Table 2 Group analysis of gene expression in potassium-starved A. thaliana roots. This experiment used a custom-made transporter array and corresponding annotations [13]. The PC-values, number of group members and of significantly changed genes are indicated. Only groups with a group-wise FDR <10% are shown. The last column indicates the number of group members that were detected by Significance Analysis of Microarrays [14] with a FDR <10%.