Morphological diversity of β-diketone wax tubules on Eucalyptus gunnii leaves and real time observation of self-healing of defects in the wax layer

Abstract

As part of the plant cuticle, epicuticular waxes build the boundary layer of a plant to its environment, fulfilling many vital functions. Epicuticular waxes are small crystalline structures which originate by self-assembly. The morphology of β-diketone tubules on Eucalyptus gunnii Hook.f. leaves was studied by field emission scanning electron microscopy (FE-SEM) and regeneration of removed waxes was investigated in real time by atomic force microscopy (AFM) on leaf surfaces. Smooth tubules as well as helically wound ribbons and transitional forms of tubules were found on adaxial leaf surfaces. Leaves of different developmental stages revealed no differences in their wax morphologies, but in the amount of wax allocation. After removal of the waxes regeneration was observed on leaves of all investigated ages. The regeneration of wax crystals started directly after wax removal and tubule growth could be observed in real time.