Montpellier Scientific Community



Biology and genetics of plant / pathogen interactions (BGPI)

Director: Jean-Loup Nottéghem
Research area
The JRU Biology and genetics of plant/pathogen interactions (BGPI) aims at improving the knowledge of the biology and population dynamics of several pathogens or weeds with a view to proposing rational control using three lines of approach: systematics, phylogeny, phylogeography; population genetics and ecology; integrative ecology of population-environment systems.
Staff profile
 
Total permanent staff Total Scientists Scientists with "HDR"[1] Post-doc fellows PhD
80
32
5
4
8
[1] French university degree for confirmed thesis supervisor
    
         
Research teams
Group 1: Detection, variability and expression of endogenous and exogenous Badnavirus
Badnavirus, belonging to the family Caulimoviridae, is an emerging viral genus on tropical crops. Four badnaviruses are particularly studied in our research topics, the cacao swollen shoot virus (CSSV), the sugar cane bacilliform virus (SCBV), the dioscorea bacilliform virus (DBV) and the banana streak virus (BSV). We study different questions related to the origin of the important molecular variability occurring in badnaviruses: the origin of the epidemics -exogenous versus endogenous origin-, the role and evolution of EPRVs and the mechanisms of their regulation.

Group 2: Caulimoviridae & Geminiviridae: Transmission & Evolution (CaGeTE)
The research group CaGeTE is interested in the impact of the mechanisms of host-to-host vector-transmission on the evolution of viral populations, developing a multi-disciplinary approach (structural biology and biochemistry of interacting viral and vector proteins, cell biology of the host-virus relationship, and population genetics applied to viruses). We use as biological models plant DNA viruses in the families Caulimoviridae (Cauliflower mosaic virus, CaMV) and Geminiviridae (Tomato yellow leaf curl virus,TYLCV). Our research is based on the idea that specific mechanisms of virus-vector interaction might have been selected, not simply securing efficient dispersal of the virus, but also leading to other phenomena.

Group 3: Genomics and molecular analysis of pathogenicity of plant pathogenic bacteria
The objectives of our team are to analyze the genetic diversity of plant pathogenic bacteria and the molecular mechanisms that confer pathogenicity toward plants, with the aim of developing new control methods. Very few data are available to-date regarding the mechanisms that confer the capacity of these pathogens to colonize host xylem. Our current goal is to identify and to study the function of bacterial pathogenicity genes involved in these mechanisms using the model Xanthomonas albilineans, a xylem-invading bacterium.

Group 4: Rice-pathogens' interactions
Using the model interaction between rice and its major pathogen, the fungus Magnaporthe oryzae, a broad range of different forms of resistance (non-host, complete and partial resistance) are under study. Plant genes involved at different steps (pathogen perception, signal transduction and defense reactions) are identified and analyzed molecularly. Susceptibility is studied from both the pathogen side (identification of effector proteins contributing to fungal pathogenicity) and the plant side (biological functions required for hosting the pathogen). M. oryzae population diversity and adaptation to the host are characterized to integrate the evolution of the pathogen into breeding strategies for disease resistance.

Group 5: Biology and evolution of plant pathogenic fungi
The team aims at identifying the factors that contribute to the emergence and adaptation of fungal pathogens in response to fungicides and plant resistance use using two complementary approaches. A modelling approach is developed to study the evolution of pathogen life histories in agronomical landscapes and subsequent potential consequences of such evolution on emergence risks, resistance to fungicide and plant resistance breaking. Population genetics and quantitative genetics approaches are conducted on several biological models to study the adaptive potential of pathogen populations by (i) estimating parameters related to evolutionary factors, such as recombination, gene flow and selection, and (ii) determining the genetic support of adaptive traits. Combining both theoretical and empirical approaches will allow improving our evaluation of emergence risks and the elaboration of rational management strategies of fungicide and plant resistance use.

Group 6: Epidemiology of vector-transmitted diseases of perennials
Researches on plant diseases transmitted by insects are conducted with the objective of understanding the dynamics of a pathosystem at temporal and spatial scales and to propose disease control strategies. Two stone-fruit trees diseases are used as biological models: the Sharka disease caused by the aphid-transmitted Plum pox virus and the European stone fruit yellows caused by ‘Candidatus Phytoplasma prunorum' transmitted by one species of Psyllidae. Complementary approaches are considered in the study of pathosystem dynamics: spatio-temporal analysis (at plant, field and regional level) of infected trees, modelling, molecular epidemiology, and insect biology.

Group 7: Transfer, diagnostic and quarantine
The team's activities are the area of application of UMR BGPI and require numerous interactions between research, extension and growers. Our quarantine service includes, according to the needs, different processes: disease indexing (sugarcane, banana, yam), transit centre (sugarcane, yam), variety decontamination (sugarcane, yam). Most of the applied diagnosis tests are aimed at detecting plant viruses and a few bacteria (including phytoplasmas) using a wide range of techniques, and one of our strategies is to develop in the future multiplex tests for the co-detection of several pathogens (multiplex-PCR, DNA/RNA microchips).
Platforms and other tools
  • Greenhouse containment level 2: 400m2
  • Growth chambers containment level 3: 5x15 m2
  • Electron microscope
Most important international partnerships
University of Florida, Department of plant pathology, Gainesville - PPT Lodi Italy
University of Glasgow Division on environnemental and evolutionnary biology. ENA Meknes laboratoire de virologie
Facts and figures
Publications in international ranking journals
2007: 20
2006: 15
2005: 17
Representative publications
Uzest M., Gargani D., Drucker M., Hébrard E., Garzo E., Candresse T., Fereres A., Blanc S. 2007. A protein key to plant virus transmission at the tip of the insect vector stylet. Proceedings of the National Academy of Sciences of the United States of America, 104 (46): 17959-17964

Jridi C., Martin J.F., Marie-Jeanne V., Labonne G., Blanc S. 2006. Distinct viral Populations differentiate and evolve independently in a single perennial host plant. Journal of Virology, 80 (5): 2349-2357

Vivien E., Pitorre D., Cociancich S., Pieretti I., Gabriel D.W., Rott P.C., Royer M. 2007. Heterologous Production of Albicidin: a promising approach to overproducing and characterizing this potent inhibitor of DNA gyrase. Antimicrobial Agents and Chemotherapy, 51 (4): 1549-1552

Ballini E., Berruyer R., Morel J.-B., Lebrun M.-H., Nottéghem J.-L., Tharreau D. 2007. Modern elite rice varieties of the 'Green Revolution' have. retained a large introgression from wild rice around the Pi33 rice blast resistance locus. New Phytologist, 175 (1): 340-350

Thébaud G., Sauvion N., Chadoeuf J., Dufils A., Labonne G. 2006. Identifying risk factors for European stone fruit yellows from a survey. Phytopathology, 96 (8): 890-899.

Hohn T., Richert-Pöggeler K., Staginnus C., Harper G., Schwarzacher T., How Teo C., Teycheney P.Y. , Iskra-Caruana M.L., Hull R. 2007. Evolution of integrated plant viruses.M. Roosinck ed., Springer in "Plant virus evolution"