Fig. 4.

Epidermal characterization of the whorl 4 organs. SEM of the surface of a wild-type leaf (A), carpel (B), and petal (C). In GRCD2 down-regulated plants the whorl 4 organs show presence of multicellular hair-like structures (D) and stomata (E). Neither stomata nor hairs are present on normal carpels, but stomata are found on the abaxial surface of petals and, like hairs, on the adaxial and abaxial sides of leaves and bracts, as well as on the surfaces of scapes. In stronger phenotypes, the anti-GRCD2 whorl 4 surface (F) resembles the ridges typical to wild-type petals (C). The carpels of the transgenic plants were not functional, as confirmed by crossing tests with nontransgenic plants. [Scale bars indicate 100 μm (A and D) and 20 μm (B, C, E, and F).]