Biology subjects

Trusch, F.

Publications and source records attributed to Trusch, F..

3 recordsLinked to original sources

bioRxiv2025

Development of a stable transformation method for Saprolegnia parasitica

Saprolegniosis in salmonids, a disease caused by the oomycete Saprolegnia parasitica, poses a serious global threat to wild salmon and to aquaculture. To be able to functionally characterise genes in S. parasitica, it is essential to develop a stable transformation method for S. parasitica. We describe for the first time a method that can generate stable transgenic S. parasitica strains. Transformants were generated following the uptake and integration of a mutated gene from Achlya hypogyna conferring imidazole resistance, CYP51 using S. parasitica protoplasts in the presence of polyethylene glycol (PEG) and lipofectamine. This leads to production of CYP51 protein which catalyses a crucial demethylation step in the biosynthesis of ergosterol. As a result, there is no disruption of ergosterol synthesis and the transformants, but not the wild type S. parasitica, can grow in the presence of imidazole. Putative transformants growing in the presence of up to 10 mM imidazole were confirmed by PCR.

microbiology↗

bioRxiv2024

Paired C-type lectin receptors mediate specific recognition of divergent oomycete pathogens in C. elegans.

Innate immune responses can be initiated through the detection of pathogen or damage-associated molecular patterns by host receptors that are often present on the surface of immune cells. While certain invertebrates like Caenorhabditis elegans lack professional immune cells, they still respond to infection in a pathogen-specific manner. It has been debated for years whether homologues of the canonical pathogen recognition receptors are also functioning in the nematode. Here we show that C-type lectin receptors mediate species-specific recognition of divergent oomycetes in C. elegans. A CLEC-27/CLEC-35 pair is essential for recognition of the oomycete Myzocytiopsis humicola, while a CLEC-26/CLEC-36 pair is required for detection of Haptoglossa zoospora. Both clec pairs are transcriptionally regulated through a shared promoter by the conserved PRD-like homeodomain transcription factor CEH-37/OTX2 and act in sensory neurons and the anterior intestine to trigger a protective immune response in the epidermis. This system enables redundant tissue sensing of oomycete threats through canonical CLEC receptors and host defense via cross-tissue communication. HighlightsO_LIA CLEC-27/CLEC-35 pair is required for recognition of the oomycete Myzocytiopsis humicola C_LIO_LIA CLEC-26/CLEC-36 pair is required for recognition of the oomycete Haptoglossa zoospora C_LIO_LIBoth CLEC pairs are co-regulated by the homeodomain transcription factor CEH-37/OTX2 C_LIO_LIBoth CLEC pairs function redundantly in sensory neurons and the intestine for host defense C_LI

immunology↗

bioRxiv2023

The WY domain of an RxLR effector drives interactions with a host target phosphatase to mimic host regulatory proteins and promote Phytophthora infestans infection.

Plant pathogens manipulate the cellular environment of the host to facilitate infection and colonization, often leading to plant diseases. To accomplish this, many specialized pathogens secrete virulence proteins called effectors into the host cell, which subvert processes such as immune signalling, gene transcription, and host metabolism. Phytophthora infestans, the causative agent of potato late blight, employs an expanded repertoire of RxLR effectors with WY domains to manipulate the host through direct interaction with protein targets. However, our understanding of the molecular mechanisms underlying the interactions between WY effectors and their host targets remains limited. In this study, we performed a structural and biophysical characterization of the P. infestans WY effector, Pi04314, in complex with the potato Protein Phosphatase 1-c (PP1c). We elucidate how Pi04314 uses a WY domain and a specialised C-terminal loop carrying a KVxF motif that interact with conserved surfaces on PP1c, known to be used by host regulatory proteins for guiding function. Through biophysical and in planta analyses, we demonstrate that Pi04314 WY or KVxF mutants lose their ability to bind PP1c. The loss of PP1c binding correlates with a reduced capacity to re-localize PP1c from the nucleolus and a decrease in lesion size in plant infection assays. This study provides insights into the manipulation of plant hosts by pathogens, revealing how effectors exploit key regulatory interfaces in host proteins to modify their function and facilitate disease.

plant biology↗