小麦幼苗拒Na^+部位的拒Na^+机理

Na^+ Exclusion Mechanism of the Na^+ Exclusion Sites in Wheat Seedlings

采用日立Z 80 0 0原子吸收分光光度计测Na+ 、K+ 含量 ,采用不连续蔗糖梯度离心分离质膜和液泡膜微囊。递增盐度和盐冲击处理下 ,耐盐品种德抗 96 1的SK ,Na(吸收 ) 值和SK ,Na(运输 ) 值均明显大于盐敏感品种鲁麦 15 ;德抗 96 1根部和鲁麦 15根茎结合部Na+ 含量均呈递增趋势 ,表现出累积效应 ;德抗 96 1根细胞质膜微囊和液泡膜微囊H+ ATP酶活性均明显大于鲁麦15 ,鲁麦 15根茎结合部液泡膜微囊H+ ATP酶活性大于德抗 96 1,在同一品种的植株里 ,盐冲击的根和根茎结合部细胞质膜微囊和液泡膜微囊H+ ATP酶活性均小于递增盐度的酶活性。小麦拒Na+ 部位细胞质膜和液泡膜H+

Na + and K + contents were determined by atomic absorption spectrometry (Hitachi Z-8000) and plasmalemma vesicles as well as tonoplast vesicles were prepared by discontinuous sucrose gradient centrifugation.Under gradually increasing NaCl concentration treatments and NaCl shock treatments, both S K,Na(uptake)and S K,Na(transport)of salt-tolerant cultivar Dk961 were higher than those of salt-sensitive cultivar Lu15 (Fig.1). Root Na + content of Dk961 and root-stem junction Na + content of Lu15 increased continuously and showed accumulative effect (Fig.2). Root plasmalemma and tonoplast H +-ATPase activity of Dk961 were all obviously higher than those of Lu15 (Figs.3A, 4A). Tonoplast H +-ATPase activity of the root-stem junctions of Lu15 was higher than that of Dk961 (Fig.4B). For the same cultivar, plasmalemma and tonoplast H +-ATPase activity of the roots and root-stem junctions after NaCl shock treatment were lower than those after gradual increasing NaCl concentration treatment (Figs.3, 4).