Fig. S8.

In vivo labeling of IAA and IAA metabolites after feeding with [¹⁵N₁]indole. Seven-day-old Col-0, dao1-1, dao1-2D, and gh3.1,2,3,4,5,6 seedlings were incubated with [¹⁵N₁]indole, and the levels of IAA and IAA metabolites were quantified after different times of incubation. The level of [¹⁵N₁]IAA-Asp in the gh3.1,2,3,4,5,6 mutant line was under the detection limit of the used LC-MS/MS method. The levels of de novo synthesized metabolites are given in picograms per milligram fresh weight (FW) or nanograms per milligram FW; n = 3. Error bars indicate SD. **Concentrations are given in log scale.