【摘要】 以两个不同耐盐力水稻品种80—85(耐盐)和83—51(不耐盐)为材料进行研究。根系Na~+总吸收随盐胁迫的加重而增高,耐盐品种始终具有较低的Na~+总吸收和较高的整株K~+/Na~+比;在10mmol/1 NaCl浓度下显示出根系具有较低的Na~+吸收速率和较强的对K~+选择性(S_K:Na)。低盐浓度(0.2％NaCl)对根质膜ATP酶活性略有提高;在高盐浓度(0.5％NaCl以上)下,质膜ATP酶活性受到明显抑制,不耐盐品种受抑程度更大。ATP酶活性的下降与根部Na~+积累以及K~+吸收的减少相伴随,推测根系K~+、Na~+吸收与质膜ATP酶有关。更多还原

【Abstract】 The absorption of Na⁺ and function of plasma membrane ATPase from rice roots ex- posed to salt stress were investigated using two varieties, 80--85 （salt-tolerant） and 83--51 （susceptible）. The rice seedlings were grown in Espino culture solution containing different NaCl concentrations. Na⁺ content in the whole plants （including root and shoot） increased with increasing ex- ternal NaCl concentration and prolonging the treatment. There was a apparent varietal difference in Na⁺ absortion of the root. For the salt-tolerant variety, with low total Na⁺ uptake by the root and high K⁺ / Na⁺ ratio in tha whole plant, the Na⁺ uptake rate was lower and selectivity for K⁺ uptake over Na⁺ uptake (S_K:Na) was higher at 10 mmol/1 ion concentration than that of the salt susceptible variety. It was observed that low NaCl （0. 2% or 34 mmol/1） caused a slight increase in the plasma membrane ATPase activity from rice roots. However, the ATPase activity was inhibited obviously by high Na⁺ （above 0. 5% or 86 mmol/1）, especially for the susceptible. The define of the enzyme activity was accompanied by accumulation of Na⁺ and decrease of K⁺ uptake in the roots. The results suggest that K⁺ and Na⁺ uptake might be controlled by the plasma membrane ATPase.更多还原