Figure 3From: Humic substances stimulate maize nitrogen assimilation and amino acid metabolism at physiological and molecular level Total protein content in leaves (a) and roots (b). Seedlings were grown for 14 days in a Hoagland modified complete nutrient solution (0) and treated for the last 2 days with HS concentrations of 0, 1 and 5 mg C L−1. The protein concentration was expressed in milligrammes of protein per gramme of fresh weight. Values are means of three independent determinations (±SE). Letters above bars indicates significant differences (P < 0.05).Back to article page