The contents of soluble sugar in the wild-type (WT) and slhak10 mutant plants. Wild-type and mutant plants were grown in a compartmented culture system. Plants were watered weekly with either high-K⁺ (2 mm K⁺) or low-K⁺ (0.2 mm K⁺) solution. The soluble sugar concentrations in the shoots (A and B) and roots (C and D) of wild-type and mutant plants were determined at 5 weeks postinoculation. AM, Mycorrhizal plants; DW, dry weight; NM, nonmycorrhizal plants. Error bars indicate se (n = 5). The asterisks indicate significant differences (P < 0.05).