Fig. 1: Loss-of-function mutation in BR biosynthesis delays vegetative phase change in Arabidopsis.
a Phenotypic characterization of the del2 mutant. 28-day-old wild type (WT, Col-0), del2, pDWF5::DWF5 del2 2#, 8# transgenic lines were grown in short days. The first leaf with abaxial trichomes was scored. Numbers indicate the first leaf with abaxial trichomes (n = 25 plants, ±SD). Different letters indicate significant difference between genotypes using one-way ANOVA at P < 0.001. Scale bar = 1 cm. b Leaf initiation rate of WT and del2 in short days. Leaf numbers were scored at 4, 8, 12, 16, 20, 24, 28, 32 DAP. DAP, days after planting. Asterisks denote significant difference from WT using two-tailed Student’s t-test (P < 0.001, n = 30 plants, ±SD). c The length-to-width (L/W) ratios of leaf 1-11 from 45-day-old WT and del2 in short days. Asterisks denote significant difference from WT using two-tailed Student’s t-test (P < 0.001, n = 10 plants, ±SD). d The chromosomal ___location of the del2 mutation. The del2 mutation was narrowed down to a region between markers ciw1 and nga280 on chromosome I. e The mutation site in dwf5. Sequencing of DWF5 identified a G-to-A substitution at the 1848th base (shown by the arrow) in the coding region, which caused an early translational termination of the DWF5 gene. Scale bar = 1 KB. f Quantitation of BL levels in 15-day-old WT and dwf5. Asterisks denote significant difference from WT using two-tailed Student’s t-test (P < 0.01, n = 3 biologically independent samples, ±SD). g Phenotypic characterization of MOCK- and BL-treated 30-day-old WT and dwf5. WT and dwf5 were initially grown on 1/2 MS plates containing 0 or 10 nM BL in short days for 10 days, then transferred to 1/2 hogland liquid medium with 0 or 10 nM BL in short days. Numbers indicate the first leaf with abaxial trichomes (n = 15 plants, ±SD). Different letters indicate significant difference between genotypes using one-way ANOVA at P < 0.001. Scale bar = 1 cm. All experiments were repeated 3 times biologically.
