Leaf cuticle topography retrieved by using fringe projection

The combination (often referred to as phase-stepping profilometry, PSP) of the fringe projection technique and the phase-stepping method allowed us to retrieve topographic maps of cuticles isolated from the abaxial surface of leaves; these were in turn sampled from an apple tree (Malus domestica) of the variety Golden Delicious. The topographic maps enabled us to assess the natural features on the illuminated surface and also to detect the whole-field spatial variations in the thickness of the cuticle. Most of our attention was paid to retrieve the highly-resolved elevation information from the cuticle surface, which included the trace (in the order of tens of micrometers) left by ribs and veins. We expect that the PSP application for retrieving the cuticle topography will facilitate further studies on the dispersion and coverage of state-of-the-art agrochemical compounds meant to improve the defending properties of the cuticle. Methodological details are provided below.

► Using phase-stepping profilometry we retrieved topographic map of cuticles isolated from leaves sampled from an apple tree.
► We assessed the natural features on illuminated surface and detected the full-field spatial variations in thickness of cuticle.
► Most of our attention was paid to retrieve the trace left by ribs and veins.
► PSP application will facilitate further studies on the dispersion and coverage of agrochemical compounds.