Biology subjects

Einspanier, S.

Publications and source records attributed to Einspanier, S..

7 recordsLinked to original sources

bioRxiv2026

Environmental drivers of heritable trait variation and lag of adaptation to climate in Hordeum murinum

1. Most plant species are genetically differentiated among populations, often reflected by phenotypic trait variation that corresponds to local adaptation. Yet the strength of local adaptation and heritable contribution to phenotypic traits vary across traits, species, and environments. Additionally, climate change is rapidly altering environmental conditions, and the climate may shift faster than populations can adapt or track the change via dispersal, resulting in adaptive lags. However, it remains unclear how widespread such adaptive lags are across plant species. 2. We focused on Hordeum murinum, an annual ruderal grass widespread in Europe. We combined continental-scale in situ measurements of 2070 plants across 207 populations with common garden experiments across two contrasting climates and two soil types to disentangle heritable variation from phenotypic plasticity and assess potential adaptive lags under climate change. 3. We found that heritable variation was pronounced in developmental traits, particularly flowering time and plant height, while seed weight, reproductive investment and SLA showed intermediate heritable contribution, and flag leaf area and total biomass were primarily plastic. Heritable trait variation was strongly associated with temperature at the populations origin, and trait clines were consistent with in situ patterns, suggesting that temperature is the main driver of genetic differentiation in H. murinum. However, we detected that fitness peaked in populations originating from warmer climates, indicating that evolutionary responses may not keep pace with rapid environmental shifts. 4. Synthesis: Our results highlight that H. murinum harbors substantial heritable variation, shaped primarily by temperature. However, the pace of evolutionary change may be insufficient to track ongoing climate change, leaving populations potentially vulnerable to future environmental conditions.

ecology↗

bioRxiv2026

Physiological responses of submerged freshwater macrophytes to multiple stressors

O_LISubmerged macrophytes are central to freshwater ecosystems functioning but are declining globally under multiple anthropogenic stressors. We aimed to identify general patterns in physiological responses and interaction types, and to assess whether a mechanistic understanding of stressor interactions can be developed from published evidence. C_LIO_LIWe systematically reviewed 12,858 records, identified 172 relevant papers, and extracted effect sizes from 124 experiments included in the meta-analysis. C_LIO_LIMost studies examined combinations of nutrient enrichment, shading, toxic trace metals, warming, and emerging contaminants such as PFAS and microplastics, typically under simplified 2 x 2 factorial laboratory designs. Additive effects dominated (50%), while synergistic interactions were relatively infrequent (14%). Antagonistic interactions often reflected dominance of a single stressor or compensatory responses, whereas synergisms were most frequent with metals combined with co-stressors enhancing bioavailability. C_LIO_LIOur synthesis suggests that accumulated stressors cause negative, but not necessarily amplified, responses, although the limited number of experiments testing more than two stressors means synergistic effects may be underestimated. We propose Stuckenia pectinata as a model organism because of its cosmopolitan distribution, experimental tractability, and available genomic resources, and argue that expanding stressor complexity, duration, and taxonomic breadth will strengthen predictions of macrophyte responses and inform freshwater conservation under global change. C_LI

plant biology↗

bioRxiv2026

Climate-driven in-situ trait variation in an annual ruderal grass across Europe

O_LIPlant functional traits link environmental conditions to plant performance and adaptation. Growing evidence shows that in-situ intraspecific trait variation can be as important as differences between species, yet large intraspecific datasets measured in situ are rare. While most studies focused on plant morphological traits, contents of elemental nutrients in the seeds received much less attention so far. C_LIO_LIWe conducted a large-scale in-situ study of the widespread ruderal grass Hordeum murinum. We sampled 2070 individuals from 207 populations from a large part of the native range in Europe and Northern Africa. In-situ, we measured seed ripening phenology and morphological traits, and analyzed the content of elemental nutrients in the seeds. C_LIO_LIWe found that Hordeum murinum grew larger, produced seeds later, and had heavier seeds in colder and wetter areas. Plants in denser vegetation were taller with heavier seeds but formed fewer spikes. Seed nutrient content generally declined with seed weight and was mainly driven by climate. Soil conditions had only minor effects on plant traits and seed nutrients. Population identity explained much of the variation, indicating a possible genetic component. C_LIO_LISynthesis: Our findings provide a comprehensive view of Hordeum murinum responding to environmental gradients across its European distribution. Climatic variables, especially temperature, are key drivers for reproductive success and seed nutrient content, while local environments, such as biotic pressures, are more critical for growth-related traits. These patterns indicate that H. murinum modulates its growth and reproductive investment along environmental gradients, balancing phenology, stress tolerance, and limited competitive capacity. C_LI

ecology↗

bioRxiv2025

Temporal Shifts in Gene Expression Drive Quantitative Resistance to a Necrotrophic Fungus in a Tomato Crop Wild Relative

Resistance breeding against generalist necrotrophic pathogens heavily relies on quantitative disease resistance (QDR). Lesion growth dynamics involve distinct phases (e.g., lag phase duration or lesion doubling time), each independently affecting the overall symptom severity. While the genetic and regulatory basis of lesion growth rate has been studied, the host-derived regulation of the lag-phase duration remains largely uncharacterised. In this study, we tested the regulatory response of Solanum pennellii genotypes exhibiting different lag-phase durations. We conducted a time-series gene expression profiling experiment dissecting genotype-specific regulatory responses to Sclerotinia sclerotiorum inoculation. We observed genotype-specific regulatory trajectories, with resistant plants displaying early activation of defence-related genes during the asymptomatic phase. These genes, regulated by a WRKY6-centered gene regulatory network, exhibited elevated basal expression in resistant genotypes and a fine-tuned longitudinal expression with induction before lesion onset. In contrast, susceptible genotypes lacked this early response, showing gene induction only post-infection. This study is the first to link host regulatory dynamics to lag-phase duration, suggesting that elevated basal expression of receptor genes and a WRKY6-mediated gene regulatory network may enhance QDR. These findings provide insights into the regulatory foundation of QDR and establish a functional basis for more focused breeding of QDR traits.

plant biology↗

bioRxiv2025

Co-optation of Transcription Factors Drives Evolution of Quantitative Disease Resistance Against a Necrotrophic Pathogen.

Wild relatives of crop species possess diverse levels of quantitative disease resistance (QDR) to biotic stresses, yet the genomic and regulatory mechanisms underlying these differences are poorly understood. In particular, how QDR against a generalist necrotrophic pathogen evolved and whether it is driven by conserved or species-specific regulatory networks remains unclear. Here, we examined the transcriptomic responses of five diverse wild tomato species that span a gradient of QDR. We initially hypothesised that conserved regulatory modules might control QDR. Instead, we use differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) to find that species-specific regulatory features, encompassing both infection-induced and constitutively expressed genes, predominantly shape QDR levels. Although we identified an ethylene response factor among candidate genes for QDR-regulation, it did not fully account for the phenotypic variation. To further dissect the evolutionary basis of these regulatory patterns, we performed phylotranscriptomic analyses on gene regulatory networks. Notably, our findings reveal that the conserved NAC transcription factor 29 is pivotal in developing disease resistance only in S. pennellii. The differential regulation and altered downstream signalling pathways of NAC29 provide evidence for its co-option in the resistance mechanisms of S. pennellii. This finding highlights the species-specific rewiring of gene regulatory networks by repurposing a conserved regulatory element to enhance resistance against pathogens effectively. These results offer new insights into the evolutionary and regulatory complexity underlying QDR and emphasise the significance of species-specific gene regulation in shaping resistance against a cosmopolitan necrotrophic pathogen.

plant biology↗

bioRxiv2024

High-resolution disease phenotyping reveals distinct resistance strategies of wild tomato crop wild relatives against Sclerotinia sclerotiorum

Besides the well-understood qualitative disease resistance, plants possess a more complex quantitative form of resistance: quantitative disease resistance (QDR). QDR is commonly defined as a partial but more durable form of resistance and, therefore, might display a valuable target for resistance breeding. The characterization of QDR phenotypes, especially of wild crop relatives, displays a major bottleneck in deciphering QDRs genomic and regulatory background. Moreover, the relationship between QDR parameters, such as infection frequency, lag phase duration, and lesion growth rate, remains elusive. High hurdles for applying modern phenotyping technology, such as the low availability of phenotyping facilities or complex data analysis, further dampen progress in understanding QDR. Here, we applied a low-cost phenotyping system to measure lesion growth dynamics of wild tomato species (e.g., S. pennellii or S. pimpinellifolium). We provide insight into QDR diversity of wild populations and derive specific QDR strategies and their crosstalk. We show how temporally continuous observations are required to dissect end-point severity into functional resistance strategies. The results of our study show how QDR can be maintained by facilitating different defense strategies during host-parasite interaction and that the capacity of the QDR toolbox highly depends on the hosts genetic context. We anticipate that the present findings display a valuable resource for more targeted functional characterization of the processes involved in QDR. Moreover, we show how modest phenotyping technology can be leveraged to help answer highly relevant biological questions.

plant biology↗

bioRxiv2021

Whole genome sequencing elucidates the species-wide diversity and evolution of fungicide resistance in the early blight pathogen Alternaria solani

Early blight of potato is caused by the fungal pathogen Alternaria solani and is an increasing problem worldwide. The primary strategy to control the disease is applying fungicides such as succinate dehydrogenase inhibitors (SDHI). SDHI-resistant strains, showing reduced sensitivity to treatments, appeared in Germany in 2013, five years after the introduction of SDHIs. Two primary mutations in the Sdh complex (SdhB-H278Y and SdhC-H134R) have been frequently found throughout Europe. How these resistances arose and spread, and whether they are linked to other genomic features, remains unknown. We performed whole-genome sequencing for A. solani isolates from potato fields across Europe (Germany, Sweden, Belgium, and Serbia) to better understand the pathogens genetic diversity in general and understand the development and spread of the genetic mutations that lead to SDHI resistance. We used ancestry analysis and phylogenetics to determine the genetic background of 48 isolates. The isolates can be grouped into 7 genotypes. These genotypes do not show a geographical pattern but appear spread throughout Europe. The Sdh mutations appear in different genetic backgrounds, suggesting they arose independently, and the observed admixtures might indicate a higher adaptive potential in the fungus than previously thought. Our research gives insights into the genetic diversity of A. solani on a genome level. The mixed occurrence of different genotypes and apparent admixture in the populations indicate higher genomic complexity than anticipated. The conclusion that SDHI tolerance arose multiple times independently has important implications for future fungicide resistance management strategies. These should not solely focus on preventing the spread of isolates between locations but also on limiting population size and the selective pressure posed by fungicides in a given field to avoid the rise of new mutations in other genetic backgrounds.

evolutionary biology↗