Biology subjects

Mauve, C.

Publications and source records attributed to Mauve, C..

6 recordsLinked to original sources

bioRxiv2026

Multi-omic analysis of maize NILs for chilling tolerance QTLs uncover regulatory and metabolic signatures

Early sowing of maize (Zea mays L.) is increasingly required to mitigate summer drought under climate change, making the acquisition of chilling tolerance a major agronomic challenge. Here, we investigated the molecular and physiological bases of cold tolerance using two maize near-isogenic lines (NILs) differing at two major chilling tolerance quantitative trait loci (QTLs) located on chromosome 4. Plants were exposed to low temperature (14{degrees}C day/10{degrees}C night) for 20 days and analyzed using an integrated multi-omics approach combining transcriptomics, soluble and cell wall proteomics, and metabolomics (primary and specialized metabolites), together with physiological measurements. Univariate and multivariate analyses revealed significant chilling-induced variability across all molecular layers, affecting [~]0.2% of genes, [~]6% of proteins, and a subset of specialized metabolites, while primary metabolites were largely stable. Integrative statistical analyses demonstrated that the soluble and cell wall proteomes contributed most strongly to the genotype effect, highlighting protein-level regulation as a major determinant of chilling tolerance. A restricted 5.15 Mb divergence region on chromosome 4 was sufficient to drive contrasting physiological responses, including differences in photosynthetic charge separation efficiency and leaf development, favoring the chilling-tolerant NIL. Notably, several components of the benzoxazinoid pathway located within the divergence region, including BX1 and associated specialized metabolites (BZX-like glucoside, DIBOA-glucoside-2, HBOA-glucoside-2), were specifically associated with chilling tolerance, suggesting a role in stress signaling and hormonal crosstalk. Overall, this study demonstrates that integrative multi-omics analyses provide a powerful framework to resolve genotype-specific regulatory mechanisms underlying chilling tolerance in maize and to identify candidate molecular targets for breeding. HighlightsO_LIFirst organ-resolved multi-omics dissection of chilling responses in maize NILs. C_LIO_LIA 5.1Mb divergence on chromosome 4 drives major physiological and molecular differences. C_LIO_LIChilling tolerance is linked to more robust photochemical homeostasis and sustained leaf development. C_LIO_LISoluble and cell-wall proteomes dominate the genotype-discriminating -omics signal. C_LIO_LIBenzoxazinoids and defense-related transcriptional modules are differentially activated. C_LIO_LICell wall remodeling enzymes and apoplastic peroxidases emerge as key tolerance players. C_LI

plant biology↗

bioRxiv2025

Enhancement of Arabidopsis growth by Enterobacter sp. SA187 under elevated CO2 is dependent on ethylene signalling activation and primary metabolism reprogramming

As atmospheric CO2 levels continue to increase, optimizing the CO2 fertilization effect which often falls short of its potential due to the physiological and metabolic limitations of plants becomes crucial. This study investigates the role of Enterobacter sp. SA187 (SA187), a plant growth-promoting bacterium, in enhancing growth and development of Arabidopsis thaliana under elevated atmospheric CO2 (eCO2) conditions. While SA187 inoculation did not have major effects under ambient CO2, it was found to significantly enhance root and shoot biomass, and to increase N- and reduce C-contents under eCO2. Moreover, transcriptomics and metabolomics suggested that SA187 modulated phytohormonal homeostasis, with activation of the salicylic acid, jasmonic acid and ethylene signalling pathways, and increased primary metabolism including the TCA cycle, N and carbohydrate metabolisms. Finally, the growth-promoting effects of SA187 were shown to be mediated through ethylene-dependent pathways, as evidenced with the ethylene-insensitive mutant ein2-1 which did not show similar benefits in plant fresh weight and altered gene expression. This beneficial plant-microbe interaction under eCO2 in a non-leguminous plant highlights a novel aspect of microbial influence on plant physiology in the context of climate change. These insights underscore the potential of utilizing SA187 to enhance plant performance and adaptability in future high CO2 environments, providing a sustainable approach to agricultural productivity as global CO2 levels increase.

plant biology↗

bioRxiv2025

Enterobacter sp. SA187-induced coordinated regulation of high-affinity nitrate transporters and ethylene signaling enhances nitrogen content and plant growth under low nitrate

O_LISustainable crop production demands solutions to reduce the overuse of synthetic nitrogen fertilizers, and plant-growth-promoting bacteria offer a promising strategy by enhancing nutrients acquisition. This study investigated ability of a non-diazotrophic bacterium, Enterobacter sp. SA187 (SA187), in enhancing Arabidopsis growth under low nitrate conditions and the underlying mechanisms. C_LIO_LIArabidopsis seedlings were grown under different nitrate concentrations with or without SA187 inoculation. Growth traits were quantified alongside shoot and root nitrate and total nitrogen contents, and C:N ratios. Transcriptomic profiling (RNA-seq) and qRT-PCR were used to assess modified gene expression. Functional validation was conducted using ethylene-insensitive (ein2-1) and high-affinity nitrate transporter (HATS) mutants (nrt2.5, nrt2.6). C_LIO_LISA187 significantly enhanced fresh weight, primary root length, and lateral root density under low nitrate, with benefits increasing as nitrate availability decreased. SA187 improved nitrate accumulation and shoot nitrogen allocation, reducing shoot C:N ratios. SA187 regulated expression of HATS and hormone-responsive genes. The growth-promoting effects were abolished in ein2-1, nrt2.5, and nrt2.6 mutants, and SA187-induced regulation of NRT2.5 occurred downstream of ethylene signaling, while NRT2.6 was partly ethylene-independent. C_LIO_LISA187 promotes growth under low nitrate possibly through ethylene-mediated and HATS-dependent reprogramming of nitrate accumulation and nitrogen allocation, supporting its use as a microbial solution for low-input agriculture. C_LI

plant biology↗

bioRxiv2024

Early seedling development in dark conditions is directly controlled by plastids through the GUN1-dependent plastid retrograde pathway

In dark growth conditions, seedlings develop specific features such as an elongated hypocotyl, a tightly folded apical hook, and non-green cotyledons. This dark-specific process, known as skotomorphogenesis, relies primarily on mitochondria and eventually etioplasts for energy. Our previous research shows that skotomorphogenesis is reprogrammed in response to mitochondrial and plastidial dysfunction. Even though the direct link between mitochondria and skotomorphogenesis was described, the impact of plastid dysfunction on early development could not be separated from mitochondrial stress. In this study, we aim to determine the direct connection between plastid functionality and skotomorphogenic response. In this situation, we analyze the phenotypic, molecular, and metabolic effects of treating etiolated seedlings using lincomycin and spectinomycin, which target plastid translation. Our results with the lincomycin treatment highlight the direct role of plastids in the control of early development, even in dark growth conditions, in the absence of any photosynthetic activity, and without the involvement of mitochondrial intermediates. Additionally, our findings suggest that GUN1 plays a regulatory role in regulating nuclear gene expression in response to plastid translation inhibition. Thanks to our study, we can now build a more precise model proposing a straight link between the reprogramming of early development and the dysfunction of plastids in dark-growth conditions. Significance statementIn underground germination conditions, seedlings follow a dark-specific development program, called skotomorphogenesis, that is required for their efficient emergence from the soil. Our study demonstrates that plastids play a crucial role in controlling skotomorphogenesis, even in the absence of photosynthetic activity and without affecting mitochondrial function, and therefore we propose that regulation of etioplast functions might contribute to the adaptation of seedling development to constraining environmental conditions.

plant biology↗

bioRxiv2023

Maize (Zea mays L.) interaction with the arbuscular mycorrhizal fungus Rhizophagus irregularis allows mitigation of nitrogen deficiency stress: physiological and molecular characterization

Maize is currently the most productive cereal crop in the world (www.faostat.org). Maize can form a symbiotic relationship with the Arbuscular Mycorrhizal Fungus (AMF), Rhizophagus irregularis. In this relationship, the fungus provides the plant with additional water and mineral nutrients, while the plant supplies carbon compounds to the fungus. Little is known about the N metabolism disruption during symbiosis in both partners. To address this issue, two genetically distant maize lines were studied in terms of physiological and molecular responses to AMF inoculation by dual RNA-seq, metabolomics and phenotyping. Interestingly, the beneficial effects of the AMF were observed mainly under conditions of limited N fertilization. Under such conditions, the AMF helped maintain plant biomass production. The availability of nitrogen was found to be a crucial factor influencing all the traits studied showing that the level of N supply plays a pivotal role in determining how maize plants interact with the AMF. Despite the two maize lines showing different transcriptomic and metabolomic responses to R. irregularis, their agro-physiological traits remained similar. Both the plant and fungal transcriptomes were more significantly influenced by the level of N nutrition rather than the specific maize genotype. This suggests that N availability has a more profound impact on gene expression in both organisms than the genetic makeup of the maize plant. To understand the metabolic implications of this symbiotic relationship, we integrated transcriptomic data into our recently built multi-organ Genome-scale metabolic model (GSM) called iZMA6517. Remarkably, this modelling approach was supported by metabolomics profiling, in particular increased leaf pyrimidine levels in response to AMF inoculation under limiting N supply. Consistently, fungal genes involved in pyrimidine de novo synthesis and salvage were found to be expressed in symbiotic roots. Our work highlights nucleotide and ureides metabolism as previously unrecognized factors contributing to the symbiotic N nutrition facilitated by R. irregularis, thereby enhancing maize growth. This study demonstrates the effectiveness of integrating multi-omics approaches with mathematical modelling to uncover novel metabolic mechanisms associated with AM symbiosis, without a priori.

plant biology↗

bioRxiv2022

Limiting etioplast gene-expression induces apical hook twisting during skoto-morphogenesis of Arabidopsis seedlings

When covered by a layer of soil, seedling development follows a dark-specific program (skoto-morphogenesis) consisting of small, non-green cotyledons, a long hypocotyl and an apical hook to protect meristematic cells. We recently highlighted the role played by mitochondria in the high energy-consuming reprogramming of Arabidopsis skoto-morphogenesis. Here, the role played by plastids, another energy supplying organelle, in skoto-morphogenesis is investigated. This study was conducted in dark conditions to exclude light signals so as to better focus on those produced by plastids. It was found that limitation of plastid gene-expression (PGE) induced an exaggerated apical hook bending. Inhibition of PGE was obtained at the level of transcription and translation using the antibiotics rifampicin and spectinomycin, respectively, as well as plastid RPOTP RNA polymerase mutants. Rifampicin-treated seedlings also showed expression induction of marker nuclear genes for mitochondrial stress, perturbation of the mitochondrial metabolism, increase of ROS levels and an augmented capacity of oxygen consumption by mitochondrial alternative oxidases (AOX). AOX enzymes act to prevent over-reduction of the mitochondrial electron transport chain. Previously, we reported that AOX1A, the main AOX isoform, was a key component in the developmental response to mitochondrial respiration deficiency. In this work, we suggest the involvement of AOX1A in the response to PGE dysfunction and propose the importance of signalling between plastids and mitochondria. Finally, it was found that seedling architecture reprogramming in response to rifampicin was independent of canonical organelle retrograde pathways and the ethylene signaling pathway. Significance statementIn underground germination conditions, seedling development follows a dark-specific program (skoto-morphogenesis) consisting of small and non-green cotyledons, a long hypocotyl and an apical hook to protect meristematic cells. We show that skoto-morphogenesis is reprogrammed when plastid gene expression is perturbed leading to an exaggeration of apical hook bending. We propose the involvement of the cooperation between plastids and mitochondria, the energy-supplying organelles of the cell.

plant biology↗