Figure 7.
Complementation of bts-1 mutant by ProBTS::BTS-GFP (BBG) and ProBTS::BTSΔHHE-GFP (BBΔHG). A, Relative BTS expression in root tissue of 7-d-old seedlings grown on +Fe medium for 4 d and then transferred to ±Fe medium for 3 d. Error bars indicate ± se of the mean (n = 4), and columns with different letters are significantly different from each other (P < 0.05). B, Root length of 11-d-old seedlings grown on ±Fe medium (4 d +Fe and 7 d ±Fe). Error bars indicate ± se of the mean (n = 32), and columns with different letters are significantly different from each other (P < 0.05). C, Rhizosphere acidification of 8-d-old seedlings grown on –Fe medium (4 d +Fe, 3 d –Fe, and 1 d bromocresol purple). Eight plants per genotype were grouped on bromocresol purple agar medium. Results shown represent four independent assays. D, Levels of AHA and IRT1 proteins in membrane fractions isolated from the roots of wild-type (WT), bts-1 mutant, and BBG and BBΔHG complemented lines. Coomassie Brilliant Blue (CBB) R-250 staining shows equal loading of protein. Results shown represent two independent assays. E, Iron reductase activity of 10-d-old seedlings grown on ±Fe medium (7 d +Fe and 3 d ±Fe). Error bars indicate ± se of the mean (n = 4), and columns with different letters are significantly different from each other (P < 0.05). FW, Fresh weight.