Biosynthesis of plant cell wall lipid polyesters
The study of the synthesis and structure of cutin and suberin is a major area of focus of our lab. These polymeric lipids form protective extracellular barriers that represent fundamental adaptations of plants to terrestrial environment. A better understanding of the synthesis and regulation of surface lipids may facilitate the development of stress-tolerant plants, as well as plants that accumulate hydrocarbons for use as renewable energy sources.
Our strategy
1) Identification of novel genes by bioinformatics using public databases or transcriptomics (RNAseq);
2) Phenotypic characterization of loss-of-function mutants of selected genes: polymeric lipids are first depolymerized from residues after solvent extraction. Individual monomers are then identified and quantified by gas chromatography;
3) Gene characterization by gain-of-function approaches, including analyses of stable transgenic plants and/or transient assays in Nicotiana benthamiana leaves.
External funding
Lipid polyester monomers
The monomeric units that form plant lipid polyesters can replace several petrochemical feedstock molecules. For instance, aliphatic diacids, epoxy fatty acids and omega-hydroxy fatty acids, some of which are rare in nature, could be used in the production of industrial bioproducts ranging from bioplastics and lubricants to cosmetics and medicines.
Plant models
We use a reverse genetics approach in Arabidopsis thaliana. This herbaceous plant has a short life cycle, is easily transformed, is not very different from many crops and mutants are available for most genes. To better track the metabolism of these complex cell wall-associated polymers, we are using wet stigmas of Nicotiana tabacum, which produce soluble polyesters of glycerol and hydroxy fatty acids that are structrually similar to cutin. We also employ hybrid poplar as a woody tree model to explore bark suberin genetics.
