Fig. S5.

(A) Auxin dose–response of YFP-tagged IAA3 and IAA7 ± ARF19. There is no difference in auxin-induced degradation between WT and ok YFP strains for both IAA3 and IAA7. ARF19 has a modest effect on the auxin-induced degradation of IAA3 and IAA7 when cells were treated with 0.5 μM auxin. Fluorescence of YFP-WT and YFP-ok IAA strains in the presence of the AFB2 auxin receptor was measured 30 min post auxin treatment. Fluorescence levels were normalized to mock treatment levels to compensate for differences in basal expression levels of IAAs. (B) PB1 mutations have little to no effect on the basal expression of IAA3, but the o and ok mutations decrease levels of both IAA7 and IAA14. (C) IAA-ok mutations result in a modest decrease of protein level compared with WT. Shown is the Western blot of YFP-IAA WT and ok variants.