A5105729917- Plant-Microbe Interactions and Immunity
- Plant Pathogenic Bacteria Studies
- Legume Nitrogen Fixing Symbiosis
- Plant Disease Resistance and Genetics
- Polysaccharides and Plant Cell Walls
- Plant Virus Research Studies
- Studies on Chitinases and Chitosanases
- Bacteriophages and microbial interactions
- Photoacoustic and Ultrasonic Imaging
- Optical Coherence Tomography Applications
- Plant pathogens and resistance mechanisms
- Plant Molecular Biology Research
- Plant Pathogens and Fungal Diseases
- Chromosomal and Genetic Variations
- Microfluidic and Bio-sensing Technologies
- Advanced Fluorescence Microscopy Techniques
- Fungal and yeast genetics research
- Animal Virus Infections Studies
- Microbial Community Ecology and Physiology
- Photosynthetic Processes and Mechanisms
- Genomics and Phylogenetic Studies
- Fungal Plant Pathogen Control
- Virus-based gene therapy research
- Polyomavirus and related diseases
- Marine and coastal ecosystems
Institut Langevin
2021-2024
Université Paris Sciences et Lettres
2016-2024
École Normale Supérieure - PSL
2014-2024
Institut de Systématique, Évolution, Biodiversité
1998-2024
Centre National de la Recherche Scientifique
2007-2023
Institut de Biologie de l'École Normale Supérieure
2014-2023
Inserm
2016-2023
ESPCI Paris
2021-2023
Sorbonne Université
2005-2023
École Pratique des Hautes Études
2016-2023
DNA methylation is essential for silencing transposable elements and some genes in higher eukaryotes, which suggests that this modification must be tightly controlled. However, accidental changes can transmitted through mitosis (as cancer) or meiosis, leading to epiallelic variation. We demonstrated the existence of an efficient mechanism protects against transgenerational loss Arabidopsis. Remethylation specific subset heavily methylated repeats are targeted by RNA interference (RNAi)...
RNA-DEPENDENT RNA POLYMERASE 6 (RDR6) is a key silencing factor initially characterized in transgene and virus resistance. This enzyme also contributes to the biosynthesis of endogenous short interfering RNAs (siRNAs) from non-coding RNAs, transposable elements protein-coding transcripts. One class transcripts that have recently emerged as major sources RDR6-dependent siRNAs are nucleotide-binding leucine-rich repeat (NB-LRR) proteins, family immune-receptors perceive specific pathogen...
The pectinolytic enzyme pectin methylesterase (PME) hydrolyses in methanol and polygalacturonic acid. In the expressed sequence tag library of Botrytis cinerea T4, we identified a 1,041 bp Bcpme1 cDNA potentially encoding 346-amino acid protein 37 kDa showing 46.8% identity with Aspergillus sp. PMEs. is single copy gene similarly glucose containing media. To evaluate role virulence, mutant was generated by disruption. showed similar growth on rich medium but reduced medium. Two isozymes pI...
Abstract Predicting responses of plankton to variations in essential nutrients is hampered by limited situ measurements, a poor understanding community composition, and the lack reference gene catalogs for key taxa. Iron driver dynamics and, therefore, global biogeochemical cycles climate. To assess impact iron availability on communities, we explored comprehensive bio‐oceanographic bio‐omics data sets from Tara Oceans context products two state‐of‐the‐art scale models. We obtained novel...
SUMMARY The complete nucleotide sequence of tobacco rattle virus (TRV) strain SYM RNA-1 was determined from a series overlapping cDNA clones. prepared by primer extension used to determine the exact 5′ terminus. RNA 6791 nucleotides in length and contained four open reading frames (ORFs). ORF nearest terminus coded for polypeptide predicted mol. wt. 134000 (134K) terminated at an opal (UGA) stop codon. Readthrough this codon would result production protein 194K. gene 29K started one base...
Dickeya dadantii is a plant-pathogenic enterobacterium responsible for the soft rot disease of many plants economic importance. We present here sequence strain 3937, widely used as model system research on molecular biology and pathogenicity this group bacteria.
We developed improved virulence assays for Erwinia chrysanthemi 3937 on African violet varieties and devised a new method the construction of precise bacterial gene knockouts. These methods were tested by constructing mutations in genes suspected to be involved with plant interactions. The hrpG hrcC mutant strains (both products presumed protein secretion) was greatly reduced leaves semitolerant varieties. An hrpN strain produced delayed symptoms an delta pel (delta = five major pectate...
During the biosynthesis of fungal melanin, tetrahydroxynaphthalene reductase catalyzes NADPH-dependent reduction 1,3,6,8-tetrahydroxynaphthalene (T4HN) into (+)-scytalone and 1,3,8-trihydroxynaphthalene (-)-vermelone. The enzyme from Magnaporthe grisea, fungus responsible for rice blast disease, has been purified to homogeneity. It is a tetramer four identical 30-kDa subunits. A full-length cDNA clone about 1 kb encoding T4HN isolated library constructed in lambda ZAP II vector...
The Tntl retrotransposon was isolated from tobacco after transposition.Tntl expression is very low at the plant level and under most stress condlUons but strongly induced during protoplast Isolation.It shown here that tranecription of ratrotreneposon can be activated by several microbial factors having common ability to elicit a hypersensitive response in tobacco.These elicitore Include Onozuka crude extracts fungus Trlchoderma v/ride, ellcitins purified Phytophthora fungsl species culture...
We describe a strategy for systematic amplification of chitin synthase genes ( chs ) in the filamentous ascomycetes plant‐pathogen Botrytis cinerea using PCR with multiple degenerate primers designed on specific and conserved sequence motifs. Eight distinct were isolated, named Bcchs I , II IIIa IIIb IV V VI VII . They probably constitute entire multigenic family this fungus, as revealed by careful analysis six euascomycetes genomes. subjected to DNA walking their deduced amino acid...
Summary Erwinia chrysanthemi 3937 secretes five major isoenzymes of pectate lyases encoded by the pelA, pelB, pelC, pelD and pelE genes. Recently, a new set was identified in E. mutants deleted those pel We cloned pelL gene, encoding one these secondary 3937, from genomic bank strain The nucleotide sequence region containing gene determined. reading frame is 1275 bases long, corresponding to protein 425 amino acids including typical amino‐terminal signal 25 acids. Comparison acid sequences...
Chitin, the second most abundant biopolymer on earth after cellulose, is found in probably all fungi, many animals (mainly invertebrates), several protists and a few algae, playing an essential role development of them. This polysaccharide produced by type 2 glycosyltransferases, called chitin synthases (CHS). There are contradictory classifications CHS isoenzymes and, as regards their evolutionary history, origin diversity still matter debate.A genome-wide analysis resulted detection more...
Botrytis cinerea is an important phytopathogenic fungus requiring new methods of control. Chitin biosynthesis, which involves seven classes chitin synthases, could be attractive target. A fragment encoding one the class III enzymes was used to disrupt corresponding Bcchs3a gene in B. genome. The resulting mutant exhibited a 39% reduction its content and 89% vitro synthase activity, compared with wild-type strain. not affected growth liquid medium, neither production sclerotia, micro-...
Unlike wild-type Erwinia chrysanthemi strain 3937, which fully macerates inoculated Saintpaulia plants, HmpX- mutants produce necrotic lesions or no symptoms. The hmpX gene was sequenced and the corresponding protein sequence analysed. We show that HmpX belongs to a family of flavohaemoproteins (HMP), previously identified in two yeasts Escherichia coli. Comparisons sequences at secondary structure level by hydrophobic cluster analysis have shown possesses functional regions, haemoglobin...
Host cells respond to infection by generating nitric oxide (NO) as a cytotoxic weapon facilitate killing of invading microbes. Bacterial flavohaemoglobins are well-known scavengers NO and play crucial role in protecting animal pathogens from nitrosative stress during infection. Erwinia chrysanthemi, which causes macerating diseases wide variety plants, possesses flavohaemoglobin (HmpX) whose function plant has remained unclear. Here we show that HmpX consumes prevents inhibition cell...