Plant defence to sequential attack is adapted to prevalent herbivores
Poelman, Erik H. et al. (2021), Plant defence to sequential attack is adapted to prevalent herbivores, Dryad, Dataset, https://doi.org/10.5061/dryad.pnvx0k6n3
Plants have evolved plastic defence strategies to deal with uncertainty of when, by which species and in which order attack by herbivores will take place. However, the responses to current herbivore attack may come with a cost of compromising resistance to other, later arriving herbivores. Due to antagonistic cross-talk between physiological regulation of plant resistance to phloem-feeding and leaf-chewing herbivores, the feeding guild of the initial herbivore is considered to be the primary factor determining whether resistance to subsequent attack is compromised. We show that, by investigating 90 pair-wise insect-herbivore interactions among ten different herbivore species, resistance of the annual plant Brassica nigra to a later arriving herbivore species is not explained by feeding guild of the initial attacker. Instead, the prevalence of herbivore species that arrive on induced plants as approximated by three years of season-long insect community assessments in the field explained cross-resistance. Plants maintained resistance to prevalent herbivores in common patterns of herbivore arrival and compromises in resistance especially occurred for rare patterns of herbivore attack. We conclude that plants tailor induced defence strategies to deal with common patterns of sequential herbivore attack and anticipate arrival of the most prevalent herbivores.
Plant mediated interactions and insect resistance:
Plants were induced with one of ten different herbivore species for one week, cross resistance/susceptibility was measured for each of the ten herbivore species. Resistance was measured in terms of aphid population growth or caterpillar weight gain.
Field observations on insect prevalence:
Field occurance of species interactions was based on weekly observations of insect presence on Brassica nigra in three years. Interaction frequency represents the percentage of B. nigra plants in the field experiments on which the inducing herbivore species was observed before or at the same time as the receiving herbivore species.
Plant gene experession:
We characterized by the expression of LIPOXYGENASE 2 (LOX2) as marker gene for the JA pathway and PATHOGENESIS-RELATED PROTEIN 1 (PR1) as a marker for the SA pathway by Real Time PCR. Leaf samples were taken at 24 or 96 hours after plants were infested with herbivores. For each herbivore treatment and time point, we sampled the youngest fully developed leaf on which herbivores had been released from five plants and combined these samples to one biological replicate per herbivore species. We repeated our experiment 10 times, obtaining 10 biological replicates per herbivore species.
Our Excel sheet contains a Read-Me file explaining the abbreviations and type of data collected. The Nature Plants manauscript has a detailed methods section that outlines data collection and methodology in statistical approach.
We appreciate notification of data re-use. Please use the contact Erik.Poelman@wur.nl