Abstract
The plants are injured with increasing Na+ content in the tissues under saline condition. Because Na+ transport depends on electrochemical potential, it is important to understand how the membrane potential is regulated under saline condition. In yeast cells, the hypothetical plasma membrane protein PMP3 contributes to regulate Na+ uptake by controlling the membrane potential. Although the homologs of PMP3 widely exist in plants, the physiological role of PMP3 remains to be unraveled. In this report, we analyzed the effects of genetic disruption of RCI2A on salt tolerance in Arabidopsis plants. The deletion of RCI2A caused increased Na+ accumulation in the root. The rci2a mutant was more sensitive to NaCl than wild type of the plants. The shoot growth of rci2a mutant was significantly suppressed under excess KCl and LiCl treatments. These data suggested that RCI2A contributes to alleviate the restriction of plant growth caused by excess monovalent cations.
