Figure 7.

Ammonium content and proton extrusion increase in roots of gapcp1gapcp2. Two-week-old Arabidopsis gapcp1gapcp2 (g1g2) and wild-type (WT) plants were grown for 6 h in one-fifth-strength MS medium at pH 5.7 without MES and containing 0.003% (w/v) Bromocresol Purple. The yellow color of the pH indicator around g1g2 roots indicates increased proton extrusion in the mutant. The table at bottom presents data of ammonium content (means ± se; n = 3) in roots of g1g2 and the wild type. The asterisk indicates a significant difference as compared with the wild type (P < 0.05). FW, Fresh weight.