Fig. 3. Phenotypic analyses of cuc and syd-2 or atbrm-1 double mutants. (A-C,E) Pictures taken at the indicated days after germination. None of the double mutants exhibit loss of shoot apical meristem function with the exception of cuc2-1 atbrm-1 (not shown); shoots form from the fused region of the cotyledons (yellow arrowheads in C-E). Genotypes are indicated in each panel. (D) Picture of a cleared seedling taken using DIC optics. Scale bars: 2 mm in A-C,E; 100 µm in D. (F) Percentage of plants showing cotyledon fusion in double mutant combination with cuc1-1, cuc2-1 or cuc3-101. Cup indicates cup-shaped seedling with substantial fusion on both sides of each cotyledon blade (as in B and E). CPF includes seedlings with complete fusion of one side of the cotyledon blade (see C), fusion of the cotyledon petiole, as well as cup-shaped seedlings. atbrm-1 mutants enhance all three cuc mutants, whereas syd-2 mutants only significantly enhance cuc1-1. The number of seedlings tested for each genotype is shown in parentheses.