Effect of Auxin Transport Inhibition on LR Development in Arabidopsis Seedlings.
(A) Arabidopsis (Col-0) seedlings were grown for 4 d on P+ and P− with 1 μM of NPA and transferred to medium with or without 1 μM NPA or to medium containing 1 μM NPA with or without 10−8 M NAA for 48 h. The seedlings were cleared and the number and stage of LRP recorded according to Zhang et al. (1999). The data represent the mean ± se of the number of LR primordia per plant (n = 10). Different letters indicate that the means differ significantly (P < 0.05).
(B) Arabidopsis (Col-0) seedlings were grown for 4 d on P+ or P− with 1 μM of NPA and transferred to medium with (+) or without (−) NPA and 10−6 M NAA for 48 h. The seedlings were cleared, and the division and cellular proliferation in the pericycle were analyzed. Nomarski micrographs are representative of at least 10 plants analyzed. In all cases, the data represent three independent experiments. Bar = 50 μm. [See online article for color version of this figure.]
