Root gene expression profiles of two maize inbred lines (Lo5 and T250) in response to nitrate treatment

Among the mineral elements necessary for plant growth, nitrogen (N) is the macronutrient required in larger amounts. The optimization of N use efficiency (NUE) in maize could be obtained through both genetic improvement and agronomic practices in order to enhance production and reduce the negative impact of the N fertilizer use on the environment. Physiological characterizations of inbred lines with different NUE are available in maize. Maize (Zea mays L.) seeds of two inbred lines (T250, Lo5) previously soaked in running water for 24 h, were allowed to germinate in the dark at 28°C for 72 h over an aerated solution of 0.5 mM CaSO4. Half part of two-d-old seedlings was grown in a nutrient solution with 200 μM of KNO3 (treated samples, +NO3-) and the other half with appropriate amounts of the corresponding chloride salt (KCl) (control samples, -NO3-). Three biological replicates were obtained by three independent experiments and collecting roots of treated (200 μM NO3-) and not treated plants after 0, 1, 2 e 4 h for Lo5 inbred line and after 0, 5, 11 and 12 h for T250.