Our socio-economical and scientific rationales

• There is a primordial need to fight pests and pathogens to reduce the use of pesticide by genetic resistance and by improving its durability.
• We work on models of strong agricultural –and Mediterranean- concerns, crops: tomato, pepper, melon, peach, and arabidopsis as a model.
• We tackle resistance to a diverse set of pests and pathogens: viruses, oomycetes, aphids and study different resistance mechanisms to biotrophs (effector-triggered resistances, loss-of-susceptibility to pathogens, polygenic resistances).

Our objectives

• Characterize the genetic and functional bases of resistance
• Unravel the diversity of plant genetic resistance factors
• Provide new alleles and new genetic combinations of loci to enlarge the resistance spectrum, level and durability
• Predict the capability of pests and pathogens to adapt to plants by exploring their interactions

Our projects

Resistance to viruses by loss of susceptibility

To successfully infect plants, viruses have to hijack host factors. Those can be turned into genetic resistances by making them unavailable to the pathogens. We characterize plant susceptibility factors in plants and develop genetic resistances to viruses of agricultural importance. by exploring the natural diversity of vegetable crops and wild related species and developing access to those wild species by studying the interactions between plant and virus and deciphering resistance pathways mechanisms by screening mutated populations or developing synthetic alleles using new biotechnological techniques

Relevant Publications

Zafirov, D, Giovinazzo, N, Bastet, A, Gallois, J‐L. When a knockout is an Achilles’ heel: Resistance to one potyvirus species triggers hypersusceptibility to another one in Arabidopsis thaliana. Mol Plant Pathol. 2021; 22: 334– 347. [link]

Bastet A, Zafirov D, Giovinazzo N, Guyon-Debast A, Nogué F, Robaglia C, Gallois JL. Mimicking natural polymorphism in eIF4E by CRISPR-Cas9 base editing is associated with resistance to potyviruses. Plant Biotechnol J. 2019 Sep;17(9):1736-1750. doi: 10.1111/pbi.13096. [link]

Bastet, A., Robaglia, C. and Gallois, J.L. (2017) eIF4E Resistance: Natural Variation Should Guide Gene Editing. Trends Plant Sci, 22, 411-419. [link]

Boualem, A., Dogimont, C. and Bendahmane, A. (2016) The battle for survival between viruses and their host plants. Curr Opin Virol, 17, 32-38. [link]

Gauffier, C., Lebaron, C., Moretti, A., Constant, C., Moquet, F., Bonnet, G., Caranta, C. and Gallois, J.L. (2016) A TILLING approach to generate broad-spectrum resistance to potyviruses in tomato is hampered by eIF4E gene redundancy. Plant J, 85, 717-729. [link]

Oomycètes

Oomycetes quickly overcome deployed plant genetic resistances, usually conferred by major resistance genes. Polygenic resistance with lower selective pressure and combining different geographical origins could slow down or hamper the pathogen’s ability to adapt to these combinations. We identify and characterize plant quantitative factors in plants (tomato and pepper) and identify the aggressiveness factors in two of their oomycetes pathogens (Phytophthora infestans and P. capsici, respectively): by exploring the natural diversity of vegetable crops and wild related species by exploring the diversity within pathogens from cultivated and non-cultivated geographical areas by studying the interactions between plant and oomycetes and deciphering partial resistance at the molecular level by assessing robustness of these resistance to environmental changes (abiotic and biotic) by developing new genotypes combining polygenic resistance alleles and challenging their efficiency to oomycetes

Relevant Publications

Caromel B, Hamers C, Touhami N, Renaudineau A, Bachellez A, Massire A, Damidaux R, Lefebvre V (2015). Screening tomato germplasm for resistance to late blight.  INNOHORT, Innovation in Integrated & Organic Horticulture. ISHS International Symposium, Avignon (France), 8-12 June 2015, pp 15-16

Mallard et al. (2013). A key QTL cluster is conserved among accessions and exhibits broad-spectrum resistance to Phytophthora capsici: a valuable locus for pepper breeding. Mol Breeding 32(2):349-364

Nicolaï et al. (2013). Genotyping a large collection of pepper (Capsicum spp.) with SSR loci brings new evidence for the wild origin of cultivated C. annuum and the structuring of genetic diversity by human selection of cultivar types. Genet Resour Crop Ev 60:2375-2390

Thabuis et al. (2003). Comparative mapping of Phytophthora resistance loci in pepper germplasm: evidence for conserved resistance loci across Solanaceae and for a large genetic diversity. Theor Appl Genet 106(8):1473-1485

Genetic and functional bases of resistances to aphids

We characterize quantitative and qualitative resistances to aphids in the genetic diversity of peach (to the green peach aphid Myzus persicae) and melon (to Aphis gossypii) and we aims to develop durable resistances by studying their genetic and functional bases. We focus on qualitative resistances (R genes) that confer both resistance to aphids and to viruses that they transmit, in peach (Rm gene) and melon (Vat gene): we characterize R genes and their homologs involved in the resistance (cloning and functional validation) and aphids effectors recognized by R genes. We study the resistance processes triggered by the recognition, we assess the aphid adaptation to resistances (avoidance of recognition and adaptation to triggered processes). We aim to improve durability by modeling to define traits related to durability,  by identifying QTLs for these traits and ultimately, by combining R and QTL genes, we develop biopesticides from secondary metabolites of peach involved in the resistance to the green peach aphid, which we found to be highly toxic to aphids

Relevant Publications

Schoeny, A., A. Desbiez, et al. (2017). Impact of Vat resistance in melon on viral epidemics and genetic structure of virus populations. Virus Research 241: 105-115. [link]

Boissot, N., A. Schoeny, et al. (2016). Vat, an amazing gene conferring resistance to aphids and viruses they carry: from molecular structure to field effects." Frontiers in Plant Science 7: 1420. [link]

Boissot, N., S. Thomas, et al. (2016). NBS-LRR-mediated resistance triggered by aphids: viruses do not adapt; aphids adapt via different mechanisms BMC Plant Biology 16: 25. [link]

Thomas, S., F. Vanlerberghe-Masutti, et al. (2016). Insight into the durability of aphid resistance from the demo-genetic study of Aphis gossypii populations in melon crops. Evolutionary Applications 9(6): 756-768. [link]

Dogimont, C., Chovelon, V., Pauquet, J., Boualem, A. and Bendahmane, A. (2014) The Vat locus encodes for a CC-NBS-LRR protein that confers resistance to Aphis gossypii infestation and A. gossypii-mediated virus resistance. Plant J, 80, 993-1004. [link]