A complex network of additive and epistatic quantitative trait loci underlies natural variation of Arabidopsis thaliana quantitative disease resistance to Ralstonia solanacearum under heat stress

Nathalie Aoun (1) , Henri Desaint (1, 2) , Léa Boyrie (3) , Maxime Bonhomme (4) , Laurent Deslandes (1) , Richard Berthomé (1) , Fabrice Roux (1)

1 LIPME - Laboratoire des Interactions Plantes Microbes Environnement
2 Syngenta France
3 LRSV - Laboratoire de Recherche en Sciences Végétales
4 Evolution des Interactions Plantes-Microorganismes

Plant immunity is often negatively impacted by heat stress. However, the underlying molecular mechanisms remain poorly characterized. Based on a genome-wide association mapping approach, this study aims to identify inArabidopsis thalianathe genetic bases of robust resistance mechanisms to the devastating pathogenRalstonia solanacearumunder heat stress. A local mapping population was phenotyped against theR. solanacearumGMI1000 strain at 27 and 30 degrees C. To obtain a precise description of the genetic architecture underlying natural variation of quantitative disease resistance (QDR), we applied a genome-wide local score analysis. Alongside an extensive genetic variation found in this local population at both temperatures, we observed a playful dynamics of quantitative trait loci along the infection stages. In addition, a complex genetic network of interacting loci could be detected at 30 degrees C. As a first step to investigate the underlying molecular mechanisms, the atypical meiotic cyclinSOLO DANCERSgene was validated by a reverse genetic approach as involved in QDR toR. solanacearumat 30 degrees C. In the context of climate change, the complex genetic architecture underlying QDR under heat stress in a local mapping population revealed candidate genes with diverse molecular functions.

Mots clés: epistasis; GWA mapping; heat stress; local score; natural accessions; Ralstonia

Domaines: Sciences du Vivant [q-bio]

Nathalie Aoun, Henri Desaint, Léa Boyrie, Maxime Bonhomme, Laurent Deslandes, et al.. A complex network of additive and epistatic quantitative trait loci underlies natural variation of Arabidopsis thaliana quantitative disease resistance to Ralstonia solanacearum under heat stress. Molecular Plant Pathology, In press, 21 (11), pp.1405-1420. ⟨10.1111/mpp.12964⟩. ⟨hal-02948127⟩