Expression pattern of SAL1. A) Expression analysis of SAL1 in roots, stems, leaf blades, leaf sheaths, and panicles. B) Response of SAL1 expression to Al toxicity at different time points. Five-day-old WT seedlings grown on a 0.5 mM CaCl2 solution (pH 4.5) were exposed to the same solution containing 20 μM Al for 0, 3, 6, 12, or 24 h, and then root tips (0 to 1 cm) were sampled for the expression analysis. C) Representative pictures (left panel) and relative protein level (right panel) of SAL1-3HA under −Al or +Al conditions. Seedlings of a sal1 complementation line was exposed to 0 (−Al) or 20 μM Al (+Al) for 6 h, and root tips were sampled for immunoblot analysis of SAL1-3HA and actin control. SAL1-3HA protein levels were first normalized to their respective Actin controls and then normalized to the protein level under the −Al condition. Data shown are means ± SD of three biological replicates. Asterisk indicates values statistically different (Student's t test, *P < 0.05). D–H) Tissue-specific GUS expression of pSAL1:SAL1-GUS transgenic lines. GUS staining in roots (D), root tip region (transverse section) (E), mature root region (transverse section) (F), leaves (G), and stems (transverse section) (H). Scale bar = 200 μm in (D, F, and G), 50 μm in (E), and 2 mm in (H).
