Curly) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti under in vitro conditions was studied. It was found that the addition of BAP (in a concentration of 0.25, 0.5, 1.0, or 2 mg/L) to the nutrient medium leads to an increase in the proportion of saturated fatty acids in phospholipids, whereas in the control variant unsaturated fatty acids predominated in phospholipids. In glycolipids, on the contrary, BAP caused an increase in the synthesis of unsaturated fatty acids (predominantly, linolenic), but the degree of its effect depended on the concentration of the hormone. In particular, when the maximum amount of the studied concentration (2.0 mg/L) was used, the use of BAP was shown to decrease the proportion of linolenic acid. It is suggested that the revealed changes in the composition of glycolipids are indicators of the stimulating effect of cytokinin (up to a certain concentration) on the structure and function of chloroplasts. Due to the photomixotrophy of shoot cultures, chloroplasts are an important factor determining not only their photosynthetic activity, but also cell proliferation and the direction of in vitro morphogenesis.