Fig. 3
ABCB6 and ABCB20 redundantly regulate Arabidopsis shoot growth. a Shoot phenotypes of 25-day-old WT and amiR1334 seedlings grown on soil under normal conditions. Scale bar, 1 cm. b Phylogenetic tree of Arabidopsis ABCBs. Orange dots indicate previously characterized auxin transporters. Green dots indicate putative transporters characterized in this study. c Representation of the ABCB6 and ABCB20 genes. Arrows indicate the position of T-DNA insertion. d Hypocotyl growth of the indicated genotypes. Seedlings were grown on 1/2 MS for 4 days and transferred to the indicated treatments. Hypocotyls were imaged and lengths quantified at day 7. Shown are averages (±SE), letters indicate statistically significant differences at P < 0.05. n = 20 plants. e Phenotypes of mature 6-week-old plants grown in soil. Scale bar, 5 cm. f Quantification of inflorescence height of the genotypes shown in (e). Shown are averages (±SE), n = 16 plants, **P < 0.01, Student’s t-test. g Phenotypes of 35-day-old plants grown in soil. Scale bar, 1 cm. h ABCB6 and ABCB20 expression level for the indicated genotypes (12-day-old seedlings). n = 3 biological replicates. i Phyllotaxis of the b6-1,20-1 double mutant (two plants at the right) compared to WT (left). Scale bar, 1 cm. j Quantification of phyllotaxis shown in (i), presented as angle frequencies. n = 256 for WT and 249 for b6-1,20-1 plants. k Silique morphology of the indicated genotypes. SEM images, scale bar, 200 μm. Abbreviations: b6 and b20 stands for abcb6 and abcb20 single mutants, respectively. b6-1,20-1 stands for abcb6-1 abcb20-1 double mutant. b6-1,20-2 stands for abcb6-1 abcb20-2 double mutant
