Search bioRxiv⌕ Search

Biology subjects

Thuermer, A.

Publications and source records attributed to Thuermer, A..

4 recordsLinked to original sources

A single pathogen-secreted protein reprograms plants for drought resilience

Climate change-enforced drought stress conditions and diseases caused by pathogens often co-occur and represent one of the greatest challenges in plant science1-3. Wilt pathogens that colonize water-conducting plant tissues can aggravate the problem and affect a wide range of agricultural crops4,5. However, whilst fungal infections with the vascular pathogen Verticillium dahliae are typically associated with wilt symptoms due to occlusion of xylem tissues, the related V. longisporum induces de novo formation of tracheary elements6,7. This promotes not only its virulence but also enables elevated water storage capacity of the infected host plant and resilience against drought stress conditions6,7. Here, we identified a secreted Verticillium protein, TRANSDIFFERENTIATION EFFECTOR (TRADE), which triggers cell identity switches of bundle sheath cells into tracheary elements. We show that TRADE interacts with the intracellular plant protein VARICOSE (VCS), a conserved component of the mRNA turnover machinery and ortholog of the metazoan protein ENHANCER OF DECAPPING 4 (EDC4/HEDLS/Ge-1)8. The TRADE-VCS interaction induces SUCROSE NON-FERMENTING 1 (SNF1)-related protein kinase (SRK)-dependent phosphorylation and thus dysfunction of VCS. This affects the abundance of mRNAs encoding master regulators of xylem differentiation and demonstrates how a single pathogen effector protein triggers complex tissue-specific developmental reprogramming and thus promotes abiotic stress resilience.

plant biology↗

Possible adaption of the 2022 Monkeypox virus to the human host through gene duplication and loss

Poxviruses are known to evolve slower than RNA viruses, with rearrangements such as gene gain and loss as the main driver for host adaption. In 2022 the world is being challenged by the largest global outbreak so far of Monkeypox virus, and the virus seems to have established itself in the human community. Here we report five MPXV genomes with extensive gene duplication and loss, including duplications of up to 18,000 bp to the opposed genome end, and deletions at the site of insertion of up to 16,000 bp, as a possible adaption to the human host.

molecular biology↗

Listeria monocytogenes gene essentiality under laboratory conditions and during macrophage infection

The Gram-positive bacterium Listeria monocytogenes occurs widespread in the environment and infects humans when ingested along with contaminated food. Such infections are particularly dangerous for risk group patients, for whom they represent a life-threatening disease. To invent novel strategies to control contamination and disease, it is important to identify those cellular processes that maintain pathogen growth in- and outside the host. We here have applied transposon insertion sequencing (Tn-Seq) to L. monocytogenes for the identification of such processes on a genome-wide scale. Our approach classified 394 open reading frames as essential for growth under standard laboratory conditions and identified 42 further genes, which become additionally essential during intracellular growth in macrophages. Most essential genes encode components of the translation machinery, act in chromosome-related processes, cell division and biosynthesis of the cellular envelope. Several cofactor biosynthesis pathways and 29 genes with unknown functions were also essential, opening novel options for the development of anti- listerial drugs. Among the genes specifically required during intracellular growth were known virulence factors, genes compensating intracellular auxotrophies and several cell division genes. Our experiments also highlight the importance of PASTA kinase signalling, glycine metabolism and chromosome segregation for efficient intracellular growth of L. monocytogenes.

microbiology↗

Characterization of three Yarrowia lipolytica strains in respect to different cultivation temperatures and metabolite secretion

Despite the increasing relevance, ranging from academic research to industrial applications, only a limited number of nonconventional, oleaginous Yarrowia lipolytica strains are characterized in detail. Therefore, we analyzed three strains in regard to their metabolic and physiological properties and in respect to important characteristics of a production strains. A flow cytometry method was set up to evaluate their fitness in a rapid manner. By investigating different cultivation conditions and media compositions, similarities and differences between the distinct strain backgrounds could be derived. Especially sugar alcohol production, as well as a agglomeration of cells were found to be connected with growth at high temperatures. In addition, sugar alcohol production was independent of high substrate concentrations under these conditions. To investigate particular traits, including growth characteristics and metabolite concentrations, genomic analysis were performed. We found sequence variations for one third of the annotated proteins but no obvious link to all phenotypic features.

microbiology↗