Biology subjects

Reneau, J. W.

Publications and source records attributed to Reneau, J. W..

5 recordsLinked to original sources

bioRxiv2026

Maize root system stiffness is determined by the size and distribution of the below-ground root system

Root system stiffness is a measurement associated with root lodging resistance in maize. This measurement combines contributions of root architecture, individual root-level mechanics, and root-soil interactions. In this study, we deconvolve the contribution of each of these factors to root system stiffness. Collectively, larger above- and below-ground root systems and stiffer individual brace roots contribute to a higher root system stiffness. When considering all traits in predictive models, the below-ground root architecture drives the prediction of root system stiffness categories. These below-ground traits describe the size and distribution of the root system. Analysis of a roothairless3 mutant revealed a reduction in root system stiffness primarily driven by a reduction in root size, with limited evidence for a contribution from root hairs. Together these results link root system stiffness to the size and distribution of the below-ground root system and highlight the importance of this measurement for both root lodging resistance and root phenotyping.

plant biology↗

bioRxiv2025

Vascular anatomy changes in tomato stems grown under simulated microgravity

Plants grown in spaceflight exhibit differences in physiology and morphology compared to those grown on Earth. While changes in gravity are a major environmental change, other space-related stressors make it difficult to identify the microgravity-specific responses. These knowledge gaps can be filled by ground-based microgravity simulators that randomize the perceived gravity vector, but these approaches have primarily been limited to smaller plants and seedlings. This study reports a set of meter-scale 2D clinostats that support the growth of plants beyond the seedling stage. Tomato plants were grown in five sequential trials under upright rotating control and clinorotated "simulated microgravity" conditions. We found that simulated microgravity impacted plant growth in each trial, but the response varied by trial. Analysis of environmental co-variates across trials revealed that temperature significantly contributed to variation in plant growth. Further, our results show that moderate heat stress can promote plant growth under simulated microgravity. Thus, this work demonstrates the potential of meter-scale clinostats to uncover interactions between the environmental and simulated microgravity, which alter plant growth.

plant biology↗

bioRxiv2025

A biphasic trajectory for maize stalk mechanics shaped by internal and external factors

Stalk mechanical properties impact plant stability and interactions with pathogenic microorganisms. The evaluation of stalk mechanics has focused primarily on the end-of-season outcomes and defined differences among inbred and hybrid maize genotypes. However, there is a gap in understanding how these different end-of-season outcomes are achieved. This study measured stalk flexural stiffness in maize inbred genotypes across multiple environments and in maize commercial hybrid genotypes under different disease states. Under all conditions, stalk flexural stiffness followed a biphasic trajectory, characterized by a linear increase phase and a sustained phase. Within a genotype, the environment or disease state altered the rate of increase in the linear phase but did not impact the timing of transition to the sustained phase. Whereas between genotypes, the timing of transition between phases varied. Destructive 3-point bend tests of inbred stalks showed that the trajectory of stalk mechanics is defined by the bending modulus, not the geometry. Together, these results define a biphasic trajectory of maize stalk mechanics that can be modulated by internal and external factors. This work provides a foundation for breeding programs to make informed decisions when selecting for optimized stalk mechanical trajectories, which is necessary for enhancing resilience to environmental stresses. HIGHLIGHTSO_LIA common trajectory of stalk mechanics was found across genotypes and conditions. C_LIO_LITransition between phases of stalk mechanics is inherent to genotype. C_LIO_LIThe rate of linear increase phase is modulated within a genotype by environmental or biotic factors. C_LIO_LIMaterial properties determine the trajectory of stalk mechanics. C_LI

plant biology↗

bioRxiv2021

Brace root phenotypes predict root lodging susceptibility and the contribution to anchorage in maize

Plant mechanical failure (lodging) causes global yield losses of 7-66% in cereal crops. We have previously shown that the above-ground nodal roots (brace roots) in maize are critical for anchorage. However, it is unknown how brace root phenotypes vary across genotypes and the functional consequence of this variation. This study quantifies the contribution of brace roots to anchorage, brace root traits, plant height, and root lodging susceptibility in 52 maize inbred lines. We show that the contribution of brace roots to anchorage and root lodging susceptibility varies among genotypes and this contribution can be explained by plant architectural variation. Additionally, supervised machine learning models were developed and show that multiple plant architectural phenotypes can predict the contribution of brace roots to anchorage and root lodging susceptibility. Together these data define the plant architectures that are important in lodging resistance and show that the contribution of brace roots to anchorage is a good proxy for root lodging susceptibility.

plant biology↗

bioRxiv2020

Maize brace roots provide stalk anchorage

Mechanical failure, known as lodging, negatively impacts yield and grain quality in crops. Limiting crop loss from lodging requires an understanding of the plant traits that contribute to lodging-resistance. In maize, specialized aerial brace roots are reported to reduce root lodging. However, their direct contribution to plant biomechanics has not been measured. In this manuscript, we find that brace roots establish a rigid base (i.e. stalk anchorage) to limit plant deflection in maize. The more brace root whorls that contact the soil, the greater the contribution of brace roots to anchorage. Previous studies have linked the number of brace root whorls to flowering time in maize. To determine if flowering time selection alters the brace root contribution to anchorage, a subset of the Hallauers Tuson tropical population was analyzed. Despite a significant change in flowering time, selection neither altered the number of brace root whorls in the soil nor the overall contribution of brace roots to anchorage. These results demonstrate that brace roots provide a rigid base in maize, but the contribution to anchorage is not linearly related to flowering time.

plant biology↗