Illuminating the evolutionary paths towards plant metabolic diversity

RDP seminar by Hugues Renault from the Institut de Biologie Moléculaire des Plantes, Strasbourg

During evolution, plants acquired the capacity to produce an astonishing number of metabolites. This vast chemical repertoire is thought to have conveyed adaptive functions that allowed plants to colonize almost all earth habitats. Our work seeks to understand the evolutionary mechanisms that drove metabolic diversification and the associated functions. We have developed an approach using the evolution of cytochrome P450 enzyme superfamily as a reporter of plant metabolism diversification. The seminar will illustrate the power of this strategy through multiple examples (1–3), which emphasize the stochastic nature of evolution.
Our current focus lies on the evolution of metabolic adaptation of plants to land. In particular, we question the plant-specific phenylpropanoid pathway. Using a molecular genetics approach in the model moss Physcomitrella patens, we discovered that a likely ancestral function of this metabolism is the production of phenolic precursors required for cuticle establishment (4). This cuticle appeared essential for organ formation, desiccation tolerance and erect growth, therefore representing a key adaptation to terrestrial conditions. From these findings also emerged the hypothesis that the four land plant apoplastic biopolymers cutin, suberin, lignin and sporopollenin, derived from a single progenitor.

1. Liu, Z. et al. A Conserved cytochrome P450 evolved in seed plants regulates flower maturation. Mol. Plant 8, 1751–1765 (2015).
2. Liu, Z. et al. Evolutionary interplay between sister cytochrome P450 genes shapes plasticity in plant metabolism. Nat. Commun. 7, 13026 (2016).
3. Renault, H. et al. Gene duplication leads to altered membrane topology of a cytochrome P450 enzyme in seed plants. Mol. Biol. Evol. 34, 2041–2056 (2017).
4. Renault, H. et al. A phenol-enriched cuticle is ancestral to lignin evolution in land plants. Nat. Commun. 8, 14713 (2017).

Date : Thursday, October 18th
Time : 11am
Location : Place de l’Ecole

RDP host : Gwyneth Ingram