Chemical Composition and Water Permeability of Fruit and Leaf Cuticles of Olea europaea L.

Abstract

The plant cuticle, protecting against uncontrolled water loss, covers olive (Olea europaea) fruits and leaves. The present study describes the organ-specific chemical composition of the cuticular waxes and the cutin and compares three developmental stages of fruits (green, turning, and black) with the leaf surface. Numerous organ-specific differences, such as the total coverage of cutin monomeric components (1034.4 μg cm and 630.5 μg cm) and the cuticular waxes (201.6 μg cm and 320.4 μg cm) among all three fruit stages and leaves, respectively, were detected. Water permeability as the main cuticular function was 5-fold lower in adaxial leaf cuticles (2.1 × 10 m s) in comparison to all three fruit stages (9.5 × 10 m s). The three fruit developmental stages have the same cuticular water permeability. It is hypothesized that a higher weighted average chain length of the acyclic cuticular components leads to a considerably lower permeability of the leaf as compared to the fruit cuticle.

Changes in Cuticle Components and Morphology of ‘Satsuma’ Mandarin (Citrus unshiu) during Ambient Storage and Their Potential Role on Penicillium digitatum Infection

“…The amounts of cutin ranged from 27.8 µg cm −2 to 52.5 µg cm −2 , which were much higher than that of total wax in the same storage period. This observation agreed with the previous results for many other fruits, such as tomato [32], olive [33], and diospyros kaki fruit [34]. Cutin content decreased significantly from 52.5 µg cm −2 to 38.1 µg cm −2 in the former 10 days of storage then it kept stable in the following 10 days of storage, while it decreased to 28.2 µg cm −2 after 40 days of storage.…”

Chemical Composition of the Cuticle Membrane of Pitaya Fruits (Hylocereus Polyrhizus)

“…Additionally, the diversity in the accumulation and amount of VLCFAs (>19 carbon chain-length), i.e., aliphates, versus the cyclic compounds including sterols and pentacyclic triterpenoids, was in a ratio of 0.7 (Table 1), which showed similar amounts accumulating for aliphates and cyclics in the cuticular wax of pitaya fruit cuticle. The n-alkanes and pentacyclic triterpenoids being the major wax components in pitaya fruit cuticle, which were similar to the wax mixtures of tomato fruit cuticle [12], sweet cherry [11], as well as similar to the leaf waxes of most previously studied plant species [13,16,21]. However, this differed from fruit cuticular waxes of many other plant species [13,14].…”

“…In pitaya fruit, the most abundant cutin monomers were of C 16 and C 18 chain length. The predominant 9/10,ω-dihydroxyhexadecanoic acid was also detected in other fruits such as Prunus avium L. [11], Solanum lycopersicum L. [12], Olea europaea L. [13], and Malus domestica Borkh. [14].…”

“…[14]. In contrast, the 9,10-epoxy-ω-18-hydroxy-octadecanoic acid detected as the second most abundant monomers in pitaya fruit cuticle (14.0% of total cutin) are commonly found in the leaf cutin matrix of examples such as Olea europaea L., Rhazya stricta and Agave Americana etc., but was scarcely detected in fruit cuticle of olive and apple [9,12,13,15,16].…”

“…The abundant accumulation of C 18 chains could lead to a slower permeability unlike that of C 16 chains. Previous investigations implied that a unique polymeric cutin matrix might result from the various characteristics of carbon chain lengths, the degree of unsaturation, and mid-chain epoxidation in both leaf and fruit cuticle [13]. The ratio of C 16 /C 18 cutin monomers was 1.7, the C 18 -long chains of 9,10-epoxy-ω-hydroxyoctadecanoic acid was detected, which might add to enhancement of the mechanical strength of the cutin matrix in pitaya fruits.…”