Biology subjects

Carton, C.

Publications and source records attributed to Carton, C..

3 recordsLinked to original sources

bioRxiv2024

Oligogalacturonides, produced by enzymatic degradation of sugar beet by-products, confer partial protection against wheat powdery mildew

Nowadays, it becomes urgent to use new alternative strategies for a more sustainable agriculture, by developing eco-friendly biocontrol compounds leading to an induction of plant resistance against pathogens. In recent years, oligogalacturonides (OGs), fragments of pectin resulting from the degradation of the plant cell wall, have been particularly under focus for their ability to induce plant defense, leading to plant protection against pathogens. In the current work, 2 mixtures of OGs, bio-sourced from sugar beet by-products, were produced and assessed for their protective efficacy on wheat against Blumeria graminis f. sp. tritici (Bgt), responsible for powdery mildew. These OGs pools were obtained by hydrolysing pectins with two A. thaliana polygalacturonases (PGs), ADPG2 and PGLR (EC 3.2.1.15), produced in heterologous system Pichia pastoris. No direct effect of OGs generated by either ADPG2, named OGs-ADPG2 (degree of polymerisation/DP 1-10 and degree of esterification/DE 41%) or PGLR, named OGs-PGLR (DP 1-16, DE 34 %), was observed on Bgt spore germination in vitro. After a preventive foliar spraying of wheat by OGs, only OGs-PGLR provided a 31 % partial protection against Bgt. Both pools of OGs triggered an increase in the expression of some plant defense-related genes (peroxidase or PR proteins encoding genes), before inoculation with the pathogen. However, only OGs-PGLR induced the expression of a gene encoding a lipoxygenase (LOX), which is the first enzyme involved in the octadecanoic pathway, leading to oxylipins production in plant defense. Taking together, these findings revealed that some OGs, produced from sugar beet by-products by enzymatic hydrolysis, could be used as an alternative of phytochemicals.

plant biology↗

bioRxiv2023

TBL38 is an atypical homogalacturonan acetylesterase with a peculiar cell wall microdomain localization in Arabidopsis seed mucilage secretory cells

Plant cell walls are made of complex polysaccharidic/proteinaceous network whose biosynthesis and dynamics implicate several cell compartments and impact plant development. The synthesis and remodeling of homogalacturonan pectins is associated with multiple developmental processes ranging from growth to response to biotic/abiotic stress. It encompasses Golgi-localized methylation and acetylation and subsequent demethylation and deacetylation in the cell wall. In the last decade, our comprehension of plant polysaccharides acetylation has increased significantly thanks to the study of the TRICHOME BIREFRINGENCE-LIKE (TBL) protein family. TBLs are mostly described as Golgi-localized acetyltransferases specifically targeting diverse hemicelluloses or pectins. Various tbl mutants showed altered wall mechanical properties and dynamics. Here, we study TBL38 that is co-expressed with PECTIN METHYLESTERASE INHIBITOR6 (PMEI6) and PEROXIDASE 36 (PRX36) during the development of Arabidopsis seed mucilage secretory cells (MSCs). We demonstrate the atypical TBL38 cell wall localization restricted to the PMEI6/PRX36 MSC cell wall microdomain. A tbl38 mutant displays an intriguing homogalacturonan immunological phenotype in this cell wall microdomain and in a MSC surface-enriched abrasion powder. This fraction was further characterized by mass spectrometry oligosaccharide profiling revealing an increased homogalacturonan acetylation phenotype. Finally, a recombinant TBL38 is shown to display pectin acetylesterase activity in vitro. These results indicate that TBL38 is an atypical cell wall-localized TBL that displays a homogalacturonan acetylesterase activity rather than a Golgi-localized acetyltransferase activity as observed in previously studied TBLs. TBL38 function during seed development is discussed.

plant biology↗

bioRxiv2018

Both rare and common genetic variants contribute to autism in the Faroe Islands

The number of genes associated with autism is increasing, but few studies have been performed on epidemiological cohorts and in isolated populations. Here, we investigated 357 individuals from the Faroe Islands including 36 individuals with autism, 136 of their relatives and 185 non-autism controls. Data from SNP array and whole exome sequencing revealed that individuals with autism compared to controls had a higher burden of copy-number variants (p < 0.05), higher inbreeding status (p < 0.005) and higher load of homozygous deleterious variants (p < 0.01). Our analysis supports the role of several genes/loci associated with autism (e.g. NRXN1, ADNP, 22q11 deletion) and identified new truncating (e.g. GRIK2, ROBO1, NINL and IMMP2L) or recessive deleterious variants (e.g. KIRELL3 and CNTNAP2) affecting autism-risk genes. It also revealed three genes involved in synaptic plasticity, RIMS4, KALRN and PLA2G4A, carrying de novo deleterious variants in individuals with autism without intellectual disability. In summary, our analysis provides a better understanding of the genetic architecture of autism in isolated populations by highlighting the role of both common and rare gene variants and pointing at new autism-risk genes. It also indicates that more knowledge about how multiple genetic hits affect neuronal function will be necessary to fully understand the genetic architecture of autism.

genetics↗