Fig. 7. Effects of weak alleles of the DEF gene on development of the ventral petal of A. majus and expression of AmMYBML1. (A) Light micrograph of the corolla tube of the ventral region of a def101 mutant flower for comparison with wild type shown in Fig. 6A. The def101 mutant petal has many fewer hairs in the throat of the corolla tube and less folds around the hinge. (B) SEM of the corolla tube of the ventral petal of a def101 mutant flower. There are far fewer hairs in the throat of the tube and fewer folds around the hinge. Scale bar: 1 mm. (C) SEM of folds of ventral petal in the region of the hinge of a def101 mutant ventral petal for comparison to the structure of this region in the wild-type corolla shown in Fig. 6F. (D) SEM of surface of the ventral petal lobe of a def101 mutant flower in the region of the hinge. The hinge is on the left. All the epidermal cells are flat. This should be compared with the wild type shown in Fig. 6F. (E) Quantitative RT-PCR of AmMYBML1 transcript levels in corollas of wild type (Def), def101 mutant, def ^chlor mutant and lines heterozygous for def101 and def ^chlor. Transcript levels of AmMYBML1 should be compared with the levels of control gene, encoding ubiquitin (UBI) in the same tissues.