Biology subjects

Schneider, H.

Publications and source records attributed to Schneider, H..

12 recordsLinked to original sources

bioRxiv2026

A thermal time framework drives coordinated below- and above-ground development in temperate cereal crops

O_LICereal architecture is underpinned by the coordinated development of modular phytomer units. While above-ground phenology is well characterized by metrics such as the phyllochron, an equivalent framework for root system development is lacking. Because each phytomer node initiates both leaves and adventitious roots, root and shoot development are inherently linked. C_LIO_LIHere, we quantified this coordination in wheat, barley, and rye across contrasting temperature regimes and validated the results under field conditions. We introduce the rhizochron, defined as the thermal time (growing degree-days, {degrees}C d) period between the emergence of nodal roots on successive stem nodes, and the root appearance interval, describing the emergence rate of individual root axes. Root development followed a highly conserved thermal sequence synchronized with shoot phenology. C_LIO_LIAcross species and environments, the rhizochron averaged 146.1{degrees}C d, closely matching the phyllochron (126.6{degrees}C d). We also identified a consistent thermal offset, with nodal roots emerging approximately 185.3{degrees}C d after the corresponding leaf on the same phytomer node. The root appearance interval averaged 45.3{degrees}C d, reflecting continuous root deployment across active nodes. C_LIO_LIBy integrating root phenology into a node-based framework, the rhizochron provides a predictive tool for crop modeling, trait-based breeding, and more target phenotyping aimed at improving resource acquisition and climate resilience. C_LI

plant biology↗

bioRxiv2025

Root anatomical gradients and cultivar differences underlie variation in root hydraulic properties in German winter wheat

Root hydraulic properties affect water uptake in wheat (Triticum aestivum L.) and are strongly influenced by root anatomy, yet how they vary along root axes and interact with cultivar differences remains underexplored. We investigated crown roots of six German winter wheat cultivars spanning one century of release, sampled from a field experiment. Roots were imaged at different positions along their axis using a high-throughput system (Rapid Anatomics Tool), and the resulting anatomical traits were coupled to GRANAR-MECHA to model radial (Kr) and axial conductance (kx). Longitudinal anatomical gradients were pronounced: tissue dimensions, metaxylem number, and apoplastic barriers decreased from the base onwards, resulting in Kr increasing and kx decreasing with distance from the base. Cultivar differences were also apparent: modern cultivars had smaller tissues and fewer metaxylem vessels, reducing both axial and radial conductance and lowering whole-root water uptake capacity ([~]20-30%). By integrating field sampling with high-throughput image analysis and mechanistic modeling, this study establishes an integrated phenotyping approach that links root anatomy to water uptake and uncovers anatomical traits relevant to hydraulic function. The results show that longitudinal gradients and cultivar-associated anatomical differences contribute to variation in hydraulic properties and persist along fully mature root segments. HighlightHigh-throughput imaging-modeling shows that longitudinal gradients and cultivar-associated anatomical differences along crown roots shape radial and axial conductance, leading to reduced whole-root water uptake capacity in modern winter wheat

plant biology↗

bioRxiv2024

In silico analysis of the evolution of root phenotypes during maize domestication in Neolithic soils of Tehuacan

Roots are essential for plant adaptation to changing environments, yet the role of roots in crop domestication remains unclear. This study examines the evolution of root phenotypes from teosinte to maize, a transition resulting in reduced nodal root number (NRN), multiseriate cortical sclerenchyma (MCS), and increased seminal root number (SRN). We reconstructed the root phenotypes of maize and teosinte, as well as the environments of the Tehuacan Valley over the last 18,000 years using a combination of ancient DNA, paleobotany, and functional-structural modeling. Our models reveal that increasing Holocene atmospheric CO2 concentrations favored the appearance of reduced NRN and MCS between 12000 to 8000 years before present (yBP), promoting deeper root systems. The advent of irrigation by 6000 yBP switched nitrogen distribution from topsoil to subsoil domains, a change which increased the utility of reduced NRN and MCS. Comparison of allelic frequencies among ancient samples ranging from 5500 to 500 yBP suggest that increased SRN may have appeared around 3500 yBP, coinciding with a period of increased human population, agricultural intensification, and soil degradation. Our results suggest that root phenotypes that enhance plant performance under nitrogen stress were important for maize adaptation to changing agricultural practices in the Tehuacan Valley. ClassificationPhysiology & Development

plant biology↗

bioRxiv2024

Welding PROxAb Shuttles: A modular approach for generating bispecific antibodies via site-specific protein-protein conjugation

Targeted protein degradation is an innovative therapeutic strategy to selectively eliminate disease-causing proteins. Exemplified by proteolysis-targeting chimeras (PROTACs), it has shown promise in overcoming drug resistance and targeting previously undruggable proteins. However, PROTACs face challenges such as low oral bioavailability and limited selectivity. The recently published PROxAb Shuttle technology offers a solution enabling targeted delivery of PROTACs using antibodies fused with PROTAC-binding domains derived from camelid single-domain antibodies (VHHs). Here, a modular approach to quickly generate PROxAb Shuttles by enzymatically coupling PROTAC-binding VHHs to off- the-shelf antibodies was developed. The resulting conjugates retained their target binding and internalization properties and incubation with BRD4-targeting PROTACs resulted in formation of defined PROxAb-PROTAC complexes. These complexes selectively induced degradation of the BRD4 protein, resulting in cytotoxicity specifically in cells expressing the antibodys target. The chemoenzymatic approach described here provides a versatile and efficient solution for generating antibody-VHH conjugates for targeted protein degradation applications but could also be used to combine antibody and VHH binders to generate bispecific antibodies for further applications.

biochemistry↗

bioRxiv2023

Evidence that variation in root anatomy contributes to local adaptation in Mexican native maize

Mexican native maize (Zea mays ssp. mays) is adapted to a wide range of climatic and edaphic conditions. Here, we focus specifically on the potential role of root anatomical variation in this adaptation. In light of the investment required to characterize root anatomy, we present a machine learning approach using environmental descriptors to project trait variation from a relatively small training panel onto a larger panel of genotyped and georeferenced Mexican maize accessions. The resulting models defined potential biologically relevant clines across a complex environment and were used subsequently in genotype-environment association. We found evidence of systematic variation in maize root anatomy across Mexico, notably a prevalence of trait combinations favoring a reduction in axial conductance in cooler, drier highland areas. We discuss our results in the context of previously described water-banking strategies and present candidate genes that are associated with both root anatomical and environmental variation. Our strategy is a refinement of standard environmental genome wide association analysis that is applicable whenever a training set of georeferenced phenotypic data is available.

plant biology↗

bioRxiv2023

PROxAb Shuttle: A non-covalent plug-and-play platform for the rapid generation of tumor-targeting antibody-PROTAC conjugates

Proteolysis-targeting chimeras (PROTACs) have evolved in recent years from an academic idea to a therapeutic modality with more than 25 active clinical programs. However, achieving oral bioavailability and cell-type specificity remains a challenge, especially for PROTACs recruiting the von Hippel-Lindau (VHL) E3 ligase. Herein, we present an unprecedented, plug- and-play platform for VHL-recruiting PROTACs to overcome these limitations. Our platform allows for the generation of non-covalent antibody-PROTAC complexes within minutes and obviates the need for prior PROTAC modification, antibody-drug linker chemistry optimization or bioconjugation. Our technology relies on camelid-derived antibody domains (VHHs) which can easily be engineered into existing therapeutic antibody scaffolds. The resulting targeted, bispecific fusion proteins can be complexed with PROTACs at defined PROTAC-to-antibody ratios and have been termed PROxAb Shuttles. PROxAb Shuttles can prolong the half-life of PROTACs from hours to days, demonstrate anti-tumor efficacy in vivo and have the potential for reloading in vivo to further boost efficacy.

biochemistry↗

bioRxiv2023

Segmental Duplications Drive the Evolution of Accessory Regions in a Major Crop Pathogen

O_LIMany pathogens evolved compartmentalized genomes with conserved core and variable accessory regions which carry effector genes mediating virulence. The fungal plant pathogen Fusarium oxysporum has such accessory regions often spanning entire chromosomes. The presence of specific accessory regions influences the host range, and horizontal transfer of some accessory regions can modify the pathogenicity of the receiving strain. However, understanding how these accessory regions evolve in strains that infect the same host remains limited. C_LIO_LIHere, we define the pan-genome of 69 diverse Fusarium strains that cause Fusarium wilt of banana, a significant constraint to global banana production. In this diverse panel of Fusarium strains infecting banana, we analyzed the diversity and evolution of the accessory regions. C_LIO_LIAccessory regions in Fusarium strains infecting the same banana cultivar are highly diverse, and we could not identify any shared genomic regions and in planta induced effectors. We demonstrate that segmental duplications drive the evolution of accessory regions. Furthermore, we show that recent segmental duplications and aneuploidy occur specifically in accessory chromosomes and cause the expansion of accessory regions in F. oxysporum. C_LIO_LITaken together we conclude that extensive recent duplications drive the evolution of accessory regions in Fusarium, which contribute to the evolution of virulence. C_LI

genomics↗

bioRxiv2021

Modelling the effects of bioclimatic characteristics and climate change on the potential distribution of a monospecific species Colophospermum mopane (Benth.) Leonard in southern Africa.

Global climate change is gradually changing species distribution and their patterns of diversity. Yet, factors that influence the local distribution and habitat preferences for southern African species remain largely unexplored. Here, we computed the suitable habitats in the southern African region for Colophospermum mopane (Benth.) using the maximum entropy (Maxent) modeling approach. We utilized one Global Circulation Model (GCM) and three Representative concentration pathways (RCPs) to determine the current and future distribution of C. mopane. The results showed that the distribution of C. mopane was mainly influenced by solar radiation, annual temperature range, and annual precipitation. According to the species response curves, this species preferred habitats with annual precipitation of 130-200 mm, an annual temperature range of 28{degrees} C, and elevations of about 500 m above sea level. The results highlight that the geographic range of C. mopane is likely to expand along the borders of Zambia and Zimbabwe in the future, particularly in the miombo plains. Conversely, suitable habitat areas reduce significantly in the eastern area of the southern African region, while the western areas expand. Overall, the appropriate habitat areas will likely decline in the 2050s under both RCPs and expand in the 2070s under the two scenarios. This knowledge is important for landscape planners and rangeland managers working to safeguard biodiversity from extinction. HighlightsO_LIHigh reliability of models in habitat suitability modelling for C. mopane C_LIO_LISolar radiation is the most significant variable for the current distribution of mopane. C_LIO_LIClimate change is and will reduce the habitat suitability of our target species. C_LI

ecology↗

bioRxiv2021

The epoxyeicosatrienoic pathway is intact in endothelial and smooth muscle cells exposed to aldosterone excess

ObjectivesEndothelial dysfunction (ED) is considered to be a major driver of the increased incidence of cardiovascular disease in primary aldosteronism (PA). Whether the epoxyeicosatrienoic acid (EET) pathway, involving the release of beneficial endothelium-derived lipid mediators, contributes to ED in PA is unknown. Preclinical evidence suggests this pathway to be relevant in the pathogenesis in various models of experimental hypertension. In addition, an orally available soluble epoxide hydrolase inhibitor, which halts the breakdown of EETs, has already passed a phase 1 clinical trial. We, therefore, exposed primary human coronary artery endothelial cells to 1 nM aldosterone. MethodsWe used qPCR to investigate changes in the expression levels of essential genes for the synthesis and degradation of EETs as well as mass spectrometry to determine endothelial synthetic capacity to release EETs upon stimulation. We also assessed primary human coronary artery smooth muscle cells for expression of putative EET receptor ion channels or downstream mediators as well as for the calcium response to EETs using calcium imaging. ResultsNo major aldosterone-related expression changes were detected on the endothelial as well as the smooth muscle side. Stimulated release of endothelial EETs was unaffected. Likewise, the smooth muscle calcium response was unchanged after aldosterone excess. ConclusionsThe EET pathway is not negatively affected by increased aldosterone concentrations as seen in PA. Modulating the EET pathway with therapeutic intent in patients with PA might therefore be assessed in future preclinical and clinical trials to address ED.

physiology↗

bioRxiv2020

Comparative analysis of early divergent land plants and construction of DNA tools for hyper-expression in Marchantia chloroplasts

Chloroplast genes are present at high ploidy in plants, and capable of driving very high levels of gene expression if mRNA production and stability are properly regulated. Marchantia polymorpha is a simple model plant that allows rapid transformation studies, however post-transcriptional regulation in plastids is poorly characterized in this liverwort. We have mapped patterns of transcription in Marchantia chloroplasts. Furthermore, we have obtained and compared sequences from 51 early-divergent plant species, and identified putative sites for pentatricopeptide repeat protein binding that are thought to play important roles in mRNA stabilisation. Candidate binding sites were tested for their ability to confer high levels of reporter gene expression in Marchantia chloroplasts, and levels of protein production and effects on growth were measured in homoplasmic transformed plants. We have produced novel DNA tools for protein hyper-expression in a facile plant system that is a test-bed for chloroplast engineering.

plant biology↗

bioRxiv2020

Ipomoeassin-F inhibits the in vitro biogenesis of the SARS-CoV-2 spike protein and its host cell membrane receptor

In order to produce proteins essential for their propagation, many pathogenic human viruses, including SARS-CoV-2 the causative agent of COVID-19 respiratory disease, commandeer host biosynthetic machineries and mechanisms. Three major structural proteins, the spike, envelope and membrane proteins, are amongst several SARS-CoV-2 components synthesised at the endoplasmic reticulum (ER) of infected human cells prior to the assembly of new viral particles. Hence, the inhibition of membrane protein synthesis at the ER is an attractive strategy for reducing the pathogenicity of SARS-CoV-2 and other obligate viral pathogens. Using an in vitro system, we demonstrate that the small molecule inhibitor ipomoeassin F (Ipom-F) potently blocks the Sec61-mediated ER membrane translocation/insertion of three therapeutic protein targets for SARS-CoV-2 infection; the viral spike and ORF8 proteins together with angiotensin-converting enzyme 2, the host cell plasma membrane receptor. Our findings highlight the potential for using ER protein translocation inhibitors such as Ipom-F as host-targeting, broad-spectrum, antiviral agents.

biochemistry↗

bioRxiv2019

Neither global nor consistent: a technical comment on the tree diversity-productivity analysis of Liang et al. (2016)

The publication of Liang et al. (2016, Science) seems to demonstrate very clearly that increasing tree species richness substantially increases forest productivity. To combine data from very different ecoregions, the authors constructed a relative measure of tree species richness. This relative richness however confounds plot-level tree species richness and the polar-tropical gradient of tree species richness. We re-analysed their orginal data, computing a regional measure of tree species richness and addressing several other issues in their analysis. We find that there is virtually no effect of relative tree species richness on productivity when computing species richness at the local scale. Also, different ecoregions have very different relationships between tree species richness and productivity. Thus, neither the \"global\" consistency nor the actual effect can be confirmed.

ecology↗