The purpose of secreting cuticle layers is to prevent the loss of water from the surface cells. But the cuticle layers are not continuous, because mechanical stress, brittleness or injury may cause the cuticle to break open here and there as small fissures. It is through these openings, water is lost to atmosphere from the under lying epidermal cells. Still the total amount of water lost is not that significant, in terms of the total amount of water transpired by stomatal mechanism.

Cuticular transpiration is important in non-leafy organs such as fruits. In some fruit, however, majority of water loss occurs through the calyx (not sure whether thorough cuticle or stomata), as in tomato, eggplant (Postharv. Biol. Technol. 13: 45-49), and pepper (J. Sci. Food. Agric. 87:68-73).

There are some excellent reviews on structure and function of plant cuticles, and specifically for fruit there is evidence that regulation of water loss is only one of cuticle roles. Please refer to the attached papers and references therein.

The cuticle has an important role as a bounding layer between the body of the plant

and its environment. It has been ascribed a function in the prevention of the loss

of plant components by leaching and as a supplement to the action of stomata in

regulating the passage of water from within the plant to the atmosphere. The

cuticle lies over and merges into outer walls of epidermal cells. Outside the

epidermal cell wall itself a band of more or less pure pectin continuous with that

of the anticlinal walls of the epidermal cells is generally believed to lie. Outside

this occurs the so-called cutinized layer or cuticular layer, in which cellulose and

pectin are encrusted with cutin. The outermost layers of this multilayered wall

consist of the cuticle proper (cuticularized layer) made up mainly or entirely of

cutin covered with a thin layer of more or less pure wax (Roelofsen, 1952; Esau,

1953; Sitte and Rennier, 1963; Crips, 1965; Martin and Juniper, 1970).

There have been several reports on the structure of the cuticle (but none on

halophytes) as revealed by transmission electron microscopy showing a fine

lamellation of the cuticle proper (Chafe and Wardrop, 1973; Sargent, 1976;

Wattendorf and Holloway, 1980). There is, however, very little experimental

evidence concerning the effects of salinity on the characteristics of the cuticle of

halophytes and the related physiological consequences of exposure to salinity. In

view of this fact, the present paper reports on the structure of the cuticle and on

cuticular transpiration in the leaves of the halophyte Suaeda maritima (L.) Dum.

grown either in the presence or absence of sodium chloride.

Both cuticle and cell wall of the epidermal cells of leaves of Suaeda maritima showed a considerable increase in thickness (approximately 1-8 times) in plants grown in the presence of 0-34 M sodium chloride when compared with plants grown without added sodium chloride.Differences in the structure of the cuticle were also observed. The rate of transpiration in thedark was markedly reduced with increasing concentrations of salt in the external medium.Cuticular transpiration appears to be related to cuticular thickness and to fall with increasingsalinity.

By means special holes called hydatodes

La micro-structure de cuticule au niveau nano-technologie montre une grande difference entre les surfaces des vegetaux : cuticule de type Lotus et celle du velamen des orchidacees; mais cette question reste a etudier.

Please excuse me; my yesterday post was added incomplete. Additional reviews you may find of interest are as listed below. This list is not exhaustive, but you will find more information in the corresponding sections of cited literature. I hope you find them useful; cuticle studies are complex indeed.

If your main focus is cuticle function rather than composition/structure, please check:

Kerstiens, 2006

Domínguez et al., 2011a and 2011b

Heredia, 2003

Yeats and Rose, 2013

Lara et al., 2014

Best wishes,

Isabel

Micro-structure of cuticule have a big difference for nano-technology.

As surface of Lotus and this one of orchid"s velamen have the opposite function.

The study supplement can be made.

Because cuticle is not a continuous layer as occurs in may stigmatic papillae as in mays setate.