Fig. 1. Effect of light on net NO^-₃ uptake by Pima (S-7) and Acala (Maxxa) cotton seedlings grown in 0.1 mM NO^-₃ at 30/20°C light/dark throughout (A) or 30/30°C light/dark for one cycle (B) prior to measurements. Uptake rates were measured at 30°C. Open and closed symbols represent measurements from different sets of plants during the time course