Rémi Ollivier

Thesis started in november 2019 - Defended december 15th, 2022
Funding: INRAE / Brittany
Direction: Akiko Sugio et Marie-Laure Pilet-Nayel

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Abstract:

In the context of sustainable agriculture, understanding the molecular mechanisms that determine the specificity of aphids to plants is an essential step in developing pest management strategies. However, the mechanisms leading to compatibility or incompatibility between the plant and the aphid remain unknown. This thesis aimed to identify the genetic basis and molecular determinants involved in pea resistance to the aphid Acyrthosiphon pisum. The natural genetic variability of pea resistance to pea-adapted and non-adapted biotypes of A. pisum was identified by screening a collection of 240 pea genotypes. An association genetics study identified the ApRVII locus controlling pea resistance to both adapted and non-adapted A. pisum biotypes. This study, coupled with transcriptomic studies of selected pea genotypes, identified candidate genes underlying ApRVII that are potentially involved in pea resistance to A. pisum. These genes indicated the involvement of biosynthetic pathways of secondary metabolites in ApRVII mediated resistance to the aphids. In addition, the transcriptomic studies identified pea molecular pathways specifically repressed during the infestation by the adapted biotype, suggesting a possible manipulation of pea transcriptome by the aphid infestation. The knowledge provided during this thesis contributes to a better understanding of the mechanisms involved in the compatibility and incompatibility between plants and aphids.

Poster pdf