盐胁迫对玉米根尖质膜上受钙激活的蛋白激酶的影响

以02mal／L的NaCl对玉米根尖进行盐胁迫，导致质膜上一种受钙激活的蛋白激酶（该激酶表现为钙依赖蛋白激酶的特性）的活性迅速增加。盐胁迫至15min时激酶的活性达到最大，较对照高30％，以后逐渐降低，盐胁迫至切50min时激酶活性仍略高于对照。10％PEG6000处理玉米很尖也可诱导质膜上受钙激活的蛋白激酶活性增加。用外源ABA处理玉米根尖，未导致上述蛋白激酶活性的变化。放射自显影显示质膜上33kD和58kD两种蛋白可能是质膜受钙激活的蛋白激酶的内源底物。

Effect of Salt Stress on Calcium-activated Protein Kinase Associated with Plasma Membrane from Corn (Zea Mays L. )Root Tips

NaCl0. 2 mol/L treatment could induce quickly the activity of calcium-activated protein kinase, which shwoed the character of calcium-depen-dent protein kinase (CDPK), in plasma membarne (PM) from corn root tips (Table 2). The activity reached its maximum after 15 min of salt stress. Then,the activity decreased gradually , remained higher than the contrdol 50 min after the beginning of salt stress (Table 3). Treatment with 10% PEG could also increase the activity of calcium iactivated protein kinase (Table 4). However , exogenous ANA did not change the activity of the calcium-activated protein kinase in PM (Fig. 3). In gels assays of SDSPAGE show that the proteins kinase contained only one polypeptide (Fig. 2). It was shown by autoradiography that two proteins in PM with molecular weights of 33 kD and 58 kD may be the endogenous substrated of the calciuma-activated protein 'kinase in PM (Fig. 1).