Phylogenetic and genomic mechanisms shaping glucosinolate innovation

Plants have created an immense diversity of specialized metabolites to optimize fitness within a complex environment. Each plant lineage has created novel metabolites often using the classical duplication/neo-functionalization model, but this is constrained by undersampled genera and an absence of high-quality genomes. Phylogenetically resolved genomes, deeper chemical sampling and mechanistic assessment of glucosinolate diversity in the Brassicales is beginning to fill in a deeper understanding of how chemical novelty arises. This is showing that small-scale duplications like tandem or distal events may have more influence on the formation of metabolic novelty. Similarly, this is showing that gene loss is playing a significant role in metabolic diversity across the entire genera. Finally, mechanistic work is showing that the glucosinolate pathway is not a defined endpoint but is being used as a launching pad for the creation of other metabolites. In combination, this work is showing the potential in combining high-quality genomes with balanced phylogenetic sampling to develop improved models on how specialized metabolite gene evolution occurs.