(A) AtDAO1 and AtDAO2 transcript abundance in the different dao1 alleles studied in this work relative to Col-0. qRT-PCR analysis was performed using cDNA from 7-d-old roots. Fold change was calculated by comparative Cycle threshold (Ct) method, and values were normalized with the expression of the ACT2 gene. Error bars indicate SDs from three biological replicates. *Expression values significantly different from those in Col-0 (Student’s t test; P < 0.05). (B) Levels of IAA metabolites in the different dao1 alleles. IAA and the metabolites oxIAA, oxIAA-glc, IAA-glc, IAA-Asp, and IAA-Glu were quantified in 7-d-old seedlings of Col-0, dao1-1, dao1-3, dao1-2D, and dao1-4D. The concentrations for all metabolites except oxIAA-glc [nanograms per milligram fresh weight (FW)] are given in picograms per milligram FW. Samples were analyzed in five independent biological replicates, and error bars represent the SDs. *Statistically significant differences from Col-0 (P < 0.05; Student’s t test).