Figure 2.

Effects of paraquat on the transcript abundance of thiamin biosynthetic genes in Arabidopsis. Four thiamin biosynthetic genes (HMP-P synthase [At2g29630], HET-P synthase [At5g54770], TMPPase/HMP-P kinase [At1g22940], and TPK [At1g02880]) were tested for their steady-state transcript levels in 9-d-old whole Arabidopsis plants grown on 0.25 μm paraquat in 100 μmol m⁻² s⁻¹ constant light. Values represent means ± sd of three to five independent experiments. Student's t tests were conducted to compare the relative fold change in mRNA abundance of stressed plants with control plants. **, Student's t test significant at P < 0.01; *, Student's t test significant at P < 0.05.