Biology subjects

Scheikl, D.

Publications and source records attributed to Scheikl, D..

3 recordsLinked to original sources

bioRxiv2026

Proteogenomics of Blumeria hordei supports RNA and protein coding innovative potential derived from transposable elements

Some filamentous plant-pathogenic fungi have comparably large genome sizes within the fungal kingdom due to the proliferation of transposable elements (TEs). Blumeria hordei (Bh), the causal agent of the powdery mildew disease on barley, is a filamentous obligate biotrophic fungus. Compared to other ascomycetes, it contains a low number of genes but a high genomic TE content of approximately 75%. Yet, a comprehensive understanding of the contribution of TEs to the RNA and protein landscape of Bh is lacking. Here, we use Bh as a model to study transcripts and proteins derived from genes and individual TEs. Therefore, we created two high-quality genome assemblies of the German Bh isolate TUM1 and the Australian Bh isolate AUS1. We applied deep proteomics with mass spectrometry, long-read and short-read sequencing on both DNA and RNA. Based on these multi-omic resources, we completed nearly gapless genome assemblies, new gene and TE annotations, and effector predictions. Using long-read RNA sequencing, we detected extensive co-transcription of TEs and genes as TE-gene chimeric transcripts. We identified previously unpredicted splice variants or genes, partially supported by proteomics. The intergenic and TE genomic space of Bh TUM1 gives rise to thousands of transcripts and several novel TE-derived proteins that lack from previous TE protein predictions. Together, this supports an existing potential for expression of novel transcripts and proteins from highly abundant TEs in the Bh genome.

plant biology↗

bioRxiv2020

Population studies in the wild tomato species Solanum chilense reveal maintenance and loss of resistance at geographically distinct locations

Natural plant populations encounter strong pathogen pressure and defense-associated genes are known to be under different selection pressure dependent on the pressure by the pathogens. Here we use wild tomato Solanum chilense populations to investigate natural resistance against Cladosporium fulvum, a well-known pathogenic fungus of domesticated tomatoes. We show that populations of S. chilense differ in resistance against the pathogen. Next, we explored the underlying molecular processes in a species wide-context. Then, focusing on recognition of the two prominent avirulence factors secreted by C. fulvum (Avr4 and Avr9) in central and northern populations of S. chilense we observed high complexity in the cognate homologues of Cladosporium resistance (Hcr9) locus underlying the recognition of these effectors. Presence of canonical genomic regions coding for Cf-4 and Cf-9, two major dominant resistance genes in the Hcr9 locus recognizing Avr4 and Avr9, respectively, does not meet prediction from Avr response phenotypes. We find both genes in varying fractions of the plant populations and we show possible co-existence of two functionally active resistance genes, previously thought to be allelic. Additionally, we observed the complete local absence of recognition of additional Avr proteins of C. fulvum. In the southern populations we attribute this to changes in the coregulatory network. As a result of loss of pathogen pressure or adaptation to extreme climatic conditions. This may ultimately explain the observed pathogen susceptibility in the southern populations. This work puts major gene mediated disease resistance in an ecological context.

ecology↗

bioRxiv2017

A small subset of NLR genes drives local adaptation to pathogens in wild tomato

O_LINucleotide binding site, Leucine-rich repeat Receptors (NLRs), are canonical resistance (R) genes in plants, fungi and animals, functioning as central (helper) and peripheral (sensor) genes in a signalling network. We investigate NLR evolution during the colonisation of novel habitats in a model tomato species, Solanum chilense.\nC_LIO_LIWe used R-gene enrichment sequencing (RENSeq) to obtain polymorphism data at NLRs of 140 plants sampled across 14 populations covering the whole species range. We inferred the past demographic history of habitat colonisation by resequencing whole genomes from three S. chilense plants from three key populations, and performing Approximate Bayesian Computation using data from the 14 populations.\nC_LIO_LIUsing these parameters we simulated the genetic differentiation statistics distribution expected under neutral NLR evolution, and identified small subsets of outlier NLRs exhibiting signatures of selection across populations.\nC_LIO_LINLRs under selection between habitats are more often helper genes, while those showing signatures of adaptation in single populations are more often sensor-NLRs. Thus, centrality in the NLR network does not constrain NLR evolvability, and new mutations in central genes in the network are key for R gene adaptation during colonisation of different habitats.\nC_LI

evolutionary biology↗