Abstract
The antiporter of tonoplast defends plants against salt and osmotic stress by maintaining the ion balance between cytoplasm and vacuole. We cloned OsChaC gene having a homology with ChaC which regulates membrane-penetrating antiporter in E. coli as one among several kinds of genes which were induced under submergence, salinity or drought stress in submergence tolerant rice cultivar FR13A. In OsChaC overexpressed tobacco, growth inhibition was reduced and photosynthesis was kept highly under salinity stress compared with wild type. Here, we tried to clarify a function of Arabidopsis ChaC. It was confirmed that three ChaC homologues are present in Arabidopsis. We cloned them separately and examined their expressions under environmental stresses. We generated ChaC overexpressed Arabidopsis and potato, and knockout Arabidopsis and evaluated their stress tolerances. We tried to purify ChaC protein from overexpressed E. coli and isolate antiporter among ChaC -binding proteins using ChaC affinity chromatography.
