Seminar: Evolving fast and slow: P450 enzymes in the phenolic metabolism
By Daniele Werck
Abstract: Our aim in the last years was to study how evolution of a large family of genes such as those encoding P450 enzymes can lead to metabolic diversification. A few examples will be presented on how duplication can lead to altered topology or to altered function.
Dr Danièle Werck is Research Director at Strasbourg University, National Research Centre, Department for Plant Molecular Biology. Her team focuses on cytochromes P450 for biopolymers, signalling and adaptation.
Topic and strategies: Cytochromes P450 are essential for the functionalization and further decoration of hydrophobic precursors in all branches of plant metabolism. The reactions they catalyze are slow, irreversible, substrate-specific and thus rate limiting. The aim of our group is to reveal new functions of this family of enzymes and the evolutionary mechanism that led to their functional diversification. This study is mainly focused on enzymes in the biosynthesis of biopolymers and of aromatic compounds, on related signalling and impact on floral development and chemical ecology.
The sequencing initiatives highlighted the complexity of the plant secondary metabolism and the essential role of the cytochromes P450 oxygenases in evolution of the metabolic grid. The function of nearly 70% of the P450 enzymes in a model plant such as Arabidopsis is still unclear or completely unknown. We have developed tools to support elucidation of their functions: expression systems, collections of recombinant enzymes, functional screening procedures, and bioinformatic analysis of public transcriptome data for the prediction of their function in the plant and in the metabolic grid. The latter analysis points to new and so far unexpected P450 functions and metabolic branches in A. thaliana. It very clearly identifies enzymes predicted to be involved in oxylipin, phenolic, hormone, or terpenoid metabolism. In the last years, we focused in priority on some of the latter. Functions in development and defence have been explored via classical functional genomic approaches and chemical ecology.