Development of the Experimental Method to Evaluate Sodium Ion Exclusion in the Mature Root Zone of <i>Arabidopsis thaliana</i>

Sodium (Na) exclusion is vital for plants to cope with salt stress, and the plasma membrane Na+/H+ antiporter, SALT OVERLY SENSITIVE 1 (SOS1), has been known play a central role in this process although function of molecule not completely understood. In study, we performed 22Na+ radiotracer experiments investigate SOS1 mature root zone. Arabidopsis thaliana seedlings were placed on gel medium, which had air gaps separate medium at zone from that apex Then, was added 4 h, radioactivity 5 mm length measured. As result, found knock-out caused accumulation reduction gel, demonstrating Na+ delivered via xylem excluded rhizosphere by