Fig. 1. 7-DHC accumulated in Sl7-DR2-homozygous-knockout lines.
a, The cholesterogenesis pathway (depicted in light green) and phytosterol biosynthesis pathway (depicted in light orange) in tomato, redrawn from Sonawane et al.16. 7-DHC is converted by 7-DR2 to cholesterol, which can be converted to vitamin D3 by exposure to UVB light. SMO, C-4 sterol methyl oxidase; C5-SD1, sterol C-5(6) desaturase 1. b, Five independent Sl7-DR2-knockout lines were generated by genome editing. Top: schematic structure of Sl7-DR2 gene, with exons indicated as grey arrows. Bottom: recovered mutations in each line are highlighted in light blue. The CRISPR–Cas9-targeted sequences and the protospacer-adjacent motif sequences are shown in blue and red, respectively. c, 7-DHC contents in wild-type (WT) and Sl7-DR2-knockout tomato fruit at different stages of ripening (IMG, immature green; MG, mature green; Breaker, fruit turning ripe; B + 7, 7 days after breaker-ripe fruit). Data are presented as the mean ± s.e.m. From left to right: n = 14, 19, 16, 15, 16, 14, 13, 11, 18, 13, 10, 15, 15, 14, 17, 11, 11, 15, 9, 17, 14, 17, 15 and 15 biologically independent fruit samples. ND, not detected. d, 7-DHC content of leaves of wild-type and Sl7-DR2-knockout lines. Data are presented as mean ± s.e.m. From left to right: n = 4, 5, 5, 4, 5 and 4 biologically independent leaf samples. Statistical significance between WT and mutants at each fruit ripening stage (c) or in leaves (d) was assessed using two-tailed t-tests (*P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001).