Figure 6

Effect of PM H⁺ −ATPase inhibitor vanadate on the net nitrate uptake by leaf discs. N-deprived cucumber plants were subjected to 4 mM NO₃^- for 12 h. Sodium vanadate was applied in the uptake solution at a final concentration of 500 μM. After addition of vanadate the pH of the uptake solution was re-adjusted to 6.0 with 0.1 mM HCl. Data are means ± SD of four replicates.