Plant defences and herbivore coexistence Sara Magalhães cE3c: Centre for Ecology, Evolution and Environmental changes Faculdade de Ciências, Universidade de Lisboa

My scientific path Arne Janssen & Mous Sabelis University of Amsterdam 1996-2004 Ecological interactions in plant-herbivore food webs Isabel Gordo Instituto Gulbenkian de Ciência 2006-2008 Evolution of competing mutations in E. coli Isabelle Olivieri University of Montpellier 2004-2006 Evolution of host-plant use in spider mites

Current position Group leader Adaptation in heterogeneous environments 2008-Present

People who did the work Diogo Godinho Jéssica Paulo

Understanding complex communities A “simplified” food web for the Northwest Atlantic

Food webs in agriculture predatory mite predatory bug Food webs in agriculture predatory mite spider mite1 thrips spider mite2 Plant

Food webs in agriculture Plant thrips predatory mite spider mite1 predatory bug spider mite2 Predation

Food webs in agriculture Plant thrips predatory mite spider mite1 predatory bug spider mite2 Competition

Three traits that define competition B Competitive ability C1 C2 Niche width A C R C1 B C2 A B Niche construction C1 C2 R These traits act simultaneously on species evolution and distribution. These traits shape and are shaped by the evolution of organisms.

To understand complex communities we need to disentangle the relative role of traits that shape the evolution and distribution of competing populations in a simplified system Just read it

The system Tetranychus urticae Tetranychus evansi Tomato plant B C1 C2

Competitive ability C1 B C2 C1 B C2 1 GEN

Niche width Resource type Resource used

Tomato, a metal-accumulating plant

The elemental defence hypothesis

Cadmium concentrations (μM) Niche width T. evansi T. urticae Cd Eggs / day Cadmium concentrations (μM)

Plant ‘quality’: Sugar leaf content

Effect of mites on plant defences Niche construction Effect of mites on plant defences Wild type T. urticae T. evansi We will focus on niche construction, a trait that has been given much attention lately, and one that is particularly important for eco-evo feedbacks. In our system, one spider mite downregulates plant defences, such that the performance of all herbivores is better on preinfested plants than on clean plants. This is a clear example of niche construction. The other species upregulates plant defences, like most herbivores do.

Effect of mites on plant defences Niche construction Effect of mites on plant defences Wild type Def-1 T. urticae T. evansi x Importantly, in our system, we have a tomato mutant (def-1, for defenceless), which is similar to the wild-type plant in all aspects except that plant defences do not respond to infestation by herbivores. So the two environments differ exclusively in the possibility of mites to construct their niche. This property is unique to our system, and it thus represents an exceptional experimental tool. x

T. evansi performance on wild-type and def-1 plants Eggs / day

Does niche construction vary with niche location? OR How do organic and elemental defences interact?

Down- and up-regulation on plants with different cadmium concentrations

Experimental evolution. Mite generation time: 12-15 days The questions Individual differences Coexistence between competitors Competition traits (Co)evolution with competitors Our second question concerns how competitive traits shape and are shaped by coevolution with competitors. To address this issue we will use the explanatory power of experimental evolution, in which populations evolve in controlled environments. This is made possible in our system by the short generation time of spider mites (at least 25 generations in one year). Experimental evolution. Mite generation time: 12-15 days

Major contributions of the project Addresses key issues: - How individual differences affects coexistence. - Evolution of niche construction and its consequences. An integrative view of how ecology and evolution shape competition. Generating predictions for the role of competition in complex communities. e.g. our recent work on plant-mite interactions: Calatayud et al. 2016 PNAS