(A) IAA measurements from 4-day-old dissected hypocotyls and cotyledon + hypocotyls combined. Error bars represent standard deviation.
(B) qRT-PCR of IAA marker genes in hypocotyl tissue from 4-day-old WT and afb4-2 mutant seedlings following 2 hr treatment with 1 μM IAA. Expression values are normalized to the PP2AA3 reference gene [20].
(C) IAA dose-response curve for WT and afb4-2. Seedlings grown for 4 days under SD photoperiod were transferred to the indicated IAA concentration for 3 days.
(D) Four-day-old WT and mutant seedlings were transferred to 29°C for 2 days. Control plates were maintained at 22°C. Hypocotyl length is expressed as a percent elongation based on the control plates.
Error bars represent standard error. See also Figure S3.