盐度对海蓬子植株膜脂及其脂肪酸组分的影响

INFLUENCE OF NaCl ON MEMBRANE LIPIDS AND THEIR FATTY ACIDS CONSTITUENT OF THE LEAVES AND ROOTS IN SALICORNIA EUROPAEA

海蓬子叶片和根膜脂主要由PC、PE、PI、PG、PA、PPG、SL、MGDG和DGDG组成,膜脂脂肪酸由14:0、14:1、16:0、16:1、18:0、18:1、18:2、18:3组成,不同盐度下海蓬子植株中MGDG和DGDG随NaCl浓度增大而减少,磷脂中的PC和PE减少,PA、PI、PG和PPG增多,SL也增多,脂肪酸不饱和指数随NaCl增多而降低,对磷脂和糖脂变化的生理学意义也进行了讨论。

Membrane lipids of the Shoots and roots of Salicornia europaea grown in the different concentrations of NaCl were found to be composed mainly of phosphatidylcholine (PC). phosphatidyl ethanolamine (PE). phosphatidylinositol (PI). phosphatidyl—glycerol (PG). phosphatidic acid (PA). polyphosphoglyceric acid (PPG). sulfolipid (SL). monogalactosyl diglyceride (MGDG) and digalactosyl dig|yceride (DGDG). The constituent of fatty acid in membrane lipids are myristic acid (14:0). palmitic acid (16:0), palmitoleic acid (16:1). stearic acid (18:0). oleic acid (18:1). linoleic acid (18:2) and linolenid acid (18:3). There is myristicolic acid (14:1) in roots, but not in shoots. The molal percentages of MGDG and DGDG in the membrane lipids of shoots and roots were decreased with the increasing concentration of NaCl. but the molal percentages of total phospholipids were increased. PC and PE of total phospholipids were decreased, however. PA, PL PG and PPG were increased. SL was increased too. Indexes of unsatrurated fatty acid (IUFA) of membrane lipids in leaves and roots were decreased with the increasing concentration of NaCl. The physiological significance of reduction of MGDG. DGDG, PC and PE and that of increase of SL. and the mechanism of reduction of MGDG and DGDG were discussed.