Biology subjects

Bernillon, S.

Publications and source records attributed to Bernillon, S..

3 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↗

bioRxiv2024

Ecophysiological Behaviour Of Major Fusarium Species In Response To Combinations Of Temperature And Water Activity Constraints

Fusarium Head Blight (FHB) is a devastating fungal disease affecting cereals, caused by Fusarium species that can produce harmful mycotoxins. Fusarium species share the same ecological niche, and their population dynamic and associated mycotoxin patterns are driven by the environment. The aim of the present study was to investigate ecophysiological characteristics of the major Fusarium species causing FHB under abiotic factors. Growth and mycotoxin production of different strains of Fusarium avenaceum, Fusarium graminearum, Fusarium langsethiae, Fusarium poae and Fusarium tricinctum were characterized under a combined effect of temperature ({Theta} = 15, 20, 25 and 30{degrees}C) and water activity (aw = 0.99, 0.98, 0.97, 0.96, 0.95 and 0.94). Using innovative statistical analyses, we demonstrated that those Fusarium species greatly differ in their responses to the studied environmental constraints. Our findings indicated that {Theta}, aw, and their interaction were the major factors with a significant impact on the species behaviour. The intraspecific variation was demonstrated as less pronounced than the interspecific one. Understanding the ecophysiological requirements of Fusarium species is crucial in the context of climate change that is predicted to worsen disease outbreaks. Our data constitute a valuable knowledge base for improving the reliability and robustness of FHB prediction models and anticipating the associated mycotoxin risk. IMPORTANCEFusarium species pose a significant threat to major cereal crops, including wheat. These fungi not only reduce yield but also produce mycotoxins harmful to animals and humans. The prevalence of each Fusarium species is influenced by environmental conditions and shifts in pathogen populations, leading to changes in mycotoxin patterns have already been observed in relation to climate changes. This study revealed distinct ecophysiological behaviours, including mycelium growth and mycotoxin production, among the five major Fusarium species when exposed to varying temperature and water activity conditions. Our findings provide a valuable foundation for a more comprehensive understanding of the challenge of mycotoxin contamination and for the development of more effective mitigation strategies in the near future.

microbiology↗

bioRxiv2023

Extensive variation of leaf specialized metabolite production in sessile oak (Quercus petraea) populations is to a large extent genetically determined but not locally adaptive.

Specialized or secondary metabolites play a key role in plant resistance against abiotic stresses and defences against bioaggressors. For example, in sessile oaks Quercus petraea, phenolics contribute to reduce herbivore damage and improve drought resistance. Here, we explored the natural variation of specialized metabolites in nine European provenances of sessile oaks and aimed to detect its underlying genetic bases. We sampled mature leaves from high and low branches on 225 sessile oak trees located in a common garden and used untargeted metabolomics to characterise the variation of 217 specialized metabolites. In addition, we used whole genome low-depth sequencing to genotype individuals for 1.4M genetic markers. We found that leaf specialized metabolites displayed extensive within-provenance variation, but very little differentiation between provenances. In addition, a genome-wide association study allowed detecting significant associations for 42% of these metabolites. Hence, our results suggest that genetic variation for most leaf specialized metabolites is unlikely to be locally adaptive, however lack of differentiation among populations suggests selection acts locally to maintain diversity at loci associated with leaf specialized metabolites variation.

evolutionary biology↗