Newest publications
Die Erweiterung des genetischen Codes als molekulare Prozesskontrolle
(2025) Hiller, Eric; Hermann, Alexander; Lilge, Lars
Bioproduction of bioactive compounds on a large-scale poses challenges that require molecular strain engineering. By integrating the principle of genetic code expansion (GCE), the biosynthesis of the surfactin biosurfactant has been controlled in the production host Bacillus subtilis depending on the supply of a defined non-canonical amino acid. The regulation of this molecular process control has been transferred to high-cell-density fed-batch bioreactor procedures, allowing an initial upscaling.
Assessment of induced resistance in Agrostis stolonifera after application of UV-C irradiation and antagonistic microorganisms
(2025) Pawar, Seema; Voegele, Ralf Thomas
Agrostis stolonifera is a cool season grass widely used on golf courses and sports turf, where disease management requires intensive maintenance. Increasing restrictions on pesticide use have intensified the search for alternative, sustainable plant protection strategies. One potential approach is the application of low-dose UV-C irradiation (280 nm) to induce protection against pathogens through the stimulation of plant defences in turfgrass.
This study investigated the effects of UV-C irradiation on A. stolonifera, with a particular focus on the expression of the defence-related genes PR3 and NPR1 (Non-expresser of PR genes).
Turfgrass was exposed to single or repeated UV-C treatments under greenhouse conditions using doses ranging from 30 to 180 mJ/cm², corresponding to irradiation times of 1–6 s. Leaf samples were collected at defined intervals following treatment, and gene expression was quantified using RT-qPCR with TEF1-α as the reference gene. Defence-related gene expression was transiently upregulated, with peak expression generally observed 30 min post-irradiation, while no comparable changes were detected in untreated controls. Relative expression was calculated using the ΔΔCt method.
In parallel, outdoor field trials were conducted on a golf course using a battery powered mobile and controllable support frame with a roller fitted with UV-C lamps during the active growth phase of turfgrass. UV-C treatments were applied twice weekly over a four-week period, and additional trials assessed the combined application of UV-C irradiation and selected antagonistic microorganisms. Here too, UV-C applications resulted in transient upregulation of the two defence-related genes. Repeated applications gave slightly stronger responses than single treatments. The combined use of UV-C and biological control agents was associated with reduced dollar spot incidence. Here, clear differences could be observed depending on the number of UV-C applications.
The transient induction of defence-related gene expression following UV-C treatment together with observable long-term effects on dollar spot incidence indicates defence priming rather than sustained constitutive activation. Together, the greenhouse and field observations indicate that UV-C irradiation can activate defence responses in A. stolonifera and may contribute to disease suppression in turf management.
Expanding the BonnMu sequence‐indexed repository of transposon induced maize (Zea mays L.) mutations in dent and flint germplasm
(2024) Win, Yan Naing; Stöcker, Tyll; Du, Xuelian; Brox, Alexa; Pitz, Marion; Klaus, Alina; Piepho, Hans‐Peter; Schoof, Heiko; Hochholdinger, Frank; Marcon, Caroline
The BonnMu resource is a transposon tagged mutant collection designed for functional genomics studies in maize. To expand this resource, we crossed an active Mutator (Mu) stock with dent (B73, Co125) and flint (DK105, EP1, and F7) germplasm, resulting in the generation of 8064 mutagenized BonnMu F2‐families. Sequencing of these Mu‐tagged families revealed 425 924 presumptive heritable Mu insertions affecting 36 612 (83%) of the 44 303 high‐confidence gene models of maize (B73v5). On average, we observed 12 Mu insertions per gene (425 924 total insertions/36 612 affected genes) and 53 insertions per BonnMu F2‐family (425 924 total insertions/8064 families). Mu insertions and photos of seedling phenotypes from segregating BonnMu F2‐families can be accessed through the Maize Genetics and Genomics Database (MaizeGDB). Downstream examination via the automated Mutant‐seq Workflow Utility (MuWU) identified 94% of the presumptive germinal insertion sites in genic regions and only a small fraction of 6% inserting in non‐coding intergenic sequences of the genome. Consistently, Mu insertions aligned with gene‐dense chromosomal arms. In total, 42% of all BonnMu insertions were located in the 5′ untranslated region of genes, corresponding to accessible chromatin. Furthermore, for 38% of the insertions (163 843 of 425 924 total insertions) Mu1, Mu8 and MuDR were confirmed to be the causal Mu elements. Our publicly accessible European BonnMu resource has archived insertions covering two major germplasm groups, thus facilitating both forward and reverse genetics studies.
Molting incidents of Hyalomma spp. carrying human pathogens in Germany under different weather conditions
(2024) Chitimia-Dobler, Lidia; Springer, Andrea; Lang, Daniel; Lindau, Alexander; Fachet, Katrin; Dobler, Gerhard; Nijhof, Ard M.; Strube, Christina; Mackenstedt, Ute
Background: Hyalomma marginatum and H. rufipes are two-host tick species, which are mainly distributed in southern Europe, Africa to central Asia but may also be found in Central and Northern Europe through introduction by migratory birds.
Methods: Ticks were collected while feeding or crawling on animals and humans, or from the environment, in different regions in Germany, between 2019 and 2021 in a citizen science study and from 2022 to 2023 in the wake of this study.
Results: From 2019 to 2023, a total of 212 Hyalomma adult ticks were detected in Germany. This included 132 H. marginatum and 43 H. rufipes ticks sent to research institutions and 37 photographic records that were only identified to genus level. The number of detected ticks varied over the years, with the highest number of 119 specimens recorded in 2019, followed by 57 in 2020. Most of the specimens were collected from horses, while some were collected from other animals, humans or found crawling on human clothes or other objects inside or outside houses. The screening of 175 specimens for Crimean-Congo hemorrhagic fever virus and of 132 specimens for Babesia/Theileria spp. by PCR gave negative results, while human-pathogenic Rickettsia were detected in 44% (77/175) of the total samples. Subsequent amplicon sequencing and phylogenetic analysis of representative samples determined the species of 41 Rickettsia aeschlimannii and one R. slovaca sequences.
Conclusions: Analysis of climatic factors indicated a significantly higher probability of Hyalomma occurrence at locations with higher average spring temperature during the years 2019 and 2020 compared to randomly generated pseudo-absence locations. Dry and hot conditions probably facilitated Hyalomma nymphs’ survival and molting into adults during these yea
An enzymatic cascade enables sensitive and specific proximity labeling proteomics in challenging biological systems
(2025) Sroka, Tommy J.; Sanwald, Lea K.; Prasai, Avishek; Hoeren, Josefine; Trivigno, Valentina; Chaumet, Valerie; Krauß, Louisa M.; Weber, Damian; Yildiz, Daniela; von der Malsburg, Karina; Walentek, Peter; Haberkant, Per; Schrul, Bianca; Feistel, Kerstin; Mick, David U.
Ascorbate peroxidase (APEX) is a proximity labeling enzyme used for subcellular proteomics at high spatial and temporal resolution. However, toxicity of its substrate hydrogen peroxide and background labeling by endogenous peroxidases limit its use to in vitro studies of specific cell types. To minimize toxicity and reduce non-specific background labeling we establish a more versatile in situ APEX activation (iAPEX) workflow by combining APEX2 with a D-amino acid oxidase to locally produce hydrogen peroxide. Using iAPEX, we profile the proteomes of a cellular microdomain, the primary cilium, in cell lines not readily accessible to conventional APEX labeling and identify unknown ciliary proteins. Our study validates common ciliary proteins across two distinct cell lines, while observed differences may reflect heterogeneity in primary cilia proteomes. Furthermore, iAPEX proximity labeling is applicable to a range of cellular compartments including mitochondria and lipid droplets and can be employed in Xenopus laevis , which provides a proof-of-concept for future in vivo applications.