Salinity-induced changes to selected transcripts in growing cells of the maize leaf. Relative quantity determined by Real-Time PCR normalized to the amount of actin (Act-3, gi:21206665). White bars represent control conditions, and hatched box represent salt-stressed conditions at two locations in the elongation zone, 15–30 and 30-50 mm from the leaf base. Data are means ± SE (n=4-5). Asterisks represent significant difference between the salt stress and the control treatments for each equivalent position along the elongation zone (P<0.05). Filled dot above a treatment bar represent significant difference between young (15–30 mm) and more mature tissue (30–50 mm) (P<0.05) for this treatment. The names of the evaluated genes are specified in the figures: inorganic pyrophosphate (PPi), vacuolar inorganic pyrophosphate (V-PPi), ascorbate peroxidase (APX), isovaleryl-CoA dehydrogenase (ICoA DH), peptidyl-prolyl isomerase (PPIase).