Did a plant-herbivore arms race drive chemical diversity in Euphorbia?

Madeleine Ernst; Louis-Felix Nothias-Scaglia; Justin Van Der Hooft; Ricardo R. Silva; C. Haris Saslis-Lagoudakis; Olwen M. Grace; Karen Martinez-Swatson; Gustavo Hassemer; Luis Funez; Henrik T. Simonsen; Marnix H. Medema; Dan Staerk; Niclas Nilsson; Paola Lovato; Pieter Dorrestein; Nina Ronsted

doi:10.1101/323014

Did a plant-herbivore arms race drive chemical diversity in Euphorbia?

Madeleine Ernst ¹ , Louis-Felix Nothias-Scaglia, ¹ Justin Van Der Hooft ² , Ricardo R. Silva ¹ , C. Haris Saslis-Lagoudakis, ³ Olwen M. Grace ⁴ , Karen Martinez-Swatson, ³ Gustavo Hassemer ³ , Luis Funez ⁵ , Henrik T. Simonsen, ⁶ Marnix H. Medema ² , Dan Staerk, ⁷ Niclas Nilsson, ⁸ Paola Lovato, ⁸ Pieter Dorrestein ¹ , Nina Ronsted ³

¹ University of California San Diego
² Bioinformatics Group, Department of Plant Sciences, Wageningen University
³ Natural History Museum of Denmark
⁴ Comparative Plant & Fungal Biology, Royal Botanic Gardens
⁵ Regional University of Blumenau
⁶ Department of Biotechnology and Biomedicine, Technical University of Denmark
⁷ Department of Drug Design and Pharmacology, University of Copenhagen
⁸ Front End Innovation, LEO Pharma A/S

Published: 15 May 2018 by Cold Spring Harbor Laboratory in Evolutionary Biology

Cold Spring Harbor Laboratory, 10.1101/323014

Abstract: 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.

Keywords: differentiation, adaptation, HERBIVORY, evolutionary, genus, Chemical Diversity, structurally, diverse Euphorbia