Fig. 3.
Heat map showing gene expression of 14 genes significantly regulated by long-term nitrate or ammonium supply and depletion in Zea mays L. roots and leaves. Seedlings were grown for 5 days in a nutrient solution containing 1mM nitrate (+NO3 –) or 1mM ammonium (+NH4 +) or N-deprived (–NO3 – and –NH4 +). At the end of the treatment, seedlings were harvested and roots were separated from leaves. The grey scale represents the level of gene expression. Values are reported as arbitrary units and are the means of three technical repetitions performed on six independent biological replicates.