Figure 4.

As(V) sensitivity of root elongation in seedlings with ptlpd1 alleles. A, Schematic diagram showing the T-DNA insertion sites in the ptlpd1-2, ptlpd1-3, and ptlpd1-4 alleles of At3g16950. Black boxes and lines represent exons and introns/intergenic regions, respectively, with the direction of transcription being left to right. B, Five-day-old seedlings (see legend to Fig. 1) of the wild type (WT), ptlpd1-2, ptlpd1-3, and ptlpd1-4 were transferred to solid medium containing As(V). Increases in root length were measured after growth in the presence of As(V) for 4 d in a vertical orientation. Values are means ± se (n = 15–20 seedlings). C, RT-PCR determination of ptLPD1 transcript abundance in plants with the wild-type, ptlpd1-2, ptlpd1-3, or ptlpd1-4 allele. Total RNA was extracted from 5-d-old seedlings and reverse transcribed. ACTIN2 (At3g18780) was used as an amplification control.