2020/04/06 by Tobias Züst, Susan R. Strickler, Adrian F. Powell +14 · 1 citation
Agricultural and Biological Sciences · #Plant Ecology and Taxonomy Studies #Essential Oils and Antimicrobial Activity #Botanical Research and Chemistry
paper · pdf · doi:10.7554/elife.51712
openalex publication_date 2020/04/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Phytochemical diversity is thought to result from coevolutionary cycles as specialization in herbivores imposes diversifying selection on plant chemical defenses. Plants in the speciose genus Erysimum (Brassicaceae) produce both ancestral glucosinolates and evolutionarily novel cardenolides as defenses. Here we test macroevolutionary hypotheses on co-expression, co-regulation, and diversification of these potentially redundant defenses across this genus. We sequenced and assembled the genome of E. cheiranthoides and foliar transcriptomes of 47 additional Erysimum species to construct a phylogeny from 9868 orthologous genes, revealing several geographic clades but also high levels of gene discordance. Concentrations, inducibility, and diversity of the two defenses varied independently among species, with no evidence for trade-offs. Closely related, geographically co-occurring species shared similar cardenolide traits, but not glucosinolate traits, likely as a result of specific selective pressures acting on each defense. Ancestral and novel chemical defenses in Erysimum thus appear to provide complementary rather than redundant functions.