msl2 msl3 double mutants develop callus at the shoot apex. (A-D) Bright-field images of 21-day-old msl2 msl3 seedlings grown on solid medium. Shooty callus is indicated with a white arrowhead in D. (E) Time course of callus formation. (F) Mean percentage of msl2 msl3 seedlings with visible callus at the indicated time after germination. Five plates of seedlings, n>10 seedlings per plate, were analyzed per time point. Error bars indicate s.d. (G) 21-day-old seedlings (top) or seedlings transferred from MS with 82 mM NaCl to MS at indicated time points (bottom). (H) Mean percentage of msl2 msl3 seedlings showing visible callus at 21 DAG after transfer from MS to MS (black bars) or from MS to MS with 82 mM NaCl (gray bars) at the indicated time points. Three plates of seedlings, n>10 seedlings per plate, were analyzed per treatment. Error bars indicate s.e.m. *P<0.01 (Student's t-test). (I-L) Close-up images of individual seedlings shown in (G) grown without NaCl (I) or transferred to NaCl plates at 2 (J), 5 (K), or 7 (L) DAG. (M) Bright-field images of 14-day-old msl2 msl3 seedlings harboring the MSL2 transgene (MSL2g) or MSL2 under the control of the SCR promoter. Scale bars: 1 mm (A-E), 5 mm (G,M) and 2.5 mm (I-L).