Figure 5.

HB52 Affects Auxin Transport by Regulating Auxin Transport-Related Genes.

(A) HB52 transcript levels in HB52 mutants harboring the DR5:GUS reporter. Seeds of the indicated lines were germinated on MS medium for 4 d and transferred to MS liquid medium with 5 μM estradiol for 24 h. The roots were detached from more 50 seedlings, and RNA was isolated for quantitative RT-PCR analysis. Values are the mean ± sd (n = 3 experiments, ***P < 0.001). Statistically significant differences were calculated based on Student’s t tests.

(B) GUS staining of DR5:GUS marker lines in various HB52 backgrounds. Seeds of the indicated lines were germinated on MS medium with 5 μM estradiol for 4 d, and the seedlings were transferred to liquid MS medium with 5 μM estradiol supplemented with and without 1 μM ACC for 24 h before staining. The seedlings (>20) were incubated in the GUS staining solution for 2 h before the photographs were taken. A representative seedling of each line is shown. Bar = 100 μm.

(C) Transcript levels of auxin transport-related genes in mutants with various HB52 backgrounds with or without ACC treatment. Seeds of the indicated lines were germinated on MS medium for 4 d and transferred to MS liquid medium with 5 μM estradiol or 5 μM estradiol + 1 μM ACC for 24 h. The roots from at least 30 seedlings for each line were detached, and RNA was isolated for quantitative RT-PCR analysis. The relative expression level of the ACC-treated samples was normalized to the wild-type control of the corresponding untreated samples. Values are the mean ± sd (n = 3 experiments). Different lowercase letters indicate significant difference based on Student’s t tests (P < 0.05).