Mismatch between cuticle deposition and area expansion in fruit skins allows potentially catastrophic buildup of elastic strain.

The continuous deposition of cutin and wax during leaf and fruit growth is crucial to alleviate elastic strain of the cuticle, minimize the risk of failure and maintain its barrier functions. The cuticular membrane (CM) is a lipoidal biopolymer that covers primary surfaces of terrestrial plants. CMs have barrier functions in water and solute transfer and pathogen invasion.

Evidence for a radial strain gradient in apple fruit cuticles.

The morphological outer side of the apple fruit cuticle is markedly more strained than the inner side. This strain is released upon wax extraction. This paper investigates the effect of ablating outer and inner surfaces of isolated cuticular membranes (CM) of mature apple (Malus × domestica) fruit using cold atmospheric pressure plasma (CAPP) on the release of strain after extraction of waxes.

Intracuticular wax fixes and restricts strain in leaf and fruit cuticles.

This paper investigates the effects of cuticular wax on the release of strain and on the tensile properties of enzymatically isolated cuticular membranes (CMs) taken from leaves of agave (Agave americana), bush lily (Clivia miniata), holly (Ilex aquifolium), and ivy (Hedera helix) and from fruit of apple (Malus × domestica), pear (Pyrus communis), and tomato (Lycopersicon esculentum). Biaxial strain release was quantified as the decrease in CM disc area following wax extraction. Stiffness, maximum strain and maximum force were determined in uniaxial tensile tests using strips of CM and dewaxed CMs (DCMs).