Biology subjects

Rouveyrol, C.

Publications and source records attributed to Rouveyrol, C..

6 recordsLinked to original sources

bioRxiv2026

Interspecific transfer of specialized metabolites in root exudates coincides with root chromatin regulation and systemic chemical defenses in rice

O_LIBenzoxazinoids are indole-derived specialized metabolites released into the soil through root exudates. Initially studied for their allelopathic and toxic effects, they are now recognized as broad regulators of plant-organism interactions, including microbiome-mediated pathogen resistance. However, whether benzoxazinoid-containing root exudates can directly influence disease susceptibility in neighboring plants remains unclear. C_LIO_LIUsing an agriculturally relevant rice-maize co-culture system, we show that benzoxazinoids naturally exuded by maize roots are taken up by rice roots and are associated with reduced rice blast disease in leaves. C_LIO_LIThis protection occurs without detectable benzoxazinoid accumulation in rice leaves, constitutive immune activation or decreased plant height. Instead, benzoxazinoid uptake by rice roots is associated with chromatin hyperacetylation, increased expression of key phenylpropanoid biosynthetic genes and broad metabolic reprogramming. C_LIO_LIThese responses extend systemically to leaves, where rice establishes a defense-related chemical state distinct from the systemic acquired resistance previously observed in benzoxazinoid-dependent, microbiome-mediated plant-soil feedbacks. C_LIO_LIOur findings support a model in which specialized metabolites exuded by one crop species are acquired by a neighbouring species and trigger chromatin-associated metabolic reprogramming linked to systemic chemical defence. This study provides a molecular framework connecting plant-plant chemical interactions, root exudation, chromatin regulation and disease susceptibility. C_LI

plant biology↗

bioRxiv2026

Paleometabolomics reveals impacts of abiotic factors on rodent midden metabolism over the last 50,000 years.

Metabolomics and paleoecology combined can reveal how past ecosystems worked, helping us predict future changes more accurately. Pioneering studies are needed to shed light on the potential of the so-called paleometabolomics and to standardise its application. Here, we deployed an untargeted metabolomic workflow on a timeline (200 to 49,600 cal yr BP) of rodent middens that efficiently and reproducibly captured rodent midden metabolic diversity, recovering 79% of the richness detected in 15 contemporary plant species. We found that midden chemical diversity and metabolites were influenced by the midden composition, age, and environment. Variation at the metabolite level in middens could fit age, past temperature and precipitation levels with an R{superscript 2} > 88% and their plant composition. Compounds and families responding to climate variation included lipids (e.g. glycerophospholipids) and other metabolites linked to redox status such as phenolics (e.g. flavonoids, lignans). The responses of significant midden chemical indices and compounds to abiotic pressures were supported by their response in plants collected near the midden sites to temperature and soil water content across an elevation gradient. Overall, our results not only showcase paleometabolomics as a powerful tool to reconstruct past ecosystem dynamics and metabolic evolutionary trajectories, but also to uncover relevant chemical families that could serve as trackers of past -and potentially future- climate fluctuations.

ecology↗

bioRxiv2026

Predictive metabolomics reveals leaf systemic metabolic signatures associated with floral traits in Camellia

The genus Camellia comprises more than 200 evergreen species of major economic and ornamental importance, characterised by high morphological and chemical diversity. While several species have been extensively studied for their bioactive compounds, the metabolic basis of floral trait variation across the genus remains poorly understood. In this study, a predictive metabolomics framework was applied to investigate the relationship between leaf metabolic profiles and floral traits, focusing on flower colour and floral form. Leaves from 315 individual trees, including 15 Camellia species and representing 1,160 samples, were analysed by untargeted metabolomics, generating a large-scale metabolic profiling dataset. A dedicated quality control strategy was implemented to ensure analytical stability across multiple injection series and flowering seasons. Penalised generalised linear models were used to uncover robust metabolic predictors associated with floral traits and to evaluate model performance through internal and external validation. Distinct sets of metabolites were associated with flower colour and floral form, with limited overlap between traits. Predictive performance was consistently higher for colour than for floral form, indicating more structured metabolic signatures for chromatic traits. The selected predictors spanned multiple major chemical classes, supporting a systemic organisation of the metabolome rather than reliance on single biosynthetic pathways. Consistently high predictive accuracies were obtained, reaching approximately 87% for both flower colour and floral form, and remaining clearly above the corresponding no-information rates ({approx} 43%). Together, these results demonstrate that leaf metabolomics can be used to robustly predict floral traits in Camellia and highlight the potential of predictive metabolomics as a tool for early phenotype inference, quality control and selection in long-lived ornamental species.

plant biology↗

bioRxiv2026

Root phenolics as potential drivers of preformed defenses and reduced disease susceptibility in a paradigm bread wheat mixture

Plant-plant interactions modulate foliar disease susceptibility in intraspecific mixtures. However, the molecular events including signals and responses underlying the reduction in disease susceptibility remain largely unexplored. Here, we developed an experimental system that can abolish root-mediated interactions between plants in a model of bread wheat varietal mixture. We then performed transcriptomic and metabolomic analyses to uncover the molecular responses linked to decreased susceptibility to Septoria tritici blotch in plant-plant interactions. Our analysis revealed that disrupting root chemical interactions impaired the reduction in susceptibility to Septoria and identified phenolic compounds as potential key mediators. The plant-plant interactions under study triggered significant molecular changes in specialized metabolism, biotic interactions, transporters, and responses to resources. Disrupting root interactions canceled both the macroscopic and molecular responses, thus providing a strong link between them. These insights provide a deeper understanding of the molecular basis of plant-plant interactions and the processes involved in reducing disease susceptibility in intraspecific mixtures. Significance statementNeighboring plants mediate resistance to leaf fungal pathogens by releasing root-derived molecules. These interactions trigger multi-omic reprogramming of defenses in both leaves and roots. Enhanced resistance in varietal mixtures is associated with the early activation of defense pathways. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=186 SRC="FIGDIR/small/699261v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@16f02a9org.highwire.dtl.DTLVardef@117b872org.highwire.dtl.DTLVardef@4e5243org.highwire.dtl.DTLVardef@1fac682_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

plant biology↗

bioRxiv2025

Investigating the intraspecific diversity of Vitis vinifera responses to esca with a physiopathology approach

Woody plant dieback involves complex interactions between pathogens, plant functional traits and environmental conditions. The role of intraspecific variation in functional strategies in shaping susceptibility to dieback remains unclear, despite its importance for understanding plant adaptation to changing environments. We used a common garden containing 46 Vitis vinifera (grapevine) cultivars to test the hypothesis that differences in grapevine susceptibility to esca, a complex vascular disease leading to dieback, result from intraspecific syndromes of leaf gas exchange, wood anatomical and metabolic traits, and microbiome. Cultivars with conservative water use strategies tended to be less susceptible to esca whereas xylem anatomy did not affect esca susceptibility. Across cultivars, symptomatic plants displayed decreases in leaf gas exchange, stem starch storage and theoretical hydraulic conductivity in response to esca. Symptomatic stems accumulated more secondary metabolites (mostly glycosylated flavonoids and terpenes) in highly susceptible than in weakly susceptible genotypes, whereas stem microbial communities were unaffected. This suggests that disease expression is linked to cultivar-specific metabolic responses. Intraspecific variation in physiological strategies contributes to differences in susceptibility to a complex vascular disease. Integrative studies unravelling plant-microorganism-environment interactions are crucial to improve our understanding of complex plant diseases.

plant biology↗

bioRxiv2025

Wood composition, rather than microbial communities, underpins varietal differences in wood degradation and esca foliar symptom expression in grapevine

Deciphering the interplay between microbial communities and host defence mechanisms is key to understanding plant health. In perennial plants, the balance between endophytes and wood (i.e. secondary xylem) defence responses governs wood degradation and vascular disease expression. Esca is a complex vascular disease contributing to grapevine decline, with an incidence variable across cultivars but the mechanisms underlying its expression and varietal susceptibility remain unclear. We assessed relationships between internal wood degradation and esca foliar symptoms in Vitis vinifera L. cultivars grown in a common garden, and, at the cultivar level, we tested for correlations between (i) susceptibility to wood decay and esca expression (n = 16 cultivars) and (ii) wood biochemical traits, and healthy wood endophytic microbial communities (n = 23 cultivars). Unlike other types of necrosis, white-rot necrotic wood was significantly more abundant in plants that had expressed esca leaf symptoms in previous years, particularly in the most susceptible cultivars. These cultivars also contained significantly lower levels of constitutive wood extractives. However, glycosylated phenylpropanoids accumulated in the wood of esca-symptomatic plants, especially in highly susceptible cultivars. By contrast, esca expression and varietal susceptibility had only a marginal effect on the diversity, composition and putative functions of microbial communities in healthy wood. They did not influence either the relative abundance of Fomitiporia mediterranea, the putative causal agent of white-rot in grapevine. Esca susceptibility appears primarily linked to wood degradability and metabolic responses, rather than healthy wood's microbial communities, suggesting that the use of less susceptible varieties together with white-rot removal might attenuate grapevine decline.

plant biology↗