François Delmotte
Research scientist
INRA Bordeaux, UMR 1065
Institut des Sciences de la Vigne et du Vin
71, av. Edouard Bourlaux
BP81 - 33883 Villenave d'Ornon Cedex
France

  Tél: 0 5-57-12-26-42 / Phone : 0033-557-12-46-42

  delmotte(a)bordeaux.inra.fr

/ CV / Research Interests /

Research Interests
My aim is to understand life bridging the theory of evolution and genetics. My specific research interests fall into three areas:
    Population genetics and adaptation of plant-pathogens
    Evolutionnary genomics of bacterial endosymbionts
    Evolution of sex in aphids

Population genetics and adaptation of plant-pathogens

This program focus on two model species that are both obligate plant-pathogenic oomycetes of american origin (downy mildews) : grapevine downy mildew (Plasmopara viticola) and sunflower downy mildew (P. halstedii). Downy mildews form a monophyletic groups of plant-pathogens that belongs to Stramenopiles, Oomycetes, Peronosporales, Peronosporaceae.

Plasmopara viticola on phylloxera galls.
Grapevine downy mildew is one of the most damaging fungal diseases of grapevine (Vitis spp) worldwide. It is caused by Plasmopara viticola (Berk. & Curt. ex. De Bary), a oomycetes native of north America. In the late 1870s, P. viticola was accidentally introduced to Europe, probably when american vine stocks that were resistant to grape phylloxera were used to graft the European varieties. Since then, GDM has expanded all over Europe and it is currently present in wine growing areas worldwide. The current strategy to control the di sease in Europe relies on the use of pesticides. The search for alternative methods to control grapevine downy mildew is of paramount importance for viticulture. The use of grapevine varieties showing durable resistance to downy mildew is a promising strategy to control the disease. However, since all V. vinifera cultivars are susceptible to P. viticola, the resistance needs to be introduced from other Vitis species through breeding programmes that ensure also the maintenance of important agronomic characteristics. Breeding programmes need to make sure that the resistance employed not only is effective, but also persists in time, despite the constant evolution of pathogens. The concept of durability of resistance is indeed especially important in “perennial ” species like grapevine, which are meant to stay in the field for at least thirty years. Therefore, we are working to improve our knowlegde on the evolution of P. vitocola and on its genetic interaction with grapevine.		Sunflower downy mildew due to Plasmopara halstedii (Berlese & de Toni) an obligate parasite that has been introduced into Europe at the start of the 20th Century. Gene-for-gene interactions have been demonstrated between this pathogen and its plant host (Helianthus spp) and many races (pathotypes) have been characterised. From 1989 to1995, races 100, 703 and 710 were the only races found in French downy mildew populations. However, pathogen evolution has accelerated since1995, due to the massive deployment of new resistance genes, such as Pl6 and Pl7, and as many as 11 new races of P. halstedii have been characterized :300, 700 (1995) , 304 (2000), 314 (2001), 307 , 704 , 714 (2002) , 334, 707, 717 (2004) and 730 (2005). Today, the total ‘population’ of French races can overcome the resistance genes in seven of the ninedowny mildew differential linesof H. annuus, and the Pl2 and Pl6 genes have each been overcome by eight races. Our understanding of the recurrent breakdown of sunflower major resistance genes can be improved by new findings concerning the key processes governing the evolution of P. halstedii populations. A population genetics/genomics approach can be used to evaluate the major forces driving evolution — i.e. selection, mutation, recombination, genetic drift and gene flow. A sound knowledge of the genetic structure of P. halstedii and of the molecular interaction of the pathogen with sunflower is required to increase the durability of plant resistance genes.

Knowledge of the evolutionary potential of plant pathogen species can improve the management of resistance genes and maximize their durability in space and time. Therefore, the objectives of this research program are multiple:

• assess the genetic variability and the population structure of P. viticola and P. halstedii at different spatial scales (from the field to the continent),
• understand the routes of introduction of these plant-pathogens from North America into Europe (through the ANR Emerfundis project on biological invasions of fungi),
• analyse plant-parasite coevolution and host-plant specialization in these pathosystems,
• create extensive genomics ressources to get new insights into the interaction between downy mildew and their host-plant - see the PLASMOPARA population genomics project founded by INRA in 2010 and achieved at Genoscope,
• increase the durability of plant resistance gene by understanding how downy mildews adapt to host-plant varieties.

Publications

30. Peressotti E., Wiedemann-Merdinoglu S., Delmotte F., Bellin D., Di Gaspero G., Testolin R., Merdinoglu D., Mestre P. 2010. Breakdown of resistance to grapevine downy mildew upon limited deployment of a resistant variety. BMC Plant Biology, 10:147.

29. Montarry M., Andrivon D, Glais I., Corbiere R., Mialdea G., Delmotte F. 2010. Microsatellite markers reveal two admixed genetic groups and an ongoing displacement within the French population of the invasive plant pathogen Phytophthora infestans. Molecular Ecology, 19, 1965–1977. [PDF]

28. Comont G, Corio-Costet MF, Larignon P, Delmotte F. 2010. AFLP markers reveals two genetic groups in the French population of the grapevine fungal pathogen Phaeomoniella chlamydospora. European Journal of Phytopahtology, 127, 451–464. [PDF]

27. REX consortium [Bourguet D, Delmotte F, Franck P, Guillemaud T, Reboud X, Vacher C]. 2010. The skill and style to model the evolution of resistance to pesticides and drugs. Evolutionnary Applications, 3, 375-390. [PDF]

26. Papura D., Delmotte F., Giresse X., Salar P., Danet J.L., Van Helden M, Foissac X. and Malembic-Maher S. 2009. Comparing the spatial genetic structures of the Flavescence dorée phytoplasma and its leafhopper vector Scaphoideus titanus. Infection, Genetics and Evolution, 9, 867-876. [PDF]

25. Giresse X, Ahmed S., Richard-Cervera S., Delmotte F. 2010. Development of New Oomycete Taxon Specific Mitochondrial Cytochrome b Region Primers for Use in Phylogenetic and Phylogeographic Studies. Journal of Phytopathology, 158, 321-327. [PDF]

24. Montarry J, Cartolaro P, Richard-Cervera S, Delmotte F. 2009. Spatio-temporal distribution of Erysiphe necator genetic groups and their relationship with disease levels in vineyards. European Journal of Plant Pathology, 123, 61–70 [PDF]

23. Montarry J, Cartolaro P, Delmotte F, Jolivet J, Willocquet L. 2008. Genetic structure and aggressiveness of Erysiphe necator populations during grapevine powdery mildew epidemics, Applied Environmental Microbiology, 74, 6327–6332. [PDF]

22. Delmotte F, Giresse X, Richard-Cervera S, Vear F, Tourvieille J, Walser P, Moinard J, Tourvieille de Labrouhe D. 2008. Single nucleotide polymorphisms reveal multiple introductions into France of Plasmopara halstedii, the plant pathogen responsible of sunflower downy mildew. Infection, Genetics and Evolution, 8, 534-540. [PDF]

21. Giraud T, Enjalbert J, Fournier E, Delmotte F, Dutech C. 2008. Population genetics of fungal diseases of plants, Parasite, 15, 449-454. [PDF]

20. Baudoin A, Olaya G, Delmotte F, Colcol JF, Sierotzki H. 2008. QoI resistance of Plasmopara viticola and Erysiphe necator in the Mid-Atlantic United States. Plant Health Progress, doi:10.1094/PHP-2008-0211-02-RS, [PDF]

19. REX consortium INRA. 2007. Structure of the Scientific Community Modelling the Evolution of Resistance. PLoS ONE, 12, e1275. [PDF]

18. Giresse X, Tourvieille de Labrouhe D, Richard-Cervera S, Delmotte F. 2007. Twelve polymorphic expressed sequence tags-derived markers for Plasmopara halstedii, the causal agent of sunflower downy mildew. Molecular Ecology Ressources, 7, 1363-1365. [PDF]

17. Chen, W. J., F. Delmotte, S. Richard-Cervera, L. Douence, C. Greif, and M. F. Corio-Costet. 2007. Multiple origins of fungicide reistance in grapevine downy mildew populations. Applied and Environmental Microbiology 2, 5162-5172 [PDF]

16. Dutech, C., J. Enjalbert, C. Fournier, F. Delmotte, B. Barrès, J. Carlier, D. Tharreau, and T. Giraud. 2007. Challenges of microsatellite isolation in fungi. Fungal Genetics and Biology, 44:933-949 [PDF]

15. Delmotte F., Chen W.-J., Richard-Cervera S., Greif C., Papura D., Giresse X., Mondor-Genson G. and Corio-Costet M.-F. 2006. Microsatellite DNA markers for Plasmopara viticola, the causal agent of downy mildew of grapes, Molecular Ecology Notes, 6, 379-381 [PDF]

1. Delmotte F., Bucheli E., & Shykoff J.A. 1999. Host and parasite population structure in a natural plant–pathogen system, Heredity, 82, 300-308 [PDF]

Collaborations :

Grapevine downy mildew
Pere Mestre - INRA Colmar, UMR SVQV, France
Annemiek Schilder - Plant Pathology, Michigan State University, US
Cyril Dutech - INRA Pierroton, Forest Pathology, UMR Biogeco, France
Giraud Tatiana - CNRS, Université d'Orsay, France
Michael Fontaine - CNRS, Université d'Orsay, France
Frédéric Austerlitz - CNRS, Université d'Orsay, France
Jean-Pierre Rossi - INRA, CBGP, Agrocampus Montpellier

Sunflower downy mildew
Denis Tourvieille de Labrouhé - INRA Clermont-Ferrand, France
Emmanuelle Mestries, CETIOM, France

Evolutionnary genomics of bacterial endosymbionts [donwload all PDF]

Bacteria have repeatedly quitted their normal free life to invade a new habitat, the eukaryotic cell. The complete transition, known as endosymbiosis, involved a revolution in the life style of the prokaryote. Endosymbiosis occurs several times in arthropods. Not surprisingly, endosymbiosis has systematically been characterized by a spectacular revolution at the genome level. With the aim to understand the process leading to this "endosymbiotic syndroma", we took advantage of the great wealth of information represented by the availability of several complete genomes of bacterial endosymbionts of insects to evaluate the effect of mutation and selection on the symbiont genes through a comparative genomic approach.

14. Delmotte F., Rispe C., Schaber J., Silva F. J., Moya A. 2006. Deep reconstruction of gene loss in endosymbiotic bacteria : random or predictable pattern? BMC Evol. Biol. 6:56 [PDF]

12. Schäber J., Rispe C., Wernegreen J., Buness A., Delmotte F., Silva F., Moya A. 2005. Gene expression levels influence amino acid usage and evolutionary rates in endosymbiotic bacteria. Gene, 352:109-117 [PDF]

11. Rispe C., Delmotte F., van Ham R.C.H.J., Moya A. 2004. Mutational and selective pressures on codon and amino-acid usage in Buchnera sp., endosymbiotic bacteria of aphids, Genome Research, 14:43-53. [PDF]

10. Gil R., Silva F. J., Zientz E., Delmotte F., González-Candelas F., Latorre A., Rausell C., Kamerbeek J., Gadau J., Hölldobler B., van Ham R.C.H.J., Gross R., Moya A. 2003. The minimum gene set to sustain endosymbiotic life: comparative analysis of reduced genomes, PNAS, 100(16), 9388-9393. [PDF]

Collaborations :
Rispe Claude - INRA, UMR BiO3P, Rennes, France
Andres Moya, Francisco Silva, Rosario Gil - ICBIBE, Valencia, Spain
Joerg Schaber, Max Planck Institute for Molecular Genetics, Berlin, Germany

Evolution of sex in aphids

[donwload all PDF]

Many theories attempt to explain why sexual reproduction has invaded life so thoroughly. Some are plausible, but there remains a need for evolutionary biologists to identify the main factors accounting for the maintenance of sex in diverse, real organisms. An increasing focus of studies on the evolution of sex concerns cyclical parthenogens and aphids in particular, which conveniently show coexistence of sexual and asexual reproductive modes. The rate and mode of emergence of asexual lineages are important factors to consider when assessing the costs and benefits of sex since they determine both the level of genetic diversity and the ecological adaptability of the resulting lineages.

In this context, I investigated the possible evolutionary routes to obligate parthenogenesis in the aphid Rhopalosiphum padi based on a survey of genetic and phylogenetic relationships of sexual and asexual lineages.

13. Halkett F., Plantegenest M., Prunier-Leterme N., Mieuzet L., Delmotte F., Simon J.C. 2005. Admixed sexual and facultatively asexual aphid lineages at mating sites, Molecular Ecology, 14, 325-336. [PDF]

9. Simon J.C., Delmotte F., Rispe C., Crease T. 2003. Phylogenetic relationships between parthenogens and their sexual relatives: the possible routes to parthenogenesis in animals, Biological Journal of the Linnaean Society, 79, 151-163. [PDF]

8. Delmotte F., Sabater B., Leterme N., Sunnucks P., Latorre A. & Simon J.C. 2003. Hybrid origins of asexual lineages in an aphid, Evolution, 57(6), 1291-1303. [PDF]

7. Papura D., Simon J.-C., Halkett F., Delmotte F., Le Gallic J.-F. & Dedryver C.-A. 2003. Predominance of sexual reproduction in Romanian populations of the aphid Sitobion avenae inferred from phenotypic and genetic structure, Heredity, 90, 397-304.  [PDF]

6. Delmotte F., Leterme N., Gauthier J., Rispe C. & Simon J.C. 2002. Genetic architecture of sexual and asexual populations of the aphid Rhopalosiphum padi based on allozyme and microsatellite markers, Molecular Ecology, 11, 711-723.  [PDF]

5. Delmotte F., Leterme N., Rispe C., Bonhomme J. & Simon J.C. 2001. Multiple routes to asexuality in an aphid species, Proceeding of the Royal Society of London B, 268, 2291-2299. [PDF]

4. Simon J. C., Martin O., Delmotte F., Leterme N. & Estoup A. 2001. Isolation and characterisation of microsatellite in the aphid Rhopalosiphum padi, Molecular Ecology Notes,1, 4-5.  [PDF]

3. Delmotte F., Leterme N., & Simon J.-C. 2001. Microsatellite allele sizing: difference between automated capillary electrophoresis and manual technique, BioTechniques, 31, 810-818. [PDF]

2. Simon J.-C. & Delmotte F. 2000. Systèmes de reproduction, structure génétique et  microsatellites, Actes de colloque CNRS-INRA "École Chercheurs Microsatellites 2000". [PDF]

Last update : September 2010