Abstract
Individual plants are usually attacked by multiple insect species. The occurrence of insect herbivores may be uncertain in terms of when, by which species, and in which order the attack will take place. To deal with uncertainty of attack, plants are phenotypically plastic in their growth and defence strategies. Remarkably, most of our understanding of plant physiological adaptations in response to insect herbivory is limited to single or dual attack. From my latest studies that pioneered in unravelling plant responses to multi-herbivore attack, a new concept arises that suggests that plants use risk management strategies. Plants optimise defence to the dynamics of attacker communities rather than maximising defence to each current attacker. Because plant species differ in the community of insects with which they interact, and closely related plant species have more similar insect communities, I hypothesize that dynamics of insect communities drive evolutionary transition in defence plasticity. Major knowledge gaps are what repertoire of defence plasticity plants have in dealing with multi-herbivore attack and how this matches with patterns of herbivore colonisation in the field. To bridge these knowledge gaps, the proposed research takes a novel multi-disciplinary integrative approach to i) Discover the repertoire of plant defence plasticity to multi-herbivore attack and its phylogenetic relationship; ii) Explore the underlying phylogenomic organisation of plasticity in defence signalling; iii) Determine how plant growth-defence strategies affect the plant fitness outcome of multi-herbivore attack; iv) Elucidate whether dynamics of insect-community assembly correspond with plant adaptations to multi-herbivore attack. The Brassicaceae plant family will be used because of its large number of sequenced plant genomes and my expertise in Brassicaceae plant-insect community ecology. The approach will result in a breakthrough in understanding of the evolution of defence plasticity to multi-herbivore attack, a central paradigm in the research fields of plant evolutionary ecology and physiology.
Netherlands