Figure 4.

Genetic analysis of pxa1 phenotypes. A, pxa1 IBA-resistant root elongation is dominant. Root elongation on 5 μm IBA was measured as described in the legend to Figure 1. Error bars indicate se values (n > 13). B, pxa1 Suc dependence is recessive. Seedlings were grown on Suc-free medium for 1 d in the light and 5 d in the dark, and hypocotyl length was measured. Error bars indicate se values (n > 16). For A and B, PXA1/pxa1 seeds are F₁ progeny from a backcross of pxa1 to wild-type Columbia (Col-0).