Fig. 5. Kinetic analysis of nitrate uptake in oocytes injected with cRNA encoding wild-type CHL1 (A), T101A (B) or T101D (C). Uptake was determined by incubating oocytes for 1.5 h at pH 5.5 with nitrate concentrations ranging from 40 µM to 30 mM; the part of the scale between 0 and 0.3 mM has been enlarged. Each data point is the mean of the results for three duplicate experiments, each consisting of five oocytes.