Figure 10.
BPBT Expression, Spatial Activity of the C. breweri Lis Gene Promoter, and Auxin Transport in Petunia.
(A) Representative RNA gel blot hybridization with total RNA (7 μg per lane) isolated from roots, stems, leaves, and corollas of 2-d-old flowers of control and BPBT RNAi-10 petunia plants. A coding region of the BPBT genes was used as a probe. Autoradiography was performed overnight. The blot was rehybridized with an 18S rDNA probe (bottom gel) to standardize samples.
(B) and (C) Histochemical analysis of GUS activity in four independent Lis-GUS transgenic plants revealed the presence of low levels of Lis-GUS expression in roots (B) and basal parts of the stems (C) of these plants.
(D) Auxin transport in roots and root-shoot junctions of 5-d-old control and BPBT RNAi-10 seedlings. Radiolabeled 3H-auxin was applied to the shoot tip, and its movement to the root-shoot transition zone and root tip over a 4-h period was monitored. Asterisks indicate significance determined by Student's t test (P < 0.02; n = 10). Bars indicate sd. DPM, disintegrations per minute.