Figure 3

SPS1 knockdown causes a decrease in intracellular PLP levels. A. Five days after SPS1 dsRNA or 4-DPN was added to the medium, intracellular PLP levels were measured as described in Methods. dsRNAs and 4-DPN used are shown on the x-axis. Experiments were performed in triplicate and error bars denote the standard deviation from the mean of three independent experiments. Statistical significance was tested by one-way ANOVA followed by Tukey's multiple comparison test. ** indicates significance at p < 0.01. B. Five days after treatment of cells with dsRNAs and 4-DPN, expression patterns of genes selected by GO analysis were measured by RT-PCR as described in Methods. Tested genes and GO terms of the gene are shown on the left of each panel. VB, vitamin B6 biosynthesis; DR, defense response; AA, amino acid metabolism; Con, internal control. The effect of 4-DPN on gene expression is represented as the PLP effect. The + and - symbol designate consistency and inconsistency of expression pattern of each gene between SPS1 knockdown and 4-DPN treated cells, respectively. rp49 was used as an internal control.