A5050783590- Enzyme Production and Characterization
- Carbohydrate Chemistry and Synthesis
- Microbial Metabolites in Food Biotechnology
- Legume Nitrogen Fixing Symbiosis
- Biofuel production and bioconversion
- Glycosylation and Glycoproteins Research
- Studies on Chitinases and Chitosanases
- Genomics, phytochemicals, and oxidative stress
- Enzyme Catalysis and Immobilization
- Polysaccharides and Plant Cell Walls
- Mycorrhizal Fungi and Plant Interactions
- Silicone and Siloxane Chemistry
- Lysosomal Storage Disorders Research
- Trypanosoma species research and implications
- Advanced Glycation End Products research
- Chemical Synthesis and Analysis
- Nematode management and characterization studies
- Plant-Microbe Interactions and Immunity
- Phytochemicals and Antioxidant Activities
- Phytase and its Applications
- Free Radicals and Antioxidants
- Agronomic Practices and Intercropping Systems
- Plant nutrient uptake and metabolism
- Plant Parasitism and Resistance
- biodegradable polymer synthesis and properties
Centre National de la Recherche Scientifique
2013-2024
Université Grenoble Alpes
2006-2024
Centre de Recherches sur les Macromolécules Végétales
2014-2023
Département de Chimie Moléculaire
2018
Iowa State University
2016
Université Joseph Fourier
1999-2013
Institut de Chimie Moléculaire de Grenoble
2008-2013
Institut Carnot PolyNat
2013
Institut Químic de Sarrià
2006
KTH Royal Institute of Technology
2006
Abstract Establishment of arbuscular mycorrhizal interactions involves plant recognition diffusible signals from the fungus, including lipochitooligosaccharides (LCOs) and chitooligosaccharides (COs). Nitrogen-fixing rhizobial bacteria that associate with leguminous plants also signal to their hosts via LCOs, so-called Nod factors. Here, we have assessed induction symbiotic signaling by (Myc) fungal-produced LCOs COs in legumes rice (Oryza sativa). We show Myc-LCOs tetra-acetyl chitotetraose...
Most land plants live symbiotically with arbuscular mycorrhizal fungi. Establishment of this symbiosis requires signals produced by both partners: strigolactones in root exudates stimulate pre-symbiotic growth the fungus, which releases lipochito-oligosaccharides (Myc-LCOs) that prepare plant for symbiosis. Here, we have investigated events downstream early signaling roots. We report expression miR171h, a microRNA targets NSP2, is up-regulated elongation zone during colonization Rhizophagus...
Summary Arbuscular mycorrhizal (AM) fungi greatly improve mineral uptake by host plants in nutrient‐depleted soil and can intracellularly colonize root cortex cells the vast majority of higher plants. However, AM possess common fungal cell wall components such as chitin that be recognized plant receptors to trigger immune responses, raising question how effectively evade chitin‐triggered responses during symbiosis. In this study, we characterize a secreted lysin motif (LysM) effector...
Abstract Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and some fungi also establish symbiotic relationships with plants, notably arbuscular ecto mycorrhizal fungi. Here, we show many other produce LCOs. We tested 59 species representing most fungal phyla, found 53 LCOs can be detected functional assays and/or mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal...
This report describes an efficient chemoenzymatic synthesis of a variety regioselectively modified β(1→4)-oligo- and -polysaccharides. successful approach was based on: (i) the use "glycosynthase" which is Glu-197-Ala nucleophile mutant retaining cellulase endoglucanase I (Cel7B) from Humicola insolens (ii) rational design acceptor donor molecules through careful examination information given by X-ray structures wild type mutated enzymes. The able to catalyze, in high yield, regio-...
The thermoacidophilic archaeon Sulfolobus solfataricus P2 encodes three hypothetic endo-β-glucanases, SSO1354, SSO1949 and SSO2534. We cloned expressed the gene sso1949 encoding 334 amino acids containing protein SSO1949, which can be classified as a member of glycoside hydrolase family 12. purified recombinant enzyme hydrolyses carboxymethylcellulose well cello-oligomers, with cellobiose cellotriose main reaction products. By following hydrolysis fluorescently labelled cellohexaoside under...
Strigolactones (SLs) influence the ability of legumes to associate with nitrogen-fixing bacteria. In this study, we determine precise stage at which SLs nodulation. We show that promote infection thread formation, as a null SL-deficient pea (Pisum sativum) mutant forms significantly fewer threads than wild-type plants, and reduction can be overcome by application synthetic SL GR24. found no evidence physical events in plant before or after since plants displayed similar induce root hair...
Root hairs are involved in water and nutrient uptake, thereby plant autotrophy. In legumes, they also play a crucial role establishment of rhizobial symbiosis. To obtain holistic view Medicago truncatula genes expressed root their regulation during the first hours engagement symbiotic interaction, high throughput RNA sequencing on isolated from roots challenged or not with lipochitooligosaccharides Nod factors (NF) for 4 h 20 was carried out. This provided repertoire displaying expression...
Crystals of the inactive mutant Glu257→Ala cyclodextrin glycosyltransferase were soaked with (CD) derivative S-(α-d-glucopyranosyl)-6-thio-β-CD. The structural analysis showed its β-CD moiety no density indication for exocyclic glucosyl unit. For steric reasons, however, position this unit is restricted to be at only two seven groups β-CD. indicated that enzyme can cyclize branched α-glucans. ligated revealed how binds predominant cyclic product. conformation was intermediate between more...
Abstract Well‐defined glyco‐polyorganosiloxanes were synthesized by the Cu( I )‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction (often simply referred to as “click” chemistry). N ‐propargylglycosylamines 2 and 4 first from cellobiose ( 1 ) xylogluco‐oligosaccharide XGOs 3 without protecting groups. The azide function was introduced into polydimethylsiloxanes [PDMS: 5 (MD′M) 7 (M′DM′)] azidolysis of counterpart epoxy silicon with NaN afford mono‐azido 6 di‐azido 8 derivatives,...
Functionalized oligosaccharides are useful intermediates to prepare products for biological research or the development of advanced functional materials. Here, we report unprecedented use aniline as an efficient organocatalyst reaction with "clickable" (azide alkyne) amine transimination-mediated reductive amination a chitooligosaccharide. Moreover, demonstrate that alkyne-bearing constitutes excellent tool easy derivatization chitosan oligosaccharides. Evidence such improvement has been...
The biosynthesis of glycosylphosphatidylinositol (GPI) precursors in Trypanosoma brucei involves the D-mannosylation D-GlcNα1-6-D-myo-inositol-1-PO4-sn-1,2-diacylglycerol (GlcN-PI). An assay for first mannosyltransferase pathway, Dol-P-Man:GlcN-PI α1-4-mannosyltransferase, is described. Analysis acceptor specificity revealed (a) that enzyme requires myo-inositol residue GlcN-PI substrate have D configuration; (b) presence NH2 group D-GlcN residue; (c) GlcNAc-PI more efficiently presented to...
Complex oligosaccharides containing α-d-xylosyl-(1→6)-β-d-glucosyl residues and unsubstituted β-(1→4)-linked d-glucosyl units were readily synthesized using enzymatic coupling catalyzed by the Cel7B E197A glycosynthase from Humicola insolens. Constituting this library required four key steps: (1) preparing unprotected building blocks chemical synthesis or degradation of xyloglucan polymers; (2) generating donor synthon in temporarily introducing a lactosyl motif on 4-OH terminal glucosyl...
Plant XETs [XG (xyloglucan) endotransglycosylases] catalyse the transglycosylation from a XG donor to or low-molecular-mass fragment as acceptor, and are thought be important enzymes in formation remodelling of cellulose-XG three-dimensional network primary plant cell wall. Current methods assay XET activity use polysaccharide substrate, present limitations for kinetic mechanistic studies action due polymeric polydisperse nature substrate. A novel based on HPCE (high performance capillary...
Xyloglucan, the most abundant hemicellulosic component of primary cell wall flowering plants, is composed a β-(1,4)-glucan backbone decorated with d-xylosyl residues. Three xyloglucan xylosyltransferases (XXTs) participate in biosynthesis Arabidopsis (Arabidopsis thaliana). Two these, XXT1 and XXT2, have been shown to be active vitro, whereas catalytic activity XXT5 has yet demonstrated. By optimizing XXT2 expression prokaryotic system vitro assay conditions, we demonstrate that...
Myrosinase is a particular glucosidase which hydrolyzes variety of plant 1-thio-beta-D-glucosides known as the glucosinolates. This enzyme, only glycosidase able to hydrolyze these naturally occurring thioglucosides, has been found previously display strong sequence similarities with family 1 O-glycosidases. therefore offers opportunity compare mechanism enzymatic cleavage S- vs O-glycosidic bonds. The stereochemistry hydrolysis sinigrin by Sinapis alba myrosinase was followed 1H NMR and...