Biology subjects

Kroll, E.

Publications and source records attributed to Kroll, E..

6 recordsLinked to original sources

bioRxiv2026

Comparative analysis of 15 chromosome-scale near T2T assemblies of Brazilian Fusarium graminearum isolates

Fusarium graminearum is the causative agent of Fusarium head blight of wheat, yet genomic resources for Brazilian populations, where it is the dominant species, remain limited to a single reference genome. We report fifteen near telomere-to-telomere (T2T) assemblies of Brazilian F. graminearum isolates generated with Oxford Nanopore sequencing. Each genome was assembled into four nuclear chromosomes, with 118 of 120 telomeres resolved, BUSCO completeness of 99.199.3%, and 14,80214,894 predicted genes per isolate. The genomes are structurally conserved, showing no chromosome-scale rearrangements and uniform transposable element content. Orthology assignment placed 90.4% of genes in the core genome. This suggests that the large phenotypic variance in aggressiveness observed between isolates likely resides in regulatory differences and/or within the small and largely uncharacterised accessory fraction. Ultimately, these assemblies provide a high-resolution resource for the global FHB community and a foundation for comparative analysis of a previously underrepresented population.

bioinformatics↗

bioRxiv2026

The impact of long-read sequencing on fungal genome assemblies: progress and disparity

Fungal genomics has expanded rapidly over the past 30 years, and recently the pace and breath has further quickened for many taxa, although many taxonomic gaps persist. With three decades of rapid growth, fungal genomics now merits a re-examination of its history, progress, and unresolved taxonomic gaps. Here, we review the development of fungal genomics from early efforts such as the Fungal Genome Initiative to current progress driven by third-generation long-read sequencing. We have compiled and summarised publicly available fungal genomes to highlight trends in assembly quality, adoption of long-read technologies, and taxonomic representation. Notably, substantial phylogenetic gaps remain, particularly outside Dikarya, and significant challenges persist for unculturable taxa. This review identifies priorities for the fungal community, including: (1) coordinated efforts to close major taxonomic gaps across the fungal tree of life; (2) improved repository metrics to facilitate identification of high-quality assemblies; and (3) improved and standardised genome annotation which is lacking for most assemblies. Together, these steps will support the development of reliable genomic resources that capture the full breadth of diversity across the fungal kingdom, generating foundational data for comparative genomics, evolutionary biology, functional studies, genetic studies and applied research.

genomics↗

bioRxiv2025

Cryptic multicellularity in wild yeast brings selective advantages under stress

Multicellularity has evolved dozens of times in many branches across the Tree of Life, in each case producing a new kind of individual that has the potential for division of labor among its constituent cells. In many of these instances, nascent multicellularity has remained facultative, manifesting only under conditions where it provides a decisive fitness advantage to the genome in which it has arisen. Here we investigate the mechanistic basis for, and the selective advantages of, cryptic multicellularity in wild strains of the yeast Saccharomyces cerevisiae. Meiotic purification of this trait, followed by genome sequencing, indicates that the genome of diploid champagne yeast DB146 is homozygous at the AMN1 locus (Antagonist of Mitotic exit Network) for an allele that dysregulates post-mitotic cell separation. Expression of this trait in haploid derivatives of DB146 results in clonal multicellular clusters in which daughters remain attached to mother cell walls. Systematic analysis of viability in haploid and diploid DB146 derivatives subjected to benign conditions as well as to starvation, desiccation, and low temperature at different cell titers demonstrates that haploid multicellular variants exhibit higher survivorship under conditions that wild yeast likely experience when they overwinter. Examining a collection of other wild strains, we find that [~]20% exhibit ploidy-dependent expression of clonal multicellularity. Altogether, our data suggest that in yeast that sporulate when starved, cryptic multicellularity may come under balancing selection because haploid multicellular progeny enjoy a transient survival advantage that fades once favorable growth conditions resume.

microbiology↗

bioRxiv2024

The Fusarium graminearum effector protease FgTPP1 suppresses immune responses and facilitates Fusarium Head Blight Disease

Most plant pathogens secrete effector proteins to circumvent host immune responses, thereby promoting pathogen virulence. One such pathogen is the fungus Fusarium graminearum, which causes Fusarium Head Blight (FHB) disease on wheat and barley. Transcriptomic analyses revealed that F. graminearum expresses many candidate effector proteins during early phases of the infection process, some of which are annotated as proteases. However, the contributions of these proteases to virulence remains poorly defined. Here, we characterize a F. graminearum endopeptidase, FgTPP1 (FGSG_11164), that is highly upregulated during wheat spikelet infection and is secreted from fungal cells. To elucidate the potential role of FgTPP1 in F. graminearum virulence, we generated FgTPP1 deletion mutants ({Delta}Fgtpp1) and performed FHB infection assays. While the number of completely bleached spikes infected by F. graminearum wild-type reached 50% of total infected spikes, the number of fully bleached spikes infected by{Delta} Fgtpp1 mutants was 25%, suggesting FgTPP1 contributes to fungal virulence. Transient expression of green fluorescent protein (GFP)-tagged FgTPP1 revealed that FgTPP1 localizes, in part, to chloroplasts and attenuates chitin-mediated activation of mitogen-activated protein kinase (MAPK) signaling, reactive oxygen species production, and cell death induced by an autoactive disease resistance protein when expressed in planta. Notably, the FgTPP1 protein is conserved across the Ascomycota phylum, making it a core effector among ascomycete plant pathogens. These properties make FgTPP1 an ideal candidate for decoy substrate engineering, with the goal of engineering resistance to FHB, and likely other crop diseases caused by ascomycete fungi.

plant biology↗

bioRxiv2024

A conserved fungal Knr4/Smi1 protein is vital for maintaining cell wall integrity and host plant pathogenesis

Filamentous plant pathogenic fungi pose significant threats to global food security, particularly through diseases like Fusarium Head Blight (FHB) and Septoria Tritici Blotch (STB) which affects cereals. With mounting challenges in fungal control and increasing restrictions on fungicide use due to environmental concerns, there is an urgent need for innovative control strategies. Here, we present a comprehensive analysis of the stage-specific infection process of Fusarium graminearum in wheat spikes by generating a dual weighted gene co-expression network (WGCN). Notably, the network contained a mycotoxin-enriched fungal module that exhibited a significant correlation with a detoxification gene-enriched wheat module. This correlation in gene expression was validated through quantitative PCR. By examining a fungal module with genes highly expressed during early symptomless infection, we identified a gene encoding FgKnr4, a protein containing a Knr4/Smi1 disordered domain. Through comprehensive analysis, we confirmed the pivotal role of FgKnr4 in various biological processes, including morphogenesis, growth, cell wall stress tolerance, and pathogenicity. Further studies confirmed the observed phenotypes are partially due to the involvement of FgKnr4 in regulating the fungal cell wall integrity pathway by modulating the phosphorylation of the MAP-kinase MGV1. Orthologues of FgKnr4 are widespread across the fungal kingdom but are absent in other Eukaryotes, suggesting the protein has potential as a promising intervention target. Encouragingly, the restricted growth and highly reduced virulence phenotypes observed for{Delta} Fgknr4 were replicated upon deletion of the orthologous gene in the wheat fungal pathogen Zymoseptoria tritici. Overall, this study demonstrates the utility of an integrated network-level analytical approach to pinpoint genes of high interest to pathogenesis and disease control.

plant biology↗

bioRxiv2019

Moisture-dependent morphing tunes the dispersal of dandelion diaspores

Animal migration is highly sensitised to environmental cues, but plant dispersal is considered largely passive. The common dandelion, Taraxacum officinale, bears an intricate haired pappus facilitating flight. The pappus enables the formation of a separated vortex ring during flight; however, the pappus structure is not static but reversibly changes shape by closing in response to moisture. We hypothesised that this leads to changed dispersal properties in response to environmental conditions. Using wind tunnel experiments for flow visualisation, particle image velocimetry, and flight tests we characterised the fluid mechanics effects of the pappus morphing. We also modelled dispersal to understand the impact of pappus morphing on diaspore distribution. Pappus morphing dramatically alters the fluid mechanics of diaspore flight. We found that when the pappus closes in moist conditions, the drag coefficient decreases and thus the falling velocity is greatly increased. Detachment of diaspores from the parent plant also substantially decreases. The change in detachment when the pappus closes increases dispersal distances by reducing diaspore release when wind speeds are low. We propose that moisture-dependent pappus-morphing is a form of informed dispersal allowing rapid responses to changing conditions.

plant biology↗