D. Canet et al., ATOMIC-FORCE MICROSCOPY STUDY OF ISOLATED IVY LEAF CUTICLES OBSERVED DIRECTLY AND AFTER EMBEDDING IN EPON(R), New phytologist, 134(4), 1996, pp. 571-577
The first results obtained by atomic force microscopy (AFM) of the fin
e structure of isolated ivy leaf cuticles are reported. Observations o
f transverse sections embedded in Epon(R) allow easy recognition of th
e general shape of cuticles as viewed by light microscopy. The surface
profile shows irregularities not revealed by transmission electron mi
croscopy (TEM). The lamellate and reticulate zones, distinguishable by
TEM, were also located by AFM. The outer zone appears as an irregular
ly thick (c. 4 mu m) homogeneous region; lamellae can be visualized on
ly after image-processing to subtract relief defects produced by secti
oning. The second region or internal zone represents the largest part
of the cuticle thickness; it appears heterogeneous and disordered. The
cuticle internal surface images show imprints of the epidermal cells.
At high magnification, the cell imprint central regions appear to be
made up of a network of fibres of c. 50 nm diameter. Some images show
that these fibres have a preferential orientation. They disappear afte
r acid-hydrolysis is used to eliminate polysaccharides. This study sho
ws that AFM can produce reproducible images of isolated plant cuticles
at a subcellular scale leading to new high-resolution representations
of cuticle substructure.