Fig. 1

Analysis of the relative expression level of AtPDF family genes in the roots of A. thaliana under different treatments. The seedlings were treated with 1/4 plant nutrient solution for 18 d, N-starved for 3 d, and then treated with 0.2 mM KNO₃, 2.25 mM KNO₃, 10 mM KNO₃, or 1.125 mM NH₄NO₃ for 6 h before roots were harvested separately for RNA analysis. a AtPDF1s. b AtPDF2s. Actin2 was used as the internal control in the quantitative real-time PCR. Bars displaying the same letters are not significantly different at P < 0.05 according to the least significant difference test