Botanik Seminar

15 October 2025: Prof. Dr. Christoph Oberprieler, Universität Regensburg, Regensburg, Germany.

Wettstein goes Carrara - Integrative species delimitation in hybridising plant groups

Host: Prof. Dr. Gudun Kadereit

22 October 2025: Dr. Emy Yue Hu, Systematics, Biodiversity and Evolution of Plants, LMU Munich, Munich, Germany.

Network Biology Across Kingdoms: From Human Systems to Plant Ecology and Evolution

Network biology offers a powerful framework for modeling the complex, multi-layered interactions that underlie biological systems. By integrating concepts from graph theory, machine learning, and multi-omic data analysis, it enables us to move beyond isolated molecular signals toward a systems-level understanding of life. In this talk, I will introduce computational frameworks for integrating heterogeneous omics data and embedding biological networks for efficient analysis and link prediction—tools originally developed to uncover mechanisms of human disease and guide drug repurposing. I will then demonstrate how these approaches can be extended to plant systems, where differential network analysis can provide new insights into how regulatory interactions shift across environments. Looking forward, I aim to explore with you the untapped potential of network biology in plant systems to reveal new dimensions of plant ecology, adaptation, and evolution.

29 October 2025: PD. Dr. Andreas Fleischmann, SNSB-BSM, Botanische Staatssammlung München, Munich, Germany.

News from the world of carnivorous plants: pollination, prey, phylogenies & photosynthesis

The ca. 860 known species of carnivorous plants cover a lot of fascinating aspects that go beyond their insectivorous nature. The talk will cover the latest research on insect pollination of carnivorous plants, avoidance of pollinator-prey conflicts, prey attraction in sticky carnivorous plants, especially in sundews (Drosera, Droseraceae), insect kleptoparasitism (prey theft from carnivorous plants), prey-driven sympatric speciation, radiation and biogeography of "modern" Drosera-lineages out of Australia and a sneak-preview on CAM photosynthesis in dry tolerant Mexican Pinguicula (Lentibulariaceae).

5 November 2025: No Seminar

12 November 2025: Prof. Dr. emer. Hebert Hurka, Universität Osnabrück, Osnabrück, Germany.

Florogenesis of the Eurasian steppe region

The Eurasian steppe belt is the largest steppe region in the world and stretches from the Hungarian basin and Danube delta in the west to the Amur in the east. It ranges from 800 to 1000 km from North to South, and about 8000 km from West to East. In contrast with the knowledge about floristic composition of the present steppe area is a lack of studies on the evolutionary and biogeographical history of Eurasian steppe plants. To understand the florogenesis of the present steppe flora we have to consider the climate/landscape history of the Eurasian steppe regions. Only limited conclusions about ancient areas can be drawn from present-day biogeography. Since modern zonal steppe formed at different times and in different geographical regions, we expect colonization from different source areas and at different times. We hypothesize that molecular signals in steppe plants reflect the florogenetic dynamics and allow finer resolution of the history of the steppe flora. Dated molecular phylogenies, haplotype networks and ancient area reconstructions appear as proper tools to achieve our aims. We explore the geographic structure of genetic diversity within species or species groups. Based on several examples, colonization histories and migration times and routes are traced and analyzed for common patterns.

Host: Prof. Dr. Gudun Kadereit

19 November 2025: Dr. Christopher Lambert, Helmholtz-Zentrum f. Infektionsforschung GmbH, Braunschweig, Germany.

Improving the systematics of Xylariales through a polyphasic approach

Fungi of the order Xylariales (Ascomycota) are worldwide distributed and harbor complex lifecycles in which they appear as saprobes, phytopathogens or endophytes and form often carbonized conspicuous teleomorphs, which have traditionally been utilized for their systematic classification. This monolithic concept is constantly being challenged by ongoing molecular phylogenetic studies, which repeatedly reveal that anamorph morphology and production of secondary metabolites – chemical compounds dispensable for survival, but thought to improve fitness in natural habitats – serve as more robust predictors of generic affinities. Nowadays analysis of a broad spectrum of assessable phenotypic characters in tandem with each other in polyphasic studies is considered the gold standard to settle their relationships. An increasing number of reports also provides full genomes, leaving the systematics of the Xylariales on the verge of revolution. Epitypification campaigns pursued in the interim build a sound fundament for this endeavor, as many type specimen are lost or cultures for in-depth characterization are lacking. This sometimes unravels unexpected taxonomic affinities of surveyed taxa. Moreover, the study of chemotaxonomic markers, such as pigments, as well as the chemical survey of understudied or novel species continually serve as sources for novel chemistry. This fact can, for example, be exploited for drug discovery screening campaigns, in which these compounds often show promising bioactivity. This talk is dedicated to the report of recent surveys of fungal biodiversity combining the search for novel chemistry with the description and characterization of fungi of the Xylariales, with special emphasis on the taxonomy of the Xylariaceae, Hypoxylaceae and allied families. Moreover, new and previously described secondary metabolites, as well as their antimicrobial and cytotoxic properties will be discussed briefly as well as their related potential for future applications.

Host: Dr. Anže Žerdoner Čalasan

26 November 2025: No Seminar

3 December 2025: Dr. Norico Yamada, Principal Investigator; CNRS, Roscoff Marine Station, Roscoff, France.

How to upgrade stolen organelles into permanent plastids: A comparative transcriptomic perspective

Plastid (Chloroplast) origins remain one of the most striking examples of endosymbiosis, yet most extant photosynthetic organisms represent the evolutionary endpoint. In contrast, "dinotom" dinoflagellates retain diatom-derived tertiary plastids spanning a continuum of integration states: from temporary kleptoplastidy to permanently retained, transcriptionally active endosymbionts. This living evolutionary spectrum makes dinotoms uniquely suited to experimentally dissect how prey microalgae transition into permanent plastids.
In this talk, I will present new comparative transcriptomic data (Yamada et al. 2025, PNAS), the first cross-species analysis across three integration states in dinotoms. These results reveal striking transcriptional autonomy of symbiont nuclei, while expression of diatom genes appears domesticated to support photosynthesis. We also find evidence of early genomic modification and emerging host control over nutrient exchange. These findings raise key questions: is the degeneration of the diatom nucleus underway in these endosymbionts, and how do controls of metabolic exchange facilitate progression from kleptoplastidy to permanence. Building on this foundation, I will outline future projects combining cell imaging, bioinformatics, genetic transformation, and proteomics to illuminate these processes.

Host: Prof. Dr. Marc Gottschling

10 December 2025: Dr. Jan Tebben, Alfred Wegener Institut, Bremerhaven, Germany.

Polyketide ichthyotoxins in a changing world: ecology, history, and the chemistry of fish kills

Fish kills caused by toxic microalgae are becoming an increasingly visible threat as marine aquaculture expands and extreme climate events increase in frequency. Recent events, such as the Prymnesium parvum bloom in the Oder/Odra River in 2022, large Chrysochromulina leadbeateri blooms in Norway in 2019 and 2025, and the recent Karenia cristata bloom in South Australia, illustrate the impact of these events on public health as well as the substantial economic losses in fisheries, aquaculture, and tourism. Yet for many of these blooms, we still know surprisingly little about their underlying causes, the interactions between toxin producers and co-occurring organisms, or the mechanisms by which the toxins exert their effects.
This talk will focus on the chemical ecology of large polyketide ichthyotoxins and their producers, such as P. parvum (prymnesins) and C. leadbeateri (leadbeaterins). I will present an overview of recent bloom events and their commonalities, recent work on isolating and measuring fish-killing toxins in situ, and initial toxicity data that reveal their biological effects on fish, cell lines, and co-occurring organisms. Finally, I will combine these mechanistic insights with historical records and monitoring data to ask whether these toxin-producing species and their blooms represent a genuinely new phenomenon, or a long-standing, climate- and human-activated hazard that we are only now beginning to recognize and quantify.

Host: PD Dr. Andreas Beck

11 December 2025 at 9:00 am (extra seminar): Dr. Charlotte Goeyers, Protistology & Aquatic Ecology, Dept. of Biology, Ghent University, Belgium.

Unlocking the full potential of moss-associated diatoms to reconstruct local climate change in alpine and arctic regions

The planet is warming at an accelerating pace, and the consequences—melting ice caps, rising sea levels, and shifting ecosystems—are becoming more tangible every day. While temperatures are rising twice as fast compared to the global average in alpine regions, Arctic warming is amplified up to four times. However, since meteorological data is extremely scarce before the 1950s, it is challenging to put climate change into a long-term perspective. In this talk, I will discuss how moss diatoms can contribute to a better understanding of past, current, and future climate change in alpine-arctic regions. Given their extreme sensitivity to changes in their environment, diatoms are excellent as bio-indicators. Due to their glass cell walls, diatoms are remarkably resistant to degradation over time, enabling their preservation in ice and sediment cores or even herbarium collections. As many herbariums contain historic moss collections sampled after the end of the Little Ice Age in alpine-arctic regions, this offers unique opportunities to reconstruct how their diatom communities responded to climatic shifts over time. I will furthermore demonstrate how both morphology and metabarcoding on modern and historic herbarium samples can be applied to reconstruct past climate regimes, facilitating future conservation efforts in these sensitive ecosystems.

Host: PD Dr. Andreas Beck

17 December 2025: Dr. Christina Steidele, TUM, Munich, Germany.

Regulatory networks driving barley’s response to Fusarium head blight in complex environments

Fusarium head blight (FHB) represents a major threat to barley and other small-grain cereals, causing substantial yield and quality losses. The disease is primarily induced by fungi within the Fusarium species complex, which can produce harmful mycotoxins. Although transcriptional responses to FHB have been characterized, the regulatory mechanisms underlying these responses—particularly under combined biotic and abiotic stresses such as drought—remain poorly understood.
We employed network inference approaches combined with the analysis of genomic resources to identify stress-responsive genes and candidate transcription factors (TFs) that may orchestrate these responses. Furthermore, we integrated multi-omics datasets, including transcriptomic, proteomic, and metabolomic profiles, to uncover a coordinated upregulation of aromatic amino acid-derived secondary metabolism as a consistent defense strategy in barley against FHB. This metabolic reprogramming involves the accumulation of tryptophan-derived metabolites (e.g., tryptamine, serotonin) and barley-specific hydroxycinnamylamides (hordatines).
Our gene regulatory network analyses predict TFs with strong influence over pathways associated with aromatic amino acid-derived secondary metabolism. By targeting key TFs and generating stable barley mutants with altered metabolic profiles, we aim to elucidate the functional contribution of these pathways to basal defense mechanisms against FHB. This integrative approach provides novel insights into the regulatory architecture of barley’s response to FHB and highlights potential targets for improving disease resistance under complex stress conditions.

Host: Prof. Dr. Silke Werth

24 December until 7 January 2026: No seminars

14 January 2026 at 11:15: Dr. Julius Jeiter, Dresden University of Technology, Dresden, Germany.

Integrating comparative morphology and development into evolutionary research

For many years, comparative morphology was the primary source of information for systematic studies. However, since the early 1990s, molecular phylogenetics and phylogenomics have revolutionised plant systematics. Technological advances and progress in our understanding of evolutionary processes have resulted in a well-resolved and stable system of plants, particularly for angiosperms. The current system of angiosperms is primarily, if not entirely, based on molecular phylogenetics.
This well-resolved, stable system provides an ideal foundation for understanding morphological and anatomical evolution. However, it is imperative for this task that morphological and anatomical characters are clearly delineated and defined. It is important to note that the 'mature' state of characters, when considered in isolation from their development, has the potential to be misleading. This is due to the fact that it has the potential to obscure significant aspects that are necessary for a comprehensive definition. It is therefore imperative to acknowledge the significance of development in character definition when formulating evolutionary hypotheses about character evolution in a molecular phylogenetic context.
I argue that, when combined with the latest technologies and a developmental approach, comparative morphology is an important modern scientific discipline that is essential for improving our understanding of the evolution of angiosperms and many other taxa.
Here, I present guidelines for conducting comparative morphological, anatomical and developmental studies. Examples from my current research show how this approach is being used. I want to encourage students and early-career scientists to adopt a comparative morphological approach in their plant systematics research.

Host: Dr. Agnes Scheunert

21 January 2026: Dr. Clara Groot Crego, Austrian Research Centre for Forests (BFW), Vienna, Austria.

The role of introgression in shaping ecological diversity and local adaptation: insights from Tillandsia and in European white oaks

Host: Dr. Thibaud Messerschmid

28 January 2026: Prof. Dr. Norman J. Wickett, Universität Wien, Vienna, Austria.

Phylogenomic approaches to understanding species radiations from deep to shallow phylogenetic scales

A phylogeny provides the foundation for comparative evolutionary biology, particularly for understanding patterns of current and past diversity. Limitations in data availability have long been overcome thanks to high-throughput sequencing technologies, but the application of this huge volumes of data to phylogenetic questions has led to a better understanding of the relationship between phylogenetic signal and the history of speciation. In this seminar, I will discuss the application of target enrichment, transcriptomes, and whole-genome sequences to studying species radiations, spanning both deep (the evolution of mosses) and shallow (species complexes within Oenothera) scales.

Host: Dr. Diego F. Morales-Briones

4 February 2026: Prof. Dr. Peter Schönswetter, Department of Botany, University of Innsbruck, Innsbruck, Austria.

Patterns of polyploid distribution in the Eastern Alps based on an unprecedentedly large dataset

Polyploidy, the possession of more than two chromosome sets, is a key feature of plant biodiversity. A recent comprehensive analysis of global chromosome count data has shown that the frequency of polyploids increases with latitude. Much less is known about ploidy variation and distribution in mountain areas. In temperate mountain ranges, the frequency of polyploids may rise towards high-elevation habitats (due to, for instance, their higher stress tolerance) and with increasing distance from glacial refugia (due to better colonizing abilities). Employing flow cytometry, we established
ploidy levels of a flora-wide sampling of almost 45,000 individuals of angiosperms from 101 elevational transects in the Eastern Alps. Unexpectedly, the highest frequency of polyploids was found in the lowest elevation belt and diploids predominate with increasing altitude. On the other hand, polyploids increase with increasing distance from Pleistocene refugia, but this effect is relatively weak. This project does not only represent an unprecedentedly broad empirical test at the landscape level of the long-standing hypothesis of a positive association between genome duplication and spatio-temporal environmental variation. It also yielded much basic ploidy level information, which forms a solid base for upcoming taxonomic studies targeting heteroploid species. Finally, our data also clearly pointed at the existence of species new to science.

Host: Dr. Simon Pfanzelt

11 February 2026: Prof. Dr. Joachim W. Kadereit, Systematics, Biodiversity and Evolution of Plants, LMU Munich, Munich, Germany.

Phylogeny, classification and the evolution of characters

Host: Dr. Andreas Gröger

25 March 2026 (extra seminar): Prof. Dr. Susanne S. Renner, Washington University, Department of Biology, Saint Louis (Missouri), U.S.A.

Understanding & solving gene tree conflicts in the angiosperms

Host: Prof. Dr. Gudun Kadereit