Biology subjects

Ojeda-Prieto, L.

Publications and source records attributed to Ojeda-Prieto, L..

8 recordsLinked to original sources

bioRxiv2026

Aphid presence and abundance, more than variation in leaf terpenoid profiles at the plant and plot-level, drive ant behaviour on the perennial forb Tanacetum vulgare

1) Differences in specialized metabolites are common both within and between plant species and are often thought to have regulating functions in ecological interactions, including herbivores like aphids. Although ants commonly rely on chemical cues in their behaviour and resource finding, very little is known about whether specialized plant chemistry regulates ant behaviour to foster successful ant-aphid mutualisms on plants and in the surrounding vegetation. 2) Using a chemodiversity experiment containing 84 plots with 6 chemotypes of Tansy (Tanacetum vulgare L. Asteraceae) planted in different proportions, i.e., plot-level chemotype richness, we tested the effects of plot-level chemotype richness, plot-level chemodiversity metrics, and individual chemotype presence on black garden ant (Lasius niger Linnaeus) nesting, patrolling and recruitment behaviour to plants and plots. Furthermore, we assessed the influence of plant chemotype on the pink tansy aphid (Metopeurum fuscoviride H.L.G. Stroyan) presence and abundance, as well as ant occurrence on Tansy plants. 3) We found that Tansy plot-level chemodiversity only minimally affected most of the observed ant behaviour, except for nesting, which was marginally positively impacted by plot-level chemotype richness. Clear effects of individual terpenoid chemotypes were observed on ant visitation rates, as well as on aphid presence and abundance. Strongly significant relationships between the probability of ant occurrence and aphid abundance and occurrence observed in our study suggest that ants and aphids are most strongly guided by the presence and abundance of their mutualist partners, rather than by specialized chemistry alone in the Tansy system.

ecology↗

bioRxiv2025

Compartmentalized above- and belowground defenses in Tanacetum vulgare are tailored to localized antagonists

Specialized metabolites, specially terpenoids, play a key role in plant defense. However, how terpenoid diversity governs inducible chemistry and root architectural development remain poorly understood. We used a combination of high-throughput root phenotyping and targeted metabolite profiling to examine three leaf terpenoid chemotypes of common tansy (Tanacetum vulgare). Using a phenotyping platform, we tested whether (i) root-chewing wireworms induce root terpenoids locally and alter shoot terpenoids systemically, (ii) phloem-feeding aphids elicit chemotype-dependent responses, and (iii) chemotypes differ in root-system development. After root establishment, the plants were exposed to wireworms (Agriotes spp.) and aphids (Macrosiphoniella tanacetaria), both separately and together, and were then monitored for 60 days. The chemotypes differed in inducible chemistry and root architecture. Chemotype 1 developed the fastest-growing root systems and the highest root:shoot ratios. Wireworms increased stored root sesquiterpenoid levels by more than twofold in chemotypes 1 and 2, whereas chemotype 3 was largely unresponsive. Aphids didn t alter root terpenoids, but significantly increased leaf monoterpenoid emissions in chemotype 1 without affecting stored pools. Therefore, storage and emission were decoupled and depended on both organ and chemotype. Our analysis reveals a compartmentalized, chemotype-specific defense strategy in tansy, highlighting the coordinated regulation of the root system and inducible chemistry. HighlightIn Tanacetum vulgare, wireworms boost root sesquiterpenoids and aphids elevate leaf monoterpenoid emissions; chemotype governs terpenoid defense and root system architecture.

plant biology↗

bioRxiv2025

Aphid colony size is affected by plant chemotype and terpenoid mixture evenness in tansy

Plants are hosts for above- and belowground insect communities that can influence each other via above-belowground plant-physiological dynamics. To mediate interactions, plants produce secondary metabolites, including terpenoids, and mixtures can differ intraspecifically. While intraspecific variation in plant chemistry gained increased interest, the extent to which intraspecific differences in plant chemistry mediate above-belowground interactions of herbivores remains unclear. We used a full factorial design with six distinct terpenoid chemotypes, differing in their chemical diversity of tansy (Tanacetum vulgare). We exposed these to the aboveground herbivore Macrosiphoniella tanacetaria (Hemiptera: Aphididae), the belowground herbivore Agriotes sp. (Coleoptera: Elateridae), no herbivore or both herbivores, to determine if chemotypes or the chemical diversity of plant compounds affected aphid performance and if the chemical profile mediated the interactions between herbivores. We found that aphid colony size differed between chemotypes, with the strongest colony increase over time in a mixed-mixtures chemotype, and the weakest in a {beta}-thujone chemotype. Root herbivory had no effect on aphid colony size and this did not differ between chemotypes. Aphid colony size was positively correlated with terpenoid evenness, but not with other diversity components. Tansy chemotypes differed in their morphological responses to aboveground herbivory, whereas belowground herbivory exerted minimal impacts. Overall, our results show that intraspecific variation in terpenoid profiles directly and indirectly modify ecological interactions on a plant, with plant chemistry mediating aphid performance and chemotypes differing in their morphological responses to herbivory.

ecology↗

bioRxiv2024

Increasing intraspecific plant chemical diversity at plot and plant level affects herbivorous, predatory, and pollinating arthropod communities

1. Plant chemistry mediates interactions between plants and their environment. While intraspecific chemodiversity at the plant level is well-studied, the effects of chemodiversity at the community level on arthropod interactions need more attention. We conducted a field experiment to test how intraspecific chemodiversity affects plant-arthropod interactions. 2. We manipulated plots of Tanacetum vulgare L., varying in chemotype richness and composition, and monitored four arthropod groups (herbivores, flower visitors, predators, and ants) over three seasons. We hypothesized that higher plot-level chemotype richness would enhance occurrence across all studied arthropod groups but have functional group-specific effects on abundance, resulting in reduced herbivore and ant abundance and increased flower visitor and predator abundance with increased chemotype richness. 3. Using mixed models, we found that increasing plot-level chemotype richness had a limited effect on most arthropod group occurrences but led to significant changes in abundance. Herbivore abundance decreased over time, and flower visitor abundance increased, while predatory arthropods and ants remained largely unaffected. Furthermore, we found that chemotype presence within a plot showed year-to-year variation in its effects, particularly on herbivores in which positive effects turned negative over time, and on flower visitors in which the presence of specific chemotypes positively affected their abundances. Predators and ants, on the other hand, showed weaker and more variable responses to specific chemotypes. 4. These results suggest that different arthropod groups may respond to plant chemicals through different ecological mechanisms. Our research underscores the role of plant chemical diversity in shaping insect communities and contributing to ecosystem dynamics.

ecology↗

bioRxiv2023

Geographic distribution of terpenoid chemotypes in Tanacetum vulgare mediates tansy aphid occurrence and abundance

AimIntraspecific variations of specialized metabolites in plants, such as terpenoids, are used to determine chemotypes. Tansy (Tanacetum vulgare L.) exhibits diverse terpenoid profiles, that affect insect communities. However, it is not fully known whether patterns of their chemical composition and associated insects vary on a large scale. Here, we investigated the geographic distribution of mono- and sesquiterpenoid chemotypes in tansy leaves and the effects of these chemotypes on colonization by insect communities across Germany. MethodsWe sampled tansy leaves from 26 sites along a north-south and west-east transect in Germany. Leaves from ten plants with and five plants without aphids was collected from each site. Hexane-extracted metabolites from leaf tissues were analysed by gas chromatography-mass spectrometry (GC-MS). Plant morphological traits, aphid occurrence and abundance, and occurrence of ants were recorded. The effect of plant chemotype, plant morphological parameters, and site parameters such as temperature and precipitation on insect occurrences were analysed. ResultsPlants clustered into four monoterpenoid and four sesquiterpenoid chemotype classes. Monoterpene classes differed in their latitudinal distribution, whereas sesquiterpenes were more evenly distributed across the transect. Aphid and ant occurrence were influenced by monoterpenoids and specific traits. Plants of monoterpenoid class 1 were colonized by Metopeurum fuscoviride and ants significantly more often than expected by chance compared to plants from monoterpenoid class 4. Aphid abundance was negatively affected by host plant height, and increasing average annual temperature positively influenced the occurrence of ants. ConclusionWe found significant geographic differences in the chemodiversity of tansy and show that monoterpenoids affect aphid and ant occurrence, while host plant height can influence aphid abundance. We show that geographic variation in plant chemistry and morphology influences insect communities assemblage on tansy plants.

ecology↗

bioRxiv2023

Intraspecific chemical variation of Tanacetum vulgare at plant and plot level affects plant growth and reproductive traits in field plant communities

O_LIIntraspecific plant chemodiversity plays a fundamental role in interactions between plants and their interaction partners. However, how chemodiversity at the stand level (plant communities that vary in the number and type of plant chemotypes that grow in them, i.e., chemotype richness) affects ecosystem functioning is not fully understood. C_LIO_LIWe describe a biodiversity experiment using six chemotypes of common tansy (Tanacetum vulgare L., Asteraceae) to manipulate intraspecific plant chemodiversity at the plot level. We tested the effects of chemotype identity and plot-level chemotype richness (1-6) on plant growth and reproductive traits at plant and plot levels. C_LIO_LIWe found that chemotypes differed in growth and reproductive traits and that traits were affected by the plot-level chemotype richness. Although morphological differences became less pronounced over time, reproductive phenology patterns persisted. It suggests that chemotypes initially adopted different growth strategies, which may facilitate their establishment in nature. C_LIO_LIAlthough chemotype richness did not lead to overyielding effects, plot-level trait means were affected by the presence or absence of certain chemotypes in a plot, and the direction of the effect depended on the chemotype. C_LIO_LIWe analyzed plot-level headspace emissions and found that blends released from plant communities were neither richer nor more diverse with increasing plot-level chemotype richness. However, we found that plots became more dissimilar in their headspace terpenoids as they were more dissimilar in their leaf-terpenoid profiles. C_LIO_LIThis long-term field experiment will allow further investigation into plant-insect interactions and insect community assembly in response to intraspecific chemodiversity. C_LI

ecology↗

bioRxiv2023

Understanding the phytochemical diversity of plants: Quantification, variation and ecological function

Plants produce a great number of phytochemical compounds mediating a variety of different functions. Recently, phytochemical diversity (chemodiversity), a way which to quantify the complex phenotype formed by sets of phytochemicals, has been suggested to be important for function. However, no study has systematically examined the potential (in)direct functional importance of chemodiversity on a general level, partly due to a lack of an agreement on how to quantify this aspect of the plant phenotype. This paper has four aims: 1) We discuss how chemodiversity (deconstructed into components of richness, evenness and disparity) may quantify different aspects of the phenotype that are ecologically relevant. 2) We systematically review the literature on chemodiversity to examine methodological practices, explore ecological patterns of variability in diversity across different levels of biological organization, and investigate the functional role of this diversity in interactions between plants and other organisms. 3) We provide a framework facilitating decisions on which measure of chemodiversity is best used in different contexts. 4) We outline open questions and avenues for future research in this area. A more thorough understanding of phytochemical diversity will increase our knowledge on the functional role phytochemical compounds, and how they shape ecological interactions between plants and their environment.

ecology↗

bioRxiv2023

Chemodiversity affects preference for Tanacetum vulgare chemotypes in two aphid species

Plants of the same species often strongly differ in morphological traits, as well as in the abundance and composition of specialized metabolite profiles. Specialized metabolites can act as mediators of interactions on plants, and affect insect presence and abundance in the field. However, how specialized chemistry shapes plant attractiveness to herbivorous insects is not fully understood. Here we used common tansy (Tanacetum vulgare L., Asteraceae) - a perennial plant that is highly diverse in terpenoid composition and is known to have variable chemotypes - to test whether 1) plants with different chemotype profiles differ in attractiveness to two specialized aphids, Macrosiphoniella tanacetaria and Uroleucon tanaceti, in pairwise choice assays. Furthermore, we tested whether 2) the diversity of the terpenoid blend affects aphid attractiveness. Lastly, we tested how 3) plant chemical traits relate to plant morphological traits, and which best explain aphid preference. We found that M. tanacetaria preferred two out of five chemotypes, dominated by -thujone/{beta}-thujone and {beta}-trans-chrysanthenyl acetate, respectively, while avoiding a chemotype dominated by -pinene/sabinene. U. tanaceti showed no clear preference towards chemotypes, but when given the choice between chemotypes dominated by -thujone/{beta}-thujone and by -pinene/sabinene, they preferred the former. Importantly, plant attractiveness to aphids tended to be negatively correlated with chemodiversity, i.e., the number of terpenoid compounds, in M. tanacetaria, but not in U. tanaceti. Interestingly, the approximate concentration and number of terpenoid compounds was generally higher in larger and bushier plants. Hence, we did not observe a trade-off between plant growth and defence. We conclude that plant chemical composition affects plant attractiveness to aphids and hence may contribute to variation in natural aphid colonization patterns on plants of the same species.

ecology↗