Clare Gough, DR2 CNRS, leader
Since 1985 when I started my PhD in Mike Daniel’s group at the John Innes Institute (UK), I have been studying how plants and bacteria interact together. Firstly, I worked in plant pathology with two phytopathogenic bacteria, Xanthomonas campestris and Ralstonia solanacearum, and their host plants. I studied the molecular mechanisms both by which these bacteria infect and cause disease symptoms on plants, and those that enable plants to resist such infection. During my analysis of the hrp genes of R. solanacearum as a post-doc in Christian Boucher’s group at the LIPM, I contributed to a major breakthrough by helping to discover that the type III secretion system conserved with bacterial mammalian pathogens, is involved in secreting elicitors for disease and the hypersensitive reaction in plants. I was recruited by the CNRS in 1998 in Jean Dénarié’s group at the LIPM. Since then I have been studying the molecular and genetic mechanisms of early symbiotic signalling between Medicago truncatula and the two endosymbiotic microorganisms of this plant, Sinorhizobium meliloti and arbuscular mycorrhizal fungi. I was involved in the pioneering work that led in 2000 to the identification of a Nod factor signalling pathway in M. truncatula. In 2007 Jean Dénarié’s group joined together with Julie Cullimore’s group, and I became co-group leader with Julie.
Julie Cullimore, DR1 INRA
My research interests have always been related to plant nitrogen nutrition, starting with studying nitrogen assimilatory pathways in Chlamydomonas (PhD at the University of East Anglia, Norwich, UK), and then in bean (post-doc at Rothamsted Experimental Station, UK, followed by eight years as lecturer and group leader at Warwick University, UK). My interests in nitrogen assimilation continue through collaboration with Helena Carvalho (Porto, Portugal) on the enzyme, glutamine synthetase. The work on bean involved studies on the legume-Rhizobium symbiosis and following the discovery of Nod factors at the LIPM in Toulouse, I became interested in symbiotic signalling and how the symbiosis is established. I thus joined INRA at the LIPM in 1991 to study the perception of these molecules using M. truncatula as the model and working in close collaboration with Jean-Jacques Bono and Raoul Ranjeva. Since the discovery of putative Nod factor receptors, we are interested in how these proteins perceive and transduce the symbiotic signal leading to activation of nodulation and infection, through studying ligand/receptor complexes and interacting proteins, using structure-function approaches. This work now includes the perception of Myc-LCOs.
Jean-Jacques Bono, CR1 INRA
I got my PhD in 1983 at the University Paul Sabatier (Toulouse). During my thesis at the Centre of Plant Physiology, I was working on the use lignocellulosics as a source of renewable carbon after biotransformation with lignin-degrading white-rot fungi. This allowed me to integrate the Biochemistry Department of the Elf Aquitaine research centre (Lacq) for a two-year contract to study the catalytic mechanisms of lignin-peroxidase and Mn-peroxidase, and their possible use as bleaching biological agents for pulp and paper industries. Meanwhile, I accomplished my military duty as a scientist at the Laboratory of Plant Physiology of IRD (Abidjan, Ivory Coast) working on a physiological disease of Hevea Brasiliensis. After my experience in industry, I integrated the Agronomy Department of INRA (Bordeaux), in 1987, to study the turn-over of soil organic matter and its impact on soil fertility. After the discovery of Nod factors in 1990, I joined the LIPM to initiate and develop th biochemical approaches aiming at characterizing Nod factor Binding Sites as potential Nod factor receptors. This work was performed in close collaboration between the group of Julie and that of Raoul Ranjeva in the neighboring LRSV where I was a former member before leading my own group. In 2011, I joined the group of Clare and Julie to reinforce the biochemistry work on the perception/signalling of LCOs in M. truncatula including the Nod factor and the recently identified Myc factors.
Frédéric Debellé, CR1 INRA
My main focus of interest is the nitrogen-fixing symbiosis between rhizobia and legumes, with particular emphasis on host range control and development of the root nodule. Together with partners at LIPM, from 1985 to 2000, I worked on Sinorhizobium meliloti, the bacterial symbiont of Medicago sp. and characterized a number of genes (nod genes) with a crucial role in the control of nodulation and host specificity. I investigated the role of these genes in the biosynthesis of Nod factors, lipooligosaccharidic signals controlling root nodule organogenesis and infection. I then switched to work on M. truncatula in order to analyze in this model legume the signaling pathways leading to nodule organogenesis in response to Nod factors. I characterized a central component of this pathway, DMI3, also required for mycorrhization, thus showing the crucial role of calcium signaling in nodulation and mycorrhization. All along I was involved in the development of genetic and genomic tools for M. truncatula in particular the sequencing of its genome. I’m currently trying to characterize M. truncatula genes involved in host range control.
Christine Hervé, CR1 CNRS
I did my PhD at the LIPM in Pierre Yot’s lab (1989-1993), where I studied the resistance induced by the introduction of the coat protein of the cauliflower mosaïc virus into host plants. Then I moved to Bernard Lescure’s group at the LIPM on European contracts and I contributed to the analysis of the transcribed genome of Arabidospis thaliana. During these analyses I characterized the first member of the lectin kinase receptor family in Arabidopsis and I carried out structural and functional studies on this new family of receptors for 6 years. In 1997 I was recruited by the CNRS in Bernard Lescure’s group on this project. In 2001, I switched to the functional analysis of transcription factors containing TCP domains in Arabidopsis, a subject which made a link between my work and Dominique Tremousaygue’s subject who worked in the same team. This group stopped in 2007 and I joined Julie Cullimore’s group to study the early steps of the signalling/transduction pathway between Medicago truncatula and two endosymbiotic microorganisms. I am particularly involved in the identification and characterization of interacting partners of symbiotic receptors.
Benoit Lefebvre, CR1 INRA
My current research project aims to understand the role of lipochitooligosaccharidic and chitooligosaccharidic signal molecules produced by arbuscular mycorrhizal fungi. The strategy consists in the identification and characterization of their plant receptors likely belonging to the family of receptors containing LysM domains using biochemical and reverse genetics approaches. In 2012, I initiated studies on model plants and crop including dicots : Nicotiana benthamiana and Solanum lycopersicum (tomato) and monocots: Brachypodium distachyon and Triticum aestivum (wheat). During my PhD (1999-2004) at Louvain-la-Neuve (Belgium) under the supervision of Professor Marc Boutry, I worked on the characterization and trafficking to the plasma membrane of H+-ATPases, proteins generating the electrochemical gradient across the plasma membrane. I joined the LIPM for a post-doc (2004-2007) in Julie Cullimore’s team and I was recruited in 2007 as an INRA research scientist. Between 2004 and 2011, I worked on the characterization of NFP and LYK3, two LysM Receptor-Like Kinases from the legume Medicago truncatula that are essential for nodulation. In 2011, I was on sabbatical and I worked in the laboratory of Professor Pamela Ronald at Davis (CA, USA) on another plant receptor kinase, XA21 involved in Oryza sativa (rice) immunity.
Sandra Bensmihen, CR1 CNRS
I did my PhD at the « Institut des Sciences du Végétal » (ISV) in Gif-sur-Yvette, working on transcription factors from the basic leucine zipper (bZIP) family and their implication in the maturation of Arabidopsis thaliana seeds, under the direction of François Parcy. Then I worked for a bit more than 2 years in Norwich, at the John Innes Centre, in the group of Enrico Coen on modelling approaches of Antirrhinum and Arabidopsis leaf development. I then moved to the symbiosis field with a second post-doc in Clare Gough’s group (LIPM, Toulouse), on genetic analysis of Nod Factor perception by the LysM-RLK gene NFP, in Medicago truncatula. Finally, I had the opportunity to “merge” developmental and symbiosis aspects, since I got a permanent CNRS position (in 2008) to work on the influence of symbiotic molecules (Nod and Myc factors) on lateral root development of Medicago truncatula.
Fabienne Maillet, IE1 INRA
Recruited in 1983 in this team, my career is linked to the story of the nitrogen fixing symbiosis and its various discoveries: the cloning and regulation of bacterial nod genes, the identification of Nod factors, the identification of the Nod signalling pathway in M. truncatula, the Research and Development work for the use of Nod factors in agriculture. Recently, I was largely involved in the project conducted by J. Dénarié, which led to the identification of fungal LCOs acting as symbiotic signals in the endomycorrhizal interaction. Now, I’m involved in the phenotypic characterization of the LysM-RLK family of genes in M. truncatula with the aim of finding the different Nod and Myc receptors.
Chrystel Gibelin-Viala, AI INRA
Recruited at INRA Poitou-Charentes, I worked in the molecular biology laboratory of URP3F, studying the functioning of the forage crop on grassland. I joined the LIPM in 2009 in the group of Clare Gough and Julie Culimore. I am involved in the research program studying the arbuscular mycorrhizal symbiosis and aimed at identifying new mycorrhizal mutants of M. truncatula. I am also involved in genetic approaches to dissect host range control in the rhizobium-legume symbiosis. I have skills in molecular biology (DNA extraction, PCR, genotyping), microscopy, plant biology (plant growth, plant experimentation, phenotyping).
Virginie Gasciolli, TR INRA
Recruited at INRA Toulouse in the UMR181 INRA / ENVT in 2001, I joined the UMR1318 at INRA Versailles in 2003 to work on the mechanisms of post-transcriptional regulation of gene expression in Arabidospsis thaliana. I then participated in the study of the biosynthesis of cellulose during the cellular elongation process of the same model plant. I joined the group of Clare and Julie in 2011. I am involved in the biochemical studies on the perception of the microbial symbiotic signals by Medicago truncatula. I contribute to the synthesis/purification/quantification of ligands needed for the characterization of the receptor/ligand interaction experiments and the work on endogenous binding proteins or putative Nod factor receptors expressed in various systems (eucaryotes or procaryotes).
Luis Buendia, PhD student
After a Bachelor’s degree in plant sciences and 6 month internship at the GAFL lab in Avignon that aimed to find molecular markers associated with ethylene release, I joined the team in 2012 in order to work on LCO perception in non-legumes. In 2014-2015, I did a Master internship and obtained a temporary position in another team of the LIPM (sunflower genetic and genomics team) to work on sunflower downy mildew effectors. In 2015, I obtained a PhD scholarship to work on the perception and the developmental effects of symbiotic fungal signals in Brachypodium distachyon under the supervision of Benoit Lefebvre and Sandra Bensmihen.
William Buhian, PhD student
I have recently graduated with a Masters degree in Biology from the University of the Philippines, where my thesis was on antimicrobial activity against multidrug-resistant bacteria of plants used in traditional medicine. I was granted a scholarship by the French and Philippine governments to do my PhD studies in Toulouse. My current PhD project, supervised by Dr Sandra Bensmihen, is on the functional characterization of a gene predicted to be involved in auxin signalisation.
Claudia Bartoli, post-doc
Claudia Bartoli received a European PhD in Plant Pathology in 2014. She carried out a part of her PhD thesis activities at the University of Tuscia (Italy) and most of her work at INRA, in the Plant Pathology Research Unit of Avignon under the supervision of Cindy Morris. During her PhD thesis, she investigated whether non-crop populations of the plant pathogenic bacterium Pseudomonas syringae are responsible for future epidemics. From September 2014, she joined the LIPM laboratory under the supervision of Fabrice Roux as a postdoctoral associate to investigate the genetic and ecological factors influencing Arabidopsis thaliana microbiota in natural habitats. From November 2016 she joined the group Symbiotic signalling to work with Benoit Lefebvre on genes related to mycorrhization in Brachypodium distachyon. She is also investigating whether wheat roots can be colonize by Rhizobium species isolated from different wheat cultivars.
Megane Gaston, Assitant IE
While I was learning for my master degree I had the opportunity to do two internships focusing on root symbiosis in the « Mycorrhizal symbiosis » team of the LRSV lab and in the « symbiotic signaling » team of the LIPM. After I graduated (master degree specialized on plant sciences in Toulouse) I was hired by the MAP lab of Villeurbanne in the « molecular genetic of yeasts » team to make mutated strains of Saccharomyces cerevisiae and a DNA bank. In 2017, back in the « symbiotic signaling » team, I joined the « WHEATSYM » project led by Benoit Lefebvre which aims to identify in monocotyledons, Myc signal receptors and test the effects of their manipulation on plant responses and interactions with symbionts.
Annélie de Régibus, Assitant IE
Camille Ribeyre, Assitant AI
After my professional degree in plant biotechnologies at the University Paul Sabatier (Toulouse), I worked on two validation projects. I studied the effects of mycorrhization on several plant species cultivated in greenhouse or in vitro. And since March 2018, I joined the team on the project Stress'n'Sym under the supervision of Benoit Lefebvre. I am studying the impact of arbuscular mycorrhizal fungi on the growth of Brachypodium distachyon.