[The role of membrane lipids in the resistance of clapsing-leaved pondweed (Potamogeton perfoliatus L.) to excess of cadmium in water].

The effect of cadmium on clapsinng-leaved pondweed (Potamogeton perfoliatus L.) within the concentration range of 1-1000 microM was studied. It was shown that P. perfoliatus leaves accumulated cadmium during three days. This process was accompanied by changes in leaf morphology. The sensitivity of biochemical metabolites to cadmium was different. Low concentrations of cadmium (1 and 10 microM) increased the content of protein, total lipids, and photosynthetic pigments, whereas high concentrations (100 and 1000 microM) decreased the content of total lipids and pigments but increased protein content. Based on cadmium sensitivity, structural lipids were divided into three groups-resistant (neutral, phosphatidylglycerol, digalactosyldiacylglycerol, and sulfolipid), the content of which increased in the presence of cadmium; labile (monogalactosyldiacylglycerol, phosphatidylcholine, and phosphatidylinositol); and nonresistant (phosphatidylethanolamine). It is concluded that the lipid component determines the resistance of P. perfoliatus to cadmium.