XVI International Botanical Congess

The phenylpropanoid pathway includes both the general pathway and the branch pathways leading to the synthesis of sinapic acid esters, flavonoids, and lignin. Among these compounds some seem to contribute to UV resistance, others might participate in the plant defense response, etc. Genes in this pathway would seem good candidates to have suffered adaptive evolution. Variation in a subset of these genes has been surveyed in Arabidopsis thaliana and its close relative Arabis petraea. The pattern and distribution of variation within and between species have been studied for the different gene regions. Comparison between regions has allowed contrasting the relative role of natural selection and genetic drift in shaping nucleotide variation in these genes.