Figure 4.

Non-enzymatic antioxidants in shoots of non-metallicolous (NM), calamine (CAL), and serpentine (SER) Silene vulgaris ecotypes treated with heavy metals (HMs). Values are mean ± SE. Means indicated by the same letters (a–f) point to statistically significant differences according to two-way ANOVA and post-hoc Fisher’s test at p < 0.05. Control means the medium without the addition of Zn, Pb, Cd ions; 1× HMs—medium enriched with 714.3 μM ZnSO₄, 3.0 μM Pb(NO₃)₂, and 16.4 μM CdCl₂; 2.5× HMs means 2.5-times higher Zn, Pb, Cd concentration than the first one.