sitl1 mutant screening and growth condition
To screen for salinity tolerance mutant lines, seeds of the M10 core collection germplasms derived from the application of gamma-ray irradiation and wild-type (WT) rice (Oryza sativa , cv. Donganbyeo) were germinated on moistened filter paper at 28 °C for 2 d. The germinated seeds were transferred to a nylon net stretched over a floating Styrofoam in a plastic container containing half-strength Kimura B nutrient solution (NS) at pH 5.6 (Worlock & Smith, 2002), which was renewed every two days in a growth chamber under a 16 h/8 h (light/dark) cycle at 28/23 °C. At the three-leaf stage (7-day-old), rice seedlings were treated with nutrient solution containing 100 mM NaCl for one more week. The lengths of shoots and roots for each individual plant were measured with 3 biological replicates.