A5031528888- Legume Nitrogen Fixing Symbiosis
- Plant nutrient uptake and metabolism
- Plant-Microbe Interactions and Immunity
- Agronomic Practices and Intercropping Systems
- Plant Pathogenic Bacteria Studies
- Plant Molecular Biology Research
- Nematode management and characterization studies
- Mycorrhizal Fungi and Plant Interactions
- Plant Parasitism and Resistance
- Plant Pathogens and Fungal Diseases
- Plant Virus Research Studies
- Carbohydrate Chemistry and Synthesis
- Plant responses to water stress
- Plant Reproductive Biology
- Plant and animal studies
- Glycosylation and Glycoproteins Research
- Photosynthetic Processes and Mechanisms
- Plant Gene Expression Analysis
- Plant biochemistry and biosynthesis
- Plant Stress Responses and Tolerance
- Insect symbiosis and bacterial influences
- Phytoplasmas and Hemiptera pathogens
- Lysosomal Storage Disorders Research
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2024
Université de Toulouse
2016-2024
Centre National de la Recherche Scientifique
2008-2024
Laboratoire des Interactions Plantes Micro-Organismes
2012-2024
Génétique Physiologie et Systèmes d'Elevage
2022
Université Toulouse III - Paul Sabatier
2020
Institut National de la Recherche Agronomique
2012-2014
John Innes Centre
2012
Laboratoire Physiologie Cellulaire & Végétale
1995
Abstract In situ immunolocalization of tubulin revealed that important rearrangements occur during all the early symbiotic steps in Medicago/R. meliloti interaction. Microtubular cytoskeleton (MtC) reorganizations were observed inner tissues, first pericycle and then cortex where nodule primordium forms. Subsequently, major MtC changes occurred outer associated with root hair activation curling, formation preinfection threads (PITs) initiation growth an infection network. From sequence...
Abstract AtTCP20 is a transcription factor belonging to the Arabidopsis (Arabidopsis thaliana) TCP-P subfamily, characterized by its capacity bind site II motifs (TGGGCY). Our aim was understand role of in plant development. The expression pattern translational fusion PromTCP20:CDS20∷GUS∷GFP suggested function for several organs and stages challenged planta inducing proteins fused with either transcriptional activator domain (VP16) or repressor (EAR). Expression both modified led severe...
Abstract Rhizobial nodulation factors (NFs) activate a specific signaling pathway in Medicago truncatula root hairs that involves the complex interplay of Nodulation Signaling Pathway1 (NSP1)/NSP2 GRAS and Ethylene Response Factor Required for Nodulation1 (ERN1) transcription (TFs) to achieve full ENOD11 transcription. ERN1 acts as direct transcriptional regulator through activation NF-responsive “NF box.” Here, we show NSP1, when combined with NSP2, can act strong positive Although...
In indeterminate alfalfa nodules, the establishment of senescent zone IV, in which both symbionts undergo simultaneous degeneration, has been considered, until now, as end point symbiotic interaction. However, we now describe an additional zone, V, proximal to IV and present nodules more than 6 weeks old. a new round bacterial release occurs from remaining infection threads, leading reinvasion plant cells that have completely senesced. These intracellular rhizobia are rod shaped do not...
The hypersensitive response (HR) is a programmed cell death that commonly associated with plant disease resistance. A novel lesion mimic mutant, vad1 (for vascular death1), exhibits light conditional appearance of propagative HR-like lesions along the system was identified. Lesion formation expression defense genes, production high levels salicylic acid (SA), and increased resistance to virulent avirulent strains Pseudomonas syringae pv tomato. Analyses progeny from crosses between plants...
Hydathodes are water pores found on leaves of a wide range vascular plants and the sites guttation. We report here detailed anatomy cauliflower (Brassicaoleracea) Arabidopsis (Arabidopsis thaliana) hydathodes. Hydathode surface presents resembling stomata giving access to large cavities. Beneath, epithem is composed lacunar highly vascularized parenchyma offering direct connection between leaf xylem vessels. hydathode were responsive ABA light similar stomata. The flg22 flagellin peptide,...
Legumes improve their mineral nutrition through nitrogen-fixing root nodule symbioses with soil rhizobia. Rhizobial infection of legumes is regulated by a number transcription factors, including ERF Required for Nodulation1 (ERN1). Medicago truncatula plants defective in ERN1 are unable to nodulate, but still exhibit early symbiotic responses rhizobial infection. has close homolog, ERN2, which shows partially overlapping expression patterns. Here we show that ern2 mutants later nodulation...
Bacterial lipo-chitooligosaccharides (LCOs) are key mediators of the nitrogen-fixing root nodule symbiosis (RNS) in legumes. The isolation LCOs from arbuscular mycorrhizal fungi suggested that also signaling molecules mycorrhiza (AM). However, corresponding plant receptors have remained uncharacterized. Here we show petunia and tomato mutants LysM receptor-like kinases LYK10 impaired AM formation. Petunia proteins a high affinity for (Kd nM range) comparable to previously reported legume LCO...
WRKY transcription factors play a key role in modulating the plant defense transcriptome. Here we show that Arabidopsis mutant wrky27-1, which lacks functional WRKY27 factor, showed delayed symptom development response to bacterial wilt pathogen Ralstonia solanacearum. Additionally, wrky27-1 plants did not express PR marker genes upon infection, as also observed resistant Nd-1 plants. Spatial expression of correlated well with route infection and propagation planta. Complementation...
ABSTRACT Reorganization of the plant cytoskeleton is thought to play an important role during nodule ontogeny. In situ immunolocalisation tubulin reveals that cytoskeletal changes, implying a transient disorganization followed by newly patterned reorganization, occur in indeterminate and determinate nodules. alfalfa nodules, changes closely parallel symbiotic differentiation features related cell infection, bacterial release, endopolyploidization, enlargement, spatial organization organelle...
The lysin motif receptor-like kinase, NFP (Nod factor perception), is a key protein in the legume Medicago truncatula for perception of lipochitooligosaccharidic Nod factors, which are secreted bacterial signals essential establishing nitrogen-fixing legume-rhizobia symbiosis. Predicted structural and genetic analyses strongly suggest that at least part receptor, but few data available about this protein. Characterization variant encoded by mutant allele nfp-2 revealed sensitivity to...
Mutualism is of fundamental importance in ecosystems. Which factors help to keep the relationship mutually beneficial and evolutionarily successful a central question. We addressed this issue for one most significant mutualistic interactions on Earth, which associates plants leguminosae family hundreds nitrogen (N2)-fixing bacterial species. Here we analyze spatio-temporal dynamics fixers non-fixers along symbiotic process Cupriavidus taiwanensis–Mimosa pudica system. N2-fixing symbionts...
The Cauliflower mosaic virus 35S promoter currently is being used in RNAi-based approaches for attenuating host gene expression during legume root nodule development and also the of fluorescent reporters tissues. In this study, we have evaluated indeterminate nodules model plant Medicago truncatula. Our results clearly show that inactive both meristem bacteroid-containing cells nodules. On other hand, Arabidopsis thaliana EF1alpha was found to be strongly expressed all nodule-invaded cells....
Rhizobia are symbiotic soil bacteria able to intracellularly colonize legume nodule cells and form nitrogen-fixing symbiosomes therein. How the plant cell cytoskeleton reorganizes in response rhizobium colonization has remained poorly understood especially because of lack an vitro infection assay. Here, we report on use heterologous HeLa model experimentally tackle this question. We observed that Sinorhizobium meliloti, other rhizobia as well, were trigger a major reorganization actin...
Rhizobium-legume nitrogen-fixing symbiosis involves the formation of a specific organ, root nodule, which provides bacteria with proper cellular environment for atmospheric nitrogen fixation. Coordinated differentiation plant and bacterial cells is an essential step nodule development, few transcriptional regulators have been characterized. Medicago truncatula ETHYLENE RESPONSE FACTOR REQUIRED FOR NODULE DIFFERENTIATION (MtEFD) encodes APETALA2/ETHYLENE RESPONSIVE (ERF) transcription factor,...
Legumes establish endosymbioses with arbuscular mycorrhizal (AM) fungi or rhizobia bacteria to improve mineral nutrition. Symbionts are hosted in privileged habitats, root cortex (for AM fungi) nodules rhizobia) for efficient nutrient exchange. To reach these plants form cytoplasmic bridges, which key predicting and guiding the cellular route of entry fungal hyphae rhizobia-filled infection threads (ITs). However, underlying mechanisms poorly studied. Here we show that unique ultrastructural...
Hydathode is a plant organ responsible for guttation in vascular plants, i.e. the release of droplets at leaf margin or surface. Because this connects vasculature to external environment, it also known entry site several pathogens. In study, we present detailed microscopic examination apical hydathodes monocots three crops (maize, rice and sugarcane) model Brachypodium distachyon. Our study highlights both similarities specificities those epithemal hydathodes. These observations will serve...
Abstract Although rhizobia that establish a nitrogen‐fixing symbiosis with legumes are also known to promote growth in non‐legumes, studies on rhizobial associations wheat roots scarce. We searched for Rhizobium leguminosarum symbiovar viciae ( Rlv ) strains naturally competent endophytically colonize roots. isolated 20 from surface‐sterilized and found low diversity of compared observed the species complex. tested ability subset these root colonization when co‐inoculated other . Only few...
Promoters with tissue-specific activity are very useful to address cell-autonomous and non cell autonomous functions of candidate genes. Although this strategy is widely used in Arabidopsis thaliana, its use study regulation root symbiotic interactions legumes has only started recently. Moreover, using tissue specific promoter drive a GAL4-VP16 chimeric transcription factor that can bind short upstream activation sequences (UAS) an efficient way target enhance the expression any gene...
Orobanche cumana Wall., sunflower broomrape, is one of the major pests for crop. Breeding resistant varieties in has been most efficient method to control this parasitic weed. However, more virulent broomrape populations continuously emerge by overcoming genetic resistance. It thus essential identify new resistances acting at various stages interaction and combine them improve resistance durability. In study, 71 wild sunflowers relatives accessions from 16 Helianthus species were screened...
Summary Although rhizobia establishing a nitrogen-fixing symbiosis with legumes are also known to promote growth in non-legumes, studies on association wheat roots scarce. We searched for Rhizobium leguminosarum symbiovar viciae ( Rlv ) strains naturally competent colonization. isolated 20 and tested the ability of subset colonization when co-inoculated other . measured effect these root architecture Arbuscular Mycorrhizal Fungal (AMF) found low diversity compared that observed species...