Biology subjects

Schneider, H. M.

Publications and source records attributed to Schneider, H. M..

6 recordsLinked to original sources

bioRxiv2026

Root phenotypic plasticity improves yield stability when directed toward an adaptive integrated phenotype

Root phenotypic plasticity is often proposed to improve crop performance under stress, yet it remains unclear how much plasticity is beneficial and whether adaptive responses require changes across many traits or adjustments in few specific traits. Using public data of 6,500 field-grown maize and barley plants, this study examined the extent and distribution of root plasticity, and when it is associated with yield stability. We quantified root plasticity across nine anatomical and architectural traits using complementary statistical models and applied a feature-discovery framework to identify the drought-associated optimal integrated phenotypes and determine whether plasticity toward these phenotypes improved yield stability. More plasticity did not mean greater yield stability. Neither the number of plastic traits nor the magnitude of plastic responses predicted yield stability. Rather, we identified species-specific high-yielding, stable integrated phenotypes defined by distinct trait configurations. Critically, genotypes whose plastic responses moved their root phenotype toward these targets achieved greater yield stability, whereas movement away from them was associated with lower stability. Root plasticity is adaptive when it shifts root phenotypes towards an optimal integrated phenotype. These findings show that the value of plasticity depends on the trajectory of phenotypic change rather than its magnitude alone.

plant biology↗

bioRxiv2026

Glucose and fructose differently mediate alcohol cocktail drinking in female and male rats: interaction of glucose and alcohol on post-ingestive behavior

Sweetened alcoholic beverages are thought to contribute to developing Alcohol Use Disorder by increasing palatability. One monosaccharide, glucose, readily enters the brain more than fructose and directly impacts the activity of central neurons. The objective of this study is to determine the impact of glucose versus fructose on alcohol drinking patterns in female and male rats. Rats drank alcohol cocktails (1.25%-10%) containing either glucose or fructose (10%) in 4-hour sessions. We sought to parse orosensory effects from post-ingestive central effects by analyzing drinking microstructure. We compared measures of palatability and post-ingestive feedback between early and later in the session when brain levels of alcohol and glucose are different. We found that rats of both sexes drank more low alcohol glucose cocktails than cocktails containing fructose by volume and by overall calories. When considering the dose of alcohol, glucose potentiated alcohol intake by shifting the dose-response curve leftward compared to similar fructose cocktails. We found that drinking patterns associated with palatability remained stable for both types of cocktails over the entire drinking session. In contrast, post-ingestive behavior related to brain mediated satiety or positive feedback showed a greater influence of the session time, as well as a greater interaction with sex. Overall, our results suggest that glucose and alcohol interact to impact central regulation of cocktail drinking. This highlights that the type of sugar within cocktails interacts and ultimately have different effects on brain regulated alcohol drinking.

pharmacology and toxicology↗

bioRxiv2025

The Rapid Anatomics Tool (RAT): A low-cost root anatomical phenotyping pipeline reveals changes in root anatomy along the root axis

Root anatomical phenotyping has become a demonstrably essential part of investigating root physiology and in acquiring a holistic understanding of plant development. However, accessible high throughput methods for root anatomical analysis are still lacking. Here, we present the Rapid Anatomics Tool (RAT), a novel, low-cost system for high throughput root anatomical imaging with a shallow learning curve for obtaining high quality images suitable for comparative analysis across a number of plant species. Its efficiency comes from combining blockface-like imaging and stain-free imaging using near-ultraviolet (nUV) autofluorescence utilising a combination of low-cost commercial equipment, readily available mechanical components, and custom designed and 3D printed tools. Using this system, we investigated the anatomy of mature tissue along the axis of wheat crown roots, revealing a tendency of reduction in vascular complexity (expressed through a reduction in metaxylem number, area, and mean area per metaxylem file) from the basal to the distal region of the root. This study highlights the importance of thorough sampling strategies for investigating root anatomy in relation to organ function and introduces an accessible, relatively high-throughput method to support such research.

plant biology↗

bioRxiv2023

Cortical parenchyma wall width (CPW) regulates root metabolic cost and maize performance under suboptimal water availability

We describe how increased root cortical parenchyma wall width (CPW) can improve tolerance to drought stress in maize by reducing the metabolic costs of soil exploration. Significant variation (1.0 to 5.0 {micro}m) for CPW was observed within maize germplasm. The functional-structural model RootSlice predicts that increasing CPW from 2 to 4 {micro}m is associated with ca. 15% reduction in root cortical cytoplasmic volume, respiration rate, and nitrogen content. Analysis of genotypes with contrasting CPW grown with and without water stress in the field confirms that increased CPW is correlated with ca. 32 to 42% decrease in root respiration. Under water stress in the field, increased CPW is correlated with 125% increased stomatal conductance, 325% increased leaf CO2 assimilation rate, 73 to 78% increased shoot biomass, and 92 to 108% increased grain yield. CPW was correlated with leaf mesophyll midrib parenchyma wall width, indicating pleiotropy. GWAS analysis identified candidate genes underlying CPW. OpenSimRoot modeling predicts that a reduction in root respiration due to increased CPW would also benefit maize growth under suboptimal nitrogen, which requires empirical testing. We propose CPW as a new phene that has utility under edaphic stress meriting further investigation. Significance StatementSuboptimal water availability is a primary constraint for global crop production that is intensifying due to climate change. The metabolic cost of soil exploration is a critical factor in plant performance under suboptimal water availability. This study highlights how increased root cortical parenchyma wall width (CPW) reduces root metabolic cost and improves crop adaptation to water deficit. Modeling results also indicate that increased CPW would be beneficial under suboptimal nitrogen availability. Therefore, CPW is a promising target for breeding crops with improved water and nitrogen use efficiency.

plant biology↗

bioRxiv2021

Genotypic variation in soil penetration by maize roots is negatively related to ethylene-induced thickening

Radial expansion is a classic response of roots to mechanical impedance that has generally been assumed to aid penetration. We analysed the response of maize nodal roots to impedance to test the hypothesis that radial expansion is not related to the ability of roots to cross a compacted soil layer. Genotypes varied in their ability to cross the compacted layer, and those with a steeper approach to the compacted layer or less radial expansion in the compacted layer were more likely to cross the layer and achieve greater depth. Root radial expansion was due to cortical cell size expansion, while cortical cell file number remained constant. Genotypes and nodal root classes that exhibited radial expansion upon encountering the compacted soil layer also thickened in response to exogenous ethylene in hydroponic culture, i.e. radial expansion in response to ethylene was correlated with the thickening response to impedance in soil. We propose that ethylene insensitive roots, i.e. those that do not thicken and are able to overcome impedance, have a competitive advantage under mechanically impeded conditions as they can maintain their elongation rates. We suggest that prolonged exposure to ethylene could function as a stop signal for axial root growth.

plant biology↗

bioRxiv2020

Nodal root diameter and node number in maize (Zea mays L.) interact to influence plant growth under nitrogen stress

Under nitrogen limitation, plants increase resource allocation to root growth relative to shoot growth. The utility of various root architectural and anatomical phenotypes for nitrogen acquisition are not well understood. Nodal root number and root cross-sectional area were evaluated in maize in field and greenhouse environments. Nodal root number and root cross-sectional area were inversely correlated under both high and low nitrogen conditions. Attenuated emergence of root nodes, as opposed to differences in the number of axial roots per node, was associated with substantially reduced root number. Greater root cross-sectional area was associated with a greater stele area and number of cortical cell files. Genotypes that produced few, thick nodal roots rather than many, thin nodal roots had deeper rooting and better shoot growth in low nitrogen environments. Fewer nodal roots offset the respiratory and nitrogen costs of thicker diameter roots, since total nodal root respiration and nitrogen content was similar for genotypes with many, thin and few, thick nodal roots. We propose that few, thick nodal roots may enable greater capture of deep soil nitrogen and improve plant performance under nitrogen stress. The interaction between an architectural and anatomical trait may be an important strategy for nitrogen acquisition. Understanding trait interactions among different root nodes has important implications in for improving crop nutrient uptake and stress tolerance.

plant biology↗