Fig. 4.

Effect of 10 mm KCl or 10 mm KNO₃ on the growth rate of maize coleoptile segments incubated in the presence or absence of 10 μm IAA, added to the incubation medium at 2 h. The growth rate of a stack of 20 segments was measured as described in Materials and methods (second measuring system). Inset on the right shows total elongation growth, calculated as the sum of extensions measured at 3-min intervals for 10 h. Inset on the left presents medium pH changes when maize coleoptile segments were incubated in the presence of IAA. All curves represent means of at least nine independent experiments. Bars indicate ± s.e. The LSD test for growth is included in Supplementary Data Fig. S2.