Biology subjects

Eilers, E.

Publications and source records attributed to Eilers, E..

5 recordsLinked to original sources

bioRxiv2026

Molecular sources of monoterpenoid chemodiversity in the Asteraceae Tanacetum vulgare suggest a new model for the evolution of specialized metabolism

Highly diversified specialized metabolism enables plant communication with pollinators, herbivores, and protectors1-4. Its chemodiversity, under which evenness, richness and variation is summarized5-7, includes many compounds without known function1-4 and presents an evolutionary conundrum about how and what is selected for8,9. Due to its complexity, it is frequently unknown how it is encoded in genomes. To produce population level chemodiversity, the traits need to allow for highly chemodiverse and highly specific individuals in the same population. Here we use metabolomics, transcriptomics, and genomics combined with field analyses and functional assays of monoterpene synthases in the Asteraceae Tanacetum vulgare (tansy) and identify forces which produce high population level chemodiversity: selection for product specificity in enzymes, loss-of-expression alleles, absence variation, and specialized metabolism islands drive individuals towards low chemodiversity while unlinked enzyme loci, expression variation alleles, presence variation, and de novo enzyme evolution enable high individual chemodiversity. Since the molecular data suggests selection for mechanisms that increase chemodiversity itself at the population level, the screening hypothesis which posited plants produce a reservoir of diverse chemicals prior to selection8 should be replaced by a chemodiversity selection hypothesis. The results demonstrate that, in addition to plant protection via individual chemicals with known targeting mechanisms for predators, being different from your neighbors even if you are closely related is likely an important element in plant protection.

plant biology↗

bioRxiv2024

mTOR signaling regulates aberrant epithelial cell proliferative and migratory behaviors characteristic of airway mucous metaplasia in asthma

In asthma, the airway epithelium is hyperplastic, hypertrophied, and lined with numerous large MUC5AC-containing goblet cells (GC). Furthermore, the normal epithelial architecture is disorganized with numerous, what we here describe as, ectopic goblet cells (eGC) deep within the thickened epithelial layer disconnected from the lumenal surface. mTOR is a highly conserved pathway that regulates cell size and proliferation. We hypothesized that the balance between mTOR and autophagy signaling regulates key features of the asthma epithelial layer. Airway histological sections from subjects with asthma had increased frequency of eGC and increased levels of mTOR phosphorylation target-Ribosomal S6. Using human airway epithelial cells (hAECs) with IL-13 stimulation and timed withdrawal to stimulate resolution, we found that multiple key downstream phosphorylation targets downstream from the mTOR complex were increased during early IL-13-mediated mucous metaplasia, and then significantly declined during resolution. The IL-13-mediated changes in mTOR signaling were paralleled by morphologic changes with airway epithelial hypertrophy, hyperplasia, and frequency of eGC. We then examined the relationship between mTOR and autophagy using mice deficient in autophagy protein Atg16L1. Despite having increased cytoplasmic mucins, mouse AECs from Atg16L1 deficient mice had no significant difference in mTOR downstream signaling. mTOR inhibition with rapamycin led to a loss of IL-13-mediated epithelial hypertrophy, hyperplasia, ectopic GC distribution, and reduction in cytoplasmic MUC5AC levels. mTOR inhibition was also associated with a reduction in aberrant IL-13-mediated hAEC proliferation and migration. Our findings demonstrate that mTOR signaling is associated with mucous metaplasia and is crucial to the disorganized airway epithelial structure and function characteristic of muco-obstructive airway diseases such as asthma. Graphical Abstract Key ConceptsO_LIThe airway epithelium in asthma is disorganized and characterized by cellular proliferation, aberrant migration, and goblet cell mucous metaplasia. C_LIO_LImTOR signaling is a dynamic process during IL-13-mediated mucous metaplasia, increasing with IL-13 stimulation and declining during resolution. C_LIO_LImTOR signaling is strongly increased in the asthmatic airway epithelium. C_LIO_LImTOR signaling is associated with the development of key features of the metaplastic airway epithelium including cell proliferation and ectopic distribution of goblet cells and aberrant cellular migration. C_LIO_LIInhibition of mTOR leads to decreased epithelial hypertrophy, reduced ectopic goblet cells, and cellular migration. C_LI

cell biology↗

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↗

bioRxiv2022

LUBAC assembles a signaling platform at mitochondria for signal amplification and shuttling of NF-ĸB to the nucleus

Mitochondria are increasingly recognized as cellular hubs to orchestrate signaling pathways that regulate metabolism, redox homeostasis, and cell fate decisions. Recent research revealed a role of mitochondria also in innate immune signaling, however, the mechanisms of how mitochondria affect signal transduction are poorly understood. Here we show that the NF-B pathway activated by TNF employs mitochondria as a platform for signal amplification and shuttling of activated NF-B to the nucleus. TNF induces the recruitment of HOIP, the catalytic component of the linear ubiquitin chain assembly complex (LUBAC), and its substrate NEMO to the outer mitochondrial membrane, where M1- and K63-linked ubiquitin chains are generated. NF-B is locally activated and transported to the nucleus by mitochondria, resulting in an increase in mitochondria-nucleus contact sites in a HOIP-dependent manner. Notably, TNF-induced stabilization of the mitochondrial kinase PINK1 contributes to signal amplification by antagonizing the M1-ubiquitin-specific deubiquitinase OTULIN.

cell biology↗

bioRxiv2021

Sex and origin-specific inbreeding effects on flower attractiveness to specialised pollinators

We investigate whether inbreeding has particularly fatal consequences for dioecious plants by diminishing their floral attractiveness and the associated pollinator visitation rates disproportionally in females. We also test whether the magnitude of such effects depends on the evolutionary histories of plant populations. We recorded spatial, olfactory, colour and rewarding flower attractiveness traits as well as pollinator visitation rates in experimentally inbred and outbred, male and female Silene latifolia plants from European and North American populations differing in their evolutionary histories. We found that inbreeding specifically impairs spatial and olfactory attractiveness. Our results support that sex-specific selection and gene expression partially magnified these inbreeding costs for females, and that divergent evolutionary histories altered the genetic architecture underlying inbreeding effects across population origins. Moreover, they highlight that inbreeding effects on olfactory attractiveness have a huge potential to disrupt interactions among plants and specialist moth pollinators, which are mediated by elaborate chemical communication.

ecology↗