Figure 3.

Ponalrestat treatment results in auxin-related defects for different root phenotypes. A, representative photos of root hairs of 5-day-old green seedlings of Col-0 grown on 1/2 MS medium supplemented with 5 μm ponalrestat or DMSO as the mock control. Scale bar = 200 μm. B, quantitative evaluation of root gravitropism. 10-day-old green seedlings of Col-0 were grown vertically on 1/2 MS medium supplemented with ponalrestat or DMSO as the mock control. The root gravitropic index (L/D) is the root length (L)/vertical length (D). Each red symbol represents the data for a single seedling. Bars represent mean ± S.D. of at least 10 seedlings. C, representative seedlings for the indicated groups from the analysis in (B). Scale bar = 10 mm. D, quantitative real-time PCR analysis of the auxin downstream marker gene GH3.3. 3-day-old seedlings were grown in the dark before treatment with liquid 1/2 MS supplemented with 50 μm ponalrestat (DMSO as the control) or 10 μm IAA (ethanol/EtOH as the control) for 4 h. Bars represent mean ± S.D. of three replicates; a Student's t test was used to compare ponalrestat-treated and mock-treated seedlings or IAA-treated and EtOH-treated seedlings (***, p < 0.001). All the above experiments were repeated for at least three times with similar results.