Biology subjects

Lavergne, S.

Publications and source records attributed to Lavergne, S..

4 recordsLinked to original sources

bioRxiv2025

Previous legume identity influences wheat protein content through organic matter depolymerization

In crop rotation systems, plant-soil feedback (PSF) effects can modulate nutrient cycling in soil, like organic carbon (C) and nitrogen (N) cycling. Organic nitrogen is present in plant and microbial necromass, and it must be depolymerized by microbes to become available for crops. Since plant identity can modulate microbial diversity and community composition, we thought that previous crop identity and its residue management would also change the microbial functional capacity, and thereby impact soil N availability, and the quality and yield of the following crop. To test this, two legumes (Vicia faba L., i.e. faba bean, and Pisum sativum L., i.e., yellow pea) were grown in two fields (Cloutier, and Palmarolle) in Abitibi-Temiscamingue, Quebec, Canada (n=3 for each field). At the end of the growing season, we harvested peas and faba beans in both fields. During the following growing season, spring wheat (Triticum aestivum L.) was sown and received, or not granulated chicken manure as an organic fertilizer. We determined the diversity and composition of the microbial communities and their enzymatic depolymerization capacity in the soil and the rhizosphere each growing season. During wheat growth, previous legumes shaped bacterial (p-value = 0.006) and fungal (p-value = 0.001) communities without modulating the enzymatic activity of wheat-associated rhizosphere microbes. However, faba bean as a previous crop increased soil ammonium and wheat grain protein content at harvest as compared to peas at Cloutier. Altogether, our results show that faba beans can enhance wheat N nutrition, without a concomitant increase in potential protein or cellulose depolymerization, suggesting more mineralization due to increases in fungal: bacterial ratio or in the availability of substrates. Understanding plant-soil feedback in crop rotation systems is crucial to improve our practices and sustainably meet crops nutritional needs. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/694934v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@129f684org.highwire.dtl.DTLVardef@1f78d20org.highwire.dtl.DTLVardef@152466dorg.highwire.dtl.DTLVardef@8da2e2_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIPrevious crop identity distinctively shaped wheat rhizosphere microbial communities C_LIO_LIPrevious legume did not altered the enzymatic activity of wheat-associated rhizosphere microbes, but increased soil ammonium C_LIO_LIWheat grain protein content was higher following faba bean than peas C_LI

microbiology↗

bioRxiv2025

ERGA-BGE genome of Androsace saussurei Dentant, Lavergne, F. C. Boucher & S. Ibanez, a recently described plant from the rooftops of Europe

The reference genome of Androsace saussurei (Ericales: Primulaceae: Primuloideae) provides a valuable resource for understanding the mechanisms of plant adaptations to the most extreme environments where flowering plants can thrive and the speciation mechanisms of plants dwelling on high alpine sky islands. The entirety of the genome sequence was assembled into 20 contiguous chromosomal pseudomolecules. This chromosome-level assembly encompasses 413 Mb, composed of 253 contigs and 101 scaffolds, with contig and scaffold N50 values of 4.95 Mb and 21.2 Mb, respectively.

genomics↗

bioRxiv2022

Phylogenomics Illuminates the Evolutionary History of Wild Silkmoths in Space and Time (Lepidoptera: Saturniidae)

AO_SCPLOWBSTRACTC_SCPLOWWild silkmoths (Saturniidae) are one of the most emblematic and most studied families of moths. Yet, the absence of a robust phylogenetic framework based on a comprehensive taxonomic sampling impedes our understanding of their evolutionary history. We analyzed 1,024 ultraconserved elements (UCEs) and their flanking regions to infer the relationships among 338 species of Saturniidae representing all described subfamilies, tribes, and genera. We investigated systematic biases in genomic data and performed dating and historical biogeographic analyses to reconstruct the evolutionary history of wild silkmoths in space and time. Using Gene Genealogy Interrogation, we showed that saturation of nucleotide sequence data blurred our understanding of early divergences and first biogeographic events. Our analyses support a Neotropical origin of saturniids, shortly after the Cretaceous-Paleogene extinction event (ca 64.0 [stem] - 52.0 [crown] Ma), and two independent colonization events of the Old World during the Eocene, presumably through the Bering Land Bridge. Early divergences strongly shaped the distribution of extant subfamilies as they showed very limited mobility across biogeographical regions, except for Saturniinae, a subfamily now present on all continents but Antarctica. Overall, our results provide a framework for in-depth investigations into the spatial and temporal dynamics of all saturniid lineages and for the integration of their evolutionary history into further global studies of biodiversity and conservation. Rather unexpectedly for a taxonomically well-known family such as Saturniidae, the proper alignment of taxonomic divisions and ranks with our phylogenetic results leads us to propose substantial rearrangements of the family classification, including the description of one new subfamily and two new tribes.

evolutionary biology↗

bioRxiv2020

Discovery of cryptic plant diversity in one of the harshest environments: the rooftops of the Alps

High altitude temperate mountains have long been considered devoid of life owing to high extinction or low speciation rates during the Pleistocene. We performed a phylogenetic and population genomic investigation of an emblematic high-altitude plant clade (Androsace sect. Aretia, 31 currently recognized species), based on plant surveys conducted during alpinism expeditions. Surprisingly, we inferred that this clade originated in the Miocene and continued diversifying through Pleistocene glaciations, and discovered three novel species of Androsace dwelling on different bedrock types on the rooftops of the Alps. This suggests that temperate high mountains have been cradles of plant diversity even during the Pleistocene, with in-situ speciation driven by the combined action of geography and geology. Our findings have an unexpected historical relevance: H.-B. de Saussure likely observed one of these species during his 1788 expedition to the Mont Blanc and we describe it here, over two hundred years after its first sighting.

evolutionary biology↗