(a) SOS1 mRNA stability in shoot and root is induced by CHX treatments. 1, control; 2. 200 mm NaCl for 5 h; 3. CHX 100 µm for 1 h; 4, CHX 100 µm for 5 h; 5, CHX 100 µm for 1 h followed by 200 mm NaCl for 5 h; 6, CHX 100 µm for 1 h followed by 200 mm NaCl with 100 µm CHX for 5 h; 7, 200 mm NaCl for 5 h followed by 1/2 MS salt solution for 2 h; 8, 200 mm NaCl for 5 h followed by 1/2 MS salt solution for 12 h; 9, 200 mm NaCl for 5 h followed by 1/2 MS salt solution for 24 h; 10, 200 mm NaCl for 5 h followed by 100 µm CHX for 2 h; 11, 200 mm NaCl for 5 h followed by 100 µm CHX for 12 h; 12, 200 mm NaCl for 5 h followed by 100 µm CHX for 24 h.
(b) Cycloheximide-induced stability of SOS1 mRNA is not due to elicited production of reactive oxygen species. C, control; CHX, CHX 100 µm for 1 h; DMTU, 15 mm DMTU for 3 h; DMTU+CHX, 15 mm DMTU for 2 h followed by 100 µm CHX with DMTU for 1 h; DF, 1 mm DF for 3 h; DF+CHX, 1 mm DF for 2 h followed by 100 µm CHX with DF for 1 h.
(c) Northern blotting showing rapid decay of SOS1 mRNA. Ten-day-old 35S:SOS1 and 35S:GUS transgenic seedlings were treated with 200 mm NaCl for 5 h (indicated as Na) and then transferred to 1/2 MS liquid medium. Seedlings were harvested at indicated time points for RNA isolation. C, control; RI, relative signal intensity. rRNA was used as a loading control.