Connective auxin transport contributes to strigolactone-mediated shoot branching control independent of the transcription factor BRC1
Fig 6
PIN347 and ABCB19 have contrasting effects on bud activation kinetics.
(A) Primary branch number at terminal flowering of plants of the genotypes indicated grown under long day growth conditions. n = 18–24. (B) Bulk stem auxin transport through 15 mm basal inflorescence internodes of 6-week old plants of the genotypes indicated. Transport was determined as basal accumulation of radiolabeled auxin, quantified as counts per minute (CPM) in the basal 5 mm of stem after 18 hours of incubation of the apical end 1 μM 14C-IAA, n = 24. (C) Mean number of active rosette branches over time following decapitation at day 0 for Col-0 (blue), abcb19 (orange), pin347 (green) and abcb19pin347 (grey) plants. Plants were grown under short day conditions for 4 weeks, shifted to long days to induce flowering and decapitated when the inflorescences reached 10 cm. The number of active rosette branches, defined as longer than 5 mm were counted daily. Error bars represent the 95% confidence interval of the mean. Non-overlapping error bars indicate statistical differences compared to wild type, verified using non-parametric tests comparing wild type and each mutant with a threshold of p < 0.05, with Holm-Bonferroni adjustment, n = 18–19. (D) Number of primary branches at terminal flowering for plants of the genotypes indicated grown under short day conditions for 4 weeks and then shifted to long days, n = 20–24. For A, B and D the boxes span the first to third quartile and the line represents the median. The whiskers indicate the variability outside the upper and lower quartiles and outliers are indicated by individual points. Tukey’s HSD tests were carried out after obtaining the least-square means for a linear model fitting the data and different letters indicate statistically significant differences at p < 0.05. For C, Holm-Bonferroni corrected Wilcoxon rank-sum tests were used to test between genotypes and time points as indicated in the text.
doi: https://doi.org/10.1371/journal.pgen.1008023.g006