Concentration of total glutathione (GSH) and the ratio between GSH and glutathione disulphide (GSSG) in leaves and roots of four Arabidopsis thaliana genotypes (wild-type, cad2-1, vtc1-1 and cad2-1 vtc1-1) exposed to 0, 1 or 5 μm CdSO₄ for 72 h in hydroponics. Statistical significance is expressed using lower case letters; n = 4 (two-way ANOVA, P < 0·05).