TY - JOUR T1 - Did a plant-herbivore arms race drive chemical diversity in <em>Euphorbia?</em> JF - bioRxiv DO - 10.1101/323014 SP - 323014 AU - M. Ernst AU - L.-F. Nothias AU - J. J. J. van der Hooft AU - R. R. Silva AU - C. H. Saslis-Lagoudakis AU - O. M. Grace AU - K. Martinez-Swatson AU - G. Hassemer AU - L. A. Funez AU - H. T. Simonsen AU - M. H. Medema AU - D. Staerk AU - N. Nilsson AU - P. Lovato AU - P. C. Dorrestein AU - N. Rønsted Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/05/15/323014.abstract N2 - The genus Euphorbia is among the most diverse and species-rich plant genera on Earth, exhibiting a near-cosmopolitan distribution and extraordinary chemical diversity, especially across highly toxic macro-and polycyclic diterpenoids. However, very little is known about drivers and evolutionary origins of chemical diversity within Euphorbia. Here, we investigate 43 Euphorbia species to understand how geographic separation over evolutionary time has impacted chemical differentiation. We show that the structurally highly diverse Euphorbia diterpenoids are significantly reduced in species native to the Americas, compared to the Eurasian and African continents, where the genus originated. The localization of these compounds to young stems and roots suggest ecological relevance in herbivory defense and immunomodulatory defense mechanisms match diterpenoid levels, indicating chemoevolutionary adaptation to reduced herbivory pressure.One Sentence Summary Global chemo-evolutionary adaptation of Euphorbia affected immunomodulatory defense mechanisms. ER -