Figure 5.

IAR4 is critical in root development, root hair formation, and auxin response. A, Phenotypes of the wild type (Col-0), the iar4 mutant, an iar4/IAR4 complementation line, and substitution lines in which Ser-296 was changed to Ala (iar4/S296A) or Asp (iar4/S296D). Analysis was performed on 6-d-old plants. B, Root hair phenotypes of Col-0, iar4, iar4/IAR4, and iar4/S296A. C to E, Quantification of primary root length (C), root hair number (D), and root hair length (E) of the investigated lines. Different letters indicate significant differences at P < 0.05. F, DR5-GUS expression in Col-0 plants and iar4 mutants (iar4-3[DR5-GUS]) under control, Fe-deficient, and phosphate-deficient conditions. Thirteen-day-old plants were analyzed for GUS expression.