Contribution of KUPs to potassium and cesium accumulation appears complementary in Arabidopsis

摘要

Cesium has no known beneficial effects on plants and while plants have the ability to absorb it through the root system, plant growth is retarded at high concentrations. Recently, we have shown that potassium influx through a potassium channel complex AKT1-KC1 is inhibited by cesium in and the resultant reduction in potassium accumulation in the plant is the primary cause of retarded growth. By contrast, a major potassium transporter, HAK5 whose function is crucial under potassium deficiency, was found to be either not affected or complementary under cesium stress in the low affinity potassium range. Here we show the effects of insertional mutation on other members of gene family in response to cesium stress. Potassium and cesium concentrations in each mutant line demonstrated that disruption of a single gene was not sufficient to significantly reduce potassium/cesium accumulation, suggesting a complementary effect among these KUP (   PTAKE  ERMEASE) transporters.