Fig. 5: A conserved local BR control of root biomass density.

a Phenotype of 10-day-old tomato WT and bri1^cu3 seedlings, grown in pots (background of the image was digitally cleaned to remove the perlite grains for a clear visualization of the roots). b Confocal images showing the root tip of 10-day-old WT and bri1^cu3 grown on plates. Scale bar, 100 μm c Quantification of biomass density index (BDI, mass per cm root length) in roots of 10-day-old of WT and bri1^cu3, grown in pots (n: WT = 16, bri1^cu3 = 22, p ≤ 0.05). d Representative images of grafted tomato seedlings 21 days after grafting (i.e., 31-day-old) of WT/WT, WT/bri1^cu3, bri1^cu3/bri1^cu3, and bri1^cu3/WT. Scale bar, 1 cm. e–g Quantification of biomass and BDI in grafts as in (d). e shoot fresh weight, f root fresh weight and g root BDI. In boxplots, the center corresponds to the median, the lower and upper hinges represent the first and third quartiles, and the whiskers extend to the largest and smallest values within 1.5× the IQR from the hinges. All data points are plotted individually. In all boxplots different letters indicate statistically significant differences (n: WT/WT = 18, WT/bri1^cu3 = 17, bri1^cu3/bri1^cu3 = 15, bri1^cu3/WT = 20, p ≤ 0.05).