Dataset Information

Plant spines deter herbivory by restricting caterpillar movement.

ABSTRACT: The spines of flowering plants are thought to function primarily in defence against mammalian herbivores; however, we previously reported that feeding by Manduca sexta caterpillars on the leaves of horsenettle plants (Solanum carolinense) induces increased development of internode spines on new growth. To determine whether and how spines impact caterpillar feeding, we conducted assays with three Solanaceous plant species that vary in spine numbers (S. carolinense, S. atropurpureum and S. aethiopicum) and also manipulated spine numbers within each species. We found that M. sexta caterpillars located experimentally isolated target leaves much more quickly on plants with experimentally removed spines compared with plants with intact spines. Moreover, it took caterpillars longer to defoliate species with relatively high spine numbers (S. carolinense and particularly Satropurpureum) compared with S. aethiopicum, which has fewer spines. These findings suggest that spines may play a significant role in defence against insect herbivores by restricting herbivore movement and increasing the time taken to access feeding sites, with possible consequences including longer developmental periods and increased vulnerability or apparency to predators.

SUBMITTER: Kariyat RR

PROVIDER: S-EPMC5454246 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Plant spines deter herbivory by restricting caterpillar movement.

Kariyat Rupesh R RR Hardison Sean B SB De Moraes Consuelo M CM Mescher Mark C MC

Biology letters 20170501 5

The spines of flowering plants are thought to function primarily in defence against mammalian herbivores; however, we previously reported that feeding by Manduca sexta caterpillars on the leaves of horsenettle plants (Solanum carolinense) induces increased development of internode spines on new growth. To determine whether and how spines impact caterpillar feeding, we conducted assays with three Solanaceous plant species that vary in spine numbers (S. carolinense, ...[more]

PMID: 28490447

Similar Datasets

Project description:Background and aimsThe processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission?MethodsWe studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission.Key resultsPoa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission.ConclusionsHerbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.

Project description:Assemblages of insect herbivores are structured by plant traits such as nutrient content, secondary metabolites, physical traits, and phenology. Many of these traits are phylogenetically conserved, implying a decrease in trait similarity with increasing phylogenetic distance of the host plant taxa. Thus, a metric of phylogenetic distances and relationships can be considered a proxy for phylogenetically conserved plant traits and used to predict variation in herbivorous insect assemblages among co-occurring plant species.Using a Holarctic dataset of exposed-feeding and shelter-building caterpillars, we aimed at showing how phylogenetic relationships among host plants explain compositional changes and characteristics of herbivore assemblages.Our plant-caterpillar network data derived from plot-based samplings at three different continents included >28,000 individual caterpillar-plant interactions. We tested whether increasing phylogenetic distance of the host plants leads to a decrease in caterpillar assemblage overlap. We further investigated to what degree phylogenetic isolation of a host tree species within the local community explains abundance, density, richness, and mean specialization of its associated caterpillar assemblage.The overlap of caterpillar assemblages decreased with increasing phylogenetic distance among the host tree species. Phylogenetic isolation of a host plant within the local plant community was correlated with lower richness and mean specialization of the associated caterpillar assemblages. Phylogenetic isolation had no effect on caterpillar abundance or density. The effects of plant phylogeny were consistent across exposed-feeding and shelter-building caterpillars.Our study reveals that distance metrics obtained from host plant phylogeny are useful predictors to explain compositional turnover among hosts and host-specific variations in richness and mean specialization of associated insect herbivore assemblages in temperate broadleaf forests. As phylogenetic information of plant communities is becoming increasingly available, further large-scale studies are needed to investigate to what degree plant phylogeny structures herbivore assemblages in other biomes and ecosystems.

Project description:Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of aboveground herbivory, and this mechanism may play a role for plant species coexistence.

Dataset Information

Plant spines deter herbivory by restricting caterpillar movement.

Publications

Plant spines deter herbivory by restricting caterpillar movement.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets