Fig. 3.

The effect of ammonium on growth rate and K⁺ uptake. (a) Relative growth rate (RGR, % day⁻¹) of 5-week-old rice plants exposed to standard medium (SM), and media containing 0mM K⁺ and zero ammonium (0K + 3NO₃), or 0mM K⁺ plus 3 or 10mM ammonium (0K + 3NH₄ or 0K + 10NH₄). (b–e) Net K⁺ uptake for WT (Nipponbare; b and c) and akt1-2 (d and e) plants from a solution containing 50 µM K⁺, either in the absence or the presence of 3 or 10mM NH₄ ⁺. Plants were pregrown in the absence of NH₄ ⁺ (b and d) or with 1.5mM NH₄ ⁺ in the growth medium (c and e). *Significant difference by t-test at a probability level of P<0.05 between each genotype and its respective wild type.