Biology subjects

Minana-Posada, S.

Publications and source records attributed to Minana-Posada, S..

3 recordsLinked to original sources

bioRxiv2026

Contrasting transcriptional responses and genetic determinants underlie Zymoseptoria tritici adaptation mechanisms to simulated host defense environments

Successful colonization of the wheat apoplast requires that Zymoseptoria tritici tolerate host-derived stresses, but the mechanisms underlying this adaptation remain poorly understood. We combined phenotypic assays, transcriptomics, and genome-wide association analyses to characterize fungal responses to acidic pH, salicylic acid, gibberellic acid, and oxidative stress. Exposure to salicylic acid inhibited in vitro growth across a global collection of 411 Z. tritici strains, whereas acidic pH promoted growth, illustrating contrasting effects on pathogen performance of environments simulating host-defense responses. At the transcriptional level, acidic pH and oxidative stress induced the strongest and most similar responses, while salicylic acid elicited a more distinct transcriptional program and gibberellic acid caused only limited transcriptional changes. Although the sets of differentially expressed genes were largely condition specific, overlapping enrichment of transport- and redox-related functions across conditions indicated shared transcriptional responses. K-mer based genome-wide association mapping identified five candidate loci associated with growth under acidic pH, gibberellic acid and salicylic acid, including four loci specific to a single growth condition. These loci colocalized with genes implicated in cell wall remodeling, nitrogen metabolite regulation, proteostasis, and ubiquitin-related processes. This study highlights the multifaceted strategies employed by Z. tritici to navigate environments simulating host-defense responses, involving shared and environment-specific adaptations. We provide new insights into the genetic and molecular basis of fungal resilience, with implications for understanding pathogen-host interactions.

genomics↗

bioRxiv2024

Responses to temperature shocks in Zymoseptoria tritici reveal specific transcriptional reprogramming and novel candidate genes for thermal adaptation

Pathogens responses to sudden temperature fluctuations, spanning various temporal scales, are critical determinants of their survival, growth, reproduction, and homeostasis. Here, we combined phenotyping, transcriptomics, and genome-wide association approaches to investigate how the wheat pathogen Zymoseptoria tritici responds to and recovers from temperature shocks. Survival emerged as the most significantly affected trait immediately following temperature shocks across 122 geographically diverse strains. In contrast, post-recovery phenotypic traits, including growth rate and melanization, showed no significant deviations from control conditions. Transcriptomic analyses of a reference strain revealed temperature stress-specific gene expression patterns, with genes involved in protein folding, redox homeostasis, membrane stabilization, and cell-wall remodeling playing central roles in the response. A multi-reference k-mer genome-wide association study (GWAS) identified six loci significantly associated with cold shock responses. Among these, two loci emerged as strong candidates for near-freezing temperature adaptation, including a 60S ribosomal protein gene involved in protein synthesis and stress recovery, and an NADH oxidoreductase gene implicated in redox homeostasis and oxidative stress tolerance. These findings shed light on the distinct molecular strategies Z. tritici employs to adapt to temperature stress and provide novel insights into fungal resilience under dynamic environmental conditions. Author summaryTemperature fluctuations, an inherent aspect of natural environments, are increasingly exacerbated by climate change, intensifying challenges for organisms to maintain homeostasis amid more frequent and severe extreme weather events. This study reveals distinct phenotypic, transcriptomic, and genetic mechanisms underlying Z. triticis responses to short-term temperature shocks. Survival-related phenotypic traits were significantly reduced by heat and cold shocks, while other traits measured after a recovery period demonstrated the resilience of Z. tritici strains to temperature stress, reflecting efficient recovery mechanisms. Transcriptomic analyses uncovered temperature-specific gene expression patterns, emphasizing unique regulatory strategies, which mostly return to baseline levels after a recovery period. The discovery of novel loci associated with cold shock responses provides valuable insights into the genetic basis of resilience to short-term temperature stress, offering a foundation for future research on pathogen adaptation to fluctuating environments.

genomics↗

bioRxiv2024

Thermal adaptation in worldwide collections of a major fungal pathogen

Adaptation to new climates poses a significant challenge for plant pathogens during range expansion, highlighting the importance of understanding their response to climate to accurately forecast future disease outbreaks. The wheat pathogen Zymoseptoria tritici is ubiquitous across most wheat production regions distributed across diverse climate zones. We explored the genetic architecture of thermal adaptation using a global collection of 411 Z. tritici strains that were phenotyped across a wide range of temperatures and then included in a genome-wide association study. Our analyses provided evidence for local thermal adaptation in Z. tritici populations worldwide, with a significant positive correlation between bioclimatic variables and optimal growth temperatures. We also found a high variability in thermal performance among Z. tritici strains coming from the same field populations, reflecting the high evolutionary potential of this pathogen at the field scale. We identified 69 genes putatively involved in thermal adaptation, including one high-confidence candidate potentially involved in cold adaptation. These results highlight the complex polygenic nature of thermal adaptation in Z. tritici and suggest that this pathogen is likely to adapt well when confronted with climate change.

genomics↗