Fig. 1

OsHKT1;4 expression increases Na⁺ hypersensitivity of yeast cells promoting Na⁺ over-accumulation. The OsHKT1;4 cDNA from rice cultivar Nipponbare was constitutively expressed in strain G19 of S. cerevisiae under the control of the GAP promoter. a, G19 cells harboring the empty vector or expressing OsHKT1;4 were grown on the arginine phosphate (AP) medium containing 1 mM KCl with or without the addition of 50 mM NaCl. 1:10 serial dilutions of each G19 line with a starting OD₆₀₀ of 0.1 were prepared and spotted on AP plates as described previously [51]. All plates were incubated at 30 °C, and photographs were taken after 5 days. b, Na⁺ content of G19 lines that were incubated in synthetic complete (SC) medium supplemented with 25 mM NaCl for the indicated time period (n = 6, ±SD). The Welch’s-t test was used for the statistical analysis and asterisks indicate a significant difference compared with vector-harboring control cells at each time point (P < 0.001)