RNA expression of investigated target genes in strain Neff, strain Neff after plate culture (NeffPl), and three clinical Acanthamoeba isolates (2HH, WIR17, JEA19) after challenge with H₂O₂ and diamide for two hours. (a) High-molecular weight thioredoxin reductase (TrxR-L), (b) low-molecular weight thioredoxin reductase (TrxR-S), (c) thioredoxin 1 (Trx-1), (d) peroxiredoxin 2 (Prx-2), (e) glutaredoxin 1 (Grx-1), (f) glutathione reductase (GR), (g) glutathione peroxidase (Gpx). Black bars: untreated control; grey bars: treated with 750 μM H₂O₂; white bars: treated with 2 mM diamide. The y-axis indicates – fold increase of mRNA levels as compared to untreated controls. Error bars show the standard deviation of the mean (SEM). Values were obtained from at least two biological replicates in triplicate. *p < 0.05, **p < 0.01, and ***p < 0.0001 according to statistical analysis (non-parametric Mann–Whitney U test).