植物调控盐胁迫下离子动态平衡

Regulation of Ion Homeostasis under Salt Stress

在盐胁迫下,植物在细胞质溶胶中维持高浓度的K+和低浓度的Na+。植物通过调控K+和Na+转运蛋白和为这些转运蛋白提供转运动力的H+泵蛋白活性及其表达量来维持。尽管盐胁迫感受器蛋白仍不清楚,但是已明确鉴定其信号转导的一些中介化合物。迹象表明,一类蛋白激酶化合物SOS3和丝氨酸/苏氨酸蛋白激酶SOS2能够被盐胁迫引起的钙信号激活。其CBL/CIPK复合物随后磷酸化和激活多种离子转运蛋白,例如位于细胞膜上的Na+/H+反转运蛋白SOS1。

Under salt stress,plants maintain a high concentration of K＋and a low concentration of Na＋in the cytosol. They do this by regulating the expression and activity of K＋and Na＋transporters and of H＋pumps that generate the driving force for transport. Although salt-stress sensors remain elusive,some of the intermediary signaling components have been identified. Evidence suggests that a protein kinase complex consisting of the myristoylated calcium-binding protein SOS3 and the serine / threonine protein kinase SOS2 is activated by a salt-stress elicited calcium signal.The protein kinase complex then phosphorylates and activates various ion transporters,such as the plasma membrane Na＋/ H＋antiporter SOS1.