Dr Christiane Nawrath, MER, Group Leader

Plant Molecular Biology Department UNIL Biophore Building CH-1015 Lausanne Tel: +41 21 692 42 56 Fax: +41 21 692 41 95 E-mail: Christiane.Nawrath@unil.ch 2 doctoral students

Research activities :

• Characterization of genes involved in the formation of cutin and the cuticle in Arabidopsis
  

Research key words :

• Plant-Environment Interactions, cutin, natural polyester, Plant-Pathogen Interactions

Link to our web site

The epidermis of the aerial portions of plants is covered with a continuous extracellular layer of hydrophobic material, the cuticle that plays an important role as interface between the plant and its environment. The cuticle consists of two major components, cutin and wax. Cutin, a unique plant biopolyester mainly composed of fatty acid derivatives, is the major structural component of the cuticle. Waxes are a complex mixture of very long chain fatty acid derivatives.

Even when a number of genes involved in cutin biosynthesis have been recently identified a large number of aspects relating to the formation of the cutin still remains to be discovered, including the mechanisms of transport of cutin monomers to the extracellular space, the polymerisation of cutin, the regulation of the well-structured deposition of cutin within the extracellular matrix, as well as the effects of an altered cutin deposition on the development and the physiology of the plant.

The research activities in my lab are aimed on further elucidating the biosynthesis of the cuticle and its different physiological functions in the model plant Arabidopsis. Different genetic screens have been undertaken to obtain mutants affected in cuticle formation. Two of the mutants have already been characterized. The botrytis-resistance 1 (bre1) mutant revealed that the LONG-CHAIN ACYL-CoA SYNTHEASE 2 is essential for cutin biosynthesis. Botrytis resistance in the bre1 mutant was conferred by the presence of additional antifungal compounds on the plant surface. The permeable cuticle1 (pec1) mutant showed that the ABC-transporter Pleiotropic Drug Resistance 4 of Arabidopsis is involved in the formation of the cuticle. In the future, additional cuticle mutants will be characterised regarding the ultrastructure and chemical composition of the cuticle, potential phenotypes in epidermal development and differentiation as well as resistance to various environmental stresses. The genes conferring the most interesting phenotypes will be cloned and characterized. The corresponding proteins will be analysed regarding their localization and function.

Representative publications :

• Christiane Nawrath (2006). Unraveling the complex network of cuticular structure and function. Curr. Opin. Plant Biol. 9: 281-287.

• Michael Bessire, Céline Chassot, Anne-Claude Jacquat, Sandra Borel, Jean MacDonald-Comber Petétot, Jean-Pierre Métraux, and Christiane Nawrath (2007). A permeable cuticle in Arabidopsis leads to a strong resistance to Botrytis cinerea EMBO J. 26: 2158-2168.

• Patrick Sieber, Martine Schorderet, Ulrich Ryser, Antony Buchala, Pappachan Kolattukudy, Jean-Pierre Métraux and Christiane Nawrath (2000). Transgenic Arabidopsis expressing a fungal cutinase show alterations in cuticle structure and properties and postgenital organ fusion. Plant Cell 12: 721-737.