Gene expression of a gene upregulated by oxidative stress (UPOX) and a defensin-like gene in roots (A) and leaves (B) of three Arabidopsis thaliana mutants (cad2-1, vtc1-1 and cad2-1 vtc1-1) under control conditions. Gene expression is expressed relative to the wild-type control (1: dashed line, n = 4, two-way ANOVA, significance level: *P < 0·05).