Effect of mutated dynamin-related protein1A (OsDRP1A^K47A) induction on degradation and polarity of OsBOR1 in rice roots. A–P, Localization of OsBOR1 (A–D and I–L) and OsDRP1A^K47A-HA (E–H and M–P) in root tip (A–H) and mature region (I–P) of crown roots. (Q and R) Signal intensity of OsBOR1 (Q) and OsDRP1A^K47A-HA (R). Transgenic seedlings (21-d-old) harboring Est≫OsDRP1A^K47A-HA were treated −B for 1 d, followed by exposing to −B solution containing DMSO (as a control) or 20 μM β-estradiol for 2 d. Subsequently, these seedlings were exposed to 0 or 30 μM B in the presence of DMSO or 20 μM β-estradiol. After 6 h, tip region (3 mm from root tip) and mature region (10 mm) of crown roots were sampled for double immunostaining of OsBOR1 and OsDRP1A^K47A-HA. Magenta and green signals indicate OsBOR1 and OsDRP1A^K47A-HA, respectively. Blue signals indicate autofluorescence of the cell wall and DAPI-stained nucleus. Signal of OsBOR1 or OsDRP1A^K47A-HA were merged with bright field and autofluorescence of the cell wall and DAPI-stained nucleus. Scale bars indicate 50 µm. Signal intensities of OsDRP1A^K47A-HA and OsBOR1 were quantified by LAS AF Lite software. All pictures were taken under the same conditions. Data are means ± sd (n = 6–10). Different letters indicate significant differences at P < 0.05 by Tukey–Kramer’s test.