Figure 7.

lacs6 lacs7 Seedlings Are Sensitive to 2,4-DB.

(A) Wild-type A. thaliana of the Ws ecotype (WT), the lacs6 lacs7 double mutant (lacs6/7), and the 2,4-DB–resistant mutant pxa1-2 were grown for 7 d on medium containing 2 μM 2,4-DB and 1% sucrose. Before photographs were taken, seedlings were removed from the media and rearranged on agar plates.

(B) Dose–response curve for wild-type and mutant seedlings grown on different concentrations of 2,4-DB. Root lengths (10 seedlings per treatment) were measured 7 d after germination and normalized to the 0 μM 2,4-DB controls. Lengths of the roots (average ± SE) in the control treament were as follows: Ws wild type (closed square), 14.0 ± 0.3 mm; Col-0 wild type (closed circle), 14.7 ± 0.4 mm; lacs6 lacs7 (open circle), 11.4 ± 0.4 mm; and pxa1-2 (open square), 13.1 ± 0.4 mm.