Laboratory of Evolutionary Ecology
Priscila received an award at the VII Congress of the Latin American Association of Chemical Ecology
Our PhD student Priscila Mezzomo received an award for her oral presentation at the VII Congress of the Latin American Association of Chemical Ecology, held in Buenos Aires - Argentina in early December 2023. In her talk, she shows how volatile and non-volatile metabolites can have contrasting roles as plant defensive strategies. Specifically, Priscila's results suggest great specificity in volatile plant responses, as induced upon feeding by different insect herbivores.
The oral presentation drew its foundation from a published paper:
Leaf volatile and nonvolatile metabolites show different levels of specificity in response to herbivory, https://doi.org/10.1002/ece3.10123
Figure 1. Main classes of herbivores used in the experiment.
A – Specialist adult beetles (three species used)
B – Generalist adult beetles (two species used)
C – Specialist beetle larvae (three species used)
D – Specialist sawfly larvae (two species used)
E – Specialist caterpillars (three species used)
F – Generalist caterpillars (eight species used)
G – Specialist sap-suckers (two species used)
H – Generalist sap-suckers (one species used)
Insect feeding drives specificity in induced defences in willows.
Plants produce diverse chemical defences with contrasting effects on different insect herbivores. Therefore, deploying herbivore-specific responses can help plants increase their defensive efficiency. Here, we explore how variation in induced plant responses correlates with herbivore species, order, feeding guild, and level of specialization. In a greenhouse experiment, we exposed plants of Salix fragilis (Linnaeus, 1753) to 22 herbivore species naturally associated with this host. The insects belonged to four orders (Coleoptera, Lepidoptera, Hemiptera, and Hymenoptera), three feeding guilds (external leaf-chewers, leaf-tying chewers, and sap-sucking), and included both dietary specialists and generalists. Following herbivory, we quantified induced changes in volatiles (GC-MS) and nonvolatile leaf metabolites using untargeted metabolomics (UHPLC-MS). We performed multivariate analyses to assess the correlation between herbivore order, feeding guild, dietary specialization, the amount of chewing damage caused by the herbivores, and induced responses. As a result, we found that the volatile composition was best explained by the amount of chewing damage and insect order, with Coleoptera and Lepidoptera eliciting significantly different responses. Furthermore, we recorded significant differences in elicited volatiles among some species within the two herbivore orders. Contrastingly, we observed that the variation in nonvolatile leaf metabolites was mainly explained by the presence of insects rather than by their identity, as plants exposed to herbivores showed significantly different metabolites from controls. Herbivore order also played a role to some extent, with beetles eliciting different responses than other herbivores. In this sense, we show that the induction of volatile and nonvolatile leaf metabolites shows different levels of specificity. The specificity in volatiles could potentially serve as an important cue to specialist predators or parasitoids, increasing the efficacy of volatiles as indirect defences. By contrast, the induction of nonvolatile leaf metabolites was largely unaffected by herbivore identity. Most nonvolatile metabolites were downregulated, possibly indicating that plants redirected their resources from leaves in response to herbivory. Our results demonstrate how diverse responses to herbivores can contribute to the diversity of plant defensive strategies.
Volf M., Fontanilla A.M., Vanhakylä S., Abe T., Libra M., Kogo R., Lilip R. , Kamata N. , Murakami M., Novotny V., Salminen J-P. , Segar S. T., (2024) High intraspecific variability and previous experience affect polyphenol metabolism in polyphagous Lymantria mathura caterpillars. Ecology and Evolution, https://doi.org/10.1002/ece3.10973