Root gene expression profiles of two maize inbred lines (Lo5 and T250) showing different nitrogen use efficiency (NUE) in response to the growth without N.

Among the mineral elements necessary for plant growth, nitrogen (N) is the macronutrient required in larger amounts. Maize genotypic-specific responses to N shortage could provide more information useful to improve NUE. Maize (Zea mays L.) seeds of two inbred lines (Lo5 and T250) previously soaked in water for 24 h, were allowed to germinate in the dark at 26°C for 4d. The seedlings were then transferred in pots containing 2.2 L of 0.5 mM CaSO4 aerated solution for 48h in controlled climatic conditions. After this period, seedlings were subsequently grown for other 4d using a nutrient solution (NS) without N. Three biological replicates were obtained repeating three independent times the growth experiment. For each experiment and both for Lo5 and T250 lines root samples were obtained pooling the roots of three seedlings collected after 0, 1 and 4d of growth without N.