We performed a microarray experiment to assess the global changes in transcription occurring in leaves and roots of the vitamin B6 deficient pdx1.3 knockout mutant in comparison to WT. Vitamin B6 (pyridoxal 5′-phosphate) is an essential cofactor of many metabolic enzymes. Plants biosynthesize the vitamin de novo employing two enzymes, pyridoxine synthase1 (PDX1) and PDX2. In Arabidopsis (Arabidopsis thaliana), there are two catalytically active paralogs of PDX1 (PDX1.1 and PDX1.3) producing the vitamin at comparable rates. Since single mutants are viable but the pdx1.1 pdx1.3 double mutant is lethal, the corresponding enzymes seem redundant. However, the single mutants exhibit substantial phenotypic differences, particularly at the level of root development, with pdx1.3 being more impaired than pdx1.1. Here, we investigate the impact of possible global changes in gene expression in the pdx1.3 mutant compared to WT on the phenotype. Four different types of samples (conditions) were analyzed, namely pdx1.3 leaves, pdx1.3 roots, WT leaves and WT roots with three biological replicates per condition (12 samples altogether). WT samples served as reference (control) for the respective pdx1.3 samples.