Abstract Detail

Development and Structure

Guzmán-Delgado, Paula [1], Fernández, Victoria [2], Graça, José [3], Gil, Luis [2], Zwieniecki, Maciej [1].

The cuticle as a lipidic epidermal cell wall region: a re-assessment of the prevailing model.

The plant cuticle is commonly defined as a ‘hydrophobic’ layer that covers the epidermal cell wall of primary aerial organs, as based on the assumption of its (mainly) lipidic nature. This conception dates back to the first half of the 19th century and despite being controversial at that time, it has not been challenged again until recently (Guzmán et al., 2014; Fernández et al., 2016) and, as such, few studies have focused on analyzing the link between cuticle structure and chemical composition. With the aim of analyzing this link, we applied various analytical and microscopic techniques to the leaf cuticle of model species (e.g., Guzmán et al., 2014; Guzmán-Delgado et al., 2016). We found no specific cuticle structural patterns in association with internal lipid constituents, but instead with cellulose in the case of cuticles containing cutin as the major lipid polymer. The cell wall constituted the framework of these cuticles, which definitely contradicts the prevailing cuticle model. Selective chemical extractions of cutan are potentially required to observe the cell wall nature of cutan-containing cuticles. We hence suggest a re-interpretation of the cuticle as a lipidic region of the cell wall instead of as free of polysaccharides or with few polysaccharides stemming from the cell wall underneath. This new cuticle interpretation highlights the major physical and chemical heterogeneity of the cuticle, which limits our capacity to establish a relationship between cuticle structure and composition. Finally, the functional role of cuticle (or cell wall) polysaccharides should be considered in relation to, for example, the transport of substances through the cuticle. Fernández V, Guzmán-Delgado P, Graça J, Santos S, Gil L. 2016. Cuticle structure in relation to chemical composition: re-assessing the prevailing model. Front Plant Sci 7:427. Guzmán-Delgado P, Graça J, Cabral V, Gil L, Fernández V. 2016. The presence of cutan limits the interpretation of cuticular chemistry and structure: Ficus elastica leaf as an example. Physiol Plantarum, doi:10.1111/ppl.12414. Guzmán P, Fernández V, Graça J, Cabral V, Kayali N, Khayet M, Gil L. 2014. Chemical and structural analysis of Eucalyptus globulus and E. camaldulensis leaf cuticles: a lipidized cell wall region. Front Plant Sci 5:481.

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1 - University of California Davis, Department of Plant Sciences, One Shields Avenue, Davis, CA, 95616, USA
2 - Technical University of Madrid, Department of Natural Systems and Resources, School of Forest Engineering, Ciudad Universitaria, Madrid, 28040, Spain
3 - Universidade de Lisboa, Centro de Estudos Florestais, Instituto Superior de Agronomia, Tapada da Ajuda, Lisboa, 1349-017, Portugal

Keywords:
cell wall
cuticle
epidermis
lipids
polysaccharides.

Presentation Type: Oral Paper
Session: 29, Development and Structure I
Location: 202/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 1:45 PM
Number: 29002
Abstract ID:594
Candidate for Awards:Katherine Esau Award