Coevolution can explain defensive secondary metabolite diversity in plants



Speed, Mike ORCID: 0000-0001-8162-2052, Fenton, Andy ORCID: 0000-0002-7676-917X, Jones, Meriel, Ruxton, Graeme and Brockhurst, Michael
(2015) Coevolution can explain defensive secondary metabolite diversity in plants. New Phytologist, 208 (4). pp. 1251-1263.

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Abstract

• Many plant species produce defensive compounds that are often highly diverse within and between populations. The genetic and cellular mechanisms by which metabolite diversity is produced are increasingly understood, but the evolutionary explanations for persistent diversification in plant secondary metabolites have received less attention. Here we consider the role of plant-herbivore coevolution in the maintenance and characteristics of diversity in plant secondary metabolites. • We present a simple model in which plants can evolve to invest in a range of defensive toxins and herbivores can evolve resistance to these toxins and we allow either single-species evolution or reciprocal coevolution. • Our model shows that coevolution maintains toxin diversity within populations. Furthermore there is a fundamental coevolutionary asymmetry between plants and their herbivores, because herbivores must resist all plant toxins, whereas plants need challenge and nullify only one resistance trait. As a consequence, average plant fitness increases and insect fitness decreases as numbers of toxins increases. When costs apply the model showed both arms race escalation and strong coevolutionary fluctuation in toxin levels across time. • We discuss the results in the context of other evolutionary explanations for secondary metabolite diversification.

Item Type: Article
Uncontrolled Keywords: chemical defence, coevolution, herbivore, secondary metabolite, specialized metabolism, theoretical modelling
Depositing User: Symplectic Admin
Date Deposited: 09 Dec 2015 17:01
Last Modified: 16 Dec 2022 12:04
DOI: 10.1111/nph.13560
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/2042099