Water and Solute Permeability of Plant Cuticles: Measurement and ...

1.4 Fine Structure of Cuticles 23
Fig. 1.8 Transmission electron micrographs of transverse sections of adaxial cuticles from Clivia
miniata at different stages of development. Numbers at the lower left corners refer to distance from
leaf base. Fixed en bloc with OsO4, and sections were stained with uranyl acetate and lead citrate.
(Taken from Riederer and Schönherr 1988)
not known if incrustation with waxes prevents penetration of OsO4 or if polar reactive
functional groups have disappeared or are covered up. At position 20 cm cutan
occurs in very large amounts (Fig. 1.2), and during transformation of ester cutin to
cutan epoxy groups and double bonds are most likely consumed. It is believed that
the dark fibrillar network (5 cm) marks the location of polar polymers embedded in
cutin, but it is not known why it is no longer visible in old cuticles.