Towards understanding the relation between the composition, structure and the function of the plant cuticle 


During recent years, we have used Arabidopsis as a model system for the identification of genes involved in the biosynthesis of cutin, the structural polyester of the cuticle. A number of Arabidopsis mutants having a permeable cuticle have been isolated using dyes that penetrate the leaves or petals only when the cuticle is disrupted. Characterization of permeable cuticle mutants lead also to a better understanding of the different roles of the plant cuticle in stress protection and plant development.


A short overview over the different research projects is given below:


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Schematic diagram of the cutin biosynthetic pathway (from Li-Beisson et al., 2013)


The biosynthesis of the polyester cutin

The polyester cutin is the major structural component of the cuticle. Cutin is hypothesized to form the scaffold for the organized assembly of the different cuticular components (wax, cutin and polysaccharides) that are necessary to form a functional diffusion barrier. The process of cutin formation can be divided into three steps: cutin precursor synthesis inside of the epidermal cell, cutin precursor export and extracellular polyester formation.
Our publications and contributions to this topic:

Kurdykov et al, 2006

Voisin et al, 20009

Bessire et al, 2011


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Polar localization of the ABCG32-GFP fusion protein at the plasma membrane towards the cuticle as visualized by confocal microscopy


The ABC transporter AtABCG32 and HvABCG31 and its role in cutin formation

Characterization of the permeable cuticle1 mutant in Arabidopsis as well as the eibi mutant in barley lead to the hypothesis that members of this clade of ABCG transporters have an essential function in the export of cutin precursors that is highly conserved between monocots and dicots. One of our current research topics is to elucidate the function of the ABCG32 transporter in vitro and in vivo.
Our publications and contributions to this topic:

Bessire et al, 2009

Chen et al, 2011


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Transmission electron microsgraph showing the layered structure of the cuticle within the nanoridges of epidermal cells of Arabidopsis petals. Picture taken by Jean Daraspe, EMF, UniL


Towards an better understanding of cuticle formation

The ultrastructure of the cuticle varies among different plant species but also between different organs of the same plant. Characterization of the ultrastructure as well as the chemical composition of the cuticular components of petals of Arabidopsis mutants are used to better understand cuticle formation.
Our publications and contributions to this topic:

Bessire et al, 2011

Bessire et al, 2011

Voisin, Kurdykov, et al, 2009


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Inflorescence of a cutinase-expressing transgenic Arabidopsis plant exhibiting fusions between floral organs


The role of cuticle in organ formation

The formation of fusions between different plant organs early in development in many plants having a permeable cuticle lead to the hypothesis that the cuticle has an essential function during plant development. The molecular mechanisms underlying this unique phenotype are still under debate, but seem to be tightly associated with the development of the organ itself.
Our publications and contributions to this topic:

Sieber et al, 2000

Kurdykov et al, 2006

Voisin et al, 2009


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Inoculation with Botrytis on wild type Arabidopsis plants (left) showing lesion formation and a plant having a permeable cuticle (right) being resistant


The role of the cuticle in plant-pathogen interactions

Although the cuticle protects plants against microbial infections, Arabidopsis plants having a permeable cuticle exhibit a strong resistance to Botrytis cinerea. This surprising phenomenon may be explained by more rapid elicitation of defense responses and the subsequent accumulation of antimicrobial compounds on the surface of the plant. 
Our publications and contributions to this topic:

Chassot et al, 2007

Bessire et al, 2007


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FTIR imaging of the distribution of ester-bonds of an Arabidopsis petal at 1734 cm-1


Technique developments

Fourier-transform infrared spectroscopy was explored for assessing the quantity and quality of cutin and other components of the extracellular matrix of Arabidopsis petals. This research was performed in collaboration with Dr. Sylwester Mazurek of the Bio-molecules Analysis Platform of the Swiss Plant Science Web.
Our publications:

Sylwester Mazurek et al, 2013


Figure 1: Structure of the epidermal extracellular matrix.

Figure 2: Appearance of the cuticle in wild type and cutinase-expressing plants.

Figure 3: Organs fusions in cutinase-expressing Arabidopsis plants.

Figure 4: Infection with Botrytis cinerea.

Figure 5: Calcoflour-stained leaves of Arabidopsis.


Toluidine blue diffuses quickly into the petals of the permeable cuticle1 mutant of Arabidopsis