E. Gouret et al., ULTRASTRUCTURE AND CHEMICAL-COMPOSITION OF SOME ISOLATED PLANT CUTICLES IN RELATION TO THEIR PERMEABILITY TO THE HERBICIDE, DIURON, New phytologist, 124(3), 1993, pp. 423-431
The ultrastructure of leaf and fruit cuticles from nine species was in
vestigated before and after their enzymatic isolation. No major altera
tion was observed in the internal ultrastructure of cuticles after the
isolation process. The isolated cuticle preparations showed several l
evels of complexity from the Pyrus communis L. leaf cuticle represente
d by a simple layer, to the Vanilla planifolia Andr. leaf cuticle prep
aration having extensive cell walls on its inner face. Two main ultras
tructural types were distinguished; cuticles characterized by an almos
t entirely reticulate structure and cuticles characterized by an outer
lamellate region with an inner reticulate region. The permeability of
isolated cuticles to diuron was measured with a double water compartm
ent device using C-14-diuron. The permeability coefficient (P) ranged
from 1.9 to 40.1 nm s-1 for seven species. The mean value of P for cut
icles having an entirely reticulate structure was higher than that for
cuticles with an outer lamellate zone. Moreover, for each of the two
ultrastructural types, the permeability decreased with an increase in
soluble wax content expressed per surface unit.