Fig. 2

Effects of Fe3O4 and ZnO NPs on nutrient element accumulation of tobacco. Heat maps showed the log2FC value of the different treatments compared with the control (a). The violin plot showed log2 Cd content under Cd stress conditions (b). The results shown are the means ± SE (n = 3; 15 plants/treatment/replicate), and the different letters indicate significantly different values (P < 0.05 according to Tukey’s test). *Significantly different values at P < 0.05 according to a Student’s t-test