Fig. 3.

Relative gene expression of SbbBiP, SbPDI, and SbbIRE1. Sorghum bicolor seedlings were submitted to different concentrations of TM: 0 µg mL⁻¹ (Control), 0.5 µg mL⁻¹, 1.5 µg mL⁻¹ and 2.5 µg mL⁻¹. The expression profiles were determined in the shoot (a, b and c) and in the roots (d, e and f). Gene expression was normalized using SbUBC18 as a reference gene. Lowercase letters compare the two varieties of sorghum. Uppercase letters compare the treatments within each variety of sorghum. All four treatments were compared by Tukey test (p < 0.05) in each TM concentration. The columns indicate the means of three biological replicates and the bars indicate the standard deviation ( ±)